OSHA Hazard Information Bulletins
December 31, 1991
| MEMORANDUM FOR: | REGIONAL ADMINISTRATORS |
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| THRU: | LEO CAREY
Director
Office of Field Programs |
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| FROM: | THOMAS J. SHEPICH
Director
Directorate of Technical Support |
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| SUBJECT: | 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:
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.
Following these modifications, the manufacturer failed to
respond to requests to supply required ANSI test data.
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.
Attachment
Figure 1. Bridgeworker Image Model No. BW 36/21 |
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Figure 2. Model No. BW 36/21 |
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