Jackelope

Will this fit in my car?

kargoboy

Ha, sweet. Can you imagine the HP just the get that thing turning?
I wonder how much it weighs....I'm thinking at least 26 tons. Althought it looks like aluminum.
I can't imagine aluminum holding up to the torque, though....

zerocover

What the hell is that off? Boat?

They should step it up to a giagantic rotory! It could be half the size

chiefmg

The correct term is ship (sorry, it's what I do for a living). That looks to be a large (duh!) slow speed diesel crankshaft. Your power to weight ratio would suck, but you would have monster torque. Figure your average ship's propulsion plant today puts out around 20,000 hp. The one I am sitting on right now has two medium speed engines putting out a combined 26,000 hp. Biggest I have ever been on was a steam plant with 43,000 hp. Now that was big!

Jackelope

yah, its a boat.

chiefmg

Yup, Sulzer slow speed engine. See the 100 rpm on the sign? Engine like that is directly coupled to the propeller.

scotty878

I've seen these pics a lot, but the never cease to amaze me!

Anarchistchiken

I thought they didnt do that anymore? Dont most modern ship engines feed a generator which turn the prop to avoid damage to the engine if the prop gets fouled or hit or something?

chiefmg

Like any engine installation, there are different ways to achieve the same basic end. What you are referring to is a diesel-electric installation. It is good because you have infinitely variable speed over the range of the motor, and you can run the diesel loaded up for better efficiency. This application is used a lot for cruise ships because it also produces less vibration (you can shock mount the crap out of the engines without worrying about alignment). You can also get away without separate engines for the ship's generators.

No one cares about vibration on a commercial merchant ship (within reason), hey, us seamen are second class citizens! It is more efficient to direct connect a slow speed engine to the propeller. Medium speed engines will use a reduction gear to give the most efficient speed for the propeller design used. Going astern (in reverse) can be accomplished through the use of either a controllable-reversible pitch propeller, or having the engines reverse directly (done by having the camshafts shift position). High speed engines are not used on large ships, the disadvantages outweigh any advantages.

As for hitting anything, if the mates know what they are doing you should never go near anything. However, even with electronic navigation (GPS, electronic charts etc) humans make mistakes (especially mates!). And sometimes there are hazards that you can't see below the water (like subs). Bottom line, no matter what is turning the prop, if you hit something with it you are going to have a big repair bill.

pass the peas

How much diesel does it use? I'm assuming they would measure consumption in gallons (hundreds of gallons?) per hour.

chiefmg

Fuel consumption is measured using either barrels (US flag ships) or metric tons (pretty much the rest of the world). One barrel equals 42 gallons. I don't have the conversion for metric tons handy right now. Again, it all depends upon the installation and use. Ship I am on now with two medium speed engines uses about 350 barrels per day. However our hull has a lot of growth which increases drag, lowering efficiency and increasing fuel consumption (like driving around with stuff on your car roof). Each ship has its own most economical speed and commercial companies will try to run it there to minimize fuel costs.