115 Main Reduction Gear (MRG) and Shafting Fundamentals

Converts the output of the GTMs (high speed/low torque) into low speed/high torque that is used to turn the shaft.

Power Turbine -> High speed flexible coupling shaft -> power turbine brake -> Triple S Clutch -> Firt Reduction Gear Pinion.

The SSS Clutch connects the GTM to the MRG power train. It is a fully automatic clutch which allows the GTM to connect to and drive the MRG

The Power Turbine Brake holds the GTM Power Turbine stationary and prevents it from spinning and transmitting torque to MRG. It is used to place a running GTM online or off-line.

• Main thrust bearings
• Starbord shaft main thrust bearing is located in AUX 2, and Port shaft main thrust bearing is located in Shaft alley. Keeps the propeller from pulling shaft aft.

1A is located in Main 2, 2A and 1B are located in Shaft Alley. Support the shaft.

Located outside the hull half way between the hull and the propeller, they support the shaft and propellers weight.

Built into the stern tubes. The water tight seal between the stern tubes and the shaft.

Shaft Alley port and starbord side aft, the point where the shaft penitrates the hull

mounted on the inboard side to the stern tubes. used when shaft seal fails

anywhere shaft penitrates a bulkhead.