The task of transferring personnel to and from offshore facilities to crew boats or offshore supply boats, as well as transferring personnel between boats has been accomplished for many years utilizing personnel transfer nets and personnel transfer baskets. Despite of the continuous efforts to improve he designs and operating procedures to eliminate identifiable hazards, accidents such as the ones described below are not uncommon.
Although there are newer designs of crane suspended personnel platforms, a typical personnel transfer net is a transport device composed of a solid cylindrical platform, a snag resistant tag line, flexible sidewall rigging, upper aluminum ring and lifting load line system, designed for the aerial transport of personnel by an offshore crane.
The following minimum lifting practices are commended for all crane assisted personnel transfer net devices:
1. Accident due to premature lifting of the transfer net: This accident occurred while an offshore worker (Occupation: Cook), was being transported to shore, after finishing his hitch on a fixed offshore platform known as Nabors Loffland 78.
On the day of the accident, the worker boarded the crew boat, and apparently the vessel proceeded toward shore, but was diverted to a fixed platform located at E. I. 172-A, because the crewboat was apparently not suitable to negotiate the heavy seas encountered.
At this location an attempt was made to transfer the offshore worker to the offshore platform first, and then, from the platform to another vessel, using the crane of the platform and a personnel transfer net, when the accident took place.
The offshore worker loaded his bags onto the personnel transfer basket, and as he was boarding the basket, before he could securely hold onto the basket, suddenly, the basket was lifted off the deck or jerked, and he was thrown about the deck, hitting a metal box. As he was attempted to react or recover from the fall, the basket which was free to swing, came back and struck the offshore worker on his lower back, throwing him about 10 feet and dumping his bags in the ocean.
The accident was witnessed by the captain of the crew boat and one deckhand who was standing by on deck. After the accident, a second deckhand was at the scene to assist the offshore worker to reach the deckhouse of the boat, since he could not get in the personnel basket due to his injuries.
The accident was the result of a combination of the following factors:
a). Improper operation of the crane. Probably there was not a qualified crane operator on the platform.
b). Crane not operating properly or malfunction of the crane.
c). Poor visibility of the crane operator, requiring the need of a signalman on the platform, which apparently was not available.
d). Improper procedure of the crew of the crew boat, that is, the deckhand designated to assist during the attempted transfer should have been attentive, holding the tag line, and giving appropriate signals to the crane operator, but instead he was occupied doing "something" else on deck. The deckhand should have had the tag line of the basket in his hand to control the swing of the basket.
e). Improper procedure of the captain of the crew boat as follows: The crew boat was not tied up to the platform by two stern lines when the transfer was attempted, and hence, was moving sideways. This could explain the substantial swing of the basket, which hit the offshore worker with enough force to throw him about 10' when the basket was returned to the deck of the crew boat. Should the crew boat have been tied up by stern lines, the captain could have held the boat steadier in position by having the propellers ahead and stern differentially. Without stern lines, the operation of maintaining the boat "on station" is extremely difficult in rough weather.
This also could explain the loss of the offshore worker's personal belongings into the water. For this loss to occur, either the boat moves sideways more than approximately 20' or the basket swung away more than 20'. For this basket to swing, the operator of the crane must rotate the crane, an operation that is unlikely to have occurred since he should have realized that no personnel were in the basket upon initiating the lift. In other words, either the crane was simultaneously lifting the basket and executing a rapid rotation of the boom, or the vessel moved sideways. The sideways movement of the vessel appears more likely, which represents an erroneous operation of the vessel by the captain.
2. Accident due to hitting the deck while lowering the transfer net: This accident occurred when a worker was being lowered on a personnel transfer net to the deck of a crew boat that was pitching and heaving violently due to heavy swells. The crane operator misjudged the timing of the elevation of the deck and the effect of the incoming swells and the transfer net hit the boat pretty hard, resulting in back injuries to the worker.
3. Accident due to the deck of the boat hitting the transfer net that was in the air because the line from the crane was tight: A worker was standing on the personnel transfer net, ready to be lifted as soon as other workers boarded the transfer net, when the boat pitched down, but the transfer net remained in the air because the line from the crane was too tight. When the boat came back up, it hit the basket and the worker fell on deck. After falling from the basket, when he was trying to get up, the transfer net was lowered and fell on top of him.
Hector Pazos, is a Naval Architect, Marine Engineer and a Registered Mechanical Engineer and has been engaged in Accident Investigation/Reconstruction for more than 40 years. He has been retained as an Expert Witness in over 1,200 Maritime cases, related to both commercial vessels and pleasure crafts, for both defense and plaintiff.
©Copyright - All Rights Reserved
DO NOT REPRODUCE WITHOUT WRITTEN PERMISSION BY AUTHOR.