Section III: Material Handling Accidents
Summary No. 3 - Unbalanced Load
Hazard
Employees were exposed to the hazard of being struck by an unbalanced load in a nylon sling attached to a crane.
Process
Employees are using a crane and a forklift to raise and tip a large press machine on its side in order to position it for shipment.
Activity at time of incident:
A crane operator was using a pendant control to raise a large press machine, as a forklift operator tipped the machine.
Incident Description
Setting:
A crane operator and a forklift operator working in a warehouse are in the process of moving a large press machine in preparation for shipping it overseas. The 3,500-pound press machine is secured in a nylon sling, which is attached to an overhead crane in a basket configuration. The workers are attempting to set the machine on its side on a skid. The forklift is used to tilt the machine as the crane helps to hoist it and lower it on its side.
Incident:
Using a pendant control, the crane operator began lowering the press as the forklift operator tilted it forward, when one end of the nylon sling securing the press slipped off the hook attached to the crane's chain sling. At the time of the incident, the crane operator was standing about two feet in front of the machine (too close) and was killed when the machine fell on him.
Relevant Factors:
The load was not balanced and the sling was subject to slippage. It appears that as the machine was being tilted the nylon sling did not slide as anticipated, creating enough slack for one end of the sling to dislodge from the hook. The use of a basket hitch on a crane during such an operation would make it impossible to balance the load to prevent the sling from sliding.
There were no established procedures for tipping the machine using a crane and a forklift, nor did the employees receive any training in such operations.
The employees had just successfully performed a similar operation on another piece of equipment. One witness reported that they had tried lifting the first unit in a choker configuration but the piece could not be lifted, so they changed to a basket hitch instead.
The victim had one notice in his personnel file for passing under a suspended load. On the day of the incident, he was told by the forklift operator twice to stand clear of the suspended load, once during the first lift and then just before the machine fell. The forklift operator should have been trained to stop the operation until the hazard was corrected.
The employees did not recall receiving training on inspection of ropes, hooks, or other crane components.
Applicable Standards and Control Measures
- 29 CFR 1917.13(a): Slinging. "Drafts shall be safely slung before being hoisted. Loose dunnage or debris hanging or protruding from loads shall be removed."
- 29 CFR 1917.45(k): Cranes and derricks - Routine inspection.
- (k)(1): "Designated persons shall visually inspect each crane and derrick on each day of use for defects in functional operating components and shall report any defect found to the employer. The employer shall inform the operator of the findings.
- (k)(2): A designated person shall thoroughly inspect all functional components and accessible structural features of each crane or device at monthly intervals.
- (k)(3): Any defects found during such inspections which may create a safety hazard shall be corrected before further equipment use. Repairs shall be performed only by designated persons.
- (k)(4): A record of monthly inspections shall be maintained for six months in or on the crane or derrick or at the terminal."
- 29 CFR 1917.50 (c)(1): Certification of marine terminal material handling devices. "Each crane and derrick shall be tested as a unit quadrennially, and shall be examined annually. Certificates of tests and examinations shall be made readily available for inspection."
The employer should have ensured that the crane was inspected in accordance with the above standards.
- 29 CFR 1917.42(a): Miscellaneous auxiliary gear - Routine inspection.
- (a)(1): "At the completion of each use, loose gear such as slings, chains, bridles, blocks and hooks shall be so placed as to avoid damage to the gear. Loose gear shall be inspected and any defects corrected before reuse.
- (a)(2): All loose gear shall be inspected by the employer or his authorized representative before each use and, when necessary, at intervals during its use, to ensure that it is safe. Any gear which is found upon such inspection to be visibly unsafe shall not be used until it is made safe.
- (a)(3): Defective gear shall not be used. Distorted hooks, shackles or similar gear shall be discarded."
The employer should have ensured that the chains on the crane were inspected in accordance with above standard. Additionally, the employer should have ensured that employees were adequately trained in the proper use of slings and cranes. Further, safety procedures for performing this type of operation, using a crane and a forklift to tilt and hoist a heavy piece of machinery, should have been developed prior to the operation.
Other Relevant Standards and/or Control Measures
- 29 CFR 1917.13(h): Slinging. "The employer shall require employees to stay clear of the area beneath overhead drafts or descending lifting gear."