HMS Affray (P421)
HMS "Affray", a British "Amphion"-class submarine, was the last Royal Navy submarine to be lost at sea, on 16 April 1951, with the loss of 75 lives. "Affray" was built in the closing stages of the Second World War. She was one of 16 submarines of her class which were originally designed for use in the Pacific Ocean against Japan. History. Early history. She was laid down at the Cammell Laird yard in Birkenhead on 16 January 1944, launched on 12 April and commissioned on 25 November 1945. "Affray" and her sisters were state-of-the-art  submarines at the time of their launching. They were the culmination of a rapid submarine development driven by the Second World War. Some elements of her design were taken from captured Nazi German U-boats. Her modular style of manufacture and all-welded hull were unique at the time. For work in the Far East she was equipped with refrigeration and two huge air conditioners, and all her accommodation was placed as far away from the engine room as possible. She also had ten torpedo tubes which made her and her class some of the most formidable submarines in the  world at that time. She was sent to the submarine tender HMS "Montclare" at Rothesay, as part of the 3rd Submarine Flotilla, before joining her sisters HMS "Amphion", "Astute", "Auriga", "Aurochs" and the submarine tender HMS "Adamant" in the British Pacific Fleet. The following four years "Affray" was on travel and took part in exercises all over the globe, visiting such places as Australia, Singapore, Japan, Morocco, South Africa, Pearl Harbor and Bergen. Modification. On 11 March 1949 she was transferred to the 5th Submarine Flotilla reserve and entered drydock to be retrofitted with a snort mast (snorkel device)—a pneumatically  raised and lowered steel tube which, when in the vertical position, worked as an air induction/exhaust emission device. Once vertical it was self-locking and drew air into the submarine at periscope depth, permitting the submarine to charge batteries and run diesels for propulsion below the surface, allowing the sub to remain underwater. At the point where the air intake entered the pressure hull of the submarine, there was a bulbous casting—set about half a metre above the hull, this housed the main induction valve. This very important casing was totally concealed and protected by the free-flooding  hull. The snort mast on the "Affray" was designed for both air intake and exhaust venting; this was later changed so the snort mast was an air intake only and the exhaust was moved to the rear of the conning tower. The snort mast had a float valve that would close automatically if the submarine dropped below periscope depth. In December of that same year "Affray" was sent to the Mediterranean; it was recorded during deep dives in this sea that she began "leaking like a sieve" and that the "Admiralty"-class diesels started leaking oil. In January 1951 "Affray" was  transferred to Portsmouth Naval base to join Reserve group "G". In March she was brought out of reserve, and Lieutenant John Blackburn DSC was appointed CO and given the task of bringing her and the new crew up to operational status. Loss. On 16 April 1951, "Affray" set out on a simulated war mission called Exercise "Spring Train" with a reduced crew of 50 from 61. They were joined by one sergeant, one corporal, and two marines from the Special Boat Service; a commander (Engineer), a naval instructor, seven lieutenants in the engineering branch, and 13 sub-lieutenants. The last  two groups were undergoing essential submarine officer training. This made her complement 75 in total. Her captain's orders were unusually flexible: the Marines were to be dropped off somewhere along the south west coast of England—the captain told the Admiralty he had chosen an isolated beach in Cornwall—come ashore and return under the cover of darkness. The exercise was expected to continue until "Affray" was due to return to base on 23 April for essential defect repairs including a leak in a battery tank. "Affray" left her home base at about 1600 hrs, and made normal contact  to confirm position, course, speed etc at 2100 hrs, and indicated she was preparing to dive. The last ship to see her on the surface was the 'Co' Class destroyer HMS "Contest" returning to Portsmouth that evening. As they passed each other, both vessels piped the side. When she missed her 0800 report due the next day she was declared missing and an immediate search began. The search. Shore stations called "Affray" all day and HMS "Agincourt" led a fleet of search vessels which eventually totalled 24 ships from four nations. The Portland 2nd Training Flotilla which included HMS "Tintagel  Castle", "Flint Castle", , and ASDIC (sonar) trials vessel "Helmsdale," left Portland. Also out of Portland, they were joined by the submarines HMS "Scorcher", "Scythian", and "Sirdar" all flying large white flags to distinguish them from the missing "Affray". "Sirdar" later sat on the bottom for six hours while the ASDIC boats familiarised themselves with the identification of a submarine sitting on the bottom. The codeword 'SUBMISS' was sent to all ships in the NATO navies to notify them of the fact the "Affray" was missing and all other "Amphion"-class boats were confined to port pending investigation as to what happened  to their missing sister. At the time "Affray" went missing it was such big news in Britain it relegated the first events that culminated in the Suez Crisis to page two of the national newspapers. There was some urgency in the initial 48 hours of the search as it was estimated the crew would not survive much longer than this if they had survived whatever had sunk the submarine in the first place. During the search a Morse code signal (via tapping on the submarine hull) had been received by two of the searching ships, reading "We are trapped on  the bottom", but this did not help in locating the sub. Differing accounts however state that a tapping, initially believed to be from the trapped crew, was heard, but after later investigation was ruled by the admiralty to be from other ships involved in the search. After three days the search was slowed down and fewer ships were used to locate "Affray". In Britain, the missing submarine was getting a lot of publicity. Rumours abounded of mutiny, and even seizure by the Russians. Meanwhile the Royal Navy continued its search. During the search many strange things happened. Another strange event  was that the wife of a skipper of one of "Affray"'s sister submarines claimed to have seen a ghost in a dripping wet submarine officer's uniform telling her the location of the sunken sub (this position later turned out to be correct)— she recognised him as an officer who had died during the Second World War, not a crew member of "Affray". As there were so many shipwrecks littering the English Channel (161 were found, most of them sunk during the Second World War), it was almost two months before "Affray" was located. Discovery. On 14 June the  primary search vessel HMS "Loch Insh" made a sonar contact on the very edge of Hurds Deep, a deep underwater valley in the English Channel. It was the same location where an oil slick had been sighted at the same time "Affray" vanished and was in an area that had been searched before. HMS "Reclaim" arrived several hours later after an excited call from the Captain of "Loch Insh" who, as an ex-submariner, was convinced this was "Affray". A dive was made down to the contact and the diver reported seeing a long white handrail before being dragged along  with the flow of the current. Due to the weather being worse than usual the crew decided to use the underwater camera that they had previously been sceptical of. As soon as it was sent down the very first thing the camera picked up were the letters "YARFFA"—"Affray" backwards. At last she had been found. She was northwest of Alderney, a lot closer to France than England. She lay slightly to port facing northeast in 86 metres of water, and during the next few months she slid a little more to port where she appears to have rested on a  roughly 50 degree angle. Divers could find no evidence of collision or damage to the hull, casing or bridge and it was noted that the search periscope and ANF radar mast were extended, indicating she had been at periscope depth when she foundered. However, the snort mast had been broken and lay next to the sub, attached by only a thin shred of metal. The hatches and torpedo doors were all shut, and the two emergency buoys were still located within the casing, although the after one could not have been released as the hinged wooden gratings retaining it had  been wired shut (it was later discovered that it had been wired shut because it often broke free whilst the sub was underway). It was obvious that no attempt to escape had been made. The only external clue that the crew had done anything to rectify their dilemma was the bow hydroplanes being set to hard arise; the bridge telegraphs also were in the stop position. The snort mast was the only part of the submarine that was recovered, and it was later found to be of faulty manufacture. This may have contributed to the sinking of "Affray" (see below ). Cause of loss. There have been many reasons put forward as to what caused the submarine to sink. The snort mast was broken and lay next to the hull so initially it was thought that this had broken and flooded the submarine. After a detailed inspection of the snort mast itself, which showed no sign of being struck, it was thought that it was more likely that it had been broken when the sub hit the bottom (the snort mast was later tested and although it was found to be of faulty manufacture, tests indicated it should still have stood  up to normal use). A battery explosion has also been suggested as a possibility. The Royal Navy had tried to scan the interior when "Affray" was first discovered using a primitive radioactive device. This yielded minimal information about the internal condition of the submarine, but it did seem to show that the internal valve for the snort mast was in the open position, which would indicate that at least one compartment flooded and some of the crew had drowned when she first hit the bottom (see USS "Squalus" for a similar situation). During this attempt one of the (pea-sized ) X-ray pods was accidentally lost near the sub and the Admiralty decided against further attempts to establish why "Affray" sank, mostly due to the various dangers to any divers (one Royal Navy diver lost his life attempting to identify another sunken submarine during the search). A more recent theory put forward by a few experts is that the snort mast dropped below the surface and the float valve (described above) jammed or somehow failed to stop the water entering the sub. With up to 13 tons of water per minute entering the submarine this could have caused her to  drop rapidly to the bottom. With a reduced crew and the trainees in the way hampering activities, there would have been a delay in stopping the inflow of water. By the time the valve was shut or the flooding compartment that contained the valve sealed off, there would have been so much water aboard that even blowing all her ballast would not have been sufficient to get her to the surface. Or if the flooded compartment/s included the control room, there would have been no one alive to blow ballast. It is also possible, with trainees on board possibly  operating systems, that a problem with the clutch caused the "Affray" to accelerate into the sea bottom disabling some parts of the submarine that would have helped her rise to the surface. Re-visited. Almost half a century after the loss, Innes McCartney, an experienced trimix diver with a passion for sunken submarines, obtained the position of "Affray" from the Ministry of Defence and dived to the sunken submarine. He reported: As we descended down the shotline, a large dark shape emerged from the gloom. Little ambient light penetrates to 83 metres even on a good day on the edge  of Hurd Deep and it was a while before we recognised the unmistakable shape of a submarine. She is a hugely impressive sight, sitting almost totally clear of a hard seabed, offering in excess of 10 metres of relief in places. Our lighting showed that she is now covered with sponges and anemones, offering some welcome colour in the darkness. The first thing that struck me about the wreck was her sheer size. She is one of the largest submarine wrecks in the Channel and a diver is hard pushed to swim all the way around her on a single  dive. She lies slightly over on her port side, with her bows pointing Northeast. She is not very heavily netted with only a few craypots caught up around the hull. The wreck is in a very good state of preservation considering the 47 years she has been on the seabed. Her bridge is completely intact with speaking tubes, the projector binnacle and radio aerials all in evidence. On the side of the conning tower her navigation lights are present and the conning tower ladder is still in place. Her periscope shafts stand proudly upright and even the cables that ran  between them are still there. Forward of the tower the foredeck is intact with the gun layers hatch clearly visible. I was keen to find the cradle in which the snort mast was located when in use. This was on the port side, aft of the tower and on our second dive on the wreck I found it. The base of the snort mast was still in place, with the area where the mast broke off clearly visible. On a later visit to the Royal Navy Submarine Museum, I saw the base of the section of the mast that was  raised. They would still fit together perfectly. The fore and aft hydroplanes are still in position and the external torpedo tubes on the bow are a very impressive sight. Aft of the conning tower, there is evidence of the salvage attempts made by the Royal Navy in 1951. The diving team discovered no other damage to the wreck apart from the missing snort mast. This is in accordance with the findings of the Royal Navy's investigation. She remains a significant and salutary reminder of our naval heritage. Very few divers in the UK have the experience and capability to  undertake such a dive. This should ensure that the "Affray" remains undisturbed for posterity. She is a war grave and the final resting place of 75 naval personnel and this should be respected. The crew remain entombed in the submarine on the northern edge of Hurd's Deep. As of 2001, under the Protection of Military Remains Act 1986, "Affray" was made a controlled site, making it illegal to dive her without a permit from the Ministry of Defence. Officers and men lost in HMS "Affray". Abbreviations used Publications. Gallop, Alan: 'Subsmash - the Mysterious Disappearance of HMS Affray' published by  The History Press, 2007