''Venture One'' diving accident

Three miles east of the North Cormorant oil field in the North Sea, the crew on board the drill rig Venture One was preparing to lower a Blow Out Preventer (BOP) to the seabed 510 feet (160 m) below. It was 10 May 1977,^[1] and International Underwater Contractors (IUC) diving supervisor Richard Pettit had been asked to inspect the Permanent Guide Base to verify that it was clear of any obstructions that might prevent the installation of the BOP.

Background

At approximately 0400, supervisor Pettit launched the bell with divers Dave Hammond, 29, and Craig Hoffman, 22, inside. Described as a “very competent diver,”^[2] Hoffman was from the state of Delaware and had worked for IUC in America before coming to the North Sea. Hammond was from Dundee, Scotland and had about 9 years diving experience, three of which were in oilfield work.

At 492 feet, supervisor Pettit stopped the bell, and for the next 90 minutes the two divers peered out of the portholes answering Pettit’s questions about the condition of the guide base.^[3] Pettit had been told by the oil company representative that he would not find any remnant wires sticking out of the posts of the guide base,^[4] but Hoffman and Hammond reported that three of the guideposts had wire rope sticking out of, and draping over, the tops of them. These wires had to be cleared before the BOP could be sent down.

At 0612, the divers opened the blow-down valve and pressurized the bell.^[5] When Hoffman exited the bell he was wearing a hot-water suit while Hammond was dressed in a dry suit.^[6] Hoffman swam to the guide base 15 to 20 feet away, and, while holding onto one of the guideposts, noticed that it was not hinged, which meant that the wires had to be cut away. After retrieving a hacksaw from the bell, he began cutting one of the wires.

Five hundred feet above, supervisor Pettit listened to Hoffman’s respirations through his communication's headset and noticed that his breathing rate had increased. On several occasions he instructed his diver “to stop and take a rest,” which he did.^[7] About 60 minutes later Hoffman had cleared two of the guideposts when Pettit decided to bring him back to bell and send Hammond out to complete the third wire.^[8] Later, at the Fatal Accident Inquiry, Pettit explained that he thought the job was going to take longer than expected. "So instead of trying to rush it through—keeping Craig cutting the third wire—I decided to let Dave do it; Craig could come back and rest, because a tender’s job is fairly relaxed."^[9]

Pettit then ordered Hoffman to the bell and asked Hammond to go out and complete the job.

The trunking is a short cylindrical passageway that allows the diver to enter and exit the bell.

The accident

Back in the bell, Hammond exchanged places with Hoffman, donning the same gear that Hoffman had used.^[10] During the exchange, Hoffman never complained of fatigue. Everything was “absolutely normal,” Hammond would later tell the Court.^[11] Twenty minutes later Hammond exited the bell feeling “terrific.” He quickly swam to the job and began work on the final wire.

In the bell, Hoffman communicated with topside through a headset, giving Pettit information about the bell oxygen content and asking him to have Hammond check part of his work. To supervisor Pettit, Hoffman’s communications were “perfectly lucid.”^[12]

A few minutes later, while Hammond was working on the guide base wire, supervisor Pettit suddenly heard a “strange high-pitched electrical noise” in his headset. He immediately called the bell to see if Hoffman was okay, but received no response. He tried a second time, but still no answer.

Five hundred feet below, Hammond was nearly finished cutting the third wire when Pettit ordered him back to the bell. Hammond answered that he was almost finished with his work, that he “had one strand of wire left to cut through” and would go back at that time, but Pettit shot back, “No, go back now!”^[13]

Sensing that something had “gone amiss,” Hammond dropped his tools and began swimming back to the bell.^[14] Roughly six feet from the bell he noticed something odd; there was a dark shape just below the bell, and when he got closer he discovered that it was Hoffman floating in a “dead-man’s position” inside the trunking with his arms and legs extending down in the water.^[15]

“Craig’s not in the bell,” Hammond shouted into his mask.

“What? Where is he?” Pettit responded. “Is he in the water?”^[16] Hammond, speaking very quickly, uttered something Pettit didn’t understand, but repeated his earlier communication about Hoffman’s position.

