The Sinking of the Truculent
On the 12th January 1950, HM Submarine Truculent spent the day at sea off the Thames Estuary carrying out trials, following a long refit in Chatham Dockyard. Apart from the full crew, there were 18 civilian dockyard officials on board to make any last minute adjustments, as she was due to sail for Scotland the next day. As she made her way up to the Medway Approaches, the Officer of the Watch conned the submarine on the surface. Traffic in the river was heavy and the steaming lights of many ships on their way into and out of the Port of London were clearly visible on all sides.
Further up the River Thames was the Swedish Tanker Divina on passage from Purfleet and bound for Ipswich and then to Sweden. She was carrying paraffin and, strictly in accordance with the Port Authority Regulations, she carried an all round red light at her masthead to indicate that she was carrying a dangerous cargo. Shortly after Truculent's escorting destroyer had left her and proceeded to Chatham, one of the lookouts reported a strange group of lights ahead on the port bow. The Officer of the Watch was unable to distinguish what they were and reported to the Captain. The Captain, having come up to the conning tower, shared in the puzzlement of these lights and concluded, not unreasonably, that they denoted a stationary ship on the northern edge of the channel. The presence of shoaling waters meant that the mysterious vessel however, was closer than the lights suggested and Truculent's bow had only just started to swing onto its new course when the Divina loomed out of the darkness. The two vessels were on a collision course. The Captain reacted immediately and ordered "Hard to Port... Full Astern". Water-tight doors were secured.
Divina's Captain also responded to the danger, but even as he took action the vessels collided. He thought he had run down a Thames lighter which had disobeyed the rule of the road and had crossed his bows and, having gone full astern, ordered one of his ship's boats away. The submarine began to rapidly sink by the bows and within minutes, the Bridge Party found themselves in the water, being swept away by the tide.
Forty-five minutes later, the Dutch vessel, Almdijk heard shouts of help coming from the water and, although unaware of the collision, quickly pinpointed the group of men in the water. Five survivors, including the Captain and Officer of the Watch were picked up and taken below. The Dutch crew generally assumed that the five were from either a barge or lighter a further 30 minutes were to elapse before the frozen and exhausted survivors were coherent enough to explain what had happened. At 2014hrs, Almdijk's SOS radio signal alerted the Authorities to the tragedy.
The men in the submarine responded when ordered to their collision stations. In the Control Room, the First Lieutenant ensured that all watertight doors were closed, ventilators and valves were shut, and closed off the lower Conning Tower hatch and voice pipes. Compressed air was still roaring into the ballast tanks as the lights went out and the crew was all ordered aft.
The First Lieutenant, realising that carbon dioxide was rapidly building up, decided on an immediate escape. He reasoned that, although there had not been enough time for the issue of a Subsunk alert, the presence of heavy river traffic would ensure that there would be plenty of rescue ships on hand when they reached the surface. The engine room and after ends twill trunks were rigged and the indicator buoy was released.
It was quickly discovered that there were not enough DSEA sets to go round, although Truculent was carrying her normal full complement plus one-third reserve. The crew decided that non-swimmers should have priority. The flood valves were opened and the compartments began to fill. Finally the water reached the twill trunks and the escape hatches were opened. The crew lined up and ducked under the twill trunks to ascend to the surface.
In all, a total of sixty-seven men made their escape from the sunken submarine, and tins figure excludes the bridge party which had been swept into the sea tat the time of the collision. This exodus was a resounding triumph for both, the Davis Escape System and the Submarine Training Program. Yet only ten men survived to be picked up alive. The rest were swept away by the tide and died of either drowning or exposure. What had been a triumph had become a tragedy.
With hindsight, it became apparent that the crew had made their escape too quickly, but precedent pointed to the necessity of an early evacuation if success was to be achieved and, with half the submarine flooded and an extra eighteen passengers on board, there was concern regarding rising level of carbon dioxide in the boat Further, propeller noises could be heard on the surface and the submarine had sunk in an area normally crowded with traffic, plus the fact that there had been a collision and the alarm would be raised quickly. With all these factors in mind, it was difficult to fault the decision not to waste time.
The most damning aspect of the tragedy was the loss of so many through drowning and exposure. An official recommendation had been made in 1946 to adopt an insulated immersion suit and, by the end of the same year, the first prototype had been successfully tested- yet three years later, these suits were only in limited production and none were carried by Truculent.
There is little doubt that the survivors would have remained afloat long enough to have been picked up had they been wearing immersion suits, and the automatic flashing light fitted to the suit would have enabled them to have been spotted as they were swept away by the tide. Putting the question of immersion suits to one side, it is said that the tragedy of the Truculent was the result of bad luck. All those concerned had acted with absolute correctness and there had been no failure of equipment. Yet, sixty-four men had died.