Here are ten safety devices that may be fitted to a propulsion engine and gearbox arrangement, along with their reasons for being installed:
- Engine Crankcase Pressure Relief Valve: Protects the engine crankcase from excessive pressure buildup caused by blow-by gases, preventing crankcase explosions.
- Engine Speed Governor: Limits the engine’s maximum RPM (revolutions per minute) to prevent over-speeding and potential component damage.
- Engine Overheating Shutdown Switch: Automatically shuts down the engine if coolant temperature exceeds a safe limit, preventing engine seizure.
- Low Engine Oil Pressure Warning Light/Alarm: Alerts the operator to a drop in engine oil pressure, indicating potential lubrication problems and prompting immediate action.
- Gearbox Oil Low Level Sensor: Warns the operator of insufficient oil level in the gearbox, preventing damage due to lubrication starvation.
- Gearbox Overheating Shutdown Switch: Similar to the engine, this switch automatically shuts down the system if gearbox oil temperature becomes excessively high.
- Shaft Vibration Sensor: Detects excessive vibration on the propulsion shaft, potentially caused by imbalance or misalignment, allowing for corrective action before major damage occurs.
- Seawater Low Flow Alarm: In marine engines, this alarm warns of reduced seawater flow for cooling purposes, prompting action to prevent overheating.
- Fuel Shutoff Valve: Allows for manual or emergency shutoff of fuel supply to the engine, stopping operation in case of emergencies or fire.
- Shear Pin/Coupling: A sacrificial component designed to break in case of excessive torque overload, protecting the gearbox or other connected components from severe damage.