Escape Or Die!

Escape training with the Royal Navy. You could lose your job if you goofed the submarine escape exercise the men here are undergoing. But in the real world, hundreds of submariners have perished because they were unable to get out of iron coffins no deeper than the 30m escape hatch from which the man on the left is ascending.

Dan Burton entered the Navy's submarine-escape training tank at Portsmouth to experience the sensation of waiting in the dark for his turn at the hatch. As I peered into the illuminated depths I could see the escape hatch 30m below, marked with a black cross. I was standing on the tenth floor of HMS Dolphin at Portsmouth - the home of the Submarine Escape Training Tank - and it seemed a very long way down.

Underneath the hatch a SETT staff member was waiting in the tower to make a rush escape while support divers and a dive supervisor hovered in and around the tank. Two staff members with snorkelling gear waited inside a small diving bell at the bottom of the tank, then in unison they took a breath and swam to the hatch.

Seconds later the hatch blew open. A shaft of light lit up the column of air and out of a mass of bubbles came a submariner wearing a highly inflated escape suit. As he emerged he quickly clipped himself onto the wire traveller in the centre of the tank and within a second he was on his way up. Seven seconds later he broke the surface. A team of SETT staff pulled him onto the poolside where medical staff quickly unzipped the suit to check for any signs of decompression injury.

The tank is not a simulator but a real experience designed to introduce the effects of underwater pressure and its inherent dangers. Trainee submariners are put through an intensive two-day course of lectures and practical training, and it is vital to pass. Failure would mean a rapid transfer to a top-side vessel.

As a build-up to the rush escape candidates are taken through a number of shallow-water escapes, starting with trial runs near the surface wearing the more conventional lifejacket and swimming goggles.

The SETT is designed with escape chambers on three levels - 9m, 18m and 30m. I joined a group of candidates on the 9m level. We all entered the chamber and the hatch was secured. Following a signal from the instructor, the compartment started to flood and before the lights were shut off I could see anxiety in the eyes of the candidates.

For effect, the staff started screaming and shouting verbal abuse. I felt a rush of adrenalin as I scrambled for a regulator from which to breathe while waiting my turn to ascend. One by one we were pulled backwards into the tank and tapped on the head as a signal to start exhaling. As we started our ascent we were tapped on the stomach as encouragement to blow out harder. It was an amazingly realistic experience.

Over the past 90 years there have been more than 170 peacetime submarine losses, and 85 per cent of these have occurred in relatively shallow water. In those incidents 60 per cent of the submarine crews survived the initial incident. However most then perished in the deteriorating atmosphere of the submarine. In the 1950s the Royal Navy conducted a study into improving its submarine escape capability. A major research and development initiative was launched to define the human psychological limitations of submarine and surface survival and through-water escape. During these studies the vital importance of pressurised ascent training was recognised. As a result the SETT was constructed in 1953, and mandatory training has been conducted ever since.

The thought of a submarine flooding is no doubt terrifying, but if it were to happen in a real situation there is always help at hand. As soon as the distress signal is set off, the Submarine Escape Rescue and Advisory Team is sent out. SMERAT is a team of volunteers from SETT who at a moment's notice, can be flown anywhere in the world and dropped in by parachute from a Hercules C130. On arrival the team awaits signals from the sub. This is done either by the release of a buoy indicating the condition of the sub and crew, EPIRBs (Electronic Position Indicating Radio Beacons) or red smoke grenades. If these all fail the last resort is to communicate by using a form of hull tapping.

As soon as SMERAT is on its way the US Deep Submergence Rescue Vehicle (DSRV) and the British LR5 rescue mini-sub are also sent out. The DSRV and the Navy's new LR5 can lock onto a submarine's tower and transfer up to 16 submariners at a time and the Navy says it can go anywhere in the world within 48 hours of calling. In spite of the various support teams available, sub escape is nonetheless vital. The Royal Navy is at the forefront of submarine escape training; and for many years Germany, Sweden, Australia, Italy and a number of other countries have followed its training methods.

For a while the US Navy relied solely on DSRVs, but it is now bringing the escape suits back into its programme. Some countries, such as Chile, do not teach these escape methods, and the results can be costly. In the late 1980s a Chilean inshore sub sank in only 30m and many lives were lost; those who escaped suffered from decompression injuries.

Much of the Royal Navy's training is drawn from practical experience at sea. In the 1960s the development of deep escape capability followed a series of trials to find out from what depth the submariners could safely escape.

In July 1987, a team of British, Norwegian and Swedish submariners took part in trials in Bjornafjorden, Norway, aboard HMS Otus. They ran a series of progressively deeper escapes, starting at 30m. At 90m individuals started to drop out. At the end of the trials two submariners reached a depth of 183m. This set a new world record which to date has not been broken.

During my visit to HMS Dolphin I was privileged to meet one of two remaining submariners who took part in those trials: Chief Petty Officer Peach. Peach has made over 2500 escapes in the SETT tower and numerous escapes in the open sea at depths below 90m. During the 1987 trials he made a successful escape from 150m.

Prior to departure Peach took part in intensive training at SETT. He practised with the lights off to simulate the darkness of the open sea. The training continued in Norway and the dives got gradually deeper.

At 183m there is a maximum no-stop decompression time of 30 seconds so everything must happen quickly. During the training the tower was pressurised within a maximum of 23 seconds and due to the rapid pressurisation a few unlucky submariners blew their eardrums.

The thought of being stranded on the bottom of the sea is daunting. It is always at the back of a submariner's mind, and if it does happen the temperature of the sub is likely to drop to near freezing.

In December 1996, the Institute of Naval Medicine in Alverstoke put a team of 11 sailors into such crippling conditions for seven days. The mission was to see if the submariners could survive a worst-case scenario. The volunteers went through an initial escape drill before being left in a mock-up crippled hull. The temperature was steadily dropped from 23C to 4C, with a foggy 95 per cent humidity to add to the torture.

The men spent a week on daily rations of 100g of barley sugar and a pint of water each. The experiment was a partial success - of the 11 volunteers who started the exercise, four made it to the end. The others were able to open the door and walk away. They were of course lucky. In a real-life situation it is possible that they would not have survived

Reproduced with kind permission from
Tartan Topics
Newsletter of the Submariners Association (Scottish Branch)

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