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.

July 26, 1994

Mr. D. Michael Barr
General Superintendent
Martin G. Imbach, Inc.
6121 Pennington Avenue
Baltimore, Maryland 21226

Dear Mr. Barr:

This is in response to your January 26 letter requesting a waiver from an America National Standard Institute (ANSI) requirement addressing the use of wire rope clips in conjunction with wedge sockets. I apologize for the delay in responding to your inquiry.

The ANSI standard in question, ANSI A10.5c-1992, has not been formally adopted by OSHA, and therefore the ANSI provisions are not OSHA requirements to which the "waiver" (or "variance") procedures of the OSH Act would apply. OSHA does, however, frequently make reference to ANSI standards as evidentiary support for citations under the Act's general duty clause. Your question, then, is really whether OSHA would cite an employer under the general duty clause for using a wire rope clip in a manner contrary to ANSI A10.5c-1992.

If an ANSI standard has not been adopted as an OSHA requirement, OSHA can independently evaluate whether noncompliance with an ANSI provision in a particular circumstance would also constitute a violation of the general duty clause. With regard to the use of a wire rope clip with a wedge socket, please be advised that in applications involving vibration, such as pile driving and clam shell operations, we would agree a wire rope clip may be used to clip the dead end of the rope to the live end to prevent the socket from working loose and the rope from jumping out of the groove of the wedge. The clip should be hand tightened with a wrench and not torqued to normal clip termination values. OSHA recommends, however, that a clip specifically designed for use with wedge sockets be used in this application.

For wedge socket applications not involving vibration, the policy is to use a wedge socket clip or to place a wire rope clip around the dead end of the line by clamping a short piece of rope, of the same diameter, to the tail.

If we can be of any further assistance, please contact me (Ext. 150) or Mr. Dale Cavanaugh (Ext. 149) of my staff at (202) 219-8136.


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


(For letter of inquiry, see printed copy)


(For Riggers Corner article, see printed copy)


(For images, see printed copy)




January 26, 1994




U. S. Department of Labor
Occupational Safety & Health Administration
1110 Federal Building
31 Hopkins Plaza
Baltimore, Maryland 21201

Attention: Area Director


We are currently working with and attempting to comply with OSHA regarding the use of anti-two block devices while hoisting personnel.

We are experiencing severe difficulty in maintaining and operating these devices on barge mounted cranes, specifically in pile driving operation. Some problems we have encountered are listed below:

1. In multiple line use on a standard taper boom, the anti-two block weight can be interfered with by the adjacent hoist lines causing sporadic crane shut down or fouled by an adjacent hoist line causing the weight to be either pulled up into the sheaves at the boom head or pulled down, breaking the devices chain.

2. The constant motion of the barge caused be wave action. other vessels' wake, or crane operation is transmitted to and exaggerated at the boom tip causing the anti-two block weight to move to a degree that continually activates and deactivates the shut-down system. This causes the operator to sporadically lose power at the boom and main hoist controls.

3. We have experienced numerous incidents where failure of the weights suspension chain has caused the weight to fall the full height of the hoist line, striking the becket and in some cases breaking the bolts containing the weight, allowing the pieces to scatter around the deck. We have attempted to solve this problem by increasing the size of the chains and shackles used to suspend the weight, but failures continue. We feel this is again due to multiple line use and barge movement.

These problems can be documented in our crane logs starting 23 May 1990. We are also using a 10 painted lead at the end of the controlled load lowering line as a guide for the operator to prevent two-blocking. While this is not as sophisticated as the anti-two block system, it is far more practical and successful on barge mounted equipment. When used in conjunction with all other OSHA requirements (i.e. prelift conference, test lift, etc.) we feel this to be a completely safe alternative, because of the very controlled nature of the lift.

We, therefore, request a waiver of the use of anti-two block shut down systems on barge mounted cranes, for reasons stated above. We propose the use of 10 painted cable lead as operators visual restrained from two blocking.

Please contact me with any questions concerning this matter.

Very truly yours,


D. Michael Barr
General Superintendent


DATE:            March 11, 1994



FROM:            LINDA R. ANKU


Enclosed is a copy of a letter being forwarded for response. In the letter, an employer is requesting permission to use a wire rope clip to attach the "dead end rope tail" to the "live part" of a wire rope used with a wedge socket. This practice is prohibited by OSHA's standards. The basis for the request is an article (copy enclosed) in the "Rigger's Corner" section of the April/May 1993 issue of Lift Equipment. The article indicates it is advisable to clip the dead end of the rope to the live end since it prevents the wedge socket from working loose. The determination made relative to this issue will have national impact.

The employer has been advised that their letter is being forwarded to your office for review.

If you require any additional information regarding this matter, please contact John McFee of my staff at (215) 596-1201.