OSHA Hazard Information Bulletins
Bridge Inspection Aerial Platform

December 31, 1991




  • Director
  • Office of Field Programs


  • Director
  • Directorate of Technical Support


  • Hazard Information Bulletin - Bridge Inspection Aerial Platform

The Philadelphia Regional Office has brought to our attention information received from Maryland Occupational Safety and Health (MOSH) indicating that a bridge inspection aerial platform called a "Bridgeworker", manufactured by J. O. Dougall, Ltd. of Rexdale, Ontario, Canada may not be safe to use.

A MOSH 7(c)(1) consultant, in response to a request from an employer, inspected a "Bridgeworker" aerial platform Model No. BW 28/21, S/N 880106TM to determine whether or not it contained design/manufacturing deficiencies which could potentially make it unsafe to operate.

The "Bridgeworker" aerial platform is hydraulically-operated, consisting of two truss towers and one work platform and is mounted on a counter-weighted turntable, stored horizontally on a single-axle flatbed truck. When in use, the towers are unfolded and raised to a vertical position over the right side of the truck. The platform is suspended underneath and perpendicular to the bridge from the outboard tower which is the longest of the two (See attached flyer on Model No. 36/21 which is similar to Model No. BW 28/21 with a different platform length).

The following defects were noted:

Following these modifications, the manufacturer failed to respond to requests to supply required ANSI test data.

  1. A swing brake was not provided. The turntable had been retrofitted with a hydraulic piston which replaced the slew ring worm gears. When this was done, it allowed the turntable to swing 90 degrees instead of 180 degrees as it had in the past. At the same time as this modification, the outrigger for the left side had been removed, and additional weight was added to the counterweight.
  2. When fully erected, the truck appeared to list dangerously on the springs towards the right side.
  3. Fall protection was not provided for the operator. In order to reach the operator's station, which is a seat located on the right side of the turntable, the operator is exposed to a fall hazard from the side of the bridge.

In an effort to address the stability issue, both MOSH and OSHA contacted the manufacturer, J. O. Dougall, Ltd for more information. However, J. O. Dougall, Ltd. did not respond.

Although defects were noted as a result of an inspection of a particular unit, it should be assumed that similar units could have the same defects. Should we receive evidence to the contrary from the manufacturer, we will share such information with you.

Compliance and consultation personnel should be aware of the possible deficiencies of the J. O. Dougall "Bridgeworker" aerial platforms. If encountered, compliance with the American National Standards Institute standard A92.2-1969 "Standard for Vehicle Mounted Elevating and Rotating Work Platforms" should be verified.

Please distribute this bulletin to all Area Offices, State Plan States and Consultation Projects.


Figure 1. Bridgeworker Image Model No. BW 36/21

Figure 1. Bridgeworker Image Model No. BW 36/21

Figure 2. Model No. BW 36/21

Figure 2. Model No. BW 36/21


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