Hammond quickly ditched his fins and tried to push his unconscious partner inside; but when that didn’t work, he pulled Hoffman away from the hatch, and crawled through the trunking into the bell.^[17]

Sitting on one of the seats, he drew Hoffman’s body part way into the bell, positioned his arms over his knees and began ventilating him, giving mouth-to-mouth resuscitation.”^[18]

Minutes later, surface-to-bell communications unexpectedly broke down. A little over a year later, supervisor Pettit would explain in Court that, after Hammond got back into the bell and worked on Craig for a while, communications began to deteriorate “and at one point it had completely disappeared and at that point I had to leave and see if we could get some help from ashore.”^[19]

Pettit phoned his company office and gave General Manager Stanley Kellogg details of his predicament—that he had lost contact with the bell and “couldn’t take a chance bringing it to the surface when the doors were open.”^[20] Kellogg offered advice and after the conversation ended, notified the Department of Energy, contacted Offshore Medical Support, and began calling rescue vessels.^[21] (Comex and Vickers)

On the Venture One, Pettit managed to re-establish communications with the bell while Hammond continued resuscitating Hoffman. But after “20 or 25 minutes,” Hoffman showed no signs of life and his eye pupils were unresponsive to light.

Pettit ordered Hammond to recover Hoffman’s body inside the bell, but Hammond was unable to do so. When asked at the Inquiry what the problem was, he answered: “Well, he weighed almost as much as I did and plus the fact he was wearing a hot-water suit is quite a heavy piece of material, that added to his own weight and the fact that it was totally a dead weight, no help at all involved and I had a very limited space to work in, I couldn’t pull him in all the way.”^[22]

Pettit asked if Hoffman was deceased and Hammond said that he was. By that time Hoffman had not been breathing for 60 minutes,^[23] and with the threat of losing bell communications looming over his head, supervisor Pettit asked Hammond to “drop back down into the trunking and lash Craig’s body to the outside of the bell…and they would then bring the bell to the surface.”^[24]

When the bell arrived at the surface, a diver was lowered into the water to free Hoffman’s body and swim it to a recovery basket. Then the bell was brought on board and locked onto the chamber system. Inside the system, diver James McLellan received Dave Hammond in the entrance lock. McLellan could not help but notice that Hammond appeared to be “very cold, very tired and very stressed.”^{[lower-alpha 1]}

Aftermath

During an investigation of the accident, authorities could not come up with a scenario that would explain why Hoffman ended up in the trunking.^[25] They found no broken diving equipment or missing equipment; no part of the system malfunctioning in any way.^[26]

Tests were conducted on the Lindberg Hammer carbon dioxide scrubber and the sodasorb. Everything checked out okay.^[27] And Dave Hammond testified that he detected nothing wrong or strange about the gas quality. When it was tested, it was found to be uncorrupted.

The bell electrical system was also examined for faults because Pettit suggested that the high-pitched noise he'd heard might have been caused by Hoffman’s comms switch going into the water. “The salt water would be going into the speakers and cause the problem in the electronics, causing this high-pitched sound,” he told the Court.^[28] But a technician found no electrical fault whatsoever, and Hammond testified that he experienced no electrical shock in the bell.^[29]

An autopsy was conducted on Hoffman, which revealed no evidence of any disease to his heart or other organs; and no evidence of electrical shock to the body.^[30] He had a one-inch vertical laceration on his forehead, which was thought to have been caused after death.^[31]

A lung dissection showed that Hoffman died by drowning.^[32] When asked to theorize how this could happen, Dr. Hendry, the autopsy doctor, testified that, “This occurred because he fell head first, maskless and presumably unconscious, into the trunking of the diving bell. As there is no evidence of illness, injury, or environmental hazard, my interpretation is that his loss of consciousness was occasioned by a faint (Syncope). This could have happened, for example, if he had risen quickly to his feet from a squatting position thereby causing a fall of blood pressure. The effects of such an action would have been exaggerated if at the same time he had been over breathing or had closed his nostrils with his fingers to clear his ears.”^[33] Dr. Hendry went on to emphasize that his conclusion was “hypothetical,” and that he had “no way of knowing [if] this happened.”^[34]

Notes

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