What Causes Vibration Issues on American Fast Battleships With

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  • Опубліковано 30 тра 2024
  • In this episode we're talking about vibration issues and propellers on American Fast Battleships
    To get your drydock merchandise:
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    The views and opinions expressed in this video are those of the content creator only and may not reflect the views and opinions of the Battleship New Jersey Museum & Memorial, the Home Port Alliance for the USS New Jersey, Inc., its staff, crew, or others. The research presented herein represents the most up-to-date scholarship available to us at the time of filming, but our understanding of the past is constantly evolving. This video is made for entertainment purposes only.

КОМЕНТАРІ • 595

  • @F-Man
    @F-Man 22 дні тому +449

    Ryan and Drach - the collaboration the world never knew it could have, but the one that we all so desperately wanted.

    • @bull614
      @bull614 22 дні тому +6

      ​@@frankbarnwell____ohio checking in lol

    • @Mountain-Man-3000
      @Mountain-Man-3000 22 дні тому +24

      Wasn't the first time, and let's hope it's not the last! Always a treat.

    • @iwantmyvanback
      @iwantmyvanback 22 дні тому +19

      Yeah not the first time. Highly recommend watching Drach climb to the top of New Jersey and overcome his Vertigo. It's a fantastic video!

    • @bull614
      @bull614 22 дні тому +9

      @@iwantmyvanback not for poor Drach lmao

    • @justinday2916
      @justinday2916 21 день тому

      Maybe the CIA is reinstating her! Don’t tell anyone

  • @derekm79
    @derekm79 22 дні тому +246

    Massive props to Ryan and Drach! 😝

  • @iwantmyvanback
    @iwantmyvanback 22 дні тому +199

    I love watching Drach answer a question with a long, rambling, multi-faceted, explanation. It scratches all the itches in my brain. Haha.

    • @S_M_360
      @S_M_360 21 день тому +8

      More isn’t less, I love it too.

    • @MaxTSanches
      @MaxTSanches 21 день тому +9

      The cobwebs in my brain are just starting clearing to remember half of the Naval Engineering course from third year. Looks like I will have to watch this a few times.

    • @muskyelondragon
      @muskyelondragon 21 день тому +3

      🥰

    • @pat8988
      @pat8988 21 день тому +7

      He’s a very good explainer.

    • @kevinshannon9917
      @kevinshannon9917 18 днів тому +1

      I disagree… I didn’t enjoy this video. Maybe some pictures or diagrams would better explain the concepts to us outsiders. But I do love when a person gets 20 minutes to talk about something they’re passionate about. I love to get behind that!

  • @jarheadcharlie2315
    @jarheadcharlie2315 22 дні тому +272

    You knew Drach wasn't going to miss the opportunity to get a look under her.

    • @craigf6277
      @craigf6277 22 дні тому +21

      He was scheduled to lead a series of the drydock tours.

    • @jimtalbott9535
      @jimtalbott9535 22 дні тому

      @@craigf6277That would be fantastic!

    • @CaymanIslandsCatWalks
      @CaymanIslandsCatWalks 22 дні тому +2

      Shame it wasn’t a hovercraft

    • @iwantmyvanback
      @iwantmyvanback 22 дні тому +10

      He's been to the top. Had to make a journey to see the bottom

    • @muskyelondragon
      @muskyelondragon 21 день тому

      He 's a dirty boy looking under her skirt, but he is our dirty boy. Excellent communication and learning in this one.

  • @josiahbingham241
    @josiahbingham241 21 день тому +42

    The guy in the scissor lift is my hero 😂

    • @holysirsalad
      @holysirsalad 21 день тому +5

      How many people watching this video checked their phones too? lol

    • @OfficialUSKRprogram
      @OfficialUSKRprogram 20 днів тому

      what the genuine fuck was he doing? lol

    • @MrGoesBoom
      @MrGoesBoom 20 днів тому +1

      @@OfficialUSKRprogram looked like he was using a drill to tighten something, counting along rows or whatnot to make sure he got em all. but that's a guess

    • @sebpeters123
      @sebpeters123 20 днів тому +3

      Like how he's working in a shipyard, but wearing shorts.

    • @MarkGeraghty
      @MarkGeraghty 19 днів тому +2

      Looks like he was using a battery drill to tighten the prop shaft.

