Probe: Watchkeeping deficiencies caused OSV to strike platform

An offshore supply vessel (OSV) struck a natural gas production platform in the Louisiana Gulf last year because of poor watchkeeping and improper operations by the captain and the mate, the National Transportation Safety Board said. Investigators also blamed the vessel owner’s failure to implement its own safety guidelines.

The OSV involved was 100.5-foot Tristan Janice, owned by TRTB Inc. of Golden Meadow, La.

Tristan Janice proceeded at full speed in restricted visibility without a proper lookout, a clearly identified person in charge, engines ready to maneuver or regular monitoring of the vessel’s progress, the NTSB investigators wrote in a September 2015 report.

Just after daybreak on Feb. 18, 2014, the OSV allided with the platform 54 miles south-southwest of Houma, La. The vessel and platform sustained a combined $545,000 in damage, and a large quantity of natural gas escaped. No one was injured and no water pollution resulted.

The night before, the OSV was moved between berths near Golden Meadow, La. A captain and a mate — both credentialed masters — and two deck hands were on board. The captain had navigational control at the time. Soon after the berths were shifted, a brief watch turnover occurred. The captain mentioned then that the starboard engine throttle had a small air leak, but he said it didn’t seem serious. In the turnover, the mate took control and Tristan Janice departed with orders to go to Port Fourchon, La. The vessel was to stay there overnight and head out to sea the next morning.

The mate steered past Port Fourchon, however, and entered Gulf waters in the early hours of Feb. 18. The captain later told investigators that he was off duty and asleep at the time. Though it couldn’t be confirmed by either data or crew statements, NTSB investigators wrote that they believe that the OSV’s steering was in autopilot during its Gulf entry.

Tristan Janice was powered by twin diesel engines, each driving a propeller. Shortly after the vessel entered the Gulf, the mate thought that the starboard engine wasn’t maintaining full speed. He told the deck hand to use a line to tie off the starboard engine throttle in the machinery spaces so that it would stay at full-ahead speed. That adjustment removed control of the starboard engine throttle from the wheelhouse.

Two of the vessel’s crewmembers later told the Coast Guard that TRTB had acknowledged the throttle problem a few days earlier but didn’t have the right part for it. Investigators found no log entry about the throttle, though entries about faulty equipment were required by TRTB’s safety management system.

According to automatic identification system (AIS) data, Tristan Janice followed a southwest course on the morning of Feb. 18. Its speed was full ahead. The on-duty deck hand told investigators that the mate asked him to awaken the other two crewmembers early that morning so they could assume watch. At 0623 hours, the vessel changed course to west-southwest. The captain told investigators he entered the wheelhouse at 0635 and found no one there. Heavy fog made visibility poor. He saw the mate, who was on the afterdeck checking on an engine vibration. The mate didn’t tell the captain that the deck hand had tied off the starboard engine throttle.

Soon afterward, the captain and mate entered the wheelhouse, where until 0700 they discussed logbook entries, along with the fog and the vessel not stopping at Fourchon. They didn’t consider posting a fog lookout, the report said. The captain went to the wheelhouse’s port side to smoke, and when he turned back, the mate had left the wheelhouse without a formal watch turnover. The captain assumed the vessel’s control. Its course was west-northwest, and its speed was 9.5 knots. Minutes later, the mate returned to the wheelhouse, where he and the captain discussed the area’s vessel traffic, but not oil and gas production platforms. The captain told investigators that he reduced speed, though AIS data showed that the OSV held its speed.

The captain said he looked up from radar and saw a gas platform 200 yards ahead. He tried to slow the vessel but its speed “was entirely too fast for (the) clutch.” He attempted to avoid a collision by turning the vessel while “throwing it into reverse,” but the turn took some time because the boat was on autopilot. Within 15 to 30 seconds, he placed the vessel in manual steering and changed course, but his actions were too late. At 0712, Tristan Janice struck the platform — Ship Shoal 119 W, which was unmanned — at a speed of 9.3 knots, the report said.

Soon after the incident, with the starboard engine still in full-ahead, the two deck hands entered the engine room and removed the line tied to the starboard engine throttle. At 0730, without reporting the allision to authorities, the crew navigated west-northwest toward Freshwater City, La., investigators wrote.

The platform sustained structural damage and more than 22,000 cubic feet of natural gas escaped. Operations ceased for 20 days at Ship Shoal 119 W and neighboring platforms. Tristan Janice sustained fractures and indentations to its bow area, broken welds to its port engine exhaust and a damaged port-engine forward main seal.

The crew’s statements didn’t clarify whether the captain or the mate was the OSV’s designated captain. The person described as “captain” in the NTSB report was, according to a TRTB representative, the company-designated captain. However, that person told investigators he didn’t believe he held the position of captain. TRTB’s safety management system didn’t provide guidance as to how captains were assigned.

According to the report, there were no records to indicate that the vessel’s position was plotted during its voyage. No lookout was posted despite the fog, and wheelhouse control of the starboard engine’s speed was defeated by its throttle having been tied off.

In early December, TRTB officers declined to comment on the NTSB’s findings about Tristan Janice and the company’s safety practices.

By Professional Mariner Staff