16 August 2011 at approximately 0815 hours, a fatal accident occurred on the offshore production platform, High Island A557 “A”, operated by Energy Resource Technology GOM, Inc. (ERT). Platform personnel were using the platform crane to move a rental generator from the platform onto a motor vessel. Two riggers were on deck close to the load, using tag lines to stabilize the lift. On the Platform deck in proximity to the generator were three tanks on the left side, and a barricaded lubricator attached to a wellhead, extending 14-ft above the deck, on the right side of the lift.
When the load was lifted, the crane’s boom hoist wire rope failed, the generator dropped to the deck, and the boom fell striking the generator. The boom subsequently broke into three sections; one section attached to the crane, the middle section resting on top of the dropped generator, while the nose section continued overboard. The crane’s main block hook subsequently disengaged releasing the connection between generator and boom nose.
The falling boom nose dragged the attached bridle/sheaves behind it as it fell overboard until its fall was arrested by the main load line and bridle pendant wire ropes. The 850-lb bridle/sheaves struck the fallen boom and pulled by the nose, ricocheted off of the end of the middle section, finally coming to rest against the platform toe-board. The rigger handling the left tag line was struck by the bridle and fatally injured.
A BSEE accident investigation Panel concluded that the Causes of the accident were as follows:
(1) The Crane’s boom hoist wire rope parted due to being weakened by internal and external corrosion, with loss of integrity, ductility and strength. The line was over four years old.
(2) The vicinity of the lift was constrained by other equipment which caused the rigger to be positioned in the path of the falling boom.
(3) The crane’s corroded and damaged boom hoist wire rope was found to be systemically lacking internal lubrication; probably because of improper lubrication, application method, frequency, and an improper lubricant type.
(4) It is probable that the annual inspection of the crane conducted six months previous by a third party contractor did not include a comprehensive examination of the boom hoist wire rope.
(5) The positioning of other equipment in proximity to the lift, especially the 14-feet high (above the deck) lubricator, probably contributed to the decision to control the load with tag lines in the early stages of the lift.
(6) The positioning of tanks near the load probably caused the rigger stabilizing the load on the left side to be positioned in an unsafe location in the path of the falling boom.
(7) Moving the interfering equipment prior to the lift was probably not considered or discussed in the JSA, contributing to the improper positioning of the rigger.
(8) The Operator had no company manual for crane operations. It is possible that an internal company policy for crane operations may have led to actions that could have prevented the incident.
(9) It is possible that the detachment of the main block hook from the load may havecontributed by allowing the bridle to be pulled all the way to the railing, striking the rigger, rather than remaining atop the fallen boom.
(10) The crane’s operator and those supervising the lift possibly did not give “special attention” to all of the crane’s wire rope lines during the pre-use inspection as per the recommendations of API RP-2D.
Recommendation to BSEE
The Panel recommends BSEE consider issuing a Safety Alert describing the incident and recommending the operators take certain actions regarding lubrication and inspection of crane wire ropes, and positioning of equipment and riggers during lifts.
The Panel recommends BSEE consider initiating a study, coordinated with API, to see if wire rope lubrication data should be recorded in crane usage records.