  • @user-vr7cy3xd3v
    @user-vr7cy3xd3v 19 днів тому +10

    As a Naval Architect and Marine Engineer with over 50 years of experience working in, on and around ships I think this conversation touches on a lot of issues but never really answers the question. The USN was well aware of the vibration issues associated with North Carolina and worked hard, as pointed out, to solve them. Until the advent of high speed modern computers Naval Architects of the 1930's could not solve the complicated hydrodynamic equations required to solve the vibration issues. Their only recourse was at sea experimentation. This they did and settled on the 4 bladed out board screws and the 5 bladed inboard screw design to move the vibration away from the cruising speed and below full speed. During towing tank testing for the IOWA design it was noted she had similar vibration issues primarily due to the skegs which were incorporated into the design to reduce drag from exposed propellor shafts and provide structural strength to the hull in the stern to support the #3 turret. Again the solution was to use different size propellers on the inboard shafts and outboard shafts. Another issue facing the designers, which is not mentioned here, is cavitation. The inboard screws are operating in the wake of the outboard screws (turbulent water) and are thus subject to cavitation at low RPM. In the 1930's propellor design was a black art (due to the lack of high speed computers) and propellors were designed by experimentation. But what was known was that if you increased the expanded area ratio of a propeller one would increase the RPM of the propellor before the onset of cavitation . Note that cavitation means vibration. The expanded area ratio is the area of all propeller blades divided by the propellor diameter.
    So bottom line; there are two different props on the IOWA class to eliminate cavitation and vibration while at the same time reducing hull drag. Also note that the SS United States also has a similar propeller arrangement and she holds the world speed record for a Trans-Atlantic crossing. The Lead Naval Architect for her design was William Gibbs who was also a member of the General Board headed by USN Captain Chantry which was responsible for the IOWA Class design.

    • @philsalvatore3902
      @philsalvatore3902 18 днів тому +2

      Wow. Great input!

    • @Transit_Biker
      @Transit_Biker 17 днів тому +1

      The stern layout was most definitely a compromise using practical observation as a best estimate. I do not think any design from that era would be "better" unless by pure luck. Gibbs was a pretty clever guy and known for attention to details - I'm fairly confident that if improvements could have been made, they would have likely been in the next class (which was cancelled).

  • @MrPedix2c
    @MrPedix2c 21 день тому +73

    We're so lucky to have Drach, who's been to NJ multiple times as Ryan and Drach seem to have become really good friends. What a treat to hear him get technical on the vibration issue.

  • @slytlygufy
    @slytlygufy 22 дні тому +95

    Love it when these two collaborate.

    • @deanieedwards8117
      @deanieedwards8117 22 дні тому +2

      Yes indeed...still think it would be fun to watch them play Battleship on the Battleship New Jersey.

    • @andy4an
      @andy4an 21 день тому

      What other vids did they colab on?

  • @mcburcke
    @mcburcke 22 дні тому +123

    Former captains of the Iowas always mentioned how surprisingly maneuverable they were, especially at higher speeds. They said that they had to warn smaller ships turning in a formation with them not to "turn inside" an Iowa-class ship's track because the Iowas could frequently out-turn the smaller ships and run the risk of cutting one in half.

    • @TheArklyte
      @TheArklyte 20 днів тому

      Any link or an example of this?

    • @philsalvatore3902
      @philsalvatore3902 18 днів тому +2

      I've read that too.

    • @mcburcke
      @mcburcke 18 днів тому +2

      @@philsalvatore3902 IIRC, the captain of the Missouri once warned his formation about that, but a destroyer pilot didn't listen and the Missouri took the flag pole off of the destroyer's fantail rigging.

  • @timandellenmoran1213
    @timandellenmoran1213 22 дні тому +222

    Remember, Drach is an engineer by training, so his input and knowledge is beyond the layman!

    • @CaymanIslandsCatWalks
      @CaymanIslandsCatWalks 22 дні тому +5

      What’s a layman?

    • @jimktrains0
      @jimktrains0 22 дні тому +20

      ​@@CaymanIslandsCatWalks a layman is an untrained person in some subject.

    • @muskyelondragon
      @muskyelondragon 21 день тому +2

      100%

    • @gobblox38
      @gobblox38 21 день тому +7

      What his description needs is an animation of the concepts he is talking about. I pictured everything he said, but I think the average person would be lost in the various phrases.

    • @w8stral
      @w8stral 21 день тому +6

      An "engineer" who has never used it. Drach only made a couple mistakes in his explanation, the water would be curling under the skegs giving the differential velocity vector, and resonance is fixed via structural rigidity or eliminating the differential velocity vector, and those skegs make the ship LESS maneuverable, not more as the thrust from the props give it the maneuverability. Otherwise good explanation by him with the obvious, you have to have a KEEL to drydock the ship and thus the skegs + survivability. The only true way to fix this would be to have drop down skegs for docking and propeller shaft tunnels which can be truly sealed. Neither of which is all that practical ultimately forcing one to be a slave regarding cost and practicality, thus the skegs.

  • @nomorenames7323
    @nomorenames7323 21 день тому +27

    I kind of want a shirt with a picture of Drach on it that says “Not entirely” on the front and “Yes and no” on the back.
    King of qualified answers.

