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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.
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.
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!
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 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!
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 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.
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.
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.
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.
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.
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.
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
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".
I don't understand, this cause and effect should have already been known from the titanic. You introduced a problem, proposed a solution, but did not look into the historical reasonability.
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/
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.
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.
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.
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
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!
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.
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!
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.
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.
Always a fan of your failure investigation stories! And love the woodworkers guild content!
Thank you sir 🙏
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.
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.
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.
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
Said, back in the day, that they were built by the mile and cut off by the yard.
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 original design was for riveted,they had extra frames,Deleted frames,by welding,They should have redesigned the ships
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
this was known at the time. i think i read about the british when they were first operating steel ships in asia.
I don't understand, this cause and effect should have already been known from the titanic. You introduced a problem, proposed a solution, but did not look into the historical reasonability.
They broke because they were cheap and built in a hurry.
Yet many of them continued to sail into the late 60’s/early 70’s. So I guess it wasn’t that fatal.
Which is why the Charpy V-notch test became a thing.
It was theorised that the Titanic was vulnerable to impact for the same reason.
Yup, I came across that theory as well while researching for this video
They killed a generation of shipbuilders with Absestos...
Sod off 🤡
2:43
I like how you found the one Knee Grow worker pic to make this a DEI Woke comment.....