It takes a whole crew to make a saturation diving operation work.
Life support technicians ensure that the air mix in the hyperbaric chamber matches the air that the divers breathe underwater. The dive control team is in charge of operating the diving bell — which raises and lowers on a crane — and monitoring the divers as they work. There are even cooks that prepare and serve meals to the men cooped up in the living chambers.
Workers called "tenders" have a very important support job. They help unspool and retract the "umbilical," the thick line of air supply tubes and communication wires that connects the divers to the surface. In the past, tenders had other responsibilities that included docking the diving bell to the pressurized living chambers.
"The saturation divers are completely at the mercy of the tender and of their supervisors on the dive control team," says Newsum.
On Nov. 5, 1983, an experienced tender named William Crammond was in the middle of a routine procedure aboard the Byford Dolphin, a semi-submersible oil rig operating in the North Sea. The rig was equipped with two pressurized living chambers, each holding two divers. Crammond had just connected the diving bell to the living chambers and safely deposited a pair of divers in chamber one. The other two divers were already resting in chamber two.
That's when things went horribly wrong. Under normal circumstances, the diving bell wouldn't be detached from the living chambers until the chamber doors were safely sealed shut. However, the diving bell detached before the chamber doors were closed, creating what's known as an "explosive decompression."
"It's a death sentence," says Newsum. "You won't survive."
The air pressure inside the Byford Dolphin living chambers instantly went from 9 atmospheres — the pressure experienced while hundreds of feet below the water — to 1 atmosphere, the normal air pressure at the surface. The explosive rush of air out of the chamber sent the heavy diving bell flying, killing Crammond and critically injuring his fellow tender, Martin Saunders.
The fate of the four saturation divers inside was far worse. According to autopsy reports, three of the men inside the chamber — Edwin Arthur Coward, Roy P. Lucas and Bjørn Giæver Bergersen — were essentially "boiled" from the inside when the nitrogen in their blood violently erupted into gas bubbles. They died instantly.
The fourth diver, Truls Hellevik, suffered the grizzliest death. Hellevik was standing in front of the partially opened door to the living chamber when the pressure was released. His body was sucked out through an opening so narrow that it tore him open and ejected his internal organs onto the deck.