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OSHA Hazard Information Bulletins
Lorain Hydraulic Rough Terrain Cranes
November 8, 1985
MEMORANDUM FOR REGIONAL ADMINISTRATORS
The Division of Occupational Safety and Health, State of California, has investigated two accidents involving the failure of the boom on Lorain Hydraulic Rough Terrain Cranes, Models LRT 275 and 1600M. Cracks were found at the boom butt section welds at the connection to the horizontal pivot tube in both accidents.
Koehring Cranes and Excavators, the manufacturer of the cranes, has acknowledged the possible presence of the defect in the above models. The manufacturer's representatives also indicated that other models with three sections, 81 foot long booms may have defective pivot tube connections. Koehring Cranes and Excavators has issued notices dated March 11 and 26 to its distributors and customers on this issue. The notices warn against the use of cranes with cracks in the boom pivot tube areas, and recommend a method for a visual inspection. In addition, the manufacturer has supplied the distributors and the users with instructions and parts for adding reinforcement plates to both sides of the boom at the boom pivot tube area. A list of crane models which require the recommended reinforcement is noted on the March 29, 1985 notice.
The boom pivot tube area referred to in this memorandum is the area where the bottom boom section is pivotally mounted on the revolving superstructure by means of a tube and an internal bar. The welds in which the failure was observed is that which connect the pivot tube to the boom. The manufacturer's report on the foot boom analysis indicates that the recommendations for the reinforcement method of the butt section is substantiated by a stress evaluation under the most severe loading conditions, and that it should result in preventing a boom failure due to weld fatigue.
Copies of the Koehring Cranes and Excavators' inspection notices, and of the boom foot reinforcement kit instructions are attached for dissemination to Area Offices, State Plan States, and Consultation Projects. It is likely that many of these cranes have been inspected and repaired as recommended by Koehring Cranes and Excavators. Nevertheless, some of the cranes may still be in use without the proper repair. Therefore, compliance and consultation personnel should be aware of the potential failure of the boom on the unrepaired Lorain and Bantam cranes.