Securing a land crane on a barge with a curbing system

October 12, 2004

Mr. Gary C. Hay

Occupational Safety Services, Inc.

[Recipient address omitted]

Re: Whether use of a curbing system for a land crane on a barge would meet the requirement in 29 CFR 1926.550(f) to positively secure the crane to the barge.

Dear Mr. Hay:

This is in response to your letter dated June 9, 2004, to the Occupational Safety and Health Administration (OSHA). You ask whether the use of a "curbing" system designed by a registered professional engineer would satisfy the requirement in 29 CFR 1926.550(f)(1)(iv) that a mobile crane mounted on a barge be positively secured. Your letter was forwarded to this office for handling on July 2, 2004.

We have paraphrased your question as follows:

Question: Scenario: a construction company would like to use the following method for restricting the movement of a land crane on a barge: a 12-inch-high solid timber box ("curbing") surrounds the area in which the crane is authorized to move. The curbing is physically attached to the barge. The dimensions are such that the crane can move fore and aft within the box, but not laterally. A registered professional engineer ("RPE") who is familiar with the use of land cranes on barges has determined that the curbing can withstand the loads imposed during pre-established parameters of use (such as wave, wind and other environmental conditions). The RPE has also certified that the movement of the crane within the curbing will not adversely affect the stability of the barge. Is this acceptable under §1926.550(f)(1)(iv)?

Answer

Section 1926.550(f)(1)(iv) of Subpart N "Crane, Derricks, Hoists, Elevators and Conveyors" states that:

Mobile cranes on barges shall be positively secured.

The purpose of the requirement to positively secure a crane and barge is to ensure that the crane is prevented from shifting/sliding -- in particular, shifting/sliding beyond the area that it must remain in for the barge to remain stable and within maximum safe amounts of list and trim.

Assuming that the facts are as stated in the scenario described above, the use of such a system, by itself, would not be considered the equivalent of physically attaching the crane to the barge. Though the curbing system prevents lateral movement, there remains a hazard from fore and aft movement of the crane during a lift.

With an addition to your scenario, however, the curbing system would be permitted. If you were to physically attach the crane to the barge1 or otherwise physically prevent fore and aft movement of the crane (such as with wheel chocks or other restraining device2) after repositioning it within the curbed area and before beginning the next lift, shifting/sliding in all directions would be prevented. So, the procedure for repositioning the crane within the curbed area would look like this:

With no load attached to the crane, remove/release the wheel chocks/restraining device that prevents fore/aft movement.

Reposition the crane within the curbing system.

Insert/attach the chocks/restraining device.

Attach the load and proceed with the lift.

The use of such a procedure would be a de minimis violation of §1926.550(f)(1)(iv).3 Key factors in this scenario are that: (1) the curbing is physically attached to the barge and designed so that it prevents movement of the crane beyond the authorized area during repositioning and prevents lateral movement when handling loads; (2) the fore and aft movement of the crane when handling loads is prevented by means of wheel chocks or other restraining device; (3) movement of the crane within the box during repositioning will not cause maximum permissible amounts of list and trim to be exceeded, or otherwise adversely affect stability; and (4) the system is designed by a registered professional engineer familiar with the use of cranes on barges.

If you need additional information, please do not hesitate to contact us by fax at: U.S. Department of Labor, OSHA, Directorate of Construction, Office of Construction Standards and Guidance, fax # 202-693-1689. You can also contact us by mail at the above office, Room N3468, 200 Constitution Avenue, N.W., Washington, D.C. 20210, although there will be a delay in our receiving correspondence by mail.

Sincerely,

Russell B. Swanson, Director

Directorate of Construction

1 Means of physical attachment include, but are not limited to, tie-downs and bolting. [ back to text ]

2 Examples of restraining devices in this scenario, other than chocks placed in front and behind the wheels/treads, include detachable cables or detachable curbing. In this scenario, such wheel chocks or other device would be approved by a registered professional engineer as sufficient to prevent the crane from shifting/sliding during the established parameters of use. [ back to text ]

3 Under OSHA's de minimis policy, de minimis violations are those which have no direct or immediate relationship to safety or health. Consequently, no citation is issued. [ back to text ]