Bob Swinney wrote:

Big ships don't stop or reverse the engine out at sea to manuever. It's

not

practical on a diesel or steam ship. Just use the rudder.


Large steam turbine-driven ships have an "astern" turbine just for that
purpose. The regular turbine can't be reversed and it is to costly to
design gearing for it.

I worked on engine room controls back in the 70's. I
recall that they had:

turbine---gearbox----propshaft

With no clutches other than to disengage the turning gear.
The turbine case had 2 sets of steam inlets, one connected
to the forward throttle and the other connected to the
reverse throttle.

The ships that I spent the most time on were from the
APL line.