OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.

November 22, 1991

Mr. Reynold J. LeBlanc
45312 Joe Guedry Road
St. Amant, Louisiana 70774

Dear Mr. LeBlanc:

This is in response to your September 24 letter requesting an interpretation of the Occupational Safety and Health Administration (OSHA) requirements addressing the use of cranes. I apologize for the delay in responding to your inquiry.

In regard to whether the Galion/Dresser cross-line relief system complies with OSHA's anti-two-block device requirements, please be advised by the following: The Galion/Dresser two block damage prevention feature suspends hoisting and allows rope payout before damage occurs in the event of a two-blocking situation. Its use, therefore, would comply with this requirement. However, if an attachment is installed on the crane that could defeat the effectiveness of the device (i.e. a jib installed without stops that could flip over backwards in the event of two-blocking) then the crane would no longer be in compliance with 29 CFR 1926.550(g)(3)(ii)(C).

In regard to your question about what are the OSHA and ANSI requirements for holding brakes and hoisting brakes on winches on hydraulic cranes, please be advised that OSHA requires load and hoist drum brakes to be engaged when a personnel platform is occupied and in a stationary position. In addition, OSHA requires that all crawler and truck cranes meet the applicable requirements for design, inspection, construction, testing, maintenance and operation as prescribed in ANSI standard B30.5-1968. The ANSI standard requires a positive means be provided (controllable from the operators station) to hold the hoist drum from rotating in the lowering direction, and that it be capable of holding the rated load indefinitely without further attention from the operator. The ANSI standard also requires that brakes and clutches be provided with adjustments where necessary to compensate for wear and to maintain adequate force in springs where used. I have enclosed a copy of section 5-1.3 "Boom Hoist and Load Hoist Mechanisms," of ANSI Standard 30.5-1968 for your information.

If we can be of further assistance, please contact Mr. Roy F. Gurnham or Dale R. Cavanaugh of my staff in the Office of Construction and Maritime Compliance Assistance at (202) 523-8136.


Patricia K. Clark
Directorate of Compliance Programs