    • @tcoradeschi
      @tcoradeschi 20 днів тому +5

      Warning: degreed engineer turned project manager: the correct answer is ALWAYS “it depends”

    • @nomorenames7323
      @nomorenames7323 20 днів тому +2

      @@tcoradeschi Yep! It applies in all cases across pretty much all fields. In history if you give a quick, categorical answer, it’s likely to be very, very reductive and incorrect.

    • @hookedupboer
      @hookedupboer 20 днів тому +2

      I think "In and of itself" is a close second

    • @marvthedog1972
      @marvthedog1972 18 днів тому +2

      I want one that has ship silhouettes with the caption, "ships that ran aground in their own waters club"...

    • @johngregory4801
      @johngregory4801 11 днів тому

      When things are much of a muchness, what're you supposed to do?

  • @virginiaorganbuilder
    @virginiaorganbuilder 22 дні тому +61

    Took the tour last weekend, and even got to meet Drach and chat with him for a while. Fantastic! And if you don't have your tickets yet- HURRY!

    • @S_M_360
      @S_M_360 21 день тому +6

      Jealous!

    • @jarodstrain8905
      @jarodstrain8905 16 днів тому

      Were you at the Victor?

    • @virginiaorganbuilder
      @virginiaorganbuilder 11 днів тому +1

      @@jarodstrain8905 I wish! Just saw him at the merch table.

    • @jarodstrain8905
      @jarodstrain8905 10 днів тому

      @@virginiaorganbuilder my son and I went to the Victor. We drove a 1500 mile round trip to do it. It was a great time. Drachinifel is such a real guy to talk to.
      There were only about a dozen of us there. Everyone just joining in the conversation. One gentleman brought some very rare photos to share.
      My son (15) shared a battleship design he'd drawn and everyone discussed. He was thrilled.
      If you ever get the chance to do a meet up, it's very much worth the effort.

  • @olpaint71
    @olpaint71 21 день тому +23

    The Navy did extensive analysis of the vibration problems and the late-war and post-war reports from DTMB (David Taylor Model Basin, now NAVSEA Carderock) are available online for all three classes of fast battleship--North Carolina, South Dakota, and Iowa. The reports characterize the vibration as axial and discuss the measurements, analysis, model testing, and full scale testing performed.

  • @AllanSitte
    @AllanSitte 22 дні тому +49

    Glad you could get a chance to see her in dry dock Drach.
    I hope it filled a bucket list item for you. I know it would for me.

  • @Norbrookc
    @Norbrookc 22 дні тому +74

    Always a blast to see Ryan and Drach together

  • @jlivewell
    @jlivewell 22 дні тому +23

    Engineers and Curators and Historians, Oh My! A very interesting conversation…Thx Ryan and Drach!

  • @Its-Just-Zip
    @Its-Just-Zip 22 дні тому +21

    BBNJ's, what I can only call, "ongoing love affair" with drach is probably the best thing ever. More reasons to get drak talking about ships is always going to get a like from me

  • @davidelang
    @davidelang 22 дні тому +78

    while you are out of the water, you should see if you can get someone to come in and do a complete 3d scan of the hull. you have the plans of how it should have been shaped, but how close to the plans is the reality? And once you have a good scan of the hull, it can then be put into a CFD program to test the various theories.
    As for a fresh Battleship design, there has never been a Battleship designed with computer support for the hull design, I'd bet that with a lot of computer design and optimization, the outer skin of the hull would gain quite a few subtle curves to manage the wake at high speed

    • @tomhenry897
      @tomhenry897 21 день тому +1

      Would have to been done after the 80s when computers were able to do this

    • @cruisinguy6024
      @cruisinguy6024 21 день тому +5

      What you’re talking about would be quite expensive and, thankfully, they’ve been very strategic with their spending on this project.
      While that would be nice to have I don’t see how it would benefit anyone or help the museum in its mission. Now if someone wants to foot the cost I’m sure they wouldn’t object.

    • @Plaprad
      @Plaprad 21 день тому +9

      @@cruisinguy6024 You're talking tens of thousands at the low end. Something that large could run into the six figure mark easy.
      When I was on C-130's we had guys come in to scan a gunship. Not the whole plane, just a handful of the antennas on the belly to update the model they already had. When we talked to them, they told us just to scan for a day was over ten grand. Though, most of the cost is in the second half importing and updating.

    • @1986arseny
      @1986arseny 21 день тому +3

      now we had CFD to aid on design of any shape interacting with fluids. Most of the issues plaguing ships like Mauritania, South Carolinas, or the Queen Mary rolling around could be avoided by today's simulation tech. You don't need to have the actual ship on sea trials, and wait several months to have a new screw designed, fitted and tested.

