* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * INFORMATION ALERT * * * * Produced by: Ontario Ministry of Labour * * Provided by: Canadian Centre for Occupational Health and Safety * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * INFO ALERT: 30 DATE: February 8, 1993 *** HAZARD SUMMARY: *** A 1976 Pierreville aerial ladder fire truck with a 100 foot ladder failed during a demonstration in Kelowna, B.C. The ladder had been elevated to 60 degrees from horizontal and extended 65 feet in preparation for a fire fighter to climb the rig when the three extended sections suddenly retracted. Damage included a broken cable, two holes punched in the turntable, end stops sheared off and bent rails on the first and second sections of the ladder, and a broken shaft on the elevating mechanism. Fatal or critical injuries could have resulted if a fire fighter had been on the ladder when it failed. An engineering analysis of the failure indicated that the shaft on the elevating device had fractured as a result of misalignment between the worm gear box and the winch drum. This misalignment had produced alternating compression and tension forces within the shaft as it was rotated, and the reulting fatigue led to crack propagation. The misalignment must have existed for some time since less than 40% of the fracture surface was fresh. Pierreville aerial ladder fire trucks manufactured between 1974 and 1987 are most likely to have this problem. *** LOCATION(S) AND SECTOR(S): *** Municipal and industrial fire services *** SUGGESTED PRECAUTIONS: *** Section 25(1)(b) of the Occupational Health and Safety Act requires the employer to ensure that "equipment, materials and protective devices provided by him are maintained in good condition." The following recommendations have been forwarded for Pierreville aerial ladder fire trucks manufactured between 1974 and 1978: 1. Eliminate the reduction in shaft diameter at the winch flange. 2. Strengthen the mechanical connection to the winch drum. 3. Design for proper alignment of the components. 4. Check alignment periodically. 5. With Pierreville aerial fire trucks manufactured between 1974 and 1978 that have not been modified, perform annual non-destructive test on the shaft. A new regulation for inspection, non-destructive testing and repair of aerial ladder fire trucks is under development. For more informtion or a copy of the engineering report please contact Ed Gulbinas, P.Eng., at (416) 326-7931 or Sam Somasundar, P.Eng., at (416) 326-1419. Dial 1-800-268-8013 for long distances calls within Ontario. NOTE: "Information Alert" is produced by the Occupational Health and Safety Branch, Ministry of Labour for use by Ministry inspectors, health and safety associations and other interested groups or individuals in Ontario. The goal of this publication is to communicate hazard information as soon as it becomes available to prevent injury to workers. Reproduction and use of these alerts is encouraged. Disponible en francais