USCG investigates Alaska drillship anchor dragging incident

JULY 16, 2012 — The Coast Guard is continuing to investigate an incident in which a drillship on charter to Shell for Alaska drilling operations apparently dragged anchor Saturday, July 14, and drifted toward shore near Unalaska Island.

Shell said yesterday that the incident occurred while the drillship Noble Discoverer was anchored off the coast of Dutch Harbor, Alaska, and that it quickly engaged one of its support vessels, the Lauren Foss, which safely towed the Discoverer back to its previous location.

A ROV (Remote Operated Vehicle) inspection of the Discoverer found no indication that the ship was damaged or ran aground. As a precaution, a dive team was to conduct another inspection.

Shell pointed out that the ship’s anchor, which is used to secure the drill ship just off the coast, is very different from the eight-anchor [PES] spread mooring system used during drilling operations.

The Coast Guard said today that it continues to investigate the incident. “There are no reports of injuries to the crew, pollution or damage to the Noble Discoverer,” said Lt. James Fothergill, supervisor Coast Guard Marine Safety Detachment Unalaska and the lead investigating officer on the case. “We are investigating the report that the vessel dragged anchor and drifted toward shore before being towed back to its original mooring point. While the vessel master reported he did not believe the vessel grounded, this cannot be confirmed by the Coast Guard at this time. Divers are expected to inspect the vessel’s hull Friday.”

According to the Coast Guard, the vessel is currently moored 500 to 750 yards from shore in Unalaska Bay with tugs standing by. A remotely operated vehicle aboard the Noble Discoverer was used to inspect the hull Saturday after the vessel was reanchored and the crew reported seeing no evidence of damage to the hull or grounding. The Coast Guard will review that footage as part of the investigation.

Divers have been contracted by Shell to inspect the exterior hull of the vessel. The Coast Guard will inspect the the interior of the vessel’s hull. The Noble Discoverer crew is working to arrange mooring at the city pier in Unalaska in advance of the divers’ arrival which is now anticipated to be Friday.

The Coast Guard says it received a report at 5:18 p.m. Saturday that the Noble Discoverer dragged anchor 175-yards from the shore of Unalaska Island and was drifting toward land. The crew immediately let out more anchor chain to slow the drift and called for a tug assist. The tugs were able to tow the vessel back to a safe anchorage. The crew aboard the Noble Discoverer stated that while they came extremely close to land they did not feel any impact or vibration to indicate a grounding.

The vessel’s mooring location is in deep water and is a common anchorage for large commercial vessels. Weather at the time of the incident was reported as sustained winds of 27 mph with gusts to 35 mph.