The air chamber burst, causing serious damage to the superstructure and the forward boiler room. The warhead then exploded, starting a fire which quickly engulfed the forward part of the destroyer. The Maillé Brézé began to list to starboard, and despite assistance from nearby British vessels, the fire spread out of control. Due to the risk of magazine explosion, the ship was abandoned at 1515. At around 1900 the fire was finally extinguished by firemen from Greenock, but an hour later the Maillé Brézé foundered in 12m (40ft) of water, leaving just the top of her bridge, the mast and three of the four funnels above the surface. The disaster had cost the lives of twenty-seven men, many trapped in the burning forecastle by a buckled hatch, and a further forty-seven were injured. Maillé Brézé was not raised until August 1954, when she was scrapped at Greenock.
A similar accident had occurred just five weeks earlier in the port of Casablanca, when the 1500-tonne destroyer La Railleuse was also lost. The commission of enquiry into the two accidents reported that:
— the extremely complex firing arrangements had made it impossible to determine the exact causes of the accidents;
— there were, in fact, two separate firing systems activated from the bridge, the main one relying on compressed air, fitted with a safety interlock, and the backup system, using a powder charge, with no safety;
— it appeared the air chambers had never been tested to full designed pressure, and in fact in the case of accidental over-pressure they represented a severe risk;
— the torpedo warheads were not fitted with a safety delay on firing — they went live the moment they left the tube.
On 23 June 1940, near Perim in the southern entrance to the Red Sea, the Royal Navy destroyer HMS Khartoum suffered an explosion in her aft quintuple torpedo mount. This caused a serious fire, which led to the explosion of the aft magazine and sank the ship in shallow water in Perim Harbour, where her wreck still lies today.
Crew members who testified at the subsequent enquiry stated that the air flask of the Mark IX** torpedo loaded in the starboard wing tube of the aft-facing rear mount had exploded. The tube was burst open, the engine of the torpedo was blown bodily overboard, and the aft part with the propellers was lodged in the rear of the tube with several propeller blades puncturing the tube rear door.
The torpedo warhead flew aft, through the galley where friction set fire to the paint. It then smashed the support for ‘X’ gun mounting on the deckhouse overhead, severing hydraulic oil pipes to the mounting, which added to the flames. The warhead did not explode, but ended up lodged against the minesweeping gear on the quarterdeck, where it burst open. The fire in the aft deckhouse could not be mastered as the water mains were severed. The aft magazine flooding panel was also smashed, and the magazine could not therefore be flooded. The ready-use 4.7in rounds on ‘X’ mounting began to burst, the explosive content of the torpedo warhead began to burn, and the fire threatened not only the aft magazine but also the depth charges.
The crew performed admirably, fighting the fire with the limited means available, small hand extinguishers. One man climbed onto the mounting to ditch overboard as many cordite charges as he could reach, while another jettisoned those depth charges not already surrounded by the flames. Meanwhile Khartoum’s captain, Commander Donald Thorn Dowler, RN, ordered the forward torpedoes to be jettisoned to lighten ship, as he knew that if the aft magazine exploded there was a serious risk she would capsize in deep water. In order to save his crew and to facilitate possible salvage he headed for the harbour at Perim at all available speed.
Unfortunately, an order to evacuate all extra hands from the engine room was misinterpreted as ‘all hands’, and steam power was lost. A crew member returned to the engine room just in time to restore enough steam to carry the ship into Perim, where Commander Dowler dropped anchor and gave the order to abandon ship. Shortly after, a large explosion took place aft, then a second more violent explosion. The ship settled by the stern and heeled to port. One boy seaman was killed by a piece of wreckage as he was swimming ashore, and several other men were injured or burned. The destroyer was a total loss.
The subsequent inquiry into the sinking addressed several points:
1. It was considered possible that a shell or shell fragment fired by the Italian submarine Torricelli, which HMS Khartoum had engaged in company with sister ships Kingston and Kandahar, plus the sloop HMS Shoreham, earlier that day could have struck the torpedo tube mounting, damaging the air vessel which subsequently failed.
This hypothesis was discarded, as Commander Dowler stated that at no time had any shell fired from Torricelli fallen nearer than 6 cables length (more than 1200yds or 1100m) from Khartoum. Also, the Torricelli had been sunk at 0524 local time; the air flask had exploded at 1150, or more than five and a half hours later.
2. Sixteen Italian survivors from Torricelli had been taken briefly on board Khartoum, and it was considered whether one of them had carried out an act of sabotage on the torpedo mount. All crew members questioned stated categorically that, although the Italians had passed the starboard wing torpedo tube which exploded, they had at all times been under guard. Again, the lapse of time made this hypothesis extremely unlikely.
3. The question of sabotage by local workmen was discussed, and quickly ruled out.
4. That left the final question: was the explosion caused by a defect in the air flask, or was it caused by the pitting that had been noted by the torpedo crew and previously reported to the dockyard? Mark IX** torpedoes on Kingston and Kandahar were examined and traces of deep external pitting were discovered on all. This was held to be the cause of the explosion and fire, which inevitably led to the loss of the ship.
HMS CLYDE, ANOTHER BLUE-ON-BLUE
The fleet submarine HMS Clyde was busy in the summer of 1940. On 21 July she sighted the battlecruiser Gneisenau and the heavy cruiser Admiral Hipper en route to attack the Atlantic shipping lanes. Clyde cut short their expedition by putting a torpedo into the bows of Gneisenau, which had to return to Trondheim for repairs.
A day later, to the west of Bergen, at 2355 Commander D C Ingram in Clyde fired six torpedoes at what he took to be a German U-boat. Luckily all torpedoes missed, as the target was the ‘T’-class boat HMS Truant, which had been supposed to have vacated this area earlier that day but was delayed. Clyde’s CO was therefore justified in carrying out an attack in an area where enemy submarines were expected.