Explosion of the minelayer Princess Irene

At a quarter past eleven in the morning on 27 May 1915, in the estuary of the Medway, a few kilometres west of Sheerness, the British auxiliary minelayer Princess Irene blew up. The ship, on whose deck several hundred mines were being prepared for action, was literally blown to pieces. About 350 people died: almost the entire crew and several dozen civilian workers from the naval dockyard. This was only half a year after the battleship Bulwark had exploded on the same river.

A passenger ship at war

Princess Irene was not designed as a warship. She was built by the Scottish yard of Denny at Dumbarton for the Canadian Pacific Railway, which intended to use her together with her sister Princess Margaret on the passenger service between Vancouver, Victoria and Seattle, on the west coast of North America. She was a fast ship of more than 5,000 tons, launched in October 1914. She never sailed to Canada. The Admiralty requisitioned both ships and converted them into minelayers, each able to carry several hundred mines. Princess Irene had a crew of about 225 men and was commanded by Captain Mervyn Cobbe. According to some accounts she had already taken part in minelaying.

The explosion

In May the ship lay at a mooring buoy in Saltpan Reach, the stretch of the Medway opposite the Port Victoria pier on the Isle of Grain. She was being prepared for another sortie. Several hundred mines, between about 400 and 500 according to different sources, had been loaded aboard, and the crew were being helped by several dozen workers from Chatham Dockyard, who were priming the mines, and by employees of Sheerness Dockyard.

At 11.14 a.m. there was a tremendous explosion. Witnesses saw a column of flame some hundred metres high, and a few seconds later a second one, just as high. Debris from the ship fell over a radius of many kilometres, and a ten-ton piece of steel structure was found on the Isle of Grain. Fragments killed a nine-year-old girl there, and a farm labourer died of shock. The explosion was heard in distant towns of the county of Kent.

There were so many victims that their exact number varies from source to source. The figure most often given is 352 dead, including 273 officers and men and 76 or 78 dockyard workers, but according to some lists more than 380 people died. A few members of the crew who were ashore at the time of the explosion survived, as did a few workers who had left the ship just before. Only one man was taken alive from the ship itself, the badly burned stoker David Wills.

The cause

At first sabotage was suspected, but the investigation did not confirm these suspicions. The naval court of inquiry concluded that the most likely cause was a faulty primer in one of the mines, which were being primed in haste by men without proper training. It recommended that from then on mines should be primed only by qualified specialists.

The disaster coincided with a black run for the Royal Navy. That same morning off Gallipoli a German submarine sank the battleship Majestic. The victims of both disasters on the Medway, Bulwark and Princess Irene, are commemorated today by shared memorials, among others at Sheerness and Gillingham.