Down, down and away ... Newtsuit to the rescue - Underwater Contractor Magazine

Travelling in the open metallic pod, whose weight ensures that the pilot reaches the target point without being driven off course by the current.
Down, down and away ... Newtsuit to the rescue
The Newtsuit may look like a tottering butterball, writes Isabelle Croizeau, but it is at the leading edge of underwater technology and the French Navy has been assessing how it can help submarines in distress. Photography by Alexis Rosenfeld.

One of the French Navy's six hunter-killer submarines has broken down and is stuck on the ocean floor at a depth of 200 metres, with no power and 60 men on board. Obviously, the chances of such a disaster actually occurring are extremely low. The crew would be drilled in emergency procedures to get the submarine to the surface - in theory.
But as there is no such thing as zero risk, the possibility of a submarine being stranded on the bottom must be considered and rescue procedures planned in minute detail. A second submarine would immediately set out to evacuate the crew - only it would be American, based on the USA's West Coast, and would take several days to arrive on the scene (see box below).
A submarine carries all the supplies needed to allow the crew to survive for a week, including stocks of food and water and cylinders of soda lime to purify the air. But as Lieutenant-Commander Diainville, who is in charge of the COMISMER project, explained: "You can easily imagine the state of mind of those 60 men, trapped in a metal cylinder with the only help possible coming from outside, and they don't know when."
So someone has to go down and "tap on the porthole" to let the crew know help is on its way.

Getting to grips with the Ariane's propeller.

Reassuring the crew
The Newtsuit can go down as soon as the alarm is raised and contact the crew. It also makes the first on-site damage report which is transmitted to the surface by radio, and if there are not enough supplies on board, it will keep the air in the submarine breathable using flexible hoses fed from the surface by powerful compressors and hooked up to special outlets. One hose pumps in pure air while the other pumps out stale air. This two-way system can also be used to adjust the pressure in the submarine, which must be controlled to enable the crew to get out quickly. The Newtsuit could also pass the crew containers of food, or medicine if needed, through a special airlock.
Of course, until now deep-sea divers had been used to help submarines in difficulty and their equipment was perfectly geared to the movements they had to make. To do the same things with the Newtsuit, some adjustments had to be made. The device has a claw at the end of each arm to grasp objects, but it is not and can never be as accurate as a human hand. Tools had to be invented to improve the precision of the aqualung's claws.
To get the Newtsuit down as far as 60 to 250 metres, the French Navy has come up with a sort of open metallic pod whose weight ensures that the aqualung reaches the target point without being driven off course by the current - much as a lead weight is attached to a piece of string to make a plumbline.

Replacing divers
With these adjustments, using the Newtsuit is much simpler than organising a traditional deep-sea dive. On the mother ship's deck, only five men are clustered round the aluminium butterball, which opens on a central hinge. The pilot climbs carefully into the cockpit, positions his legs and checks that the motor and monitoring pedals are working. "OK, you can close it."

A pilot practices hooking up the air hoses

Guided by a hydraulic jack, the top part of the Newtsuit is slowly lowered and clunks into place, as the crew make sure no leads are trapped. The pilot moves each of his limbs, one after the other. The Newtsuit is responding perfectly and the claws that will be the pilot's hands open and close at will.
In the control centre, another crew member remains in permanent radio contact with the pilot and supervises every stage of the operation. He ensures that the device's lifeline is supplying power correctly and monitors the parameters of the dive on a computer screen. Only the quality of the air in the aqualung is outside his control. In this respect the Newtsuit is completely autonomous.
The entire procedure may appear complicated to an outsider but it requires only half as many crew as a deep-sea dive and makes it possible to use smaller boats. And when the Newtsuit resurfaces, the pilot will not have to go through the interminable decompression stages that usually turn a deep-sea dive into a longer business than a trip to the moon.

