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SECTION III: MATERIAL HANDLING ACCIDENTS
Summary No. 9 - Inadequately Rigged Load
Employees unloading bundles of scrap steel from a ship's hold were exposed to the hazard of being struck by the raised load.
A barge-mounted crawler crane is used to unload bundles of steel rails from a bulk carrier vessel.
Activity at time of incident:
Longshoremen were in the cargo hold while a crane lifted one end of a bundle of scrap steel with a "breakout" wire. The bundle was being raised so that the two wire rope slings used with the crane could be placed under the bundle to unload it.
A bulk carrier vessel (with no tween decks) is moored with its starboard side against two steel-decked barges. Each barge is moored to the pier and equipped with a crawler crane which is used to discharge the vessel carrying 46,000 tons of used steel, banded together in bundles. The cranes have a 75,000-pound capacity and are mounted on the barges because the pier cannot support their weight. Each bundle is about 24 feet long and weighs approximately 17.5 tons. Two gangs, each consisting of a "leadman" (supervisor) and 4 laborers, are working aboard the vessel unloading the scrap steel. The leadman communicates by radio with the crane operator, who relies on the leadman to direct his movements and to ensure the load is properly rigged for unloading.
Each bundle of steel is transferred from the cargo hold in two wire rope slings, which are rigged in a basket hitch configuration to the crane's spreader bar. To allow the laborers to place the lifting wire rope slings under the bundle, it first had to be lifted at one end by a wire called a "breakout wire", which is a longer and smaller diameter wire placed under one end of a bundle. The leadman directs the laborers to stand clear of the bundle and signals the crane operator by radio to begin raising the bundle high enough to allow the laborers to place the actual lifting wire rope slings under both ends of the bundle. The leadman then signals the crane operator to lower the load so that the laborers may remove the breakout wire from the crane's spreader bar and hook the lifting wire rope slings to the crane's spreader bar. Once the bundle is rigged to the crane, the leadman directs the laborers to stand clear of the load and signals the crane operator by radio to lift the bundle out of the hold.
At the time of the incident, the breakout wire had been placed under one end of a bundle of steel and hooked to the crane's spreader bar. At the leadman's direction, the laborers moved to the corners of the hold in order to stand clear of the load. The leadman then directed the crane operator to slowly raise the end of the bundle. After the end of the bundle was raised about 3 feet, the leadman contacted the crane operator by radio to stop raising the load so that he could check the cable. After the leadman determined that the breakout cable was properly rigged, he signaled to the crane operator to continue to slowly raise the end of the bundle. As the two laborers approached the bundle to place the wire rope slings, the bundle began to swing towards them. They attempted to run out of the way, moving in opposite directions, but the bundle struck one of the laborers in the back. The leadman then directed the crane operator to halt the lift and hold the bundle in a raised position. The laborer who was struck died as a result of his injuries.
It appears that the primary cause of the accident was that the 2 laborers came out from their position in the corner of the hatch to the bundle of steel rails while it was being lifted. Additionally, the leadman failed to ensure that the laborers were clear of the load prior to directing the crane operator to begin raising the bundled steel for the second time. Initially it was believed that the bundle of steel swung because it had become caught in between the ribs of the vessel, but the bundle's movements were later attributed to the boom angle of the crane and the angle at which the breakout wire was
rigged to the crane.
The use of two-way radios for communication between the leadman and the crane operator was determined to be an appropriate and necessary means of communication for this operation. The leadman was down in the hold with the cargo, the crane operator was in the crawler crane mounted on the steel deck barge berthed between the ship and the dock.
This was the fourth ship carrying steel rails that the crew had unloaded. The three previous ships had been unloaded without incident. The crane operator was experienced and was licensed by the state. He had been the crane operator for the three previous ships. None of the previous loads had slipped while they were being lifted, but in a few instances the breakout wire had slipped off the end of the bundle.
The breakout wire, slings, and crane were in good condition. However, the crane was not equipped with a load-indicating device, and the accessible areas within the swing radius of the crane were not properly guarded.
Applicable Standards and Control Measures
The load should not be picked up while the lifting wires are at an angle which could cause the load to swing when lifted.
Hold workers, and flagmen should be trained to observe the angle of the lifting wires and to anticipate possible swinging of the load.
Other Standards and/or Control Measures
Page last updated: 04/13/2010