Now this is displacement!

[polarmystery]

You changed your avatar!

 

[skyking]

Interesting, still using piston and crank arrangement, I thought turbines were the norm for that type of (large) power needed to propel an 700+ foot vessel..

Turbines use .55 LB/HP/hr of fuel.
Piston engine diesels like that Wartsila in the pictures use about half that,
.278LB/HP/HR

The turbine has the highest output per pound of engine, but a big ship is not adversely effected by the added weight. Only high performance military ships can afford the fuel consumption of a turbine.

 

[Rubycon]

And if that's not enough the engines don't actually propel the ship! They are actually part of a 60MW power plant that powers everything onboard. The main propulsion is from two azimuthing pods (called azipods) with 20MW motors in each. Three tunnel thrusters forward in the bow provide maneuvering ability and these are 3MW each.

 

[polarmystery]

^You did it again!!

 

[Rubycon]

^You did it again!!

 

[Anubis]

Reminded me of this for some reason...

Also, I can't believe that's how those ships are launched! When I saw the first video, I thought something had gone wrong and it was sliding toward the water by mistake. I guess as long as nothing binds up, it's a sound way of doing things. I would have thought there was some sort of ramp with rollers or something which would allow ships that big to go bow-first into the water. Cool vids.

That vis is of Test Baker
http://en.wikipedia.org/wiki/Operation_Crossroads

 

[Kanalua]

http://youtu.be/4Af5Tl6EqI0

 

[phoenix79]

The ship in the first video looks like it hardly has any draft at all. Hard to imaging that it would be very stable in rough seas.

 

[Rubycon]

The ship in the first video looks like it hardly has any draft at all. Hard to imaging that it would be very stable in rough seas.

That's because she's empty. When loaded the bow bulb is submerged and there's plenty below the water line. When they don't have cargo they pump water into ballast tanks to provide draft.

The system that manages this can be completely automated and is quite complex.

Regulations require monitoring of water as well due to possible spread of undesirable organisms. If water is used for ballast in a port with a known hostile organism it cannot be released in a distant port with waters foreign to said life forms. Of course things (mainly in the past before technology existed to monitor/control them!) do slip through. This is how insects can get across the pond, for example.

 

[Judgement]

http://www.youtube.com/watch?v=o8T095mFdW8

 

[MotF Bane]

Imagine four of those and that's our engine room!

I'd be more interested in seeing the engine room than the rest of the ship.

 

[Rubycon]

I'd be more interested in seeing the engine room than the rest of the ship.

A lot of people say that except the ones that work down there. To them the most interesting part of the ship is the bar!

 

[bobdole369]

In Miami in particular the waves coming in on a perfectly calm day are impressive. I'd imagine at 15 knots there would be some flooding on the streets

I can't recall anything like that in recent memory. Of more concern is steady easterlies which erode the beach and deposit it on the street. It takes a good day long set of head-high or greater sets to seriously impinge on the streets. Not too sure on the causeways though, I think they tend to be higher than they seem.

The system that manages this can be completely automated and is quite complex.

Yup. I'm a couple tiers below that level doing luxury yachts. We automate fuel valves/pumps, bilges/trim ballast tanks, report doors, engine alarms, etc.

It always amazed me that the larger vessels get so unstable when unloaded that they'd rather take the massive hit in fuel economy than run empty.

I was also shocked that the load shedding done onboard (at least on our vessels) is by heating seawater.

What kind of stabilizers work on a boat that uses azipods Ruby? I'd imagine its completely different than the zero-speeds often used on the boats on which I work.

 

[Bignate603]

Turbines use .55 LB/HP/hr of fuel.
Piston engine diesels like that Wartsila in the pictures use about half that,
.278LB/HP/HR

The turbine has the highest output per pound of engine, but a big ship is not adversely effected by the added weight. Only high performance military ships can afford the fuel consumption of a turbine.

This. I work at a company that makes turbine engines. Fuel burning turbines (rather than steam turbines) can be competitive in efficiency against smaller diesels at full power but diesels are more efficient at part power conditions (when you're using only a portion of the maximum rated power from the engine). Against large engines like the pictures in this thread there's absolutely no way they can compete. As diesels get larger there are some advantages that can be used to make them incredibly efficient.

That's because she's empty. When loaded the bow bulb is submerged and there's plenty below the water line. When they don't have cargo they pump water into ballast tanks to provide draft.

The system that manages this can be completely automated and is quite complex.

Regulations require monitoring of water as well due to possible spread of undesirable organisms. If water is used for ballast in a port with a known hostile organism it cannot be released in a distant port with waters foreign to said life forms. Of course things (mainly in the past before technology existed to monitor/control them!) do slip through. This is how insects can get across the pond, for example.