    • @davidelang
      @davidelang 21 день тому +2

      @@1986arseny I really wonder what generative optimizations would do.
      And I have to wonder about the Ford class carriers and their hull efficiencies

  • @charleslachman4637
    @charleslachman4637 20 днів тому +6

    Thank you so both for this well done and informative episode, fascinating info. In 1940, my father, who had a Doctorate in Mechanical engineering, was working at Electric Boat trying to improve the design for the hull and propellers for quieting the fleet submarine designs. Once the extreme prop vibrations on the North Carolina class became evident he was tasked by the Navy to help diagnose the problems and recommend solutions. I was unaware of his participation, partly because I wasn’t born until 1945, but the real reason was he and his team were sworn to secrecy as the Navy wanted both the problems and solutions to be secret. I didn’t know about this until upon his death in 1973 at his memorial a retired representative from the Navy informed us of his accomplishments. I respect the need for National Security but I certainly would have liked to know of his work especially since the Carolina Class were scrapped beginning in 1959!

  • @ronswinford4952
    @ronswinford4952 22 дні тому +31

    Talk about diving down the rabbit hole, but everything you talked about made sense. Maybe some baffles in the tunnel to slow the water would have helped, but that would me more drag as well.

    • @w8stral
      @w8stral 21 день тому +1

      Drach only made a couple mistakes in his explanation, the water would be curling under the skegs giving the differential velocity vector, and resonance is fixed via structural rigidity, and those skegs make the ship LESS maneuverable, not more as the thrust from the props give it the maneuverability. Otherwise good explanation by him

    • @marvthedog1972
      @marvthedog1972 18 днів тому

      yeah.,., that rabbit hole was the holland tunnel it seems

  • @twilightroach4274
    @twilightroach4274 21 день тому +7

    Also worth remembering, that most designs were evolving improvements, from previous designs, and were done with pencil and paper and slide rules. Really amazing work

  • @russellhltn1396
    @russellhltn1396 21 день тому +16

    The whole water flow situation reminds me of the B-36 with it's pusher props mounted on the trailing edge of the wing. The air coming over the top of the wing is at a different speed that the air along the bottom. This led to a unique "muttering" sound.

    • @gordonrichardson2972
      @gordonrichardson2972 21 день тому +3

      The Cessna Skymaster with its twin push-pull propellers makes a very distinctive sound.

    • @philsalvatore3902
      @philsalvatore3902 18 днів тому +1

      @@gordonrichardson2972 TU-95 Bears with their counter rotating props also have a distinct sound.

    • @gordonrichardson2972
      @gordonrichardson2972 18 днів тому

      @@philsalvatore3902 We don't get many 'Bears' where I live, but the old Avro Shackleton also had twin contra-rotating propellers, with a very harsh sound.

    • @philsalvatore3902
      @philsalvatore3902 18 днів тому +1

      @@gordonrichardson2972 True. Our battle group had the mandatory Bear visits crossing the Pacific in a region known as "the Bear box".

  • @ChrisHessert
    @ChrisHessert 21 день тому +13

    Been watching BSNJ and Drach's videos for years. This is absolutely one of the best I've ever seen. Super informative, and thought provoking. Thank you both for your continued collaborations!

  • @johnauerbach1372
    @johnauerbach1372 22 дні тому +30

    One of the most interesting videos about New Jersey, kudos. A typical solution to resonance is to stiffen the offending element to change its natural frequency to range that is outside the normal operating frequencies of the rotating elements. My father and his friends worked on the construction of the ship as welders. They all lived in a nearby Philadelphia neighborhood. Sometimes they commuted to Camden by auto when there were sufficient gas rationing stamps to operate one car occasionally.

  • @briancisco1176
    @briancisco1176 22 дні тому +31

    Hooray for Drach!

  • @andersed1
    @andersed1 22 дні тому +16

    The fluid dynamics are so complicated, the only way to “solve” the vibration issues would be to take a Time Machine with a pretty decent data center, along with the software back to 1940.
    Even then, there may not be a perfect solution given the Panama Canal constraints.

    • @BlueSpruce2
      @BlueSpruce2 22 дні тому +6

      I agree. It's chaos back there and there are probably complex cavitation effects from the washes of the outboard propellers that are contributing factors as well.

    • @holysirsalad
      @holysirsalad 21 день тому

      @@BlueSpruce2 I barely know my arse from a hole in a ground and once Drach started describing the interaction of the outboard water from the stuff shooting out from the hull tunnel I immediately thought of the mess coming off of those propellers. Like wouldn't they just be shooting pure turbulence at the inboards?

    • @kurtlangford1895
      @kurtlangford1895 20 днів тому

      Because the propeller shafts are not level but are angled downwards somewhat, (right?) so are the propellers.
      This results in more pitch in the propeller blade while rotating downwards (in this case the outboard blades on the inboard propellers) and less pitch in the blade rotating upwards (their blades on the inboard side).
      If the inboard propellers were swapped, then there would be the greater pitch on their inboard sides where the faster moving water is instead of where they are now in the slower water. Of course the shafts would have to be rotated in the opposite direction from what they do now.

