Staff, The Telegraph
21 July 2015
Two workers were accidentally entombed inside the ballast tank of a nuclear submarine, it has emerged.
A pair of workers were sealed inside the ballast tank of a nuclear submarine in Plymouth and had to bang on the hull with a drill to raise attention.
The electricians who had been inspecting sonar equipment finally managed to get a weak signal on a mobile phone and get help to set them free.
The incident at Devonport Naval Base in Plymouth which saw the men accidentally sealed in by colleagues has been described as "extremely unpleasant".
The two were working on a submarine when it was in dry dock last December when a seal was placed over the hatch they were using.
A report reads: "In an attempt to raise the alarm they used the only thing they had to hand - a battery powered drill to hammer against the tank boundary but to no avail.
"There was no-one in the dock bottom to hear them.
"They switched on their mobile phones but there was no signal at the bottom of the tank so they progressively climbed to the upper reaches of the tank until fortunately one phone managed to get a one bar signal."
The men were trapped for 20 minutes and were said to be "shaken but unhurt".
A spokesman for the union Unite said: "We feel for the men involved and what they had to go through because it must have been an extremely unpleasant situation.
"The incident was actually caused by poor management and poor communication.
"We are disappointed it was not in line with Babcock's normal standards."
Babcock said it was "continually focused on delivering and maintaining the highest standards of safety procedures and practices".
It said an internal investigation was carried out and "changes to work control arrangements have been made".