This is the Royal Navy Type 23 Class Frigate. SSS Clutches disconnect the gearbox and GT from the propeller shaft which has an integral electric motor (EM).
There is a fixed pitch propeller with reversing on the electric motor. The shaft bearings and SSS Clutch are dip lubricated and the lube oil system is shutdown during EM drive. There is low/no maintenance and the SSS internal thrust bearing positions the gearwheel from main thrust. Since 1989, 16 ships of this type have been built employing 32 SSS Clutches with no maintenance having ever been required.