Question 20 AEL01 - Assistant Engineer - Limited

The Correct Answer is D. **Why option D ("the system can be manually recharged") is correct:** In a survival craft (lifeboat) setting, reliability and redundancy are paramount. While a hydraulic starting system typically uses a high-pressure accumulator charged by an engine-driven pump, the key advantage in an emergency setup is the backup capability. If the primary charging mechanism (the pump or the ship's power supply) fails, the hydraulic accumulator can often be manually recharged using a hand pump integrated into the system. This manual recharge capability ensures that the lifeboat engine can be started even if primary power or automatic systems are completely compromised, offering crucial redundancy that is vital for saving lives. **Why the other options are incorrect:** * **A) hydraulic starters are the least expensive of all starting systems:** This is generally false. While cost varies, simple electrical starter systems are often the least expensive. Hydraulic systems involve specialized pumps, high-pressure accumulators, and valves, often making them more expensive than comparable electric or simple air systems. * **B) the system does not require high-pressure piping:** This is incorrect. Hydraulic starting systems operate at extremely high pressures (often 2,000 to 3,000 psi or higher) to store sufficient energy in the accumulator. They absolutely require high-pressure rated piping, hoses, and fittings. * **C) hydraulic systems turn diesel engines at higher rates of speed than air starters:** This is not reliably true and is not the primary factor for selection in lifeboat applications. Both well-designed air and hydraulic systems can achieve the required starting speed (cranking RPM). The choice is driven more by reliability, maintenance, and the ability to restart without external power (i.e., manual recharge capability).