REG NASA-LLIS-0239-1993 Lessons Learned - Lifting Slings for Cranes.pdf

1、Lessons Learned Entry: 0239Lesson Info:a71 Lesson Number: 0239a71 Lesson Date: 1993-07-09a71 Submitting Organization: LERCa71 Submitted by: S. PapellSubject: Lifting Slings for Cranes Description of Driving Event: During a crane disassembly, a cable sling broke, dropping a 10 ton crane counterweight

2、. The crane crew was removing the front counterweight from the crane to place it on a flat bed trailer when the mishap occurred. The sling used was a rusty, 4 leg, 5/8 inch diameter cable about 15 feet long. Only two legs were used during this lifting operation.The investigating committee found that

3、 calculations made from a standard table published by U.S. Steel showed that the allowable working load for a new cable of this size using 2 legs was only 5.28 tons. The crane operators, based on their experience and intuition, grossly underestimated the strength of the sling.Lesson(s) Learned: Impr

4、oper choice of lifting slings can occur if only intuition obtained by experience is used.Recommendation(s): Instruct crane operators to use calculations made from standard ANSI publications to determine safe sling working loads.Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Le

5、sson: Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-N/AMission Directorate(s): N/AAdditional Key Phrase(s): a71 Lifting DevicesAdditional Info: Approval Info: a71 Approval Date: 1994-06-08a71 Approval Name: Maria Havenhilla71 Approval Organization: LERC/EBASa71 Approval Phone Number: 216-977-1483Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-