14 cyl 109,000 HP engine submerged

[CaptainRob]

Top posts Captain!!! Is it true the fuel these ships use is like a soup? And not sure if its true but a mate told me yes ago that the ship motors can be "two stroke" to save on weight?

Yep, you're right. These big ships run on heavy fuel which is un-refined and cheap. At normal temperature it's very thick and heavy, and it smells f***** aweful! The ships heat it up, to make it thinner, and then cleans it through centrifugal purifiers. The sludge is stored in tanks onboard. This is a daily process to keep up with the daily consumption. The big ships engines are reversing (they can run in either rotation) but they generally can only start and stop and start again on diesel fuel (we call it gas oil). So when the ship approaches port, the engineers start to merge the gas oil in with the heavy oil, until its eventually running on gas oil only. Then it can be stopped and restarted. There are big accumulators of compressed air to start the engine, but usually only enough for 5 or 6 starts. Then you have to wait a long time while the compressors recharge the accumulators. If you stop, then go astern, then stop, and go ahead - that's 2 starts - you've only got three left! That's why big ships don't like to stop, and sometimes can't stop. Coming into a port and maneuvering into a wharf needs a bit of thinking out! As a Pilot, (12 years i did it for) the first thing you ask the Captain is 'how many starts, and where's the main engine start air guage!' Sometimes going from ahead to astern the engine won't 'catch' - you've just wasted one start. No wonder Pilots burn out early and have an alcohol problem? Some of the big engines use individual piston braking with compressed air used to bring each piston to a stop, then the same air pressure starts the engine rotating in the opposite direction. At the same time the cam shafts are moved along by hydraulic rams to another set of lobes, the fuel is injected into each cylinder, and away she goes. Easy!