Nordhaven has also done something interesting with a "come home" engine
in the 62'. Next to the main engine
was a smaller (about 30 hp) diesel. I can't remember the exact clutch
arangement, but this setup would drive the main shaft in the event that the main engine crapped out. I can see this being cheaper than the electric alternative.
after another read, it's not clutched to the same shaft, rather is independent. see below.
"Get Home" power is a major concern for those venturing to far off places, and Nordhavn again gives this area special attention. Each 62 is equipped with a separate 4-cylinder wing engine that drives a feathering prop. The boat can be driven in open ocean conditions and is perfectly capable of being brought home if the main engine is disabled. The wing engine is installed with its own electrical system
and is used to power the hydraulic systems for the bow thruster, windlass
and emergency bilge pump