Ship

[Vladislav]

18 hours ago, david wild said:

Do the same with a truck if drivers didn't set out to destroy them from day one, could never understand why they need carve  their name on everything, or drill 20 holes to mount one radio and stickers all over the dash ??????? like why does a driver need a convex mirror inside the cab  ??

The most amazing fact is the reason of that matter is the mother-nature. A driver is a kind of a male animal. So he just marks his territory. No doubt he doesn't understand that himself.

[HeavyGunner]

20 hours ago, david wild said:

Do the same with a truck if drivers didn't set out to destroy them from day one, could never understand why they need carve  their name on everything, or drill 20 holes to mount one radio and stickers all over the dash ??????? like why does a driver need a convex mirror inside the cab  ??

I never understood the guys who go waste money putting chrome crap (mostly fake I’m sure) and other accessories on a company truck they don’t own?  Never did make sense to me but I’ve also never bought a new set of rims either. Always used and usually more on the utilitarian side than vanity. 

[Bullheaded]

Yep, I can't understand drivers we have had. Wash the truck and make it all shiny and then you go inside the cab and it's an all out pig pen with holes drilled all over in everything.

[Lmackattack]

Have you guys ever seen the videos of these ships traveling in shallow narrow channels? as the ship nears its displacement is pushing water into all the local channels on the shore line even with the ship 1/4 mile off shore. then as the ship passes it pulls the water out. looks like it can really cause issues to nearby homes with their boat docks. youtube it .... its pretty cool to see

[Bullheaded]

29 minutes ago, Lmackattack said:

Have you guys ever seen the videos of these ships traveling in shallow narrow channels? as the ship nears its displacement is pushing water into all the local channels on the shore line even with the ship 1/4 mile off shore. then as the ship passes it pulls the water out. looks like it can really cause issues to nearby homes with their boat docks. youtube it .... its pretty cool to see

Funny you mention that. I'm on the lake, but my aunt and uncle lived on the narrow part of the shipping channel before they get to the Sault Locks. And I used to see that. It was really freaky. Two ships would pass and the water would disappear from the shore. I still don't understand the science before it. I can see how they would increase the water level, but not how they pull the water out.

[Mack Technician]

On our honeymoon we took a ride on the Tokaido Shinkansen Bullet Train. When it entered a tunnel it would begin to compress an air column in front like a snow plow and the windows would slowly bow in deeper the longer you stayed underground. Vacuum sucks at the trains rear and air accelerates forward to chase the void. You “banged” out the other end and everything returned to normal. Wonder if it’s not a similar, slower, effect with the ships channel? 

[41chevy]

57 minutes ago, Bullheaded said:

Funny you mention that. I'm on the lake, but my aunt and uncle lived on the narrow part of the shipping channel before they get to the Sault Locks. And I used to see that. It was really freaky. Two ships would pass and the water would disappear from the shore. I still don't understand the science before it. I can see how they would increase the water level, but not how they pull the water out.

It's called a Bernoulli Wave it's the displacement  of the water surface around the vessel hull due to the pressure distribution of the ships displacement and speed in the water around it.Easy way to think of it is when the ship generates a bow wave and the wake the water around it is pulled towards the ship to replace the water in the bow waves and wake. Does exactly the same in deep or shallow water, just more noticeable in a narrow area. Learned all about the effect at the Webb Institute when they demo'd  the hull design on the Grumman H.S. Denison Hydrofoil verses our Scarab when we were trying to squeeze out max speed. Showed that a pair of  air foil shaped skegs on the mid hull would give us 20 to 30 more mile per using the Bernoulli Effect.

Edited April 13, 2020 by 41chevy

[Bullheaded]

Ok, makes sense. I know on this channel they have a speed limit for ships and you could always tell when they were above it. Then add two ships passing each other and it really made some effects.

[Bullheaded]

I just looked, because the winds here are the strongest we've had all winter and they are calling for big snow, but the Indiana Harbor is the only freighter on the lakes right now. And it's right out in the middle of Superior. I can't even imagine the waves that is taking right now.