The first 1,000 people to use my link will get a full year of Premium membership to Woodworkers Guild of America for only $1.49: go.wwgoa.com/theengineeringhub/
@@misterhat5823 Exactly and Thanks. This guy is full of crap. I've seen video's about this and it was attrubited to way overloading the ship especially in very cold water and in rough conditions. Keep in mind they considered the ship a success if it only made one trip to Europe. No return or second trip which many made several. My Dad served as E.M. on a Liberty ship.
Canada also made lots and lots of Liberty ships, the small shipyard I work for put out one every six weeks. Shipbuilding was in panic mode and if they made one Atlantic crossing they were considered a success. Let us not forget all the Merchant Seamen that also paid the ultimate price.
@@frosty3693 This is not generally correct. It's not correct at all for US merchant mariners. Under US law, merchant mariners were paid in full for every day from their departure until they reached friendly shores. At that point, they still received base pay, but combat area pay stopped. Base pay was 87 per month starting. Combat area pay was a 100 per month bonus. In the event of injury, pay was transitioned to the insurance payout which was 200/month up to 5000. On death, there was a fixed 5000 insurance payout. There is one area where you are correct. That is how it was under british law pre-ww2, though the contract offered by the employer may or may not supersede this. The british changed this rule in may of 41. So even with the british, this was only the case for about 1 3/4 years of the war, which lasted 6 years for them.
My 99 year old was an Engineering Officer on Liberty Ships in WW2. His convoy was bound for England when the worst WW2 winter storm in the North Atlantic struck. As 3rd in command he was on watch at night when he observed other Liberty ships breaking in 1/2. He felt very lucky his ship didn't break in 1/2. On the return voyage, when he arrived in Halifax, he was shocked to see that the recovered 1/2s were being welded back together. The allies were desperate for shipping capacity. Dad said that the most common Crack was in through the hold just ahead of the main housing. The initial fix was to weld a band of steel around the hold hatch way. This extra steel was sufficient to stop cracks. Ships that Dad served on were torpedoed, staffed and V1 landed next to his ship while tied up in Holland. He said the guys he felt sorry for were the crews of oil tankers because when they were torpedoed the sea burned
My Father was a merchant seaman from 43 til 45 and had sailed on Atlantic convoys aboard Liberty ships . He would never talk of the hardships of life at sea , only the funny stories . Through third parties I was informed that my Father had unfortunately been aboard a Liberty ship when it split in two on the high seas . When , as a kid , I asked him if it were true he never answered me or looked at me . I was totally ignored and immediately understood he would never answer . Thank you for an excellent video .
@@TheEngineeringHub I’d often wondered as to the cause of his ship breaking up . I’d imagined it might have been a torpedo attack but thanks to your video I now understand a bit more . Torpedo or metal fatigue / temperature failure I imagine the experience of sinking in the Atlantic in winter was not a memory my Father wanted to share . He was only 16 years old in February 1943 . He survived , others weren’t so lucky . I consider the Merchant men as unsung heroes. Technically civilians but in practice on the frontline .
@@davidrussell8689 wow stories like this really make you think how good we have it today! Thank you for sharing, I hope your father had a long and happy life after the war!
Terrific content. Thank you so much for this information. This ties in with a story my father told about his experiences in the navy in WWII. He described how in 1943 after he completed his training, he shipped out from San Diego to Hawaii. His transport ship was caught in a storm and started breaking apart. He described how they were carrying "railroad tracks" which were welded onto the hull as reinforcement which allowed them to limp back into San Diego where he caught another ride to Hawaii and later New Caledonia to find the ship to which he was assigned.
I feel like you have left us hanging for the answer. You identified the problem with the Liberty Ships, but stopped short of showing us the solutions that were adopted. This video really needs a Part 2 to close out the whole story. Mark from Melbourne Australia
The hatches were made with sharp corners for ease of manufacture, that is where the cracks started. The solution for new Liberty ships (as far as I remember) was to make the hatches with rounded corners that didn't crack. There was also some reinforcement, added.
@@ptonpc There was a reinforced band or belt that was welded on the outside of some ships as an emergency measure but the added weight and drag reduced speed and capacity so that idea was abandoned.
These events led to new research and the science of “Fracture Mechanics”…..Brittle Fracture/Notch ductility, at various temperatures/ Stress Concentration Factors/ Steel quality etc etc etc…. The fix was to reshape and reinforce the hatch corners to reduce the stresses, but reinforcement attracts load (in general) so it’s self defeating in some respects. The rapidity of crack growth in the Liberty ships was the surprise. Edit: Some great posts below…..lewisdoherty etc
@ptonpc The de Havilland Comet, the first commercial jet airliner, DH106, had square windows. It first flew in 1949. Cracks would form there causing structural failure problems, and crash. At first the engineers didn't understand the problem, but soon figured it out. The hole for the ADF, automatic direction finding, antenna, had square corners. Also, the riveting was poorly done. These problems were identified, fixed, and the type went back into service as a Comet 4 in 1958 and was retired in 1981. The remaining one was retired from service in, I believe, 1981. The other manufacturers learned this lesson. Also, if there's an interest, look how small the windows on a Concorde are.
Dr Constance Tipper was Britain's first high-profile woman materials scientist (from Imperial College London via the UK's Department of Mines and also Cambridge University). British naval architects designed the Liberty ship - the first being named 'Empire Liberty'- and then went on to build about 1000 similar ones in British yards during WW2, known as as the 'Ocean' class. American Liberty ships were a close copy of the Ocean series. It was initially believed that the plate cracking was due to poor quality in Kaiser yards however, Dr Tipper demonstrated that cracking was much, much less common in rivetted (as opposed to welded) hulls, riveting being a fairly common practice in British yards for either some, or all of the hull. She also went on to show that crack failures were commoner in American welded hulls than British welded hulls and she was able to demonstrate that this was down to generally lower quality American steel (having a lower manganese to carbon ratio than British steel). The British involvement in the Liberty ship programme is almost always overlooked. Sorry, Yanks.
I did my degree dissertation on this subject, and there wasn't a lot of information about Dr Tipper easily available at the time. Her contribution seems to be much more widely recognised now which is great because she really was a significant figure in the development of material science.
Although there were other factors involved, I remember reading that the Titanic, built in Ireland, had too high of a sulphur content in it's steel. It's hull was also riveted. However, the Atlantic water temp, coupled with brittle steel, were two big factors causing the Titanic to rip open upon hitting the iceberg. Traveling at a high speed didn't help either. Plus, the watertight bulkheads didn't travel all the way from the hull to the deck and there could have been more, leading to higher structural strength and better watertight integrity. Lastly, there just weren't enough lifeboats-My dollars worth-John in Texas
"British naval architects designed the Liberty ship - the first being named 'Empire Liberty'- and then went on to build about 1000 similar ones in British yards during WW2, known as as the 'Ocean' class. American Liberty ships were a close copy of the Ocean series." Wikipedia (article title: Ocean Ship) disagrees. "The Ocean ships were a class of sixty cargo ships built in the United States by Todd Shipyards Corporation during the Second World War for the British Ministry of War Transport under contracts let by the British Purchasing Commission."
My step-father worked as a welder building Liberty Ships in Maine before he was drafted for the war. He told me that the prefab panels often weren't as precise as they should be, and that they would lay several welding rods in the gaps and weld over them. When he crossed the channel on D-Day, he was on a ship that he helped build. He said that it scared the hell out of him.
Not having to build lots of Liberty ships (British shipyards actually built more than 1,000), the Brits could concentrate on warship production. For example, smaller yards built 'Flower; class corvettes - hundreds and hundreds of them for the Royal Navy, the Canadian Navy, and yes, the US Navy and the US Coastguard (amongst other countries). Equipped with state of the art British sonar, radar, HF/DF and the 'Hedgehog' depth charge system, these 800-1000 ton anti-Sub vessels became the workhorses of Atlantic convoy protection, greatly reducing the number of fast destroyers needed for convoys and racking up themselves a huge number of successful sub kills. My school physics teacher was greatly influential in my life. I admired him greatly. He recounted his experiences serving on these fierce little ships in the north, North Atlantic in the depth of winter. It was a hellish naval posting and those guys never really got the recognition they deserved. I realise now that if anyone in my life deserved me saying 'Thank you for your service' it was my school physics teacher.
@@gandydancer9710 They weren't, all the strictly 'Liberty ship' production was in the States. Of course British ship manufacturers were busy producing their own ships-that was the reason the British government went looking of additional supply. The British also built a lot of cargo ships during WW2, but they were not Liberty ships and their designs included a lot of hull riveting.
My Metallurgy professor taught about the poor steel used in the liberty ships. He used this as an example to teach about the brittleness of certain steels in cold environments. He served as a rifleman in the US Army. He said he never felt more alive than when bullets were whizzing over his head. The most valued things were dry socks. He was a great professor.
My engineering professor was part of the Oxford team investigating these failures. Ships of the same design and steel spec were made in England by riveting. Thus the welding was not the only cause. After exhaustive testing low temp embrittlement was found, yet the Britt ships survived. In the end the cause was found to be the sulphur/phosphorus ratio difference between the 2 difference US and British steels - not originally specified. Their tests included filling 2 ships with strain gauges. One ship welded, one riveted and sailing across the Atlantic to be sure of the stresses experienced.
My father was in the navy and on a liberty ship in the Pacific during WWII. I think the fix was to weld a band of four foot plate to the likely failuring locations. I also heard a contributing factor was that riveted plates for which was traditionally designed were able to slightly flex between each other while the welded plates were unable to flex as much between each other.
Riveted joints are stronger than welded joints in the same thickness metal. (That’s why aircraft still use them). The act of welding changes the composition and properties of the metal in the heat affected zone around the weld. Welds are more water tight but more likely to catastrophically fail.
All-welded ships were a relatively new idea in the 1940's. The problem with welding is that the plating effectively becomes one giant, continuous plate. Any crack just keeps on going. Riveted plates are still 2 separate plates. There is no flex. One of the design changes the builders incorporated, was to add a riveted section every 5th plate to act as a crack arrester. It was found that the steel used in British built ships was not prone to this low temp. embrittlement. It was called "Arctic D" and had a small percentage of manganese in it, which drastically reduced the problem.
@ the cracks in welded plates propagate up the welds that are weaker than the parent metal. (About 80% the strength with a GOOD weld). Not knowing that welds are weaker is a common mistake (even among experienced welders).
As a teenager, my father was a welder in the Kaiser shipyards in Washington. After the war, he became a civil engineer, with his first job out of school as a welding inspector for the Kansas Highway Department. He told me the problem was the square hatch opening, which created a stress riser. A small redesign made the corners rounded.
Yes, that is what I remember reading years ago. The square hatches were easier to make but that is where the cracks started. It would have been nice if the video had mentioned that and the fix.
In 1949 the de Havilland Comet, the worlds first commercial airliner was designed with square windows and the constant pressure and temperature changes caused the plane to fail at the window corners. There were two catastrorhic failures with 56 souls lost before the planes were deemed not airworthy. You would think the engineers who designed the plane would have known that from Metalurgy 101.
A problem they identified and remedied in the 1940's but repeated the same problem with the COMET airliner in the 1950's. He who does not learn from history is bound to repeat history.