  • @tripple49
    @tripple49 22 дні тому +8

    I believe there was some success on ocean liners by opposing the rotation of props. So basically reverse rotation of the inboard props or the outboard props. I dont remember if it was the Mauretania class or the Normandie where they tried this. Both had similar issues.

  • @mmusser62
    @mmusser62 22 дні тому +9

    Love this. A lot of thought provoking discussion. Drach knows his stuff and always enjoy his point of view.

  • @andrewhoward9870
    @andrewhoward9870 10 днів тому +1

    Very interesting and informative. When Mighty Mo got to 30 knots, there was an obvious vibration in her stern. Even so, with eight burning and four turning, moving at that speed was exhilarating!

  • @kolt4d559
    @kolt4d559 21 день тому +3

    Love the smile face under the last block on the keel.

  • @jeffcamp481
    @jeffcamp481 22 дні тому +8

    This is a great collaboration, love hearing the physics of Iowa class! So interesting!

  • @kumaflamewar6524
    @kumaflamewar6524 18 днів тому +2

    That lucky gentleman who gets to listen to the live premiere of the episode while working on a battleship prop.

  • @AbrasiveCarl
    @AbrasiveCarl 21 день тому +3

    Two guys just bein dudes talkin about what they love... what a great thing to sit down with a cup of coffee to ( or spot of tea)

  • @muskyelondragon
    @muskyelondragon 21 день тому +4

    Drach throwing down some real vital engineering knowledge. Love you both!

  • @longsighted
    @longsighted 22 дні тому +26

    A similar vibration effect is seen in wind turbines as each blade crosses in front of the column. Momentarily that blade loses some power causing the whole rotor to place unequal loads across the bearing and at a given frequency that happens to be near that of the column. The third blade in a wind turbine does not produce much extra energy it is there to offset the resonance by halving the rotational speed needed for two bladed sails whose needed rotational speed is well in the range of the severe resonance of the column. Perhaps the Titanic may had the solution with three propeller system and utilized a very pressure turbine to drive the middle shaft. However vibration problems are always a nightmare in these as the easiest solutions always interfere with the some other critical design feature.

    • @cruisinguy6024
      @cruisinguy6024 21 день тому +2

      Oooh boy you stirred the pot by mentioning the Titanic. Apparently she and her sisters went through several iterations of propellor layouts and blade counts. Apparently there’s still no clear consensus on what the configuration was for the Titanics fateful voyage.

    • @longsighted
      @longsighted 21 день тому +1

      @@cruisinguy6024 Err .... Yes. Seems there is no ideal configuration. Titanic had a neat engine efficiency configuration. When you are dealing with this level of power the amount of energy from even a small mid configuration can set everything a tremble.

  • @Gunfox61
    @Gunfox61 19 днів тому +1

    Welcome back to the US Drach. I hope you are enjoying your stay.

  • @stevenedington6265
    @stevenedington6265 22 дні тому +6

    Watching this my mind went in a different direction. As a Sonar technician with an ASW rating I can see the different number of blades on the propellers rendering a technique of ASW ineffective. I do not feel I can be more specific because of the confidential of the subject, but I cannot imagine trying to use the technique against the New Jersey.

    • @philsalvatore3902
      @philsalvatore3902 18 днів тому +1

      That's funny you say that because the Midway class had much the same hull as an Iowa class, the same propulsion and props and sonar operators I was familiar with told me they were both noisy and had an instantly recognizable acoustic signature.

    • @stevenedington6265
      @stevenedington6265 11 днів тому

      I agree there noise signature made them easily recognizable. I was referring to the passive technique of turn counting.

  • @stevenkessler1279
    @stevenkessler1279 21 день тому +1

    Fantastic discussion, so much involved in ship design. Remember this was designed in the 1930's and 40's with slide rules!

  • @MolsonCnM
    @MolsonCnM 22 дні тому +9

    Great vid!!! But..... The burning question is what the guy on the lift is doing?!? Waving what looks like a drill at a prop? Inquiring minds want to know!

    • @matthewkramer7089
      @matthewkramer7089 22 дні тому +2

      Thank you! It's bothering me so much, I have no idea what buddy is actually accomplishing

    • @gregoryegan4132
      @gregoryegan4132 22 дні тому +1

      @@matthewkramer7089 using a heat gun to dry the epoxy.

    • @tomhenry897
      @tomhenry897 21 день тому

      Not wear much safety gear

  • @MakeMeThinkAgain
    @MakeMeThinkAgain 20 днів тому +1

    I started learning about the Pacific War in 1965 when I read all 15 volumes of Samuel Eliot Morison. I've seen all 300 Drydocks and many episodes of Battleship New Jersey. And I still learned so much from this episode.
    And this is something you simply can't cover in a book or in a classroom. Being under the ship makes it so much easier to understand.
    Should we be thinking of Drach as the "Bono" of Naval history?

