A drill ship holding position offshore was due to carry out the annual servicing of its two auxiliary boilers. The boilers were used only for well test operations and had not been operated since the last annual service, except for maintenance operations.
The duty engineers brought the boilers up to temperature and pressure specifications in preparation for the annual checks. As this was underway, the pressure safety valves opened. They appeared to open at 1.9 bar for boiler 1 and 5.9 bar for...