What about the 'field fix' for cracks that I remember hearing about years ago....where a small hole would be drilled right at the leading edge of the crack, thereby dissipating the straight -line forces?
@@terryjohnson3479 "You would think the engineers who designed the plane would have known that from Metalurgy 101." The calculations were a little off.
When I was still an Engineer in the Merchant Navy, there were still some Liberty ships working. We used to get accident reports sent to us in the post in port, from around the world. Some of them were quite amusing. One report was from the 2nd Mate on watch at about 02:00 hrs in the morning. The sea had been little more than a force 3 with a long swell. He reported that he had heard a loud cracking and tearing noise from behind the bridge and felt a rumble through the deck as the lights went out. There were some more crashing noises and he went on to the bridge wing to have a look at what he could see, as the ship had also slowed down. He reported seeing the aft accomodation block and engine room overtaking the front of the vessel as he stood there. Still in full light and and with the engine apparantley still under full steam. I wish I could remember the name of the magazine the reports came in, but too many years and too many pints ago.
@andrewwmacfadyen6958 Yes, they had an astonishingly long life considering they were considered to be almost one trip disposable. That accident report would have been in about 1984 I think. I was on Tankers with Sanko by then.
@@andrewwmacfadyen6958 Loaded there several times. The iranians are so vilified by the west yet they were always so good to us. There was a wreck that had been bombed by the iraqis, they towed the burning hulk off the berth then it sat there half sunk for years. Back in the early 90's the berth was still full of bomb holes, the end end of the jettey was gone, just a twisted heap of burned black steel.
@@billdoodson4232 Captain on Sanko tankers here 2005 to 2009. Sanko Bright, Sanko Abilty, Sanko Breeze, Sanko Amity. You probably sailed with Capt DeRuiter. I really liked Sanko too bad their foray into the offshore oil supply vessels bankrupted them. There was no warning we all had jobs then suddenly we all did not have jobs. I remember on Sanko Breeze they sent us to S'pore saw a dozen or more sanko supply boats, newbuilds right our from the yard all lined up at anchor no charter for them.
Liberty ships were designed for a 5 year lifespan, the whole idea was to produce ships as quickly as possible to support the war effort and not worry about their long term durability. That companies were still using Liberty ships for commercial cargo DECADES after the war ended shows that the basic design was pretty sound. Aristotle Onassis acquired a lot of Liberty ships from US storage that he used to start his shipping business after the war. I'm sure those ships kept the maintenance folks busy!
As a boy I travelled to Hong Kong and back on an RFA Liberty ship delivering cargo to all UK ports on the way. Three months there and three back in 1948 and 1951. I'm glad the ship didn't fall apart!
The RFA, , the Royal Fleet Auxiliary did not carry cargo to from Port to Port. They provided support to the Royal Navy. They also did not carry passenger's.
I reckon johndobbie528 knows better than you what ship he travelled to Hong Kong on. He also would have seen and remembered perfectly well cargo being offloaded, probably to British bases. As for RFA's ever taking passengers, well during the time of Empire, British people and institutions were far more flexible and practical than the beancounters running things today can even imagine in their wildest dreams.
Merchant Seamen had the highest relative casualty rate of any group in WW2. They were more likely to die than Bomber Crews over Germany, or the Marines storming Japanese held islands in the Pacific. And, for the most part, they couldn't fight back. They were civilians. Not military personnel. Dodging bombs and U-Boat torpedoes in the freezing North Atlantic, was simply their job. They didn't get "combat pay". And their families did not receive "Survivor's Benefits". Nor did they qualify for Veterans Benefits, or the GI Bill, after the war. And if they were lucky enough to survive their ship's sinking, they weren't paid at all, once they abandoned ship. (The Company wasn't paying you to sit in an open lifeboat for 40 days. Or for any time you spent as a POW, in those very rare instances that the Enemy rescued you.) Nor did they get any metals or awards, even when they engaged in combat with their anti-aircraft, and 3 inch deck guns. Yet, without these incredibly brave men, victory would not have been possible. We, today, still owe a lot to those guys.
My father was 2nd mate on Liberty ships in the European Theater for much of the war and damn proud of it. He (finally) talked on their losses and credited winning the war by the US out producing Germany (& Japan). When we needed 10 tanks, we sent 18. Just as we knew the ships (& tanks) were lesser quality than we'd like, they were expendable; as were the crew.
Are you sure about that? By the end of the war, the Eighth Air Force would have more fatal casualties-26,000-than the entire United States Marine Corps. Seventy-seven percent of the Americans who flew against the Reich before D-Day would wind up as casualties.
@JohnWHoff-gt2uf : My dad served in the Navy, mostly in the Pacific. He never really talked directly to me about his experiences. What little I learned, can from overhearing conversations he had with other veterans. The job your dad did, was absolutely vital to winning the war. It's a shame that the Merchant Marine Seamen don't always get the credit they deserve. Your "ol' man", was a hero. Pure and simple.
Some glaring inaccuracies here. The liberty ships where the first to use more constructed modules and welding. As a result unknowable failures happened. The ship builders fairly quickly discovered the problems with welding, and resolved the issue by annealing the weld. The fracturing of the hill was due to sharp angles around the holds. That was cured by rounding the joint. After the second world war, liberty ships went on to give sterling service in the merchant marines around the world and many shipping companies rebuilt their fleets with them. The technique s used to build liberty ships are used today in ship building. The liberty ships had their faults, which where resolved. Don't knock em, they gave good service.
The liberty ship was superseded by the Victory ship. To prevent the hull cracks that many Liberty ships developed-making some break in half-the spacing between frames was widened from 30 inches (760 mm) to 36 inches (910 mm), making the ships less stiff and more able to flex. Like Liberty ships, the hull was welded rather than riveted.
I am 75, my father-in-law was a WW2 merchant seaman on the Murmansk run. He said that in the really cold conditions if a steel handrail etc was hit hard, it would shatter. No wonder thermal embrittlement was a problem. Our modern mild steel is a far cry from the hurried wrought iron from then.
Sorry, but Liberty ships' hulls were built from steel, not wrought iron. (See p 436 of The Last Liberty" by Walter Jaffee. Even in 1912, Titanic's hull was built from steel (see p 139 of "Titanic, The Ship Magnificent") but some of her hull's rivets were wrought iron and some steel (p52 & 59 of the same book.)
@@ianm452 he probably didn't mean literal wrought iron, he meant that the steel was far lower quallity than modern mild steel or at least wasn't as suited to shipbuilding
They didn't use wrought iron on Liberty ships, wrought iron is a cast product with practically no carbon in it but fibrous slag inclusions. The plate used on Liberty ships was low carbon steel of about .08-.10% carbon content, or better known as CRS (cold rolled steel). It had embrittlement issues in extremely cold weather because the US plants set up to produce that product had too low manganese content in it. Ship welding was fairly new and the worldwide ship industry was feeling their way, and learning the lessons as they did. One of the fixes for Liberty ship crack issues was to improve the chemistry of the steel which improved low-temperature toughness.
My father was very critical of the Liberty Ships and talked in disparaging terms about them breaking in half in the Atlantic and killing their British crews. His view of the situation was poor welding skills and the rush for completion of the ships. A simplistic view of the time and quite understandable - however, it left him very bitter.
8 hours between launches, not 8 hours to build. They had dozens in process at a time. Average time to build was 42 days, fastest time was 4.5 days. But still Very impressive timing!
There is a documentary out there which shows a Liberty ship being built in 24 hours. It was done as a moral booster for the Allies, but also as a moral lower for the Nazis, to show them that we could build our ships quicker than their U-boats could sink them.
I’ve heard that the US ship yards refused to take the contracts due to the time requirements, so the steel company’s/non-shipyards were asked and said sure. I think his plot showed at one peak failure month, 16 ships cracked in half when there were 2700 in surface. That’s just over 0.5%. Weren’t the U-boats a more significant loss factor?
My father was an engineer in Shell Tankers from 1945. He used to say that his fellow seamen hated the Liberty Ships and dreaded being posted to one of them because "they break their backs".
There were many Liberty class ships that had developed cracks but there were only three (!) which broke completely in half due to design flaws. That figure is from a study done by Bethlehem Steel just after the war and I poses a copy of that report. One of the major issues was the square corners on the cargo hatches which functioned as a stress riser. Another issue that you did not mention is that welding was a new technology at the time. In riveted hull plates a crack could only propagate through the plate but not to the other adjacent plates. When the plates were welded however, the crack could potentially propagate through the entire length of the hull. I should point out that West coast ship's hulls were entirely welded and welded to the ships ribs. East coast ships had the hull plates riveted to the ribs. The simple fix was to weld a curved steel member to the square corners of the cargo hulls. You can see this fix on the SS Jeremiah O'Brien in San Francisco. I am currently the head of the Docent Department on the O'Brien and must often correct the misinformation that is out there.
In engineering, three brittle crack failures are famous. First the Belgian Hasselt bridge failure in 1938. Second the Liberty ships. Third the Kings Bridge in Melbourne in 1962.
I am Cindy’s husband, I’m using her account just for this comment. -- My uncle was the engineer on the “SS Joseph Wheeler” liberty ship. He told stories about convoys they sailed in to Murmansk in Russia.And survived. He told his experiences to his younger brother, my dad. Who was shipped down to Orangeburg, SC as a primary flight instructor to raw recruits from the US and France to see who could become talented pilots and then advanced them to train to become fighter or bomber pilots. Everyone else “washed out”. Which ment the infantry or they crashed and died taking the instructor with them.😢My uncle was lucky until December’43 when his convoy successfully crossed the Atlantic and docked in Bari, Italy on the Adriatic Sea with many other liberty ships. At least one of them carrying a top secret cargo of mustard gas bombs and the rest were loaded down with aviation gas or high explosive bombs to support the allied invasion of Italy. Apparently the British who managed the unloading of the ships ( I’ll be polite) did not expedite the unloading of the liberty ships. This allowed the Luftwaffe to spring a surprise attack on the unprotected harbor. The result was a total disaster. The SS Joseph Wheeler was the first direct hit and disintegrated completely. There were no survivors.😢 We will miss our uncle Otto forever. RIP. Ironically, my father’s family immigrated from Germany in 1925. Otto was aged 10, my Dad, Werner was aged 5. My Grandfather Siebo was a veteran of the Kaiser’s WWI defeated army. He had also lost his brother in the War and was “SICK of guns and war”. A direct quote. from him. Thankfully his youngest son, my dad ended up living the American dream. I thank God for this country with all its flaws. And he did too. He knew what his ancestors had lived/died through and he became a compassionate democrat after seeing that his Republican Party had lost its way. God bless you Pop, and Grandma. You were certainly THE GREATEST GENERATION. To your 4 sons……………. Not perfect, but who the hell is !!!
Sadly today's democratic party would be unrecognizable to their own parent's generations ... sadly,. its obvious that Democrats have been captured by kultyooral marks-ist eyedeeology
THE HERO OF THE MYSTERY Briefly mentioned. Wikipedia Bio: Constance Tipper (born Constance Fligg Elam) 1894 - 1995 was an English metallurgist and crystallographer. She investigated brittle fracture and the ductile-brittle transition of metals used in the construction of warships, and was the first female full-time faculty member at Cambridge University Department of Engineering.
