Secondary wire rope suspension systems. | Occupational Safety and Health Administration

Standard Number:

1926.451(g)(3)(iv)

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.

September 3, 1993

Mr. Victor Saleeby
Executive Vice President
Scaffold Industry Association
14039 Sherman Way
Van Nuys, California 91405-2599

Dear Mr. Saleeby:

This is in response to your April 12 letter in which you seek further clarification of the Occupational Safety and Health Administration (OSHA) policy regarding secondary wire rope suspension systems. I apologize for the delay in responding to your inquiry.

With respect to securing the second wire rope to both its own anchorage (separate from the primary rope anchorage) and to the outrigger or other suspension device, please be advised that this arrangement would be acceptable provided the line is taut on both sides of the outrigger point of attachment. It is important to note that if this arrangement is used, it may not function as a tieback for the scaffold unless the connection at the outrigger is made in such a way that the secondary wire rope can function as though it was two separate lines, one for the scaffold platform, and one as the tieback. In other words, the method of securing the rope must be such that if the rope is cut or disconnected on either side it will continue to support the other side.

With respect to your trolley line arrangement, looping the ends around both the primary and the secondary lines above the hoist and brake at each end of the scaffold, would be an acceptable arrangement.

If you require further assistance, please don't hesitate to contact me or Mr. Dale Cavanaugh of my staff at (202) 219-8136.

Sincerely,

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

April 12, 1993

Roy Gurnham,
Director of Construction
& Maritime Compliance Assistance
USDOL/OSHA
Room N-3610
200 Constitution Ave., N.W.
Washington, DC 20210

Dear Mr. Gurnham:

With respect to your previous letter recognizing secondary wire rope suspension systems, we would like to advise scaffold dealers and their customers of the proper and best way to comply with your letter.

In addition to attaching the 2nd wire rope to the required separate fixed anchorage, we propose connecting the two wire ropes and anchorages so they reinforce each other. This can be done by attaching the 2nd wire rope to a structural part of the building and also attaching it to the main wire rope outrigger or other suspension. An example is shown in the attached sketch. As a result:

1. If the main wire rope fails, the platform will be supported by both the outrigger and the separate 2nd wire rope anchorage.

2. If the outrigger becomes unstable or fails, the 2nd wire rope and its anchorage will prevent the outrigger and its weights from falling off the building onto the platform or persons below.

With respect to the trolley line, we propose looping the ends around both wire ropes, above the hoists and both wire rope brakes:

1. The trolley line will be high and allow a short lanyard.

2. The trolley line will remain secure and independent if the platform or its connections should fail.

3. The tendency for the suspension ropes to move inward under a side load will help cushion the fall.

This proposed procedure was recently approved by the ANSI A10.8 Committee for inclusion in the next revision of the standard.

Please advise us if you agree and if the information outlined in the attached letter, which we may use in instructing dealers/distributors regarding this procedure, will comply.

Sincerely,

D. Victor Salecby
Executive Vice President

SUGGESTED LETTER TO DEALERS/DISTRIBUTORS.

The attached letter confirms that OSHA now recognizes the use of a secondary wire rope in place of vertical lifelines on all installations.

The letter specifies that installations comply with ANSI A10.8-1988 or OSHA 29 CFR 1910.66(F)(5)(L) and (M). Copies of these ANSI and OSHA provisions are attached. The provisions require that the second wire rope be fastened to a fixed anchorage (other than the scaffold support) and the workmen be attached to the stage. The 2nd wire rope keeps the platform level in case the main rope or the rigging fails. The workmen's lanyards are attached to a trolley line in case they fall off the platform.

The platform will have two potential supports:

1. The main wire rope, attached to the outrigger.

2. The 2nd wire rope, separately attached to a structural part of the building.

In addition, we propose connecting the two supports so they reinforce each other. This can be done by attaching the 2nd wire to a structural part of the building and also attaching it to the outrigger. As a result:
1. If the main wire rope fails, the platform will be supported by both the outrigger and the separate anchorage. 2. If the outrigger becomes unstable or fails, the 2nd wire rope and its anchorage will prevent the outrigger and the weights from falling off the building and onto the platform or persons below.

The 2nd wire rope can attach to any fixed anchorage. It does not need to be attached to a separate outrigger. It can also be attached to a separate parapet clamp (or cornice hook) on the front or back wall, or to any structurally sound part of the building. Any attachment point that would qualify as an attachment point for a lifeline should be satisfactory.

The 2nd wire rope is an "emergency" device, not a working device. If it is protected form sharp edges, like the rope lifelines, the 2nd wire rope can be led directly over the edge of the building (or parapet) to an attachment point.