Section III: Material Handling Accidents
Summary No. 6 - Unstable Stacked Slabs
Employees were exposed to the hazard of being struck by stacked steel slabs.
Longshoremen are using a forklift to transfer slabs of steel from a pier to a flatbed truck.
Longshoremen at a marine terminal are loading steel slabs onto flatbed trailer trucks. The slabs are each seven inches thick, about two feet wide, and 20 feet long, and are stacked one atop another lengthwise in tiers of seven slabs. Pieces of wood blocks (chocks 4 inches by 4 inches, each about 2 to 3 feet long) are placed in between the steel slabs to serve as spacers to separate the slabs so that the forklift truck operator can slide the forklift blades under each slab. The stacked tiers are placed very close together. Three employees are performing this operation. One employee drives the forklift truck, and the other two employees remove the wooden spacers that are exposed after a steel slab is lifted and removed so that the forklift truck could get the next slab. It was raining fairly steadily on the afternoon of the accident.
At the time of the incident, the employees were working on a pile that had three steel slabs left. Just behind this pile was a tier of seven steel slabs about seven feet high. One employee (the victim) was attempting to remove a wooden spacer from the front stack that had protruded into the rear tier and had become embedded in that tier. The employee had to remove the spacer so that the forklift truck could load the next steel slab in the front stack. As the employee attempted to pull the wooden spacer that was stuck and protruding out of the rear stack, three slabs from this rear tier, weighing about 20,000 pounds, fell and struck the employee. He was killed after being crushed by the slabs of steel.
An adjacent stack of steel slabs was leaning at a 5-degree angle, and the asphalt ground on which the stacks were placed was uneven and had numerous holes. Workers were observed tripping and falling as a result of the holes, and the victim's foot may have become caught in a hole as he attempted to move out of the way of the toppling stack.
The forklift truck was likely a contributing factor destabilizing the back tier by inadvertently striking it with overlength forks. The forklift blades were about six feet long, and the stacks were about two feet deep. This would allow several feet of the length of the blade of the forklift to go into the tier that was behind the tier being worked. The rear stack itself was only inches from the stack in front. The forklift truck did not have a backup alarm, which is recommended but not required.
Applicable Standards and Control Measures
- 29 CFR 1917.14: Stacking of cargo and pallets. "Cargo, pallets and other material stored in tiers shall be stacked in such a manner as to provide stability against sliding and collapse."
The steel slabs were not stacked to prevent sliding or collapsing. The slabs were stored in tiers seven high, on an incline, close together, and on asphalt paving.
This hazard may have been prevented if the employer had ensured that the stacks of steel slabs were placed in a stable arrangement. For example, the stacks should have been positioned far enough apart to avoid unintended contact with the forklift blades and they should have been placed on a level surface.
Other Relevant Standards and/or Control Measures
Develop and implement procedures for performing this task safely.Back to Top