My grandfather was a foreman building Liberty Ships in Richmond California. My father was a welder there as well. There is a book called "Swing Shift" by Joseph Fabry about the building of the ships A photo of my grandfather's crew is on the cover. The book is not about him, they just needed some photos, and used that one.
The Liberty ship program was a classic example of build first and ask questions about its viability later. Metal fatigue was not a well understood field back in WW2 time period. The Liberty ship program debacle is taught in all first year engineering fracture mechanics classes nowadays. Nice finite element fringe plot of an angle bracket near the end highlighting the crack growth through the part. It brings back memories.
Especially when all the residual stresses from welding without preheating before welding, and not Stress-Relieving due to the overly fast construction were left in the welds...
In 1949 the de Havilland Comet, the worlds first commercial airliner was designed with square windows and the constant pressure and temperature changes caused the plane to fail at the window corners. There were two catastrophic failures with 56 souls lost before the planes were deemed not airworthy. You would think the engineers who designed the plane would have known that from Metalurgy 101.
I had a Friend who was a recent Jr College graduate in Highway Engineering just as Kaiser began Liberty Ship construction in Richmond Calif. They did a lot of cutting and fitting to get them to go together,. This resulted in many of the ships having a curve to the hull. He and another 20 year old figured out how they could use a Transit to lay out the keel and ribs. They ended up explaining to Henry Kaiser and Stephan Bechtel how to do it and never again had to go back to the shipyard. Later he was in charge of the moth ball fleet in Benicia
A lot was learned about fracture mechanics during and right after the war as so much production and changes in products happened in such short time. Fracture toughness was always an issue but when you build something with a lot of material it doesn't show up. When you start reducing the amount of material and stressing things higher then you see the issues. Ship failures, steel bridge failures, airplane failures have this in common.
Sailed on several T2 Tankers and Liberties during the 1960s and hit a rogue wave on a T2 Tanker out of Seattle. Thank goodness that they had been jumbalized (modified) with straps the full length of the hull on both sides.
The technical term for this is cold shortness. It caused issues on ships long before WWII, even though the problem wasn’t identified until then. Certain impurities can lead to steel having diminished ductility at low temperature. This also caused the loss of several ore boats on the Great Lakes (including the Carl Bradley, built 1927 and broke in half 1958, and the Daniel Morrell, built 1906 and broke in half 1966)
I was told years ago that a lack of manganese, caused by a shortage of that element during the war, was the leading cause of the ship hulls cracking. Further you did not clarify where the T-2 tanker Schenectady was located when it cracked. That tanker was berthed at the dock on the calm waters of the Columbia River at Portland OR.
ust for the record I was the third engineer on a TexacoMississippi T-2 oil tanker in 1984 49 years later for a few weeks . But in 1971 the T-2 Texaco Oklahoma broke in half killing much of the crew
I was a merchant marine engineer on bulk ships for a few years before I retired and to see how much the ship's hull flexes in heavy seas is a bit startling at first.
A lengthy report was commissioned in the 1950's to determine the loss of so many liberty ships during the war. The report concluded that many ships fractured and broke in two in the same area of the Atlantic where the cold Labrador current meets the warmer Gulf stream. The sudden drop in temperature was recorded on each ship and the fractures correlated with this drop in temperature. However the brittleness was just a contributing factor. Some of the ships broke when they were struck by high waves which caused the ships to flex and break much easier due to the thermal stress involved. This is exactly why the Titanic broke in two amidships. On that night the temperature dropped significantly as she approached the Labrador current. When she struck the iceberg she compressed her starboard bilge and bottom plates as she steamed over the spur of the iceberg and may even have cracked the ice underneath her as she steamed over it. The ship settled in the water, listed to starboard, then rolled to port, and as soon as her stern attempted to lift just a few degrees her hull fractured amidships and she broke. Her stern rolled to port and her bow rolled to starboard. The stern rose up a second time and broke again. The survivors witnessed in amazement as the ship twisted from one side to the next and broke apart twice on the surface. The loss of the liberty ships and the Titanic in the same proximity to the Labrador current and Gulf stream is a testament to the dangers of rapid thermal change and how even the strongest of vessels can break apart on their maiden voyage.
Regardless of fracturing Kaisers ships played a vital role in the war effort. The government was not capable of producing these ships in the sheer quantities and time frames needed. Henry kaisers ships disprove the new dealers false narrative that big government interventionalist policy saved the day and won the war when, in fact, it was the genius and capability of private businessmen like kaiser, Higgins, Ford, and Kneudsen that won the war. The fact that these men were able to accomplish such extraordinary feats while having to deal with shackling government regulation( regulation and poor economic policies that prolonged the depression and the war) is absolutely amazing.
This might unnerve a lot of travelers when I point out that airliner wing box structures, whose main structural member is the upper and lower "plank" (the machined top and bottom aluminum skin between the front and rear spars), sits there flexing in turbulence at -40 to -65C pretty much all the time.
I worked as a shipfitter building ships for 24 years. We used several different steels. In most cases, these WW2 ships broke apart where the ships were welded. No one knew at the time ((when all welded ships were a new thing)) that all longitudional stringers needed to overlap the welded seam by at least three feet. Just by doing this in all ships since has mostly ended ships breaking in half. The sole exception was and still is ships like bulk ore carriers built too long for their width. Several of these have broken and sunk since WW2.
In the early 70's I was completing a qualification for special electric arc welding and we were taught about different welding techniques and one of them was the processes used on the liberty ships when you join 2 sheets of steel it is a butt weld with a vee preparation and to speed the processes they would lay a route run joining the materials and then fill the remainder of the groove they would just lay the welding rods in the groove and then just lay a layer of weld over the top saving hours of work so you just had 2 very thin layers but it looked a great weld visually because of the extremely high work load these practices became common also relating to the high losses
Analysis of a souvenir rivet leftover from the construction of the Titanic (taken home by a dockworker as a momento) led to the conclusion that high sulfur steel was used in its construction. Less brittle more malleable steel that might have less propensity to shatter in low temperatures was available but not used. After the discovery of the wreck, steel samples recovered from the wreckage matched the rivet in composition perfectly.
I believe the Titanic used wrought iron rivets-and least in come cases-rather than steel rivets. Wrought iron indeed does not have the physical properties of steel. Don't know if steel rivets would have prevented that tragedy, but they might have provide a stronger hull and reduced the extent of the damage.
Sadly the truth is that so many ships were lost in action that just getting them there was a victory. a return trip, amazing, anything after that, just gravy. the merchant marines don't get any of the glory but they are responsible for their ships namesake, liberty.
Thank God that the allies had Liberty ships, we wouldn't have won without them, albeit sad that many lost their lives because of the flawed metallurgy. Engineering has advanced and we have since benefited from Dr. Tipper's discovery and the corresponding improvement of steels. It is and always will be the case that "You don't know what you don't know". Nevertheless, whilst Engineers put everything they do know into a design, they should never be scared to fare-forward. Aye, live and learn laddie. Good video, thanks, but could have gone on to explain the correction in steels and what was done to offset the problem at the time. .
It should also be noted that the Truman Committee discovered that the Carnegie-Illinois Steel Corporation was selling steel slabs to liberty ship builders that didn’t pass inspection or strength tests.
I have in my possession two pieces of flawed steel hollow bar sourced from a Scandinavian country, circa 1968/1970. They are remnants of several bars purchased, by my boss, for the production of press tool guide bushes. The flaws are not unlike a rolled up newspaper. Unbelievably, a world famous Scandinavian steel company produced a defective product, shipped it all the way to South Australia, only for me to discover the defects, after having cut them to length and machining them. My point is, if these highly regarded people can "get it wrong" who else can?
What alloy of steel was being used? What element or lack of causing this issue? It seems to me by that time there was adequate knowledge of the properties of steel. As a kid I remember talk of these failures being due to solid welded construction, no rivets so basically there was no flex in the ship. Thank you for this video.
Rivets act as crack stop points. Riveted structures don’t have the discontinuities imbedded inside them that act as stress raisers that welds do. Welding changes the material composition and heat treatment characteristics of the metal around the weld - proper choice of welding filler material and post weld heat treatment are critical to avoid this.
The key issue was low temperature ductile / brittle crack transition. The North Atlantic was cold enough that the steel would crack like glass rather than stretch and tear.
Something called Boiler Plate. Hastily produced from any number of scrap sources some parts of the plate. Were soft others were hard dueto the presence of bed springs Areal crap shoot to machine
The steel quality was really very poor. Qinetiq did some testing on steel samples from WW1 through to post WW2, and the steel used in to construct the liberty ships was by far the worst. It had extremely high notch sensitivity, and high ductile brittle transition temperatures. At least one of the ships fractured while the ambient temperature was well above 10C. The poor quality was actually recognised during the war, but the significance of it was not initially. Truman mentions in his autobiography: "We saw the seamy side of the war effort. We had to investigate crooked contractors on camp construction, airplane engine manufacturers who made faulty ones, steel plate factories which cheated, and hundreds of other such sordid and unpatriotic ventures. We investigated procurement, labor hoarding, army and navy waste in food and other supplies. But when we were coming to our conclusions, we all decided that by and large the greatest production and war preparation job in history had been done." Steel manufacturers were often turning out junk to get paid. The yards building warships and submarines got the best quality output, and everyone else got the rest. It being wartime, the quantity of output was deemed more important than cracking down on that sort of fraud. The lack of rivets did not affect the flexibility of the ship, but rather a riveted construction had natural crack arrestors where one plate ended and another began - if one plate cracked, it didn't matter so much because the next plate was a separate piece of steel. With welded construction, the hull is effectively all one piece, so if a crack starts to propagate there is nothing to stop it going right through the hull. Part of the wartime fix for the hull fracture problem was to add crack arrestors in the deck in the vicinity of the likely fracture points, so that any fractures that did occur would not be catastrophic. The knowledge of steel properties was not comprehensive - the mechanics of brittle fracture were still largely unknown at the time, and it was only researched post war, mainly as a result of this particular failure case.
Also as a note here - *every* currently commonly available steel today is much better on ductile/brittle transition temperature, because it was found to be a menace for almost everything in cold climates eventually. But the American Bureau of Shipping established specific steel grades with much better ductile / brittle transition temperatures and more predictable yield for permanent deformation when overloaded so ideally no hull part would be stretched more than its neighboring pieces of steel. These steels are most common shipbuilding standards worldwide now.
A classic case of Quantity over quality. Transport ship losses where huge in this period due to the Atlantic Gap, so these ships where essentially expendable. It was about flooding the sea lanes with cheap easily built ships as much as anything.
Interesting analysis. I sailed on the SS Jeremiah O'Brien Liberty ship a couple of times in the San Francisco Bay, CA USA. Wonderful ship! We were given complete tours.
The major flaw of Liberty Ships was that they were so slow that they couldn't out-run a row boat, much less a pack of U-Boats. They were grossly underpowered and had a top speed of about 8 knots (9 miles per hour). The were so slow that they may as well have been at anchor. U-Boats had plenty of time to get from wherever they were patrolling to where the Liberty Ships were at permanent anchor in the North Atlantic Ocean. Had they been able to go (for instance) 33 knots per hour. the sinkings rate would have been decreased by around 90%.
