What is a shaft generator ?
Shaft Generator is an alternator driven by main propulsion unit through clutch and gearing to produce electricity.
It can be used while vessel at sea running with a sea speed.
It must be able to supply normal sea load.
A shaft generator is coupled to the main engine. It uses the main engine as its prime mover and has a frequency converter (thyristor controlled) that converts the variable engine speed to near constant speed and produces electrical power. It can only be employed at sea speed (full speed) and not at manoeuvring speed.
Slightly reduce total fuel consumption.
Reduced running hours of auxiliary generator. Reduced noise in E/R.
Can made overhauling the aux: G/E at sea.
Can not be used at rough sea.
Increase load on main engine More complicated mechanism.