Standard Interpretations - (Archived) Table of Contents|
| Standard Number:||1925.451(l)(4)(5) ; 1926.552(c)|
April 18, 1980
Mr. Perry Hallberg, Jr.
Peabody Continental-Heine Company
2350 East Devon Avenue
Des Plaines, IL 60018
Dear Mr. Hallberg:
This is in reference to our discussions on April 2, 1980, with you and other representatives of chimney erector/liner companies granted variances from sections 1926.552(c) Personnel Hoist and 1925.451(l)(4) and (5) Boatswain's Chairs, of the Occupational Safety and Health Regulations for Construction.
As agreed, an actual dynamic broken rope test will be performed on the safety cage suspension system. This test should establish the effectiveness of the safety clamps in the event of any component failure on the special workmen's hoist system.
The test(s) should confirm:
1. The effectiveness of the safety clamps under maximum drag effects due to the position of the safety cage in its travel when the rope is cut at the footblock.
2. Computations necessary for additional rope weight which can adversely affect balance conditions essential for the activation of the safety clamps.
3. The impact of the free fall headache ball on the safety clamps, safety cables, and safety cage.
4. The tension required on the safety cables to prevent unnecessary motion on the traveling cage.
Dummies should be used during the test(s) to simulate workers inside the safety cage. We also suggest taking high speed photographs of the entire test.
The test(s) should be performed as soon as possible - hopefully within 30 days after the receipt of this letter. Please contact Juanita Jones after the test(s) have been completed to inform her of the test(s) results.
In addition, we request that all computations and test results of the dynamics of the safety cage suspension system be submitted to us immediately after the test(s) is performed. Also, please submit the results of any additional tests you deem necessary to ensure the safety of the special workmen's hoist system.
James J. Concannon Director
Office of Variance Determination
|Standard Interpretations - (Archived) Table of Contents|