Main Engine Reversal

A place to exchanges questions and ideas of a technical / procedural nature. Go ahead, try to stomp us !
Post Reply
Marine
Bilge Dweller
Posts: 6
Joined: Tue Nov 06, 2007 2:08 am

Main Engine Reversal

Post by Marine »

Hi,

Could anyone comment on the problems associated with reversal of Main engine (low speed diesels)? How likely is it that then engine would not follow astern and would rather shut down. Obviously speed is important too.

Are newer engines more safer against reversal problems ?

Thanks!
User avatar
ArkSeaJumper
Engineering Mentor
Posts: 124
Joined: Fri Sep 07, 2007 8:02 am
Currently located: Ireland

Post by ArkSeaJumper »

Hi
When you reverse a slow speed engine, first the engine has to stop, and that should include all rotation transmited back from the prop still running through the water.
If you are trying to do this in automatic the system will most likely not allow a start until the engine is completly stopped.
If you are 'On the sticks' in manual you may be able to break or stop the engine on air.

On older engine the whole camshaft had to shift forward or aft, to change the timing of the fuel pumps and the exhaust valve. (and of course the air start distributer)
Then it was just the air and fuel cam.

Now with common rail, its probably just the air start distributer, (I havent had the pleasure yet)

Hope that helps
Post Reply