MALFUNCTIONING OF SOLENOID VALVE IN PNEUMATIC CONTROL SYSTEM :
It was a oil tanker with B&W engine. V/L finished loading in a port in Brazil around 1850hrs V/L shifted to anchorage awaiting for port papers. Around 0200 hrs, E/R was told pilot boarding. ME plant was ready, so only second generator was started and put on load. Engine blown through with as from ECR and handed over to bridge to try out. Found ME engine was only turning on air but not picking up. Control changed over to engine control room and tried out, still no progress. Changed over to emergency control but still no progress. By this time pilot left informing the port authorities and agents.
After careful investigation found that cams for some 3 units were in ahead direction while others were in Astern. Further investigation revealed that ahead solenoid valve No.10 was not functioning properly while trying to reverse. The ship had a spare and the solenoid valve was changed and engine tried out many times from all controls satisfactory.
The agents were informed to call the PSC, PSC boarded and wanted six starts from engine control only. PSC authorities were satisfied ,clearance was given to sail. Pilot was on board in next half hour and ship proceeded.
When I joined the vessel made sure I had the spare which was blessing.