Five pilots
At the moment there are five Newtsuit pilots, chosen from the French Navy's divers. As they are already in their element deep down, they were ready to take the controls of the device after two weeks of intensive training.
"That's when they really started to learn how to manoeuvre the Newtsuit, to grasp the finer points of manipulating and moving around in it," says Lieutenant Commander Diainville. Every day, exercises and simulator training familiarised them with the device.
From the start, tests were carried out in conditions as close to real life as possible. They first used the wreck of the Ariane, a submarine taken out of service in the late 1970s and sunk by the Navy for diver training off Saint Mandrier, near Toulon. The submarine, 30 metres long and weighing 400 tonnes, made it possible to recreate some of the conditions of a real exercise, even though it is only about 20 metres down.
Life-sized
This training phase enabled the pilots to learn to move around both in the water and in an area obstructed by rocks and steel plates. Next the pilots used a life-sized model of a conning tower equipped with the same airlock as real submarines but 155 metres down, and practiced hooking up the air hoses.
They also had to learn how to use the Newtsuit's specially designed tools, assess how long they take to react and judge the path of the cord linking them to the descent pod so that it does not get stuck anywhere. All these details helped make them matchless rescuers - even locked inside 300 kilos of aluminium. Now when the aqualung hits the water and disappears beneath the surface, the pilot does not have a moment's hesitation. He knows that, come what may, he will complete his assignment.
Before reaching a final decision on the military future of the Newtsuit, the French Navy is seeking ways to co-operate with other European navies interested by this new rescue technology. This would both improve its operational efficiency and, of course, share the cost burden.

The Newtsuit can make contact with the crew as soon as the alarm is raised. Air hoses are attached to special outlets to keep the submarine's air breathable.

Waiting for the Americans
What happens when a submarine breaks down underwater? The drill for rescuing a submarine crew stranded deep down is invariable. As soon as the vessel runs out of power and comes to a halt, a radio buoy automatically shoots to the surface, giving the submarine's position to within a few miles. This triggers the rescue plan. In France, ships with sonar immediately set out for the area to pinpoint the submarine's exact location.
Meanwhile, in the United States, one of the two crew rescue submarines - the Mystic and the Avalon - is dismantled and loaded onto a huge Super Galaxy-type cargo plane. These deep submergence rescue vehicles (DSRVs) are ready to move into action in France under the terms of a NATO agreement. The rescue submarine is then launched at Brest, Brittany, and hooked up to a MOSUB, or mother submarine.
When they get to within a few hundred metres of the submarine in distress, or DISSUB as it is known, the DSRV takes off on its own. It is secured to a special airlock on the DISSUB and the rescue operation is ready to go ahead. It can bring up 24 people at a time, each round trip taking four to five hours. The Newtsuit was designed to provide assistance to the DISSUB while waiting for the DSRV to arrive.

A cross between an aqualung and a submarine
Like a submarine, the Newtsuit maintains stable atmospheric pressure, doing away with the tedious business of decompression, and can operate independently for between five and six hours.
The pilot, equipped with cylinders of soda lime and oxygen, breathes on a closed circuit, so if the cord linking the device to the boat breaks he can survive for 48 hours until help arrives.
Like an aqualung, the Newtsuit is easy to manoeuvre. Once in the water it weighs only one or two kilos. It has four engines - two horizontal and two vertical - operated by pedals that enable the pilot to move in three dimensions: back and forth, up and down, and pivoting from side to side. They are powerful enough to keep the Newtsuit moving against a two-knot current.
The Newtsuit is fully articulated using a system of 20 moving joints immersed in an oil bath. They offer a previously unheard-of flexibility but can never be dismantled because how they work is a trade secret. The Newtsuit comes with torso and leg extensions to fit different pilots.
The only real constraint is the lifeline, which means a support vessel has to be used that can maintain position right over the site. The cord both keeps radio contact and supplies power to the Newtsuit, whose two 200-watt headlights enable it to move around in almost total darkness.