Drastic times call for drastic measures. The very fact they could build and launch such vessels so rapidly and in such numbers is incredible. To second guess or criticize from the safety of decades of hind site does a serious disservice to the people who pulled off what was literally impossible to pull off.
Whenever I see the start of any crack, regardless of material, I drill a small hole”check stop” hole at the end of the crack to stop the continued cracking. Works were well.
Was there also a problem of ductile-brittle transition caused by the localized heating of the metal at the welding site when done in cold weather? I assume that would have shown up as a difference in ships built in colder northern yards vs warm year round southern yards? (the metal would cool faster after welding?)
No it was the steel itself that became brittle at low temperatures. In combination with the internal tensions created when the weld cooled after welding. Remember that a weld is essentially a casting.
While the Liberty Ships had their problems they were later resolved. Problems like these were not unique at that time. US submarine torpedos had problems that took years to fix. Another was initially under powering the P-51 Mustang fighter, which then received the British Merlin engine which made it a world-beater. I’m sure there are may more examples that other could cite. In the end, however, the these systems were fatal: to the enemy.
That failure, still helped win the war! The best 'weapons' of WW2 were: the liberty ship, the Dakota, the Deuce and a half and the Jeep. It doesn't matter if you have the bestest ever equipment and men, if you cant supply them.
Considering the overall situation, in the US, in Europe, "winning" that war was not a win. As master Yoda said, war doesn't make anyone great. Yikes, look where we're at in the so called "West"!
The M1 and the BAR should be on that list too. While most soldiers were using bolt action rifles the M1 was semi-automatic. The 50 cal "ma duce" was also a game changer... Of course the brains of the people using them was the most important. Some troops waited for orders while others innovated and figured out new uses for everything...
Yeah I remember when I found out about this. Its part of the reason we switched from the Liberty to the Victory ship. Of course these ships were considered expendable. It was considered that if they completed 1 run they were successful. Volume took precedence over quality. Improvement was only allowed when it didnt interfere with production rate.
The Australian Antarctic Division used a liberty ship for re - supply in the 1950s, the Wyatt Earp, on a return trip from Antarctica it developed a crack, it returned safely but wasn't used again, these ships were invaluable for the success of the allies and served their purpose well
My father as a freshly minted ensign, was assigned as a gunnery officer on a liberty ship in the North Atlantic acting as chum for u boats . After surviving that he assigned to T2 tanker as executive officer . My grandfather would assure my grandmother that my father would never make it home, as she didn’t approve of my father
102 of the Liberty ships were built in Panama City, Florida. And when I was younger it was a common sight viewed from the Hathaway bridge to see them being scrapped through the 1970s. One of them was sunk offshore for an artificial reef.
Hmm, I remember Aristole Onasis the shipping magnate bought a bunch of the Liberty ships after WW2 to make his fortune. I recall stories of his ships breaking up and suddenly sinking which as I recall many took it to be lack of maintenance, but this design flaw makes sense as the reason.
Many of the Liberty Ships were re-purposed as bulk carriers after the war. Despite the supposed "fixes" sited in many of the posts here, these ships continued to suffer catastrophic hull fractures in cold waters for years and years, resulting in many lives lost at sea. Two such ships sank in the Atlantic Ocean off the Northeast coast of the US in 1952, virtually simultaneously. This tragedy was recounted in a book titled "Two Tankers Down". The cause in both cases was catastrophic hull fracture (ie, the ships broke in two at sea). In 1966 the SS Morell, another converted Liberty Ship, broke in two and sank in Lake Huron with only one crew member surviving. Finally, in Feb. 1983, the SS Marine Electric (a 40 y/o converted Liberty ship) broke in two and sank in the Atlantic Ocean off of Chincoteague Va. with 33 lives lost and 3 survivors. To say that this problem was "solved" in the 1940's is ridiculous. The problem was the quality of the steel as described in the video. Following the 1983 sinking of the Marine Electric all of the remaining converted Liberty Ships were scrapped.
The fatal flaw of this video isn’t that liberty ships cracked, but that the cover picture for the video shows not a Liberty, but what looks to be a T-2 tanker (bridge midships and engine room/stack well aft). NOT the same ship. Thanks
Awesome engineering showcase. I understood that aluminum hulls are not to be welded along the entire face, but only at points which connection reinforces another as the welding alters the metallurgical properties, creating a weak link ?...
The ultimate solutions were: 1. A riveted crack arrester strake just below the main deck. 2. Ultimately, notch-resistant steel alloys. Kind of pricey, so they tended to have just one run just below the main deck.
During the war there was no time for 'several years of research'. The point was to win the war and it did, and the Liberty ships greatly contributed to this.
The T-2 tanker wasn't a Liberty Ship. the Liberty Ship was a specific design of dry good cargo ship built by Kaiser shipbuilding, and they weren't intended to last long. The increasing lose in the Atlantic to German U-boats made it risky for ANY transport ship to sail between the US and England during the early to late parts of the war, and so the Liberty ships were built as cheaply and quickly as possible, wasting no effort on making them durable or lasing, since they were expected to be sunk by U-boats anyway. This was not a design flaw but the result of the main design features of the ship - cheap and quick - later ships (once the U-boat war was considered under control) of the same basic design were built, but with much more effort to durability. These are not "Liberty Ships", though they look the same, but "Victory Ships". The survivors, SS John W. Brown, SS Jeremiah O'Brien, SS Arthur M. Huddell & SS Albert M. Boe are actually Victory Ships not Liberty Ships.
Bru, if you like these ship stories you might like to look into how they figured out why ships kept disappearing in the open ocean. Seems like when these ships got out there on the long swells the ships would ride out on the swell and the back half of the ship would be supporting the whole weight of the front half of the ship, and . . . snap . . . the ship breaks in the middle, 'cause . .. you know the back half of the ship was not designed to support the front half on a wave.
I sailed on US Lines Mariner class container ships in the 1:50 ’70’s which were the late WWII designs after the Victory ships. Every time we came into Boston the Coast Guard boarded us because they knew they could find cracks in the hull and fail our inspections until we had welders repair the cracks.
I realize that lower temperature causes many materials to be more brittle but I was under the impression that steel brittleness would occur at much colder temperatures than encountered in open oceans.
Sadly the steel used for the Liberty ships became brittle a few degrees over water freezing. Nowadays when we know the cause, different steels are used depending on expected temperature. It was also the inevitable remaining 3 axis tension after welding. Plus stress concentrations.
Surely a problem that appears in cold weather and disappears in warm weather would alert even a moderately intelligent engineer to the cause of the issue.
We had to unload these ships in the early days in Vietnam. Our Vietnamese helpers would steal some of everything. One took a big drink out of a Brown bottle he thought was booze. It was choral hydrate or some other anesthetic drug. He was dead before he hit the ground.
I heard decades ago that welders were given a can of welding rods and finished when it was empty. If the dry rods were packed in a joint and then welded over the job was done.
@roysutton9592 In the research, I came across a case where a person was sent to jail for doing that! They were not messing around back then 😅 and rightly so, by doing that, you are essentially rolling the dice on someone freezing in the Atlantic
The first ones were riveted hulls. They are the ones that failed. In 1961 we took one from San Francisco to Honolulu. No problem with the welded hulls.
people forget that if a war of that magnitude comes again our modern panamax freighters will be sitting ducks and modern versions of liberty ships will again be essential
on a displacement hull, that is a ship, extra horse power doesn't do anything regarding speed in practical terms. Yes another 1/2 to 1 knot, but at great expense to fuel consumption. The speed that a ship can travel is governed mainly by it's length with some other factors also affecting it. You will often see the term 'hull speed'.... which means the design speed of the ship/hull thru the water. Any extra power means it can tow or carry a heavier load, but not go (much) faster than hull speed. They had a 2,500 HP engine and about 11 to 11.5 knot speed. 11 knots is not bad back then for a cargo ship. They were not a jet enginned racing boat.
They only had a 2500 HP Triple Expansion Piston Steam Engine which isn't much, but their real problem was their hulls were designed for easy assembly-not for speed. Streamlining was an afterthought, they wanted to be able to build ships from easy to produce templates and that meant more square hulls and less curves. The Victory Ships, a later design, used more streamlining and had a 17 knot top speed compared to the Liberty Ship 11 knots, but Victory ships also had a much more powerful steam turbine engine.
just a reminder that if an actual ww3 does break out the massive panamax container ships are among the first things to be sunk, modern liberty ship sized containerships may well be the way to go. the battle of the atlantic allone saw over 3500 merchant ships sunk primarily by submarines and submarines are more potent than ever whilst drones and missiles pose further dangers to modern shipping.
The first 1,000 people to use my link will get a full year of Premium membership to Woodworkers Guild of America for only $1.49: go.wwgoa.com/theengineeringhub/
Nearly as much shill as content and in the middle no less. Have a well earned thumbs down.
@@misterhat5823 Exactly and Thanks. This guy is full of crap. I've seen video's about this and it was attrubited to way overloading the ship especially in very cold water and in rough conditions. Keep in mind they considered the ship a success if it only made one trip to Europe. No return or second trip which many made several. My Dad served as E.M. on a Liberty ship.
Canada also made lots and lots of Liberty ships, the small shipyard I work for put out one every six weeks. Shipbuilding was in panic mode and if they made one Atlantic crossing they were considered a success. Let us not forget all the Merchant Seamen that also paid the ultimate price.
The other thing about merchant mariners, was their pay was stopped when their ship was sunk.
@@frosty3693 This is not generally correct.
It's not correct at all for US merchant mariners. Under US law, merchant mariners were paid in full for every day from their departure until they reached friendly shores. At that point, they still received base pay, but combat area pay stopped. Base pay was 87 per month starting. Combat area pay was a 100 per month bonus. In the event of injury, pay was transitioned to the insurance payout which was 200/month up to 5000. On death, there was a fixed 5000 insurance payout.
There is one area where you are correct. That is how it was under british law pre-ww2, though the contract offered by the employer may or may not supersede this. The british changed this rule in may of 41. So even with the british, this was only the case for about 1 3/4 years of the war, which lasted 6 years for them.
Merchant navy and sailors were among the unknown saviours of the allies in both world wars. Men of steel.
My 99 year old was an Engineering Officer on Liberty Ships in WW2. His convoy was bound for England when the worst WW2 winter storm in the North Atlantic struck. As 3rd in command he was on watch at night when he observed other Liberty ships breaking in 1/2. He felt very lucky his ship didn't break in 1/2. On the return voyage, when he arrived in Halifax, he was shocked to see that the recovered 1/2s were being welded back together. The allies were desperate for shipping capacity. Dad said that the most common Crack was in through the hold just ahead of the main housing. The initial fix was to weld a band of steel around the hold hatch way. This extra steel was sufficient to stop cracks. Ships that Dad served on were torpedoed, staffed and V1 landed next to his ship while tied up in Holland. He said the guys he felt sorry for were the crews of oil tankers because when they were torpedoed the sea burned
My Father was a merchant seaman from 43 til 45 and had sailed on Atlantic convoys aboard Liberty ships . He would never talk of the hardships of life at sea , only the funny stories . Through third parties I was informed that my Father had unfortunately been aboard a Liberty ship when it split in two on the high seas . When , as a kid , I asked him if it were true he never answered me or looked at me . I was totally ignored and immediately understood he would never answer .
Thank you for an excellent video .
