How much larger can ships get?

[chengkp75]

Wouldn't that apply to any ship though? Does it being larger make it less safe? And if they were tipping over left and right, people wouldn't be cruising. With any form of transportation there is always a small risk involved.

 

One thing you will learn as you gain time on CC. "cb at sea" is a classic "drive by poster", who will post to a thread, and then never, ever return. Most of the posts are also either off topic or incorrect.

 

Yes, any ship can be "tipped over". However, as I've stated, the farther a ship is tilted, the more "righting moment" or force it generates to stand itself upright, is generated. The only problem comes when there is a shift in the centers of gravity or buoyancy, caused by large weights shifting (like engines breaking loose (not real likely)) or downflooding caused by the non-watertight doors above the promenade being submerged. So, you have to get a force great enough and sustained enough to tip the ship over 35* (most ships more like 45*) to induce downflooding, and ships very rarely get over 20* of roll, even though most passengers think otherwise.

[nimiq]

Yes, the engines, boilers, propulsion equipment, and all the stuff that provides the cruise the ability to do what it does, is heavy and down below the waterline. Also, things like fuel, potable water, and ballast water account for tens of thousands of tons of weight, and this is kept in the very bottom of the ship. Also, the superstructure of the ship (all decks above the promenade deck), add almost nothing to ship strength, so it is built with lighter materials, and thinner metals than the hull, further moving the center of gravity down.

 

 

 

One way to look at it, the passenger spaces (the vast majority of the volume of the ship) is filled with air and passengers, while the engineering spaces are filled with heavy machinery. Think of the "punch-em" clown blow up toys, where it is nearly 5 feet high, but a small weight in the bottom keeps it coming back upright no matter how hard you hit it.

 

 

This is a good one to remember :-)

 

Thanks for the comparative with the clown toy.

 

 

Eric

 

 

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[BoiiMcFly]

One thing you will learn as you gain time on CC. "cb at sea" is a classic "drive by poster", who will post to a thread, and then never, ever return. Most of the posts are also either off topic or incorrect.

 

Yes, any ship can be "tipped over". However, as I've stated, the farther a ship is tilted, the more "righting moment" or force it generates to stand itself upright, is generated. The only problem comes when there is a shift in the centers of gravity or buoyancy, caused by large weights shifting (like engines breaking loose (not real likely)) or downflooding caused by the non-watertight doors above the promenade being submerged. So, you have to get a force great enough and sustained enough to tip the ship over 35* (most ships more like 45*) to induce downflooding, and ships very rarely get over 20* of roll, even though most passengers think otherwise.

 

Thanks for the heads up. Just out of curiosity, how many cruises have you been on so far?

[chengkp75]

Thanks for the heads up. Just out of curiosity, how many cruises have you been on so far?

 

That depends on whether I was working or not. About 130 while working, and 6 as a passenger.

[BoiiMcFly]

That depends on whether I was working or not. About 130 while working, and 6 as a passenger.

 

Very nice. What was/is your position on the cruise ship?

[chengkp75]

Very nice. What was/is your position on the cruise ship?

 

I worked for NCL as First Engineer, Staff Chief Engineer, and Chief Engineer. I am now working for a tanker company as Chief. Been sailing for 42 years, 35 as Chief.

[biker@sea]

I worked for NCL as First Engineer, Staff Chief Engineer, and Chief Engineer. I am now working for a tanker company as Chief. Been sailing for 42 years, 35 as Chief.

 

Off topic but, are tanker's really the best ride in rough sea's?

 

Thank's

 

.

[BoiiMcFly]

I worked for NCL as First Engineer, Staff Chief Engineer, and Chief Engineer. I am now working for a tanker company as Chief. Been sailing for 42 years, 35 as Chief.

 

Very cool, thanks for sharing.

[chengkp75]

Off topic but, are tanker's really the best ride in rough sea's?

 

Thank's

 

.

 

That depends. The old single hull tankers were just like pushing a cinder block through the water, very slow peaceful rolls. The newer double hull tankers, when loaded will still give a pleasant ride, but somewhat choppier on the rolls. When in ballast, they are the worst, because the amount of ballast able to be carried becomes a very small portion of the volume of the cargo tanks, so stability suffers, and you are probably worse than a cruise ship. Since a tanker has its center of gravity near or at the waterline when loaded, the metacentric height is very small, so she will roll easily, but the rolls will take a minute or two to complete, and she may "hang" at the end, as if thinking about coming back upright.

 

Due to the low freeboard of tankers, you tend to plow through seas, rather than ride up over them. I've been on several ships in a few storms where you could literally not see any part of the ship forward of the house, as we plunged through a sea. Tankers tend to take a lot of damage on deck from this (handrails, walkways, fire stations, etc.)

[ErikM321]

I think ships are limited as to how much bigger they can get for the simple reason that port are limited by how big they are to accommodate them (not just in depth of water but supplying them with supply's and

 

 

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[ErikM321]

I think ships are limited as to how much bigger they can get for the simple reason that ports are limited by how big they are to accommodate them (not just in depth of water but supplying them and allowing passengers on and off).

 

Not only that but they are limited by height by some bridges getting into some ports. They are limited by width and length by the Panama and Suez Canals.

 

 

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[Pyrate13]

The canals do limit the size of ships using them but you can cruise completely around the world without using the canals so they don't cause a limit to ship sizes. Depth of ports can also be altered and in some cases has been. Bridges would limit use of some ports but certainly not all.

 

Not saying it's a good thing or bad but bigger ships may come along, maybe not in our lifetime but someday. Who knows what the future holds.

[chengkp75]

The Suez canal, since it does not have locks, has no maximum length, and even the largest cruise ships don't approach the depth maximum. So, building longer, narrower, and shorter mega-ships would be allowable in the Suez.

 

Most ports, with the exception of places like the Caribbean islands, have water depth limits much greater than the largest cruise ships. Cargo ships ride much lower in the water than cruise ships.

 

As for port infrastructure, that can be designed for in most cases, and just needs capital investment in terminals, parking, and roads.

[navybankerteacher]

This is a good one to remember :-)

 

Thanks for the comparative with the clown toy.

 

 

Eric

 

 

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And that ties in with NCL's ships being painted like circus clown cars.

[AmazedByCruising]

Do you think cruise ships will ever plateau at a certain size, or we will constantly find ways to make them bigger?

 

You may like this thread.

[BoiiMcFly]

You may like this thread.

 

I did like it, gracias. :D