OSHA Hazard Information Bulletins
March 22, 1996
MEMORANDUM FOR: |
REGIONAL ADMINISTRATORS |
FROM: |
STEPHEN MALLINGER
Acting Director
Directorate of Technical Support |
SUBJECT: |
Hazard Information Bulletin - Hitachi EX3500 and
EX1800 Hydraulic Excavators Equipped With Front
Shovel Attachments |
______________________
The Directorate of Technical Support issues Hazard Information Bulletins
(HIBs) in accordance with OSHA Instruction CPL 2.65 to provide relevant
information regarding unrecognized or misunderstood health hazards,
inadequacies of materials, devices, techniques, and safety engineering
controls. HIBs are initiated based on information provided by the field
staff, studies, reports and concerns expressed by safety and health
professionals, employers, and the public. Information is compiled based on a
thorough evaluation of available facts, literature and in coordination with
appropriate parties. HIBs are used as an outreach tool for accident
prevention.
The Mine Safety and Health Administration (MSHA) forwarded to the
Occupational Safety and Health Administration (OSHA) a draft Program
Information Bulletin informing MSHA enforcement personnel and mine operators
of a potential failure of bolt flanges utilized on the hydraulic system of
the Hitachi EX3500 and EX1800 Hydraulic Excavators equipped with front shovel
attachments. Recently, a hydraulic spool on a Hitachi 3500 Excavator was
projected from its valve body, killing a miner. The Hitachi Construction
Machinery (America) Corporation (HCMA) is presently assisting MSHA in
investigating this incident. The purpose of this HIB is to familiarize OSHA
personnel of the MSHA incident and to assist in recognizing similar
situations at other workplaces.
Although the investigation has not yet been finalized and the cause of the
bolt failure has not been determined, Hitachi decided to begin a modification
program immediately on October 30, 1995, in consultation with MSHA. This
program is intended to eliminate the possibility of a similar occurrence.
The program primarily consists of:
a. Requiring that the four bolts be replaced by an authorized
Hitachi dealer/representative. It is strongly recommended that operators do
not attempt to replace the bolts themselves;
b. Placing guards on the switch valve assembly;
c. Asking that operators who wish to make some type of immediate
interim correction do get guidance from an authorized
dealer/representative.
d. Asking that operators do not attempt to tighten the old or new
bolts beyond recommended torque, as this could increase the likelihood of
bolt failure.
Although there is no guarantee that there will be an obvious
indication that one of the bolts is failing, a hydraulic oil leak around the
end cap could indicate that a potential fatigue failure is in process.
If
this should occur, immediately contact an authorized dealer/representative
for instructions.
According to Hitachi, all bolts have been replaced, or are scheduled to be
replaced, on all Hitachi EX3500 and the EX1800 machines operating in the
United States. Guards have been installed on all EX3500s and on 90 percent
of the EX 1800s. All EX1800 owners have been notified of the advisability of
installing guards and several have elected to schedule this modification with
routine maintenance procedures in the near future.
This bulletin may be used for accident prevention and outreach purposes.
Please distribute this bulletin to all area offices, State Plan States,
Consultation Projects and appropriate local trade and union groups for their
information.
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