Thanks for sharing this story with us. It's interesting to hear first or second hand experiences about the Liberty story
@@TheEngineeringHub I’d often wondered as to the cause of his ship breaking up . I’d imagined it might have been a torpedo attack but thanks to your video I now understand a bit more . Torpedo or metal fatigue / temperature failure I imagine the experience of sinking in the Atlantic in winter was not a memory my Father wanted to share . He was only 16 years old in February 1943 . He survived , others weren’t so lucky . I consider the Merchant men as unsung heroes. Technically civilians but in practice on the frontline .
@@davidrussell8689 wow stories like this really make you think how good we have it today! Thank you for sharing, I hope your father had a long and happy life after the war!
@@davidrussell8689 Absolutely agree, statistically being in the merchant convoys (especially in the first years) was as bad as being at the front.
Terrific content. Thank you so much for this information. This ties in with a story my father told about his experiences in the navy in WWII. He described how in 1943 after he completed his training, he shipped out from San Diego to Hawaii. His transport ship was caught in a storm and started breaking apart. He described how they were carrying "railroad tracks" which were welded onto the hull as reinforcement which allowed them to limp back into San Diego where he caught another ride to Hawaii and later New Caledonia to find the ship to which he was assigned.
I feel like you have left us hanging for the answer. You identified the problem with the Liberty Ships, but stopped short of showing us the solutions that were adopted. This video really needs a Part 2 to close out the whole story.
Mark from Melbourne Australia
The hatches were made with sharp corners for ease of manufacture, that is where the cracks started. The solution for new Liberty ships (as far as I remember) was to make the hatches with rounded corners that didn't crack. There was also some reinforcement, added.
@@ptonpc There was a reinforced band or belt that was welded on the outside of some ships as an emergency measure but the added weight and drag reduced speed and capacity so that idea was abandoned.
These events led to new research and the science of “Fracture Mechanics”…..Brittle Fracture/Notch ductility, at various temperatures/ Stress Concentration Factors/ Steel quality etc etc etc…. The fix was to reshape and reinforce the hatch corners to reduce the stresses, but reinforcement attracts load (in general) so it’s self defeating in some respects. The rapidity of crack growth in the Liberty ships was the surprise.
Edit: Some great posts below…..lewisdoherty etc
@ptonpc The de Havilland Comet, the first commercial jet airliner, DH106, had square windows. It first flew in 1949. Cracks would form there causing structural failure problems, and crash. At first the engineers didn't understand the problem, but soon figured it out. The hole for the ADF, automatic direction finding, antenna, had square corners. Also, the riveting was poorly done. These problems were identified, fixed, and the type went back into service as a Comet 4 in 1958 and was retired in 1981. The remaining one was retired from service in, I believe, 1981. The other manufacturers learned this lesson. Also, if there's an interest, look how small the windows on a Concorde are.
The problem was with the steel which was made to too little manganese which left it brittle at cold temperatures.
Dr Constance Tipper was Britain's first high-profile woman materials scientist (from Imperial College London via the UK's Department of Mines and also Cambridge University). British naval architects designed the Liberty ship - the first being named 'Empire Liberty'- and then went on to build about 1000 similar ones in British yards during WW2, known as as the 'Ocean' class. American Liberty ships were a close copy of the Ocean series. It was initially believed that the plate cracking was due to poor quality in Kaiser yards however, Dr Tipper demonstrated that cracking was much, much less common in rivetted (as opposed to welded) hulls, riveting being a fairly common practice in British yards for either some, or all of the hull. She also went on to show that crack failures were commoner in American welded hulls than British welded hulls and she was able to demonstrate that this was down to generally lower quality American steel (having a lower manganese to carbon ratio than British steel). The British involvement in the Liberty ship programme is almost always overlooked. Sorry, Yanks.
I did my degree dissertation on this subject, and there wasn't a lot of information about Dr Tipper easily available at the time. Her contribution seems to be much more widely recognised now which is great because she really was a significant figure in the development of material science.
Common of many aspects of technology and intelligence in the war.
@@alastairbarkley6572 L8ke Cecilia Payne, grossly under recognized
Although there were other factors involved, I remember reading that the Titanic, built in Ireland, had too high of a sulphur content in it's steel. It's hull was also riveted. However, the Atlantic water temp, coupled with brittle steel, were two big factors causing the Titanic to rip open upon hitting the iceberg. Traveling at a high speed didn't help either. Plus, the watertight bulkheads didn't travel all the way from the hull to the deck and there could have been more, leading to higher structural strength and better watertight integrity. Lastly, there just weren't enough lifeboats-My dollars worth-John in Texas
"British naval architects designed the Liberty ship - the first being named 'Empire Liberty'- and then went on to build about 1000 similar ones in British yards during WW2, known as as the 'Ocean' class. American Liberty ships were a close copy of the Ocean series."
Wikipedia (article title: Ocean Ship) disagrees. "The Ocean ships were a class of sixty cargo ships built in the United States by Todd Shipyards Corporation during the Second World War for the British Ministry of War Transport under contracts let by the British Purchasing Commission."
My step-father worked as a welder building Liberty Ships in Maine before he was drafted for the war. He told me that the prefab panels often weren't as precise as they should be, and that they would lay several welding rods in the gaps and weld over them. When he crossed the channel on D-Day, he was on a ship that he helped build. He said that it scared the hell out of him.
Not having to build lots of Liberty ships (British shipyards actually built more than 1,000), the Brits could concentrate on warship production. For example, smaller yards built 'Flower; class corvettes - hundreds and hundreds of them for the Royal Navy, the Canadian Navy, and yes, the US Navy and the US Coastguard (amongst other countries). Equipped with state of the art British sonar, radar, HF/DF and the 'Hedgehog' depth charge system, these 800-1000 ton anti-Sub vessels became the workhorses of Atlantic convoy protection, greatly reducing the number of fast destroyers needed for convoys and racking up themselves a huge number of successful sub kills. My school physics teacher was greatly influential in my life. I admired him greatly. He recounted his experiences serving on these fierce little ships in the north, North Atlantic in the depth of winter. It was a hellish naval posting and those guys never really got the recognition they deserved. I realise now that if anyone in my life deserved me saying 'Thank you for your service' it was my school physics teacher.
"...Liberty ships (British shipyards actually built more than 1,000)...
I can't find any sign that ANY Liberty ships were built in British shipyards.
@@gandydancer9710 They weren't, all the strictly 'Liberty ship' production was in the States. Of course British ship manufacturers were busy producing their own ships-that was the reason the British government went looking of additional supply. The British also built a lot of cargo ships during WW2, but they were not Liberty ships and their designs included a lot of hull riveting.
@@heyfitzpablum You need to address that comment to alistairbarkley, not me since it contradicts him and not me.
My Metallurgy professor taught about the poor steel used in the liberty ships. He used this as an example to teach about the brittleness of certain steels in cold environments. He served as a rifleman in the US Army. He said he never felt more alive than when bullets were whizzing over his head. The most valued things were dry socks. He was a great professor.
Great story. Ties the Liberty Ship story to this great professor.
My engineering professor was part of the Oxford team investigating these failures. Ships of the same design and steel spec were made in England by riveting. Thus the welding was not the only cause. After exhaustive testing low temp embrittlement was found, yet the Britt ships survived. In the end the cause was found to be the sulphur/phosphorus ratio difference between the 2 difference US and British steels - not originally specified.
Their tests included filling 2 ships with strain gauges. One ship welded, one riveted and sailing across the Atlantic to be sure of the stresses experienced.
My father was in the navy and on a liberty ship in the Pacific during WWII. I think the fix was to weld a band of four foot plate to the likely failuring locations. I also heard a contributing factor was that riveted plates for which was traditionally designed were able to slightly flex between each other while the welded plates were unable to flex as much between each other.
Riveted joints are stronger than welded joints in the same thickness metal. (That’s why aircraft still use them).
The act of welding changes the composition and properties of the metal in the heat affected zone around the weld. Welds are more water tight but more likely to catastrophically fail.
All-welded ships were a relatively new idea in the 1940's. The problem with welding is that the plating effectively becomes one giant, continuous plate. Any crack just keeps on going. Riveted plates are still 2 separate plates. There is no flex. One of the design changes the builders incorporated, was to add a riveted section every 5th plate to act as a crack arrester. It was found that the steel used in British built ships was not prone to this low temp. embrittlement. It was called "Arctic D" and had a small percentage of manganese in it, which drastically reduced the problem.
@ the cracks in welded plates propagate up the welds that are weaker than the parent metal. (About 80% the strength with a GOOD weld). Not knowing that welds are weaker is a common mistake (even among experienced welders).
5:43 @@allangibson8494
The next design the "Victory" Ship had a riveted band at deck level. Sulfer contamination in wartime steel was an issue too.
As a teenager, my father was a welder in the Kaiser shipyards in Washington. After the war, he became a civil engineer, with his first job out of school as a welding inspector for the Kansas Highway Department. He told me the problem was the square hatch opening, which created a stress riser. A small redesign made the corners rounded.
Yes, that is what I remember reading years ago. The square hatches were easier to make but that is where the cracks started. It would have been nice if the video had mentioned that and the fix.
In 1949 the de Havilland Comet, the worlds first commercial airliner was designed with square windows and the constant pressure and temperature changes caused the plane to fail at the window corners. There were two catastrorhic failures with 56 souls lost before the planes were deemed not airworthy. You would think the engineers who designed the plane would have known that from Metalurgy 101.
A problem they identified and remedied in the 1940's but repeated the same problem with the COMET airliner in the 1950's. He who does not learn from history is bound to repeat history.
What about the 'field fix' for cracks that I remember hearing about years ago....where a small hole would be drilled right at the leading edge of the crack, thereby dissipating the straight -line forces?
@@terryjohnson3479 "You would think the engineers who designed the plane would have known that from Metalurgy 101."
The calculations were a little off.
When I was still an Engineer in the Merchant Navy, there were still some Liberty ships working. We used to get accident reports sent to us in the post in port, from around the world. Some of them were quite amusing. One report was from the 2nd Mate on watch at about 02:00 hrs in the morning. The sea had been little more than a force 3 with a long swell. He reported that he had heard a loud cracking and tearing noise from behind the bridge and felt a rumble through the deck as the lights went out. There were some more crashing noises and he went on to the bridge wing to have a look at what he could see, as the ship had also slowed down. He reported seeing the aft accomodation block and engine room overtaking the front of the vessel as he stood there. Still in full light and and with the engine apparantley still under full steam. I wish I could remember the name of the magazine the reports came in, but too many years and too many pints ago.
I recall in the mid-1970s seeing a Jumboized T2 Tanker being loaded at Kargh Island the ship had been massively stretched in both length and beam.
@andrewwmacfadyen6958 Yes, they had an astonishingly long life considering they were considered to be almost one trip disposable. That accident report would have been in about 1984 I think. I was on Tankers with Sanko by then.
@@andrewwmacfadyen6958 Loaded there several times. The iranians are so vilified by the west yet they were always so good to us. There was a wreck that had been bombed by the iraqis, they towed the burning hulk off the berth then it sat there half sunk for years. Back in the early 90's the berth was still full of bomb holes, the end end of the jettey was gone, just a twisted heap of burned black steel.