Didn't that ship carrying all those Mazdas tip over a few years ago because they were changing out the water in the ballast tanks before it came into US waters for that reason? If I remember right the system to keep the ballast balanced malfunctioned and they vented all the water on one side.

Link to story about the ship

Car carrier tips

 

[techs]

Interesting, still using piston and crank arrangement, I thought turbines were the norm for that type of (large) power needed to propel an 700+ foot vessel..

IIRC it has to do with environmental regulations on the coal to power a turbine engined ship.

 

[bobdole369]

I thought turbines were the norm

No sir, and

environmental regulations on the coal

Absolutely no coal in working fleets on the high seas. Not for a long long time. There are always exceptions. I know riverboats and historical vessels still use boilers. Probably a good chunk of stuff running in the great lakes too.

Turbines will burn anything from heavy oil to gasoline and naptha, but typically the same hugely available and non-explosive fuel-oil (aka basically diesel).

http://en.wikipedia.org/wiki/Gas_turbine

Trouble with gas turbines is the narrow power band, its all or nothing. The large piston engines are also easily serviced and have entire industries behind them. The gas turbines need things like tracking the parts that go into them for eternity.

 

[Balt]

damn : http://www.youtube.com/watch?v=64dAv9sk7GE&NR=1

She looks a bit heavy in the back.

 

[Bignate603]

IIRC it has to do with environmental regulations on the coal to power a turbine engined ship.

A turbine doesn't need to be a steam turbine which you'd find in a ship burning coal. A gas turbine engine can be made to burn whatever flammable gas or liquid you want as long as it burns relatively clean. The AGT1500, the engine in the Abrams tank, can burn burn kerosene, jet fuel, gas, diesel, or even high proof vodka.

 

[MotF Bane]

A lot of people say that except the ones that work down there. To them the most interesting part of the ship is the bar!

I didn't say I want to work there, just see it!

 

[MotF Bane]

Car carrier tips

It's the failboat!

 

[Gothgar]

http://www.youtube.com/watch?v=o8T095mFdW8

:awe:

 

[Rubycon]

I can't recall anything like that in recent memory. Of more concern is steady easterlies which erode the beach and deposit it on the street. It takes a good day long set of head-high or greater sets to seriously impinge on the streets. Not too sure on the causeways though, I think they tend to be higher than they seem.



Yup. I'm a couple tiers below that level doing luxury yachts. We automate fuel valves/pumps, bilges/trim ballast tanks, report doors, engine alarms, etc.

It always amazed me that the larger vessels get so unstable when unloaded that they'd rather take the massive hit in fuel economy than run empty.

I was also shocked that the load shedding done onboard (at least on our vessels) is by heating seawater.

What kind of stabilizers work on a boat that uses azipods Ruby? I'd imagine its completely different than the zero-speeds often used on the boats on which I work.

If there is an advisory for coastal flooding and the astronomical high tide coincides with arrival things can get closer to flooding if someone would speed through.

Larger passenger vessels use hydraulic vane stabilizer systems. Also fully computerized control.

Didn't that ship carrying all those Mazdas tip over a few years ago because they were changing out the water in the ballast tanks before it came into US waters for that reason? If I remember right the system to keep the ballast balanced malfunctioned and they vented all the water on one side.

Link to story about the ship

Car carrier tips

It's possible. The system only allows water to be pumped at a certain rate for a reason. Sometimes human intervention can overcompensate you have a serious issue. This happened in July 2006 on Crown Princess with the healing incident. Scary stuff. At least there were no human casualties. The cars are insured.

She looks a bit heavy in the back.

I'm glad no one says that about me!

I didn't say I want to work there, just see it!

I'd love to do a video walkthrough and put on youtube but the rules probably won't allow it. It would have to be dubbed anyway since the SPL is ridiculous there anyhow.

 

[nutxo]

http://www.youtube.com/watch?v=dtw3B3yQi1U&feature=related

 

[bobdole369]

things can get closer to flooding if someone would speed through.

Big issue the yachts always seem to have whilst docked - some jackass in a 80ft sunseeker goes blasting by at 20kts and the wake screws up the fenders. Do it big enough, or enough times and they'll ask the next bridge tender to help identify the vessel and bring the owner into court for a new paint job / body work.

 

[Rubycon]

Big issue the yachts always seem to have whilst docked - some jackass in a 80ft sunseeker goes blasting by at 20kts and the wake screws up the fenders. Do it big enough, or enough times and they'll ask the next bridge tender to help identify the vessel and bring the owner into court for a new paint job / body work.

Those are the guys that deserve a D cell battery toss at their windscreen from a deck mounted clay pigeon thrower!