The PNEUMASTAR clutch is a torsionally stiff, double-cone, friction clutch. The clutching components consist of two inner and two outer friction cones of which the inner ones are pneumatically pressed against the outer tapered friction faces via a clutching cylinder operated pneumatically. Rubber elements form the torsionally stiff portion of the clutch.

As a result of the high rsilience of the rubber sleeve springs the PNEUMASTAR clutch is capable of effectively compensating radial, axial and angular misalignments within predetermined limits. Moreover, as the clutching components are moved over the rubber sleeve springs during the actuation of the clutch, a wear-causing axial sliding movement between the various contacting parts is avoided.

Pneumatic operation of the clutch enables speedy and precise manoeuvring, which is a prerequisite to qualify the clutch for use in the marine application. For example, a twin-engine installation can be manoeuvred with a counter-rotating propeller, without the need to reverse the engines continually. This is achieved by having engines running in opposite rotation to each other and connected via the manoeuvring clutch onto a twin-input/single-output reduction gearbox. Selective engagement/disengagement of the clutches will provide the manoeuvring facility.