@@billdoodson4232 Captain on Sanko tankers here 2005 to 2009. Sanko Bright, Sanko Abilty, Sanko Breeze, Sanko Amity. You probably sailed with Capt DeRuiter. I really liked Sanko too bad their foray into the offshore oil supply vessels bankrupted them. There was no warning we all had jobs then suddenly we all did not have jobs. I remember on Sanko Breeze they sent us to S'pore saw a dozen or more sanko supply boats, newbuilds right our from the yard all lined up at anchor no charter for them.
Liberty ships were designed for a 5 year lifespan, the whole idea was to produce ships as quickly as possible to support the war effort and not worry about their long term durability. That companies were still using Liberty ships for commercial cargo DECADES after the war ended shows that the basic design was pretty sound. Aristotle Onassis acquired a lot of Liberty ships from US storage that he used to start his shipping business after the war. I'm sure those ships kept the maintenance folks busy!
As a boy I travelled to Hong Kong and back on an RFA Liberty ship delivering cargo to all UK ports on the way. Three months there and three back in 1948 and 1951. I'm glad the ship didn't fall apart!
The RFA, , the Royal Fleet Auxiliary did not carry cargo to from Port to Port. They provided support to the Royal Navy. They also did not carry passenger's.
I reckon johndobbie528 knows better than you what ship he travelled to Hong Kong on. He also would have seen and remembered perfectly well cargo being offloaded, probably to British bases. As for RFA's ever taking passengers, well during the time of Empire, British people and institutions were far more flexible and practical than the beancounters running things today can even imagine in their wildest dreams.
@@sandyallsopp6778 You know nothing, go back to Jewish Space Lasers
Merchant Seamen had the highest relative casualty rate of any group in WW2. They were more likely to die than Bomber Crews over Germany, or the Marines storming Japanese held islands in the Pacific.
And, for the most part, they couldn't fight back.
They were civilians. Not military personnel. Dodging bombs and U-Boat torpedoes in the freezing North Atlantic, was simply their job. They didn't get "combat pay". And their families did not receive "Survivor's Benefits". Nor did they qualify for Veterans Benefits, or the GI Bill, after the war.
And if they were lucky enough to survive their ship's sinking, they weren't paid at all, once they abandoned ship. (The Company wasn't paying you to sit in an open lifeboat for 40 days. Or for any time you spent as a POW, in those very rare instances that the Enemy rescued you.)
Nor did they get any metals or awards, even when they engaged in combat with their anti-aircraft, and 3 inch deck guns.
Yet, without these incredibly brave men, victory would not have been possible.
We, today, still owe a lot to those guys.
that is the same around the world for merchant seamen.
No campaign medals, no extra pay, no rehab in them thar days
My father was 2nd mate on Liberty ships in the European Theater for much of the war and damn proud of it. He (finally) talked on their losses and credited winning the war by the US out producing Germany (& Japan). When we needed 10 tanks, we sent 18. Just as we knew the ships (& tanks) were lesser quality than we'd like, they were expendable; as were the crew.
Are you sure about that? By the end of the war, the Eighth Air Force would have more fatal casualties-26,000-than the entire United States Marine Corps. Seventy-seven percent of the Americans who flew against the Reich before D-Day would wind up as casualties.
@JohnWHoff-gt2uf : My dad served in the Navy, mostly in the Pacific. He never really talked directly to me about his experiences. What little I learned, can from overhearing conversations he had with other veterans.
The job your dad did, was absolutely vital to winning the war. It's a shame that the Merchant Marine Seamen don't always get the credit they deserve.
Your "ol' man", was a hero. Pure and simple.
@@colonelfustercluck486 The U.S. Maritime Administration's website now has a section of "Mariner Medals."
Some glaring inaccuracies here. The liberty ships where the first to use more constructed modules and welding. As a result unknowable failures happened. The ship builders fairly quickly discovered the problems with welding, and resolved the issue by annealing the weld. The fracturing of the hill was due to sharp angles around the holds. That was cured by rounding the joint. After the second world war, liberty ships went on to give sterling service in the merchant marines around the world and many shipping companies rebuilt their fleets with them. The technique s used to build liberty ships are used today in ship building. The liberty ships had their faults, which where resolved. Don't knock em, they gave good service.
Onassis !!
The liberty ship was superseded by the Victory ship.
To prevent the hull cracks that many Liberty ships developed-making some break in half-the spacing between frames was widened from 30 inches (760 mm) to 36 inches (910 mm), making the ships less stiff and more able to flex. Like Liberty ships, the hull was welded rather than riveted.
I am 75, my father-in-law was a WW2 merchant seaman on the Murmansk run. He said that in the really cold conditions if a steel handrail etc was hit hard, it would shatter. No wonder thermal embrittlement was a problem. Our modern mild steel is a far cry from the hurried wrought iron from then.
@@howardsimpson489 imagine being in the middle of the ocean on a vessel essentiali made out of glass. Scary!
Sorry, but Liberty ships' hulls were built from steel, not wrought iron. (See p 436 of The Last Liberty" by Walter Jaffee. Even in 1912, Titanic's hull was built from steel (see p 139 of "Titanic, The Ship Magnificent") but some of her hull's rivets were wrought iron and some steel (p52 & 59 of the same book.)
At 0:09 in the video above, the narrator correctly states "steel hulls of the Liberty ships"
@@ianm452 he probably didn't mean literal wrought iron, he meant that the steel was far lower quallity than modern mild steel or at least wasn't as suited to shipbuilding
They didn't use wrought iron on Liberty ships, wrought iron is a cast product with practically no carbon in it but fibrous slag inclusions. The plate used on Liberty ships was low carbon steel of about .08-.10% carbon content, or better known as CRS (cold rolled steel). It had embrittlement issues in extremely cold weather because the US plants set up to produce that product had too low manganese content in it. Ship welding was fairly new and the worldwide ship industry was feeling their way, and learning the lessons as they did. One of the fixes for Liberty ship crack issues was to improve the chemistry of the steel which improved low-temperature toughness.
My father was very critical of the Liberty Ships and talked in disparaging terms about them breaking in half in the Atlantic and killing their British crews. His view of the situation was poor welding skills and the rush for completion of the ships. A simplistic view of the time and quite understandable - however, it left him very bitter.
8 hours between launches, not 8 hours to build. They had dozens in process at a time. Average time to build was 42 days, fastest time was 4.5 days. But still Very impressive timing!
There is a documentary out there which shows a Liberty ship being built in 24 hours.
It was done as a moral booster for the Allies, but also as a moral lower for the Nazis, to show them that we could build our ships quicker than their U-boats could sink them.
All built with the lowest bidders material...
@@thomasdragosr.841 i mean
Whos gonna make that much good quality steel with in soo little wsrning time?
I’ve heard that the US ship yards refused to take the contracts due to the time requirements, so the steel company’s/non-shipyards were asked and said sure.
I think his plot showed at one peak failure month, 16 ships cracked in half when there were 2700 in surface. That’s just over 0.5%. Weren’t the U-boats a more significant loss factor?
My father was an engineer in Shell Tankers from 1945. He used to say that his fellow seamen hated the Liberty Ships and dreaded being posted to one of them because "they break their backs".
After the crack issue was "fixed" the T2 were quite popular with BP tanker officers because they all had fridges in the cabins
He would not have sailed on Liberty Ships, they were General Cargo vessels not tankers. The prevalent War built tankers were the T2s
There were many Liberty class ships that had developed cracks but there were only three (!) which broke completely in half due to design flaws. That figure is from a study done by Bethlehem Steel just after the war and I poses a copy of that report. One of the major issues was the square corners on the cargo hatches which functioned as a stress riser. Another issue that you did not mention is that welding was a new technology at the time. In riveted hull plates a crack could only propagate through the plate but not to the other adjacent plates. When the plates were welded however, the crack could potentially propagate through the entire length of the hull. I should point out that West coast ship's hulls were entirely welded and welded to the ships ribs. East coast ships had the hull plates riveted to the ribs. The simple fix was to weld a curved steel member to the square corners of the cargo hulls. You can see this fix on the SS Jeremiah O'Brien in San Francisco. I am currently the head of the Docent Department on the O'Brien and must often correct the misinformation that is out there.
In engineering, three brittle crack failures are famous. First the Belgian Hasselt bridge failure in 1938. Second the Liberty ships. Third the Kings Bridge in Melbourne in 1962.
I am Cindy’s husband, I’m using her account just for this comment. -- My uncle was the engineer on the “SS Joseph Wheeler” liberty ship. He told stories about convoys they sailed in to Murmansk in Russia.And survived. He told his experiences to his younger brother, my dad. Who was shipped down to Orangeburg, SC as a primary flight instructor to raw recruits from the US and France to see who could become talented pilots and then advanced them to train to become fighter or bomber pilots. Everyone else “washed out”. Which ment the infantry or they crashed and died taking the instructor with them.😢My uncle was lucky until December’43 when his convoy successfully crossed the Atlantic and docked in Bari, Italy on the Adriatic Sea with many other liberty ships. At least one of them carrying a top secret cargo of mustard gas bombs and the rest were loaded down with aviation gas or high explosive bombs to support the allied invasion of Italy. Apparently the British who managed the unloading of the ships ( I’ll be polite) did not expedite the unloading of the liberty ships. This allowed the Luftwaffe to spring a surprise attack on the unprotected harbor. The result was a total disaster. The SS Joseph Wheeler was the first direct hit and disintegrated completely. There were no survivors.😢 We will miss our uncle Otto forever. RIP.
Ironically, my father’s family immigrated from Germany in 1925. Otto was aged 10, my Dad, Werner was aged 5. My Grandfather Siebo was a veteran of the Kaiser’s WWI defeated army. He had also lost his brother in the War and was “SICK of guns and war”. A direct quote.
from him. Thankfully his youngest son, my dad ended up living the American dream. I thank God for this country with all its flaws. And he did too. He knew what his ancestors had lived/died through and he became a compassionate democrat after seeing that his Republican Party had lost its way. God bless you Pop, and Grandma. You were certainly THE GREATEST GENERATION. To your 4 sons…………….
Not perfect, but who the hell is !!!
Thank you for sharing your family's story with us, sad but also very fascinating🙏
Sadly today's democratic party would be unrecognizable to their own parent's generations ... sadly,. its obvious that Democrats have been captured by kultyooral marks-ist eyedeeology
(For more info on the attack on the port of Bari, Italy read the book “Disaster at Bari” by Glenn B. Infield, published by Macmillan)
THE HERO OF THE MYSTERY
Briefly mentioned.
Wikipedia Bio:
Constance Tipper
(born Constance Fligg Elam) 1894 - 1995
was an English metallurgist and crystallographer. She investigated brittle fracture and the ductile-brittle transition of metals used in the construction of warships, and was the first female full-time faculty member at Cambridge University Department of Engineering.
My grandfather was a foreman building Liberty Ships in Richmond California. My father was a welder there as well. There is a book called "Swing Shift" by Joseph Fabry about the building of the ships A photo of my grandfather's crew is on the cover. The book is not about him, they just needed some photos, and used that one.
The Liberty ship program was a classic example of build first and ask questions about its viability later. Metal fatigue was not a well understood field back in WW2 time period. The Liberty ship program debacle is taught in all first year engineering fracture mechanics classes nowadays. Nice finite element fringe plot of an angle bracket near the end highlighting the crack growth through the part. It brings back memories.
