Engine Room Fire Safety – Treat QCV with Respect

By George Backwell at November 05, 2011 23:50
Filed Under: General

Most fires on board ships start in the engine room. One of the built-in safety features increasingly found compromised by U.S. Coastguard Port State Control Officers are malfunctioning fuel Quick-Closing Valves (QCVs). Some  QCV’s are espied deliberately blocked by a variety of means according to Marine Safety Alert 01-11 putting the vessel and its crew at greater risk in a fire emergency.

QRV Wedged Open: Photo credit US Coastguard

Perhaps an overzealous application of the recommendation by the USCG that routine checks of QCV systems be carried out led to the following incident reported in the October 2011 edition of MARS (the Nautical Institute’s voluntary and confidential ‘Mariners’ Alerting and Reporting Scheme’) which again focussed attention on the operation of QCV’s.
 
Blackout, Propulsion & Steering Shutdown Follows QCV Test at Sea


A loaded small-sized gas tanker nearing the end of a coastal voyage had on board a company superintendent who with the ship’s chief engineer decided to test (with unforeseen consequences) the operation of the fuel oil (FO) and diesel oil (DO) service tank QCV’s. First the FO valve was tripped from the remote emergency control station while they waited nearby to reset it. Confirming the QCV had responded properly they quickly reopened it manually, reset it and then went up for lunch.

An hour or so later the tanker was navigating the traffic separation lane in the outer approach to the destination port when the No. 1 diesel generator suddenly stopped, the electric lights went off and propulsion and steering were lost. The captain had the ‘NUC’ signal hoisted and a safety message was broadcast, meanwhile No. 2 generator was started manually and  put on load, but after about fifteen minutes it also shut down.

Checking what had gone wrong, with a sense of urgency one imagines, the chief engineer found that the QCV of the DO tank was in the closed position. After opening the valve it took another 20 minutes to restart the generator and then the main engine, as the common outlet diesel line had to be purged of air. The tanker then made her way to anchor safely in the port anchorage to wait for an escort tug.

Subsequent investigation of the cause of the mayhem described here indicated that, unnoticed by the testing team, the DO QCV had been inadvertently activated at some point.  Unsurprisingly, amongst other recommendations by MARS, the testing of QCV’s when a vessel is underway was given the thumbs down.

QCV – State of the Art: Image credit LK Valves

 

 

 

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