201124 Main engine failure

One of our vessels was manoeuvring with pilot on board during a routine berthing operation. Without warning, the main engine suddenly failed and could not be re-started from the control room or from the emergency stand. The problem could not be identified or rectified immediately, hence the berthing operation was aborted and vessel re-anchored safely.

On further investigation, it was found that the pneumatic direction control slide valve of the manoeuvring system was sticking due to excess moisture in the system. It was further noticed that the pneumatic control air bottle contained a lot of water.

Root cause
- Lack of compliance: Engine room crew neglected to follow routine procedures for regularly draining water from the main air bottle.

Lessons learnt
Clean and dry air is vital for the smooth functioning of any pneumatic control system;
Regular draining of control air bottle as well as main air bottle is to be included in the regular watch routine;
Control air drier or dehumidifier if fitted in the system must also be checked and maintained at all times;
Improper maintenance of pneumatic controllers can lead to their sudden failure and can seriously affect ship's safety and commercial operations;
Such incidents will cause the vessel to undergo increased scrutiny by flag and port state authorities, charterers and other inspectors.