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.

February 23, 1994

Mr. George S. Kennedy
National Utility Contractors Association
137 Ruhle Road
Ballston Spa, New York 12020

Dear Mr. Kennedy:

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

As you point out in your letter, OSHA's construction standards do not specifically address safety procedure associated with the use of wheel or track propelled excavators that are engaged in pipe laying operations. As you know, when there are no specific standards, the Agency relies on the general duty clause to address hazards that are recognized by the concerned industry. With regard to guarding the swing radius of excavators, the Agency considers being caught between the rotating superstructure of an excavator and the carrier or other object a serious hazard and one that is recognized by the excavation industry. Therefore, not only is the employer required o instruct each employee, who could be exposed, on the danger of working near the rotating superstructure (see 1926.21(b)(2)), but must also take the necessary precautions (e.g., erect barricades, warning lines, or other excavation industry recognized procedures) to prevent entry into a swinging superstructure's radius.

We have enclosed a copy of Fatal Facts No. 50 for your information and further guidance.

If you have any further questions, please contact me or Mr. Dale Cavanaugh of my staff at (202) 219-8136.


Roy F. Gurnham, P.E., J.D.
Office of Construction and
Maritime Compliance Assistance


September 9, 1992

Mr. Roy Gurnhum
U.S. Department of Labor
Office of Construction and
Maritime Compliance Assistance
200 Constitution Ave., N.W.
Room N. 3610
Washington, D.C. 20210

Dear Roy:

During the last year our members have been faced with interpretations of standards that do not seem to apply with the type of work. They have also been faced with interpretations that differ from region to region and in state programs from state to state. In order to help us provide accurate information to construction management personnel please provide us with an official interpretation for the following question.

The "Crane and Derrick" standard 1926.550(a)(9) requires barricading or guarding the rotating superstructure swing radius of cranes. Does this standard apply to wheel and/or track propelled excavators when used to set a length of pipe in the trench? There is no mention of this type of operation in the construction standards yet some of our members have been told by OSHA that they must guard the swing radius even though this operation is no different that excavating soil and placing it on the side of the trench or in a dump truck.

We are very concerned that OSHA is interpretating standards that were written for crane operations and applying them to backhoe and excavator operations. How does OSHA expect contractors to comply with standards when they were clearly written for equipment and operations unrelated to the type of work the contractor's crews are trying to perform?

Our instructors are providing the NUCA Competent Person Training Program all over the country and we want to be able provide accurate information.

Thank you for your assistance.


George S. Kennedy, CSP
Director of Safety

P.S. Please send response to: 137 Ruhle Road, Ballston Spa, NY 12020