🔍 Key Concepts

• Review how a gas generator is defined in a marine gas turbine (which shaft/rotor it refers to). • Identify on the illustration where the N_g (gas generator) speed pickup is drawn and what component it is mounted on. • Recall how the accessory gearbox is typically driven and where speed sensors are most conveniently installed.

💭 Think About

• On this type of split‑shaft gas turbine, which rotating assembly actually represents the gas generator—compressor, high‑pressure turbine, or power turbine? • Looking closely at GT‑0017, which component shows a small probe or pickup symbol labeled for gas generator speed, and what is that probe physically attached to? • From a maintenance standpoint, which location would give easy access to the speed sensor while still measuring true gas‑generator RPM?

✅ Before You Answer

• Be sure you can clearly distinguish the gas generator section from the power turbine section on the drawing. • Confirm which housing in the illustration is identified as the accessory gearbox and what is mounted on it. • Verify that the chosen location would rotate at the same speed as the gas generator shaft, not the free power turbine.