When the Canadian Navy recovered the remains of Swiss Air Flight 111 it completed the largest, most extensive underwater operation conducted in the history of the country. Lifting pieces of wreckage, recovering bodies and searching for the elusive "black box" was done in freezing cold water under the worst imaginable conditions.
The lessons learned by the Canadian Navy both in terms of diving technology and search techniques were the subject of a special briefing held last month in Toronto at the Toronto Boat Show.
Over 50 police divers from across Ontario came to the Boat Show to meet the Swiss Air Flight 111 recovery team, to look at some of the equipment used in the operation and learn about some of the underwater problems faced by scuba divers. Swiss Air Flight 111 crashed on September 2nd seven nautical miles off the coast of Peggy's Cove, Nova Scotia. 229 people were killed, and it was left to the Canadian Navy to recover the bodies and to locate and bring to the surface the remains of the ill-fated aircraft.
"We used remote operated vehicles (ROV), surface supplied air and more often than not, scuba to work on the recovery. Believe me, with the weather, the temperature and the tragedy itself, this was not an easy assignment," explained Navy diver Lieutenant Tyrone David. "There were thousands of dives made. We had three chambers at the crash site, but we only had three diver incidents that required treatment."
A total of 70 Navy divers were on site and in the water during the fall recovery. They used every tool available, including the camera-equipped, remote-operate ROVs in the recovery operation. There were two navy tender boats operating out of Peggy's Cove and the aging HMCS Okanagan diesel submarine was pressed into service to aid in the underwater search.
"We expected to find that the airplane would be spread out over a wide distance underwater but that wasn't the case. The plane must have gone nose in because it was all right there in a small area of the ocean," continued Lieutenant David. "It was a relatively small search area and we were able to use scuba on many of the dives."
Even though the crash site was not spread out over the ocean floor, the search area was large enough that the divers found two shipwrecks during the airplane recovery. One of the ships found had a metal hull and was 150 feet in length, the other was a smaller wooden vessel.
The Navy recovery team did not use dry suits. Each diver was equipped with a device that warmed the sea water before it circulated in the wet suit.
"This system has its drawbacks," continued the navy diver. "There were body parts and body fluids in the water and that was a concern. One of the passengers was an Aids researcher and we were concerned".
"Here in Toronto that wouldn't happen," commented Metro Toronto Police diver James Murphy who attended the January Swiss Air 111 briefings on behalf of the city's Marine Unit. "We only use dry suits. However, we are very interested in how they use ROVs to assist in the recovery."
The Toronto police has the largest dive unit in the province. Although they have been involved in major air disaster recov eries of their own (the last was a British Air Force Nemrod that crashed into Lake Ontario while appearing at the city's Labour Day air show) the police force doesn't have an ROV in its inventory.
Up until the Swiss Air disaster, the use of ROVs in recoveries has been limited because of the difficulty of actually tracking where the unmanned sub is underwater. A new onboard navigation system has Ontario police officers like Murphy looking again at the robotic vehicles.
The Navy learned a number of other important underwater lessons as a result of the Swiss Air Recovery. At the Toronto briefing divers were told about the benefits of Kevlar and the use of military rebreathers.
"We had terrrifc visibility underwater but with so much twisted metal and wires filling the wreck site, it was dangerous going even though we could se well," explained Lieutenant David. "After hoses and suits were ripped we started covering both our divers and the ROV with Kvelar."
Rebreathers are not usually used in recoveries. During the Swiss Air 111 recovery, a military rebreather was used effectively to recover the aircraft 's black box. The electronic recording device was found 150 feet down and initial attempts to dive for this important piece of evidence, using surface supplied air, were hampered by debris, bad weather and high seas. Divers using deepwater rebreathers were able to swim unhampered by long air hoses and tethers, were able to quickly reach the bottom of the ocean and recover the much sought after black box.
Following the Toronto briefing, the Canadian naval team returned to their home base in Halifax to get back into the water. The Canadian Navy will be spending the rest of the winter and ealy spring underwater at Peggy's Cove to continue recovering pieces of Flight 111.
Seen At The Big Boat Show:
A Prince Edward Island company has developed and is marketing a new underwater craft. DAK Design Works debutted the new Sea Hawk in Toronto. Shaped like an oversized T-square, the fibreglass Sea Hawk is designed to be towed behind a power boat. With two independant side wings, the Sea Hawk can be "flown" up, down and sideways behind a boat. At a cost of under a thousand dollars, the Sea Hawk can be used for fun or to conduct underwater searches. DAK Designs sells the adjustable Sea Hawk for under a thousand dollars and hopes to have the craft available soon in stores across the country.
Age now matters! Federal cabinet minister David Anderson came to the Toronto Boat Show in January to announce changes to the regulatory framework governing recreational boating in Canada. The big news for divers is that along with a C-card a new card will be needed to go out on the water. Proof of "operator competency" (i.e. licence) will soon be required to operate a boat in Canadian waters. Along with putting a minimum age to operate personal watercraft and most moterboats, an operator com
petency card will be needed by 2002.