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.

October 8, 1991

Mr. Daniel E. Guadagno
Supervising Safety Engineer
Environmental, Health, and Safety
Inland Steel Flat Products Company
3210 Watling Street
East Chicago, Indiana 46312

Dear Mr. Guadagno:

This is in response to your letter of July 23, in which you requested an interpretation of 29 CFR 1910.179(f)(6) (Application of bridge brakes.) Specifically, you asked if there were any requirements for automatic activation of bridge travel brakes where the bridge controller is centered in the neutral position, and you stated that the question applied to all types of cranes, overhead, floor, and remote.

As you are aware, the requirements for brakes on overhead and gantry cranes are specified at 29 CFR 1910.179. Specifically, the requirements for stopping the motion of bridge travel are provided at 29 CFR 1910.179(f)(6). The requirements are as follows:

1. The standard requires that cab-operated cranes with cab on bridge, be equipped with bridge travel brakes conforming to the requirements specified at 29 CFR 1910.179(f)(4). The standards do not require that cranes equipped with cab on bridge be equipped with an automatic bridge brake. It should be noted however, that the standard at 29 CFR 1910.179(f)(4)(viii) specifies, if holding brakes (automatic brakes) are provided they shall not prohibit the use of a drift point in the control circuit. "Drift point", is defined at 29 CFR 1910.179(a)(36).

2. On cab-operated cranes with cab on trolley, a bridge brake of the holding type is required. The definition provided at 29 CFR 1910.179(a)(20) clarifies this requirement. A holding brake is defined to be an automatic brake which is activated when the power is off. OSHA interprets this to mean that, when the controller is centered in the neutral position and the power is off to the drive motor(s), an automatic bridge brake is required on cranes with cab on trolley.

3. On all floor, remote and pulpit-operated crane bridge drives, a brake or noncoasting mechanical drive is required. OSHA believes that, this requires the brake or braking capability to automatically become effective whenever the drive components cease to be activated. An automatic bridge braking action is required on floor, remote and pulpit-operated crane bridge drives.

The appropriate portions of the standard are enclosed.

Your interest in workplace safety and health is appreciated.


Patricia K. Clark, Director
Directorate of Compliance Programs