I believe that another contributing factor might have been that the heat affected zone tended to become even more brittle in low temperatures.
Especially when all the residual stresses from welding without preheating before welding, and not Stress-Relieving due to the overly fast construction were left in the welds...
In 1949 the de Havilland Comet, the worlds first commercial airliner was designed with square windows and the constant pressure and temperature changes caused the plane to fail at the window corners. There were two catastrophic failures with 56 souls lost before the planes were deemed not airworthy. You would think the engineers who designed the plane would have known that from Metalurgy 101.
Metallurgy 101 did not include fatigue then, as it was not well understood.
>
Uhhh, no, the Comet was not the worlds first commercial airliner. It was, however, the world's first commercial JET POWERED airliner.
the latest research may have revised the original diagnosis, more to do with the placement of rivet holes if I remember correctly
I had a Friend who was a recent Jr College graduate in Highway Engineering just as Kaiser began Liberty Ship construction in Richmond Calif. They did a lot of cutting and fitting to get them to go together,. This resulted in many of the ships having a curve to the hull. He and another 20 year old figured out how they could use a Transit to lay out the keel and ribs. They ended up explaining to Henry Kaiser and Stephan Bechtel how to do it and never again had to go back to the shipyard. Later he was in charge of the moth ball fleet in Benicia
A lot was learned about fracture mechanics during and right after the war as so much production and changes in products happened in such short time. Fracture toughness was always an issue but when you build something with a lot of material it doesn't show up. When you start reducing the amount of material and stressing things higher then you see the issues. Ship failures, steel bridge failures, airplane failures have this in common.
Sailed on several T2 Tankers and Liberties during the 1960s and hit a rogue wave on a T2 Tanker out of Seattle. Thank goodness that they had been jumbalized (modified) with straps the full length of the hull on both sides.
Constance Tipper is a HERO! Someone should make a movie about her contribution.
I made my engineering degree in the early 1980s. In the material science course we discussed exactly this case.
The technical term for this is cold shortness. It caused issues on ships long before WWII, even though the problem wasn’t identified until then. Certain impurities can lead to steel having diminished ductility at low temperature. This also caused the loss of several ore boats on the Great Lakes (including the Carl Bradley, built 1927 and broke in half 1958, and the Daniel Morrell, built 1906 and broke in half 1966)
The Titanic suffered from this as well.
I was told years ago that a lack of manganese, caused by a shortage of that element during the war, was the leading cause of the ship hulls cracking. Further you did not clarify where the T-2 tanker Schenectady was located when it cracked. That tanker was berthed at the dock on the calm waters of the Columbia River at Portland OR.
ust for the record I was the third engineer on a TexacoMississippi T-2 oil tanker in 1984 49 years later for a few weeks .
But in 1971 the T-2 Texaco Oklahoma broke in half killing much of the crew
I was a merchant marine engineer on bulk ships for a few years before I retired and to see how much the ship's hull flexes in heavy seas is a bit startling at first.
A lengthy report was commissioned in the 1950's to determine the loss of so many liberty ships during the war. The report concluded that many ships fractured and broke in two in the same area of the Atlantic where the cold Labrador current meets the warmer Gulf stream. The sudden drop in temperature was recorded on each ship and the fractures correlated with this drop in temperature. However the brittleness was just a contributing factor. Some of the ships broke when they were struck by high waves which caused the ships to flex and break much easier due to the thermal stress involved. This is exactly why the Titanic broke in two amidships. On that night the temperature dropped significantly as she approached the Labrador current. When she struck the iceberg she compressed her starboard bilge and bottom plates as she steamed over the spur of the iceberg and may even have cracked the ice underneath her as she steamed over it. The ship settled in the water, listed to starboard, then rolled to port, and as soon as her stern attempted to lift just a few degrees her hull fractured amidships and she broke. Her stern rolled to port and her bow rolled to starboard. The stern rose up a second time and broke again. The survivors witnessed in amazement as the ship twisted from one side to the next and broke apart twice on the surface. The loss of the liberty ships and the Titanic in the same proximity to the Labrador current and Gulf stream is a testament to the dangers of rapid thermal change and how even the strongest of vessels can break apart on their maiden voyage.
Regardless of fracturing Kaisers ships played a vital role in the war effort. The government was not capable of producing these ships in the sheer quantities and time frames needed. Henry kaisers ships disprove the new dealers false narrative that big government interventionalist policy saved the day and won the war when, in fact, it was the genius and capability of private businessmen like kaiser, Higgins, Ford, and Kneudsen that won the war. The fact that these men were able to accomplish such extraordinary feats while having to deal with shackling government regulation( regulation and poor economic policies that prolonged the depression and the war) is absolutely amazing.
Always a fan of your failure investigation stories! And love the woodworkers guild content!
Thank you sir 🙏
This might unnerve a lot of travelers when I point out that airliner wing box structures, whose main structural member is the upper and lower "plank" (the machined top and bottom aluminum skin between the front and rear spars), sits there flexing in turbulence at -40 to -65C pretty much all the time.
I worked as a shipfitter building ships for 24 years. We used several different steels. In most cases, these WW2 ships broke apart where the ships were welded. No one knew at the time ((when all welded ships were a new thing)) that all longitudional stringers needed to overlap the welded seam by at least three feet. Just by doing this in all ships since has mostly ended ships breaking in half. The sole exception was and still is ships like bulk ore carriers built too long for their width. Several of these have broken and sunk since WW2.
The Liberty ships were the backbone of many startup shipping companies after WW2. My uncle worked on one.
In the early 70's I was completing a qualification for special electric arc welding and we were taught about different welding techniques and one of them was the processes used on the liberty ships when you join 2 sheets of steel it is a butt weld with a vee preparation and to speed the processes they would lay a route run joining the materials and then fill the remainder of the groove they would just lay the welding rods in the groove and then just lay a layer of weld over the top saving hours of work so you just had 2 very thin layers but it looked a great weld visually because of the extremely high work load these practices became common also relating to the high losses
Analysis of a souvenir rivet leftover from the construction of the Titanic (taken home by a dockworker as a momento) led to the conclusion that high sulfur steel was used in its construction. Less brittle more malleable steel that might have less propensity to shatter in low temperatures was available but not used. After the discovery of the wreck, steel samples recovered from the wreckage matched the rivet in composition perfectly.
I believe the Titanic used wrought iron rivets-and least in come cases-rather than steel rivets. Wrought iron indeed does not have the physical properties of steel. Don't know if steel rivets would have prevented that tragedy, but they might have provide a stronger hull and reduced the extent of the damage.
Sadly the truth is that so many ships were lost in action that just getting them there was a victory. a return trip, amazing, anything after that, just gravy. the merchant marines don't get any of the glory but they are responsible for their ships namesake, liberty.
Thank God that the allies had Liberty ships, we wouldn't have won without them, albeit sad that many lost their lives because of the flawed metallurgy. Engineering has advanced and we have since benefited from Dr. Tipper's discovery and the corresponding improvement of steels. It is and always will be the case that "You don't know what you don't know". Nevertheless, whilst Engineers put everything they do know into a design, they should never be scared to fare-forward. Aye, live and learn laddie. Good video, thanks, but could have gone on to explain the correction in steels and what was done to offset the problem at the time. .
It should also be noted that the Truman Committee discovered that the Carnegie-Illinois Steel Corporation was selling steel slabs to liberty ship builders that didn’t pass inspection or strength tests.
I have in my possession two pieces of flawed steel hollow bar sourced from a Scandinavian country, circa 1968/1970. They are remnants of several bars purchased, by my boss, for the production of press tool guide bushes. The flaws are not unlike a rolled up newspaper. Unbelievably, a world famous Scandinavian steel company produced a defective product, shipped it all the way to South Australia, only for me to discover the defects, after having cut them to length and machining them. My point is, if these highly regarded people can "get it wrong" who else can?
30 years on, I purchased from similar supplier 4140 bar with longitudinal crack, certainly an eye opener when your making critical components.
It was a real scare for the sailors back in the war, to have to worry about the ship just cracking open like an egg...
What alloy of steel was being used?
What element or lack of causing this issue?
It seems to me by that time there was adequate knowledge of the properties of steel.
As a kid I remember talk of these failures being due to solid welded construction, no rivets so basically there was no flex in the ship.
Thank you for this video.
Rivets act as crack stop points. Riveted structures don’t have the discontinuities imbedded inside them that act as stress raisers that welds do.
Welding changes the material composition and heat treatment characteristics of the metal around the weld - proper choice of welding filler material and post weld heat treatment are critical to avoid this.
The key issue was low temperature ductile / brittle crack transition. The North Atlantic was cold enough that the steel would crack like glass rather than stretch and tear.
Something called Boiler Plate. Hastily produced from any number of scrap sources some parts of the plate. Were soft others were hard dueto the presence of bed springs Areal crap shoot to machine
The steel quality was really very poor. Qinetiq did some testing on steel samples from WW1 through to post WW2, and the steel used in to construct the liberty ships was by far the worst. It had extremely high notch sensitivity, and high ductile brittle transition temperatures. At least one of the ships fractured while the ambient temperature was well above 10C. The poor quality was actually recognised during the war, but the significance of it was not initially.
Truman mentions in his autobiography: "We saw the seamy side of the war effort. We had to investigate crooked contractors on camp construction, airplane engine manufacturers who made faulty ones, steel plate factories which cheated, and hundreds of other such sordid and unpatriotic ventures. We investigated procurement, labor hoarding, army and navy waste in food and other supplies. But when we were coming to our conclusions, we all decided that by and large the greatest production and war preparation job in history had been done."
Steel manufacturers were often turning out junk to get paid. The yards building warships and submarines got the best quality output, and everyone else got the rest. It being wartime, the quantity of output was deemed more important than cracking down on that sort of fraud.
The lack of rivets did not affect the flexibility of the ship, but rather a riveted construction had natural crack arrestors where one plate ended and another began - if one plate cracked, it didn't matter so much because the next plate was a separate piece of steel. With welded construction, the hull is effectively all one piece, so if a crack starts to propagate there is nothing to stop it going right through the hull. Part of the wartime fix for the hull fracture problem was to add crack arrestors in the deck in the vicinity of the likely fracture points, so that any fractures that did occur would not be catastrophic.
The knowledge of steel properties was not comprehensive - the mechanics of brittle fracture were still largely unknown at the time, and it was only researched post war, mainly as a result of this particular failure case.
Also as a note here - *every* currently commonly available steel today is much better on ductile/brittle transition temperature, because it was found to be a menace for almost everything in cold climates eventually. But the American Bureau of Shipping established specific steel grades with much better ductile / brittle transition temperatures and more predictable yield for permanent deformation when overloaded so ideally no hull part would be stretched more than its neighboring pieces of steel. These steels are most common shipbuilding standards worldwide now.
A classic case of Quantity over quality. Transport ship losses where huge in this period due to the Atlantic Gap, so these ships where essentially expendable. It was about flooding the sea lanes with cheap easily built ships as much as anything.
Interesting analysis. I sailed on the SS Jeremiah O'Brien Liberty ship a couple of times in the San Francisco Bay, CA USA. Wonderful ship! We were given complete tours.
