HMS Glatton was originally built as coastal defence ship for the Royal Norwegian Navy, as P/S Bjørgvin; P/S stands for Panserskip (“armoured ship”), while Bjørgvin was the old name for the Norwegian city of Bergen. She was purchased from Norway at the beginning of WWI, but was not completed until 1918 although she had been launched over three years earlier on 08 August 1914.
She was commissioned on 30 August 1918 but on 16 September 1918, before she had even gone into action, she suffered a large fire in one of her 6-inch magazines, and had to be torpedoed to prevent an explosion of her main magazines that would have devastated Dover.
After completion, Glatton sailed for Dover on 11 September 1918 to prepare for the offensive planned for later that month. At 18:15 on the evening of 16 September, Glatton’s midships 6-inch magazine had a low-order explosion that ignited the cordite stored there. Flames shot through the roof of ‘Q’ turret, starboard midside, and started to spread aft. The ship’s captain—Commander N. W. Diggle—ordered the forward magazines flooded, but the crew were unable to flood the rear magazines as the flames blocked access to the magazine flooding controls. The presence of the ammunition ship Gransha only 150 yards (140 m) away risked a massive explosion that would devastate Dover if Glatton’s rear magazine exploded and set off Gransha’s ammunition. Vice-Admiral Keyes—who had been walking with Commander Diggle when Glatton’s magazine exploded—boarded the recently arrived destroyer Cossack once apprised of the danger. He ordered Cossack to torpedo Glatton in an attempt to flood the magazine before it detonated. Cossack’s first 18-inch (460 mm) torpedo struck the anti-torpedo bulge amidships, but failed to explode because it had been fired too close to Glatton. Her second torpedo blew a hole in Glatton at 19:40, but the torpedo’s 200-pound (91 kg) warhead was too small to penetrate through her bulge and Glatton remained afloat, still burning. Keyes transferred to the destroyer Myngs and ordered her to fire on Glatton with her 21-inch (530 mm) torpedoes at 20:15. They were aimed at the hole blown in Glatton’s starboard side by Cossack’s second torpedo and succeeded in causing Glatton to capsize until her masts and superstructure rested on the harbour bottom and dousing the fire. Casualties were heavy: 60 men were killed outright and 124 were injured of whom 19 later died of their burns.
A Court of Enquiry held immediately afterwards found that the explosion had occurred in the midships 6-inch magazine situated between the boiler and engine rooms. The cause was more difficult to establish, but the Court did note that the stokers were in the habit of piling the red-hot clinker and ashes from the boilers against the bulkhead directly adjoining the magazine to cool down before they were sent up the ash ejector. The magazine was well insulated with 5 inches (13 cm) of cork, covered by wood planking .75 inches (1.9 cm) thick and provided with special cooling equipment so it was not likely that the cordite had spontaneously combusted. The magazine of Glatton’s sister ship Gorgon was emptied and examined. The red lead paint on the bulkhead was blistered beneath the lagging and tests at the National Physical Laboratory demonstrated that it had been subject to temperatures of at least 400 °F (204 °C). Recorded temperatures inside the magazine did not exceed 83 °F (28 °C) and a test of red-hot ashes was inconclusive as the temperature in the lagging only reached 70 °F (21 °C) with occasional hot spots of 150 °F (66 °C). Other tests did reveal that the cork could give off flammable fumes under high heat and pressurized air. While not entirely satisfied with this conclusion it found in April 1919 that “The slow combustion of the cork lagging of the 6-inch midship magazine of the Glatton led to the ignition of the magazine and then to the ignition of the cordite in it and so caused the explosion.”
As a precaution, Gorgon’s lagging was stripped out and replaced by silicate wool which revealed the real cause. Part of the cork was missing and folded newspapers were found in the empty space which were left there by the dockyard workers during construction. Furthermore, a number of rivets were entirely missing which meant that .50 inches (12.7 mm) holes were present which could have ignited the newspapers when exposed to the hot ashes. The forced-draught pressure in the boiler room would have supplied air through the rivet holes which would have caused the cork to given off the flammable gases and eventually ignited the cordite charges.
Glatton remained in Dover Harbour, an obstruction to shipping, with her hull visible at low tide as the Harbour Board could not afford the £45,000 quoted on average by salvage companies. Finally they asked the Harbourmaster, Captain John Iron, if he could do it for less. He estimated it would cost about £5,000 if he was granted use of the salvage craft already at Dover. The Board accepted his offer and work began in May 1925. Some 12,000 short tons (11,000 t) of silt were removed from underneath Glatton and her mainmast and superstructure were blasted away from the wreck. Four lifting lighters, with a capacity of 1,000 long tons (1,000 t), were hired, but they would not suffice to lift a water-logged 5,000 long tons (5,100 t) ship. It was necessary to seal all of the holes on her topside and pump air into each compartment at a rate of 70,000 cubic feet (2,000 m3) per minute to restore her buoyancy. The first attempt to lift her began on 02 December 1925 and was successful in breaking the suction holding her to the bottom in combination with the rising tide. That was enough for the first try and the major lifting effort began the following day. Slowly she was moved, taking advantage of the tides, until on 16 March 1926 she was moved to a deep gully next to the western pier of the submarine harbour, close by the shore.
There she remains, buried by landfill underneath the current car ferry terminal.
HMS Glatton