🔍 Key Concepts

• Cross-compounded turbines and how many turbine elements (HP/LP) they have • The layout of an articulated double-reduction gear (what meshes with what) • Difference between pinions and gears/wheels in reduction gearing

💭 Think About

• First picture how many turbine shafts are driving the gear train in a cross-compounded setup. How many separate turbine elements feed power into the reduction gears? • For each turbine shaft, think about how many stages of reduction are in a double-reduction system and where pinions are needed in each stage. • Ask yourself: does each turbine element need one pinion or more per reduction stage to drive the main gear wheel(s)?

✅ Before You Answer

• Be clear on the definition of cross-compounded vs single or tandem compounded turbines. • Confirm how many reduction stages are in a double-reduction gear and how many pinions per stage are typically shown in standard marine engineering diagrams. • Verify that you are counting only pinion gears (driving gears on turbine shafts), not the large main gear wheels on the propeller shaft.