SPARKS from cargo transfer pumps have been identified as a potential cause of the explosion on board two liquefied petroleum gas carriers that killed at least 14 crew in the Kerch Strait.

According to initial verbal statements from surviving crew members, a failed earthing system together with some electrical sparks from cargo transfer pumps could have caused the explosion that led to a fire on board both the Tanzanian-flagged vessels Maestro and Candy on January 21.

The two vessels were said to have been engaged in a ship-to-ship transfer of cargo at the time of the explosion.

While the crew statements will prove to be an obvious line of inquiry by any subsequent casualty investigation, the possibility of sparks from a motor has raised questions from technical experts who spoke to Lloyd’s List.

According to Andrew Clifton, the general manager of the Society of International Gas Tanker and Terminal Operators, any cargo pump on an LPG vessel would have been designed not to produce a source of ignition, such as sparking.

The vessels would not necessarily have had to use pumps to make the transfer, but if they did Mr Clifton suggests any ‘deepwell pumps’ would have been fitted with what are known as IS, or Intrinsically Safe, motors specifically designed to be used in a hazardous gas zone.

A total of 31 crew were on board the vessels and only 12 have been confirmed as rescued, according to Lloyd’s List Intelligence Casualty Reporting Service.

The fire, which quickly spread across both vessels, is still burning and being fuelled by the LPG cargoes.

While fire-fighting tugs were initially able to get the blaze under control, concerns about the amount of water being pumped into the burning vessels led to stability concerns and a break in the fire-fighting operations on Tuesday evening.

The search for missing crew members is understood to have been suspended by the local Maritime and Coast Guard Authority, according to Lloyd’s List. Intelligence.