  • @GenasysMech
    @GenasysMech 21 день тому +11

    A transient vibration occurring at distinct speeds within its range suggests to me that the Holland tunnel could be equipped with some sort of active flaps or rotatable eccentric cylinders that would minorly reshape the tunnel enough to rapidly "skip" the harmonic causing the vibration by preferably transferring it to a previously attained speed.
    Anyway, I greatly appreciate both of you on sharing your wealth of knowledge regarding the history of naval vessels. Fantastic.

  • @Mopartoolman
    @Mopartoolman 22 дні тому +6

    Great video guys!!! That was very fascinating listening to all the different theories on what could possibly cause the vibration. Very informative, and really makes you think….

  • @Isteak80
    @Isteak80 22 дні тому +9

    I agree with the suggestion of getting rid of the Panama Canal requirement. There are shipyards on both coasts, they could build 2 or 3 for the Pacific and the same for the Atlantic and just rotate within their own ocean

    • @ronhudson3730
      @ronhudson3730 22 дні тому +1

      This. And expand the canal at the same time.

    • @mlehky
      @mlehky 22 дні тому +7

      Canal was expanded. At the time the Iowas were built the canal was 110 ft wide and allowed the passage of Panamax ships. The expanded waterway began commercial operation on June 26, 2016. The new locks allow transit of larger, Neopanamax ships, up to 160 ft wide.

    • @tomdolan9761
      @tomdolan9761 22 дні тому +3

      It’s not really an issue for large Navy carriers these days. For example the USS George Washington is on her way to Japan by way of the Magellan Strait

    • @tomhenry897
      @tomhenry897 21 день тому +1

      Even in WW2 didn’t have enough for 2 oceans
      Had to move them back and forth as needed

    • @tomhenry897
      @tomhenry897 21 день тому +1

      That were the low water issue comes from?
      Now wider so need more?
      Is it deeper?

  • @bruceyoung1343
    @bruceyoung1343 17 днів тому +1

    Very Very interesting Ryan & Drach. Much food for thought

  • @robertf3479
    @robertf3479 22 дні тому +10

    Welcome back to the U.S. Drach. I love your collaborations with Ryan.

  • @philsalvatore3902
    @philsalvatore3902 18 днів тому +1

    To correct Iowa Class vibration problems (periodical publications have issues) I would model the hull using computational fluid dynamics software to experiment with different stern configurations including a transom stern and test different kinds of propellers with skewed blades, along with Prairie and Masker to see of bubbler systems affect vibration.

  • @jaysonmates6343
    @jaysonmates6343 22 дні тому +5

    The best combo period

  • @Imnotyourdoormat
    @Imnotyourdoormat 19 днів тому +1

    *I get it. What he's saying is if you drove that ship through the snow. As they're many videos of R/C Boats being driven thru the snow and they perform quite well. In the cycled-through snow, there'd be much bigger piles left behind from the "Rooster Tails" in the inboard props grooves in the snow than the outboard props grooves. And there's the unequalized vibration.The P-51 Mustang used the **_"Meredith Effect"_** to turn aerodynamic drag from its radiator cooling ductwork into usable jet thrust increasing its top speed from 410 mph to 440.*

  • @timandellenmoran1213
    @timandellenmoran1213 22 дні тому +2

    WOW, more about the Washington BB-56 than I ever knew. Thanks Drach and Ryan!

  • @bobbenson6825
    @bobbenson6825 21 день тому +2

    I enjoy both of your channels but your teamups are a treat! Who needs the Marvel Universe when we have this one? So glad Drach could get in there for a closeup view of her in drydock.

  • @russelltaylor535
    @russelltaylor535 21 день тому +1

    What Drach seems to be describing is vortex shedding off the skegs because of the unequal velocities inside the Holland Tunnel and outside. If the vortex shedding frequency is near a characteristic frequency of the prop then it can result in a resonant interaction that will vibrate the stern. The vortex shedding frequency and the prop frequency are dependent on the speed of the ship and the rpm of the prop respectively so that is why the vibration only shows up at certain speeds.

  • @mhyotyni
    @mhyotyni 21 день тому +2

    The main vibration excitation in the modern passenger cruisers and most other ship types as well is propeller blade cavitation, creating major load pulses at blade frequency. While Drachinifel makes many valid points, that phenomenon has certainly existed in battleships also and should have been mentioned at least as a very possible trembling elephant in the room 🐘

    • @philsalvatore3902
      @philsalvatore3902 18 днів тому +1

      Low cavitation skewed props with the right number of blade might have helped, but engineers of that era hadn't figured out skewed props.

  • @patrickshannon4854
    @patrickshannon4854 22 дні тому +10

    Wow! A combination of my 2 favorite ship oriented channels. Great video!

  • @CorvetteBob
    @CorvetteBob 21 день тому +2

    BEST dry dock video to date! Great work Ryan, thanks @Drachinifel!

