If it can't bend, it will break.

I understand the principle, but this is the best visual I have ever seen.

This is a corridor in a container ship in rough seas.

All I can say is Wow.

http://www.youtube.com/watch?v=qEkErF51Uxg

I hate sailing anyway....

Whatever these guys are paid is NOT enough!

Save the video.

Anytime one of your friends puts "Sail around the world" on their bucket list, show them this.

I wonder if the bit you see in the submarine movies with the guy stretching a string across the inside of the sub and watching it sag as the boat dives is true.

Shawn

Planes are just as bad. I read once that the Concord was three feet longer tip to tail at Mach 1 than it was stationary...

I sat in the last row of a stretch DC-8 years ago and you should see how much flex you can see in one of those during take-off.

First time I flew it was a bit nerve wracking to look and see the wings flapping. And this was after a fellow grad student had warned me it was going to happen.

I read somewhere the average aircraft carrier 'bows' up to two feet (sometimes more) in rough seas, this is accounted for during the design process.

As a (very) amateur engineer, I realize stuff has to flex or it will break. That doesn't mean it feels good to experience it. I got stuck on the Pearman bridge in Charleston a couple of times, while sitting still you'd get the distinct and very creepy feeling that you were 'bouncing'. You look over at the car next to you and realize ZOMG THEY ARE BOUNCING TOO! IT'S REALLY HAPPENING!

I used to work on the 14th floor of a 20 story building and could feel the sway when the winds picked up. On seriously tall buildings they build in motion dampers (large masses that are somewhat free floating at/near the top of the building) to help prevent people from getting sick from the movement way up top.

Long time ago I was in Cherry Point NC staying at a beach house during the winter months, there was a 'nor'easter' coming through. The house was on pilings and the damn thing felt like a weathervane.

the mall near me.. some stores "bounce" when there is heavy traffic inside the mall.

And yes... Ships have to bend.. last thing you want to do is break a ship's back

i've been in the way back seats on the 737s and little regional jets in rough weather. flexing/bending is fine, when it gets a little nerve-wracking is when you can see the fuse twist as the wings rock

Boeing has a lot of money riding on the "bend not break" thing:

Then again, they're pretty good at it:

i'd say so:

http://www.youtube.com/watch?v=sA9Kato1CxA

Yeah, I know about the bend or break, I've watched the wings on a plane flap. I've even seen the fuselage flex and twist on a bumpy landing. I've sat on the bridges with them bouncing up and down. I've never thought about the fact that a ship does the same thing. That's as vivid a reminder as I have ever seen. It's not only moving up and down, it's moving side to side, a lot.

Trans_Maro wrote: I wonder if the bit you see in the submarine movies with the guy stretching a string across the inside of the sub and watching it sag as the boat dives is true. Shawn

Yes, that is true.

This ship, the USS Schenectady, broke in tow while tied up to the pier. Brittle fracture is not your friend at sea. Built before there was a really good idea about material science.

That ship was flexing more than a C4 convertible.

nice that it kept the break above water

T.J. wrote: This ship, the USS Schenectady, broke in tow while tied up to the pier. Brittle fracture is not your friend at sea. Built before there was a really good idea about material science.

I don't know if it's still the prevailing theory, but when I was in school (~2000), there was some new work that speculated part of the reason the titanic was so bad was that it used some fairly high-sulfur steel, which went into the brittle fracture range because of the low sea temperatures, and thus cracked a lot more readily than the designers were expecting.

I can believe it about the titanic. The problem with that disaster is that so many factors conspired to sink that ship and kill it's crew and passengers.

Id read that the SR71 spyplane would actually leak fluids when siting in the hangar because the seals were made to expand due to the heat of friction from the air slipping over the skin of the plane at mach speeds. No idea if its true or not,.

One of my first outings on a submarine was a dive to test depth, as deep as you can safely go. In the middle level there are two pipes inside each other, one with 1/2" OD, the other 1/2 ID. At every 100 ft. of depth we drew a pencil line where the two met. We did an emergency blow to get back to the surface and the pencil lines were spaced out over an inch and a half! The hull collapsed that much, every fitting and pipe that passes through the middle of the boat has to have room for expansion & contraction.

Dan

All the bridges in the Mall of America are designed with the same properties in mind- It's a little freaky to be walking along and feel the floor shaking under you .

Even more off-putting than watching ships flex... watch youtube videos of buildings designed to wobble rather than crumble from earthquake. It is pretty cool to watch but I bet it is flat-out terrifying to be running down the taircase while that goes on.