​@@AlexanderBrown77wat

Every time!

I caught the the pause after the "thin skin" comment at the beginning.

Was just thinking about this…. Imagine ships with ice breaker hulls…. The hull shrinks in the cold, and steel under tension is strong, but deep sub zero steel is brittle. I wonder how they prevent ships that serve in heat and ice from having major hull issues.

@@rizash A better grade in steel alloy and/or heat treatment meant for those temperature ranges. Thicker than average plating. Extra structural members behind the ice breaking side.

@@rizash The steel that is used for building ship hulls varies tremendously, according to intended use. I've never worked on an ice breaker, but I would guess that the bow and along the waterline would be similar to armor plating. Most ice breakers work by riding up on the ice and use the weight and inertia of the ship to break the ice from the top, vs cutting through it. I can't confirm, but it seems as though I read an article about a breaker that had a large weight they rode up on the ice with it placed aft, to raise the bow, then once atop the ice, it was brought forward to help break through with it's weight added to the bow. Kinda like the Dahli in Baltimore with an Interstate Highway on it.

It's not just settling, it's also flexing. I've been on both short and long boats and while you don't "see" it on short boats, they flex as well. On long boats... oh boy, ever been in an empty metro? :)) When that happens, the resistance the boat has against it is in part because of the skin acting like "lattice" between frames and horizontal segments (name escapes me atm). So it "crumples" and deforms as a result, because it stretches diagonally and makes a "belly" as a result. One place one can see this all the time, old bug doors or frames. The older it gets, the more "belly" it has, it's also why old doors that aren't fit anymore crack their windows.

Now we solved that issue why do we call it spanking new

Yep, I worked Dept. O9 at the yard in the mid 2000s and I only ever saw the weather deck plating being straightened. I assume because indentations would make a puddle and/or a tripping hazard. A bunch of the old timers I talked to said that the Arleigh Burke DDG-51 was beautifully smooth. Apparently, they flame straightened everything for the first run of ships. I'm sure it got cut for cost. Keep up the good work, brotha'. Bath Built Is Best Built! 🇺🇸

Bath Iron Works?

Thanks for what you guys did at Bath Iron Works. I was a sailor for a couple years on U.S.S. Preble DDG-46, and I’m sure you didn’t work on that particular ship, but Preble was built at BIW way back when. The tin can fleet owes a hearty salute to all the shipyard workers and engineers who turn out great ships. 🫡 🇺🇸 ⚓️

Until they invent a metal that can stretch and regain its shape, this isn't so much an issue as it is a design choice. You could most definetly make a rigid enough ship to not have oil canning, but do you want to? - is the question. The more they travel, the more stretch they get, until the "belly" between frames reaches its max potential and it just exists there. Oil canning are ... essentially tiger stripes on boats - for the same reason we have them as well. Moving about, the skin stretches between rigid portions.

I worked @ BIW in the early '80s in production planning department - some of the "oil canning" is caused by welding heat shrinkage (the heat makes the metal shrink and pucker). I worked with the IHI (Japanese) consultants on flame straightening / bending techniques. We watched them lay out and form a piece of shell plating with nothing more than a torch, a water hose, and some wedges/sledgehammer in less time than the yard guys could do it with the 3-roller bending press. Took incredible skill and lots of experience to do that.

I was stationed at Barksdale AFB from 2002-2005. They said it was designed this way, as flying high up in altitude, the pressurized cockpit will even those wrinkles out.

A lot of aircraft get it.

The wings on a B-52 "flap" in flight. The wing tips move up and down. If they didn't flap, turbulence would cause them to break off. 🤠

@jamesburns2232 pretty sure that's most aircraft. Wing has to be strong but flexible. Especially at the tip when there's no winglet or fence.

Mesh doors have it too. Same reason. Rigid framing for a thin skin + movement = stretch and deformation in the skin. It's actually part of the design in most applications of this methodology. I might have it wrong, because this is just based on what i've visually seen, but i think in some parts of airframes, they specifically reinforce (extra fabric - fiberglass or carbon or whatever they may use) the edges leaving an oval shape of lesser material towards the center of the "segment" to allow it to buckle and move rather than be rigid and crack. It's also the reason why long, lloooooooong boats, when you look down the centerline in rough seas look like a 3D variant of the empty metro, bending and twisting ... but not breaking apart (like they used to, for example, on the great lakes, where many a boat was lost because they were too rigid).

I've seen "oil canning" on bulkheads on the cargo holds and engine rooms. I've worked 3 decade in shipbuilding and I have questions about his explanation. Also I've never heard of any ship with 48 inch frame spacing. I guess it might happen however I've only seen ships with 36 inch frame spacing. Even the metric blueprints I expected 1 metre space however the print where 9144 mm 🙄

​@@davea4245 haha on 9144. There is no single frame spacing. We choose frame spacing to optimize structural efficiency balanced with cost considerations.

I believe he is partially right but welding full frames and longs on military ships is a large cause of distortion, after all strength not appearance is what they want..