  • @JohnShields-xx1yk
    @JohnShields-xx1yk 19 днів тому

    I love props in general but those are awesome, just size, wow, picture them churning through the ocean firing the guns. God bless America 🇺🇸

  • @joshjones3408
    @joshjones3408 16 днів тому +1

    Holy smokes I know that voice... pretty cool seeing a face with it.👍👍👍

  • @charlierumsfeld6626
    @charlierumsfeld6626 19 днів тому

    I didn't know of the vibration issues. Drach's explanation though long was extremely interesting. I had no idea of the physics behind water movement and forces the ship generates while in motion. Thank you

  • @EstorilEm
    @EstorilEm 20 днів тому +1

    Clicked this without reading the title, was shocked when the video started and you didn’t introduce him, I was like “omg that’s Drach!!!” 🤣😂

  • @tracygallaway36
    @tracygallaway36 22 дні тому +4

    Awesome, thanks!

  • @keithbarron3654
    @keithbarron3654 22 дні тому +3

    Great conversation, thoughts for Alex, what about spray deflectors on bow to move water into tunnel area, other thoughts are done after laid, flat plate on top of tunnel, similar to E-boats and Fairmile D stern. To knock water to props and similar hysocat, trim plane across bottom of skegs. I wonder if David Taylor center ever worked on fix or was busy with development projects.

  • @deckape714
    @deckape714 21 день тому +2

    Love this Thanks!

  • @trevortrevortsr2
    @trevortrevortsr2 20 днів тому +1

    William Froude is the man who conducted thousands of test tank experiments and formulated hydrodynamic theories that still form the basis of our understanding today - resonance can be astonishingly destructive when one cycle builds on another and can quickly get out of control

  • @ChloeReynolds-es9kn
    @ChloeReynolds-es9kn 19 днів тому

    Hell yeah! I love Drachinifel making a cameo! His extensive knowledge of all things warship amazes me.

  • @henrycarlson7514
    @henrycarlson7514 21 день тому

    So Wise , Thank You .

  • @leod1671
    @leod1671 22 дні тому +1

    Exellent discussion

  • @user-us8td3pg9s
    @user-us8td3pg9s 20 днів тому

    Great explanation!

  • @paulmccowage1681
    @paulmccowage1681 19 днів тому

    Great explanation of how it all works and the complexity of the design issues

  • @27526
    @27526 22 дні тому +1

    Awesome. Thank you for this info, both of you. Outstanding job.

  • @marting1056
    @marting1056 19 днів тому

    thanks for the collabaration video, it was a pleasure to listen.
    To Ryans question, what would we do to reduce vibrations. I see two approaches:
    1. with the overall geometry fixed because of panamacanal and docking etc, we could still alter the properties of the surfaces. Like a noisy room with hard surfaces, by adding absorbing materials to the surface you can alter the acoustic behaviour of the whole room. alternative you may alter the flow of the water near the surfaces by materials anlog to a Golfball or sharkskin. there is a lot of develpment in this field ongoing in the aviation industrie.
    2. changing the symetrical layout of the "Tunnel" to a asymetrical. We are used to prefer symetrical solutions for our constructions, but this is a risky aproach in fields where resonances are occuring. May be shorten one side or/and altering the curve of the hull on the other

  • @rmerlin733
    @rmerlin733 21 день тому +2

    Fairing the insude of the Holland Tunnel to reduce the rise in height as the tunnel transitions to the stern would reduce the volume of water at greater velocities versus the outboard side of the skegs.
    You could today's run effective FEI modeling analysis to obtain similar computer generated results. In essence a 3D equivalent to a "water" version of a wind tunnel. Ideally lowering the exterior hull while retaining the aft hull rise. Along with applying new prop technologies an overall reshape of the tunnel with newer prop design might well be appropriate for this ship and otherks smilar in design and build.
    Anyway just a thought considering fluid dynamics of water transiting down the hull.

  • @dw8555
    @dw8555 21 день тому +1

    You guys are both studs!

  • @SunnnyDay
    @SunnnyDay 22 дні тому +2

    Fascinating !! Well done, Gentlemen, thank you !!

  • @nlo114
    @nlo114 21 день тому +1

    Learning every day! Drach has answered a lot of questions that I didn't know existed. For prop-vibes, try an IOM ferry: I out my bike on the centre-stand for the crossing out to the TT one year. When I rode it off, the stand had broken from the vibes, and one half was clattering on the ground.

  • @drittal
    @drittal 21 день тому +1

    Unique stern design to get satisfactory TDS depth about the wide triple turret barbette and weight restrictions and speed requirements.

  • @rodmaloney5484
    @rodmaloney5484 22 дні тому +5

    Excellent commentary

  • @paulg2132
    @paulg2132 22 дні тому +1

    That was fascinating information. Great input!

  • @casterman2
    @casterman2 22 дні тому +1

    Absolutely terrific video! Great collaboration!

