Rescue of Roger Mallinson and Roger Chapman

The Rescue of Roger Mallinson and Roger Chapman occurred between 29 August and 1 September, 1973 after their Vickers Oceanics' small submersible Pisces III was trapped on the seabed at a depth of 1575 ft, 150 miles off Ireland in the Irish Sea. The 76-hour multinational rescue effort resulted in the deepest sub rescue in history.

The men
The Pisces III submersible was crewed by 28-year-old pilot Roger Chapman (a former Royal Navy submariner) and 35-year-old engineer and senior pilot Roger Mallinson.

The accident
During the early hours of Wednesday, 29 August 1973 Chapman and Mallinson commenced a routine dive in their Canadian commercial submersible, Pisces III (which measured (20 ft long by 7 ft wide by 11 ft high). They were working on laying [Transatlantic communications cable|Transatlantic telephone cable]] on the seabed, approximately 150 mi south west of Cork in southern Ireland. Their job entailed an eight-hour shift in the six foot diameter submersible which moved along the seabed using water jets to liquefy the mud and laying cable that was then recovered. The submersible would usually take approximately 40 minutes to reach a depth of 1600 ft.

For Mallinson, this dive was additional fatiguing as he had spent over a day previously repairing a broken manipulator on the sub. During the repair he changed the oxygen tank for a full one. During each dive the pilots had to ensure that after every 40 minutes they turned on a lithium hydroxide fan to remove carbon dioxide from the atmosphere and also add additional oxygen. Additionally, they maintained a video commentary record during every dive.

Shortly after 9 A.M., with the submersible about to be lifted out of the water with a towline back onto the ship, an alarm sounded in the aft sphere, a self-contained part of the submersible containing machinery and oil storage. Then with the sound of water entering the aft compartment, Pisces III became inverted and began to sink back to the seabed. The aft machinery sphere hatch had been wrenched off and the compartment was now fully flooded. The additional weight of water now added over a tonne of extra weight to the submersible.

At 200 ft the submersible jolted to s stop - held at the maximum length of the nylon towline. The crew now swung about in the sea currents until the rope snapped. The pilots immediately closed down all the electrical systems which instantly plunged the sub in total blackness. They also managed to release a 400 lb lead ballast weight as they descended. They both now readied themselves for the impact on the sea floor which occurred at approximately 9:30 A.M at a speed judged later to be at 40 mph.

Initial contact
Using a torch, the crew were able to review their surroundings and also called their mother ship to update them. The full tank of oxygen Mallison had added had a capacity to last approximately 72 hours of oxygen, but eight hours had already been used, leaving just 66 hours left.

Mallison and Chapman spent the first few hours sorting out the submersible which was almost upside down. They checked all the watertight doors for leaks and prepared for rescue to come. To preserve oxygen they knew they had to make as little physical exertion as possible and not to even speak. They made themselves as comfortable as possible as high up as they could get to avoid the foul air that sank down.

The pilots had just a single sandwich and one can of lemonade on board. They also decided to allow the carbon dioxide in the air to build up beyond the normal 40 minutes to conserve oxygen but it resulted in making both men lethargic and drowsy.

Rescue efforts begin
Shortly after 1030 A.M., the support ship Vickers Venturer, then in the North Sea, was ordered to return the nearest port with the submersible Pisces II aboard (which could be removed and flown to Ireland). Additionally, at midday the Royal Navy ship HMS Hecate steamed to the accident location to offer assistance with special ropes. The US Navy offered a submersible belonging to the US Salvage Department, called a Controlled Underwater Recovery Vehicle (CURV III) which was sent from California and the Canadian Coast Guard ship John Cabot left from Swansea.

On Thursday 30 August the Vickers Voyager arrived in Cork at 08:00 and loaded the submersibles Pisces II and Pisces V, which had been flown in overnight. The ship left Cork at 10:30.

At 2 A.M. on Friday 31 August the Vickers Voyager had reached the scene and launched Pisces II with a special rope attached. However, the lifting rope broke free of the manipulator arm and the submersible had to return to the surface for repairs. An attempt made by Pisces V failed to find the crashed Pisces III and returned to the surface after it ran out of power. Relaunching Pisces V had more success and found the crew at approximately 1 P.M. However, an attempt to attach a rope failed. Pisces V now remained with the stricken Pisces III. An attempt to send Pisces II down again had to be called off when it suffered a leak.

Even the newly arrived CURV III aboard the John Cabot was unable to launch due to an electrical fault. Just after midnight Pisces V was ordered to the surface, which left the men once again alone. They were now running out of both oxygen and the lithium hydroxide to scrub the carbon dioxide from the deteriorating atmosphere in the submersible. Both men were cold and wet and suffering from severe headaches.

Rescue
On Saturday 1 September,shortly after 4 A.M. Pisces II was launched once more. By 5 A.M. it had managed to attach a specially designed toggle and polypropylene tow rope to the rear sphere of Pisces III. Shortly before 10 A.M. the CURV III had managed to fix another rope to the submersible. It was at this point that the crew ate and drank the only sustenance aboard.

At 10:50 A.M. the lifting of the stricken Pisces III began. It caused immense jolting of the submersible which further disorientated the crew. At 350 ft the lift was halted to disentangle the CURV III and then the lift was remporarily halted again at 100 ft so that heavier lifting cables could be fixed by divers.

At 1:17 P.M. Pisces III finally broke through the surface dragged clear of the water. Immediately divers scrambled onto the submersible to open the hatch to let air in, but it took them almost 30 additional minutes to do this. When the hatch did open finally, both men found it hard to extricate themselves from the craft after being cramped inside for 84 hours and 30 minutes. It was later determined that there was just 12 minutes of oxygen left aboard Pisces III.

Books
In 1975, Roger Chapman published "No Time On Our Side", which covered the rescue.

Movie adaptation
In August 2013 it was announced that a film depicting the events of the rescue would be made starring Jude Law and Ewan McGregor.