The major flaw of Liberty Ships was that they were so slow that they couldn't out-run a row boat, much less a pack of U-Boats. They were grossly underpowered and had a top speed of about 8 knots (9 miles per hour). The were so slow that they may as well have been at anchor. U-Boats had plenty of time to get from wherever they were patrolling to where the Liberty Ships were at permanent anchor in the North Atlantic Ocean. Had they been able to go (for instance) 33 knots per hour. the sinkings rate would have been decreased by around 90%.
the one i was on could make 10.6 at 66 rpm. uss protector ag11(ex warren p. marks), it too had crack problems
Drastic times call for drastic measures. The very fact they could build and launch such vessels so rapidly and in such numbers is incredible. To second guess or criticize from the safety of decades of hind site does a serious disservice to the people who pulled off what was literally impossible to pull off.
Interesting video. I was never aware of the cracking problem.
Whenever I see the start of any crack, regardless of material, I drill a small hole”check stop” hole at the end of the crack to stop the continued cracking. Works were well.
You added a stress-arrester by drilling that hole. Simple, but effective!
Was there also a problem of ductile-brittle transition caused by the localized heating of the metal at the welding site when done in cold weather? I assume that would have shown up as a difference in ships built in colder northern yards vs warm year round southern yards? (the metal would cool faster after welding?)
No it was the steel itself that became brittle at low temperatures. In combination with the internal tensions created when the weld cooled after welding. Remember that a weld is essentially a casting.
That was actually very interesting, well done!
While the Liberty Ships had their problems they were later resolved. Problems like these were not unique at that time. US submarine torpedos had problems that took years to fix. Another was initially under powering the P-51 Mustang fighter, which then received the British Merlin engine which made it a world-beater. I’m sure there are may more examples that other could cite. In the end, however, the these systems were fatal: to the enemy.
That failure, still helped win the war! The best 'weapons' of WW2 were: the liberty ship, the Dakota, the Deuce and a half and the Jeep. It doesn't matter if you have the bestest ever equipment and men, if you cant supply them.
And a bayonet, sir, with some guts behind it.
Considering the overall situation, in the US, in Europe, "winning" that war was not a win. As master Yoda said, war doesn't make anyone great. Yikes, look where we're at in the so called "West"!
And the German response, who needs engineering when we’ve got Neddy the horse……
The M1 and the BAR should be on that list too. While most soldiers were using bolt action rifles the M1 was semi-automatic. The 50 cal "ma duce" was also a game changer...
Of course the brains of the people using them was the most important. Some troops waited for orders while others innovated and figured out new uses for everything...
@@HarryFaber-z7l Great line out of 'Zulu'.
Yeah I remember when I found out about this. Its part of the reason we switched from the Liberty to the Victory ship. Of course these ships were considered expendable. It was considered that if they completed 1 run they were successful. Volume took precedence over quality. Improvement was only allowed when it didnt interfere with production rate.
The Australian Antarctic Division used a liberty ship for re - supply in the 1950s, the Wyatt Earp, on a return trip from Antarctica it developed a crack, it returned safely but wasn't used again, these ships were invaluable for the success of the allies and served their purpose well
I remember the Liberty ship fracture problem being discussed in my materials science class in university in the mid-70's.
My father as a freshly minted ensign, was assigned as a gunnery officer on a liberty ship in the North Atlantic acting as chum for u boats . After surviving that he assigned to T2 tanker as executive officer . My grandfather would assure my grandmother that my father would never make it home, as she didn’t approve of my father
102 of the Liberty ships were built in Panama City, Florida. And when I was younger it was a common sight viewed from the Hathaway bridge to see them being scrapped through the 1970s. One of them was sunk offshore for an artificial reef.
Hmm, I remember Aristole Onasis the shipping magnate bought a bunch of the Liberty ships after WW2 to make his fortune. I recall stories of his ships breaking up and suddenly sinking which as I recall many took it to be lack of maintenance, but this design flaw makes sense as the reason.
Many of the Liberty Ships were re-purposed as bulk carriers after the war. Despite the supposed "fixes" sited in many of the posts here, these ships continued to suffer catastrophic hull fractures in cold waters for years and years, resulting in many lives lost at sea. Two such ships sank in the Atlantic Ocean off the Northeast coast of the US in 1952, virtually simultaneously. This tragedy was recounted in a book titled "Two Tankers Down". The cause in both cases was catastrophic hull fracture (ie, the ships broke in two at sea). In 1966 the SS Morell, another converted Liberty Ship, broke in two and sank in Lake Huron with only one crew member surviving. Finally, in Feb. 1983, the SS Marine Electric (a 40 y/o converted Liberty ship) broke in two and sank in the Atlantic Ocean off of Chincoteague Va. with 33 lives lost and 3 survivors. To say that this problem was "solved" in the 1940's is ridiculous. The problem was the quality of the steel as described in the video. Following the 1983 sinking of the Marine Electric all of the remaining converted Liberty Ships were scrapped.
The fatal flaw of this video isn’t that liberty ships cracked, but that the cover picture for the video shows not a Liberty, but what looks to be a T-2 tanker (bridge midships and engine room/stack well aft). NOT the same ship. Thanks
Awesome engineering showcase.
I understood that aluminum hulls are not to be welded along the entire face, but only at points which connection reinforces another as the welding alters the metallurgical properties, creating a weak link ?...
Ah, that terrible positive feedback. This is why, as an engineer,* I prefer negative feedback.
(* Not actually. Just an electronics hobbyist.)
As an IAC engineer, I worry about no feedback
The ultimate solutions were:
1. A riveted crack arrester strake just below the main deck.
2. Ultimately, notch-resistant steel alloys. Kind of pricey, so they tended to have just one run just below the main deck.
During the war there was no time for 'several years of research'. The point was to win the war and it did, and the Liberty ships greatly contributed to this.
The T-2 tanker wasn't a Liberty Ship. the Liberty Ship was a specific design of dry good cargo ship built by Kaiser shipbuilding, and they weren't intended to last long. The increasing lose in the Atlantic to German U-boats made it risky for ANY transport ship to sail between the US and England during the early to late parts of the war, and so the Liberty ships were built as cheaply and quickly as possible, wasting no effort on making them durable or lasing, since they were expected to be sunk by U-boats anyway. This was not a design flaw but the result of the main design features of the ship - cheap and quick - later ships (once the U-boat war was considered under control) of the same basic design were built, but with much more effort to durability. These are not "Liberty Ships", though they look the same, but "Victory Ships". The survivors, SS John W. Brown, SS Jeremiah O'Brien, SS Arthur M. Huddell & SS Albert M. Boe are actually Victory Ships not Liberty Ships.
This fracture scenario is what is believed to have caused the catastrophic failure of the steel used to build Titanic.
Bru, if you like these ship stories you might like to look into how they figured out why ships kept disappearing in the open ocean. Seems like when these ships got out there on the long swells the ships would ride out on the swell and the back half of the ship would be supporting the whole weight of the front half of the ship, and . . . snap . . . the ship breaks in the middle, 'cause . .. you know the back half of the ship was not designed to support the front half on a wave.
I sailed on US Lines Mariner class container ships in the 1:50 ’70’s which were the late WWII designs after the Victory ships. Every time we came into Boston the Coast Guard boarded us because they knew they could find cracks in the hull and fail our inspections until we had welders repair the cracks.
Metal fatigue was Not well understood in the 40s.
I realize that lower temperature causes many materials to be more brittle but I was under the impression that steel brittleness would occur at much colder temperatures than encountered in open oceans.
Sadly the steel used for the Liberty ships became brittle a few degrees over water freezing. Nowadays when we know the cause, different steels are used depending on expected temperature. It was also the inevitable remaining 3 axis tension after welding. Plus stress concentrations.
hi from england, the Jerimiah o' Brien is ok so how come it still floats without damage or has it been seen to. ?
Short and to the point. Good job on that though I wish you would have mentioned the Victory ships.
Surely a problem that appears in cold weather and disappears in warm weather would alert even a moderately intelligent engineer to the cause of the issue.
The US Navy Perry class FFG's had hull cracking problems too. Sometimes big cracks.
Miner's rule of irreversible damage, stress-risers, and fracture mechanics.
I don`t know if it is correct, but I have read somewhere that the steel used was the same as in rivited ships and not sutible for welding.
We had to unload these ships in the early days in Vietnam. Our Vietnamese helpers would steal some of everything. One took a big drink out of a Brown bottle he thought was booze. It was choral hydrate or some other anesthetic drug. He was dead before he hit the ground.
It would also be interesting which role the weather played in the seasonality of the problems.
I heard decades ago that welders were given a can of welding rods and finished when it was empty. If the dry rods were packed in a joint and then welded over the job was done.
@roysutton9592 In the research, I came across a case where a person was sent to jail for doing that! They were not messing around back then 😅 and rightly so, by doing that, you are essentially rolling the dice on someone freezing in the Atlantic
Nice job nice research nice presentation. Many thanks. Read up on this Maritime sailors who worked these vessels. Saved the Free world they did.
Residual stress from poor weld sequencing was also a factor.
Very good, concise summary. THANK YOU.
Thank you for stopping by!
Very well done video!!! Keep it up E.H.!!
When I was a sailor back in the 60's there were plenty of liberty ships to be seen everywhere,
Excellent work! I'm delighted to be a new subscriber!
Welcome aboard!
The first ones were riveted hulls. They are the ones that failed. In 1961 we took one from San Francisco to Honolulu. No problem with the welded hulls.
The original design was for riveted,they had extra frames,Deleted frames,by welding,They should have redesigned the ships
Many liberty ships were riveted, these tended not to crack. I have dived on the James Eagan Lane in Whitesand Bay.
Short and to the point, thank you.
people forget that if a war of that magnitude comes again our modern panamax freighters will be sitting ducks and modern versions of liberty ships will again be essential
From what I’ve read about the Liberty ships, their fatal flaw was they were grossly underpowered. This made them easy targets for the German U-Boats.
on a displacement hull, that is a ship, extra horse power doesn't do anything regarding speed in practical terms. Yes another 1/2 to 1 knot, but at great expense to fuel consumption. The speed that a ship can travel is governed mainly by it's length with some other factors also affecting it. You will often see the term 'hull speed'.... which means the design speed of the ship/hull thru the water. Any extra power means it can tow or carry a heavier load, but not go (much) faster than hull speed.
They had a 2,500 HP engine and about 11 to 11.5 knot speed. 11 knots is not bad back then for a cargo ship. They were not a jet enginned racing boat.
@@colonelfustercluck486 Thankyou for that info.
They only had a 2500 HP Triple Expansion Piston Steam Engine which isn't much, but their real problem was their hulls were designed for easy assembly-not for speed. Streamlining was an afterthought, they wanted to be able to build ships from easy to produce templates and that meant more square hulls and less curves. The Victory Ships, a later design, used more streamlining and had a 17 knot top speed compared to the Liberty Ship 11 knots, but Victory ships also had a much more powerful steam turbine engine.
just a reminder that if an actual ww3 does break out the massive panamax container ships are among the first things to be sunk, modern liberty ship sized containerships may well be the way to go. the battle of the atlantic allone saw over 3500 merchant ships sunk primarily by submarines and submarines are more potent than ever whilst drones and missiles pose further dangers to modern shipping.