  • @rrice1705
    @rrice1705 17 днів тому

    Always fun to see two of my favourite UA-camrs/historians working together. Fixing the problem would be tricky. Maybe try gutting the second-class area and adding more internal bracing and supports?😁

  • @googacct
    @googacct 22 дні тому +9

    I am a little confused by Drach's comment regarding the Venturi effect.around 7:40 in the video. I would think with increasing cross sectional area, the speed of the water would be lower and not higher. Of course this is not a fully enclosed volume, so maybe some additional factors come into play?

    • @physicsphirst191
      @physicsphirst191 19 днів тому +1

      Absolutely correct. That area of the hull is a diffuser, where the flow is decelerated to match the external flow and reduce drag.

    • @philsalvatore3902
      @philsalvatore3902 18 днів тому

      Yes. As the volume increases, the velocity of the water decreases and pressure rises. Anyone who has tuned carburetors knows this. The narrow venturi in a carb throat causes the intake air to speed up, and as it speeds up pressure drops. That pressure drop is what pulls fuel up from the float bowl, through the needle jet and into the air stream where it is atomized.

    • @physicsphirst191
      @physicsphirst191 18 днів тому +1

      @@philsalvatore3902 Thank you. There's a lot of pseudoscience in this thread.

    • @philsalvatore3902
      @philsalvatore3902 18 днів тому +1

      @@physicsphirst191 I was surprised to hear an engineer make that mistake, but that video was like trying to do math on Excel real time during a Teams meeting O_O Your boo-boos and brain farts are there for all to see and, um, enjoy.

    • @physicsphirst191
      @physicsphirst191 18 днів тому +1

      @@philsalvatore3902 He didn't use many engineering terms to describe the phenomenon... such as static pressure, dynamic pressure, skin friction, drag, pressure recovery, drag coefficient, flow separation, Bernoulli's equation, angle of attack, etc, and I don't think it was because he didn't want to baffle the audience. It was gibberish to me, and I'm an engineer, so I think the lay audience was mislead.

  • @johnwallace9002
    @johnwallace9002 20 днів тому

    Very interesting, thank you.

  • @joesilverbliss1721
    @joesilverbliss1721 22 дні тому +2

    Super interesting! Thanks for the video.

  • @kingtulabi1005
    @kingtulabi1005 21 день тому +1

    What an awesome video!!!

  • @bigsarge2085
    @bigsarge2085 21 день тому +2

    Fascinating!
    And I appreciate the collaborations.

  • @frankornelaz8234
    @frankornelaz8234 22 дні тому +1

    Great video. Very interesting subject and explanation.

  • @joeycerelli
    @joeycerelli 11 днів тому +2

    The guy in the background on the scissor lift having to pretend to be busy for 14 minutes straight lol

  • @bluerebel01
    @bluerebel01 22 дні тому +3

    What a very informative video, thanks to you both for sharing this knowledge.

  • @billbillson3129
    @billbillson3129 21 день тому

    Outstanding!!!

  • @cartjj
    @cartjj 21 день тому

    Awsome analysis, Gentlemen.

  • @joe6167
    @joe6167 21 день тому

    Fascinating discussion, thanks!

  • @tombieg957
    @tombieg957 22 дні тому +2

    I saw both of you guys on Saturday may 25th and got to go under the ship very cool experience checked off my bucket list

  • @davidansley1731
    @davidansley1731 22 дні тому +2

    It would be my guess , that the rez frequencies are hull deformation, or skeg flexing . There is a lot of stored energy in that hull . Prop pulse , yea , if you get everything just right , hard to stop. At the beginning of the prop tunnel , the shape should be arched at the beginning , ovel shaped , then move to a open bottom box shape.

  • @johngallus1735
    @johngallus1735 19 днів тому

    Thank you Ryan and Drach, love it when you two talk ship

  • @S_M_360
    @S_M_360 21 день тому +5

    $100 usd or British pound sterling - these two had this conversation last night over beers and Ryan was like “Drach, this is my update, just tell YT tomorrow”

  • @randyhavard6084
    @randyhavard6084 20 днів тому

    Very well explained, it looks like the tunnel under a race car

  • @Beechnut985
    @Beechnut985 22 дні тому +8

    What a beast!

  • @bananafoneable
    @bananafoneable 20 днів тому +1

    No way! I knew he'd be there!!

  • @user-ru2qn1ow1d
    @user-ru2qn1ow1d 22 дні тому

    Very nice, thank you.

  • @daviddavies2072
    @daviddavies2072 21 день тому +1

    Good video thank you , very informative , great job 👍🇬🇧❤️🇺🇲

  • @eskhawk
    @eskhawk 19 днів тому

    I loved seeing Drach

  • @scottmaciver6093
    @scottmaciver6093 20 днів тому

    utility fascinating , Physics and engineering, explained so perfectly. We all can learn from this , Thanks Ryan