201068 Fire due to improper oxy-acetylene rig

Fire due to improper oxy-acetylene rig
MARS Report 201068

On one of our vessels, a fire occurred in the masthouse where oxygen and acetylene cylinders were stored. Hot work was being carried out on the windlass drum, which required intensive heating. For this purpose, the engineers had arranged two gas torches in tandem, connecting them in parallel from the same pair of gas cylinders by temporarily fitting non-standard 'tee joints' at the regulator valves. At some time, during the hot work, it was decided to use one gas torch to carry out brazing repair work on the other torch while it was still connected to the pressurised gas hoses. Flashback from the torch being heated travelled through the hoses up to the masthouse, rupturing the hoses at the regulator valve connections and causing a fire inside. Fortunately, the backfire arrestors on the regulators prevented a major explosion of the cylinders.

Corrective/preventative actions
Ships' crews in the fleet instructed to:

Comply with manufacturers' specifications for flashback arrestors to be fitted on hoses at the torch and for backfire arrestors at the cylinder valve regulators;
Strictly avoid carrying out unauthorised modifications to hot work equipment;
Never attempt repairs on pressurised oxy-acetylene equipment. All maintenance to be done only after safely dismantling components and strictly as per makers' service manual.