🔍 Key Concepts

• Characteristics of a worm gear (direction of power flow, speed ratio, reversibility) • Which shipboard systems need high torque at very low speed • Which gears must NOT be back-driven by the shaft or engine

💭 Think About

• Think about which of these applications most often needs to turn a large shaft very slowly and with high mechanical advantage. • Ask yourself which system must be able to move the shaft but must NOT allow the shaft to drive the gear train in reverse. • Consider where compact gear arrangements that provide large speed reduction in a single stage are especially useful on board.

✅ Before You Answer

• Identify which listed system routinely operates at very low RPM but high torque. • Decide which system must be non-reversible for safety (cannot be driven backwards by the shaft). • Check which application usually uses simple, strong gearing rather than very efficient, high-speed reduction gearing.