@@davea4245 i dont buy his theory either. most people just dont think how much ships flex, because on most of them you cant see it happening. my first ship in the navy, i caught it in the PI, we pulled out on the edge of a typhoon, so it was a bit sporty out, not to mention it was a flat bottom lst, but on this lst you can look from the stern to the bow, right through the superstructure. first morning out my lpo says come here, look at the jack staff. mind you we were almost at the fantail at muster, and i looked through the superstructure to the bow, and holy heck the danged ship was bending 4-5 foot while riding through the waves. imo, the twisting, bending, and flexing is what causes the skin of the ship to stretch, causing the "oil can" affect.

As a person who uses KZfaq often, I also guessed that would be the case.

I’m still going with the atmospheric and physical pressure changes over the giant invisible thumb chasing ships… 😂

Yep I thought the same.

You are actually also correct. Not heard it called 'Oil canning' before, maybe its an Americanism? We UK seafarers call this 'panting' and it refers to the flexing in and out like an oil can when a ship is making way in large seas. If you Google Panting in ships, it will describe exactly this

You are correct. ( I am a nav arch. ) Look at the hungry horse appearance along the waterline that is hydro loading. The sup.side of the new ship is weld shrink and possibly some global deflection induced buckling.

If people didn't ask questions Ryan's job would be much harder. Finding topics for one video per day is not an easy feat.

Did you really laugh out loud? I doubt it.

A sailor got angry, and went psycho with a power hammer. Simples i dont think. But funny image to me!

@@Michael_Brock Yep, Popeye after downing too much spinach! 😃

@@ronsamborski6230 Popeye eating some rotten spinach and having a bit of a backwards burp. :))

put a big suction cup onit and it may pop out..

Haha wow, sounds like you saw Troutbridge come in to dock!

I saw cops smash one of their twin merc 250 outboards by backing in to a piling. My laughter resulted in a rather hostile safety inspection.

@@davidncw4613 Were they state cops? They 're the most fragile egotistical tyrants.

There's a saying in the USN. If your ship runs a ground, so does your career. Same with running into a dock and causing damage. Funny thing. We were at lunch and I asked if one of the Nuclear Carriers ran a ground. I forget which one. It turned out that carrier had run a ground in California. It caused a lot of damage. He went on to tell me what happened to that guy.

yeah I always thought it was caused by waves hitting the ship over time

Exactly - water hammer

I was on the FFG 37 in the Gulf of Alaska during a September storm. A roller coaster was a tame ride after that.

Ah, thanks for posting. That's what I was told it was called years ago. Thanks for confirming my memory!

I used those oil cans when I was a kid. They were round. I don’t know what Ryan is talking about with the triangle shape.

@@bebo4807 They were funnel shaped, I guess that's what he meant to say. 🤔

Not the oil cans I used. They were a half sphere with a flat bottom with a spout in the center. You depress the flat part with your thumb and out comes the oil.

Exactly 👍​@@bebo4807

I've inherited two of those. Now we have cans that dispense oil for 3 times the cost.

The video was 3 yrs ago- How to become a ship museum curator.

Fun fact, you can actually still buy oil in cans like that, BUT only if your daily driver has a turbine engine. For whatever reason, jet/gas turbine oil still comes in cans, so if you daily an M1 Abrams or a Cirrus VisionJet you still gotta have the funky little spout.

Me too

The oil cans he is talking about are quite old. Using them made a cool "poink" noise as you oiled, clicking your thumb in and out on the thin metal bottom. My grandfather had one back in the 70's and we would play with it as kids.

@@wbstaple8387 Ever time I hear about those oil cans I think of the Tin Man in the Wizard of Oz.

I still have my old oil spout I used years ago. It got put in the tool box thinking someday the plastic containers wouldn’t be used any more and the cans would be back. I looked at it a couple years ago thinking I should just throw it away but I wiped it off and put it back.

It actually makes the ship go faster!

@@tedmoss Is that like the dimples on a golf ball? 😃

They make a big difference. You can’t waterski off the back without these speed ripples…

yeah I always thought it was caused by waves hitting the ship over time

@@geronimo5537 I'm sure that this *can* cause it to some degree or deepen existing oil canning by stretching out the metal. That being said, you can find pictures of oil canning on ships that are still under construction and haven't even touched a wave yet. For instance, search up 'DDG 123 under construction Ingalls Shipbuilding'. You can find a picture of her port bow before she was launched and you'll see some pretty pronounced oil canning going on. There are ways to eliminate oil canning. Both to minimize its formation during welding and to correct it after the fact. That being said, I don't think anyone considers it to be a priority on warships. No one goes to go to the work and expense to do anything about it. If you want to know more about those sorts of techniques, you can find accessible versions looking into videos by guys that do sheet metal work on custom cars. Same principles, just at a smaller scale.

Every B-52 I have seen pictured has those. I wonder if there is a different cause on aircraft?

that's exactly what I was thinking on b52s after I heard his explanation

Almost every aircraft has them, it's normal for aluminum.

It's the air pushing against the fuselages. With water it's hydraulic action.

I would have figured on aircraft it's from the the airframe flexing. Ryan stated in the video it's due to heat on the ships hull, is that not correct?