|Description of the accident:
A mechanic suffered two fractured arms as a result of an accident he had while working on a hydraulically-operated, scissor-type, mobile, aerial platform.
The day before the accident, a fellow millwright removed the lift cylinder from the machine to replace the seals which were leaking. To gain access to the cylinder, he elevated the platform approximately three feet off the ground. To prevent it from falling, he supported it with a stack of wooden 2 X 4's.
He removed the cylinder and replaced the seals. Upon completion of the repairs, he installed the cylinder, and connected the hoses. His shift ended and he left work. He did not attempt to start the machine.
The mechanic on the second shift assumed the task of completing the repair. After inspecting the cylinder installation, he decided to start-up, and test the machine. While inspecting the machine he noticed the stack of 2 X 4's supporting the platform. Since he was about to start the machine, he decided to remove them.
He stuck his arms in through the scissor lift assembly and began knocking the 2 X 4's out with a hammer. As the stack of 2 X 4's collapsed, the platform came crashing down, crushing his arms in the scissor lift assembly.
This is yet another testimony to the fact that on-the-job training in hydraulics simply doesn't work. The victim of this unfortunate accident had no more than a few years of on-the-job experience with hydraulics. Sure, he knew that the platform was powered by hydraulic oil and a pump. However, because he had no formal training in hydraulics he did not fully understand the correlation between the oil and the load-locking components in the system which are essential to the safe and proper operation of the machine. In fact, because he did not have the proper training, he should have been prohibited from working on the scissor-lift by his supervisor.
It's important to realize that years of experience don't always equal years of safe operation. It is said, that 10 years of on-the-job training is equal to one year of experience10 times!
Aircraft technicians are required by law to be certified by the FAA to work on aircraft hydraulic systems. The term operators use to describe the operation of aerial platforms is "flying." Consequently, the same strict protocols that apply to aircraft technicians, should apply to personnel who service and repair aerial platforms, since a malfunction, for any reason, could put the operator/s at risk of a serious accident. ALL equipment needs regular, ongoing attention in terms of inspection and maintenance, and ALL personnel need regular, and ongoing maintenance and safety training.
Recommendations on how this type of accident can be prevented:
- Require that all technicians who service and repair aerial platforms be appropriately trained and certified. Training should include, but not be limited to:
- Service procedures
- Repair procedures
- Adjustment procedures
- Hydraulic systems with an emphasis on load-holding valves specifically, pilot-operated check valves, counterbalance valves, and velocity fuses.
- Require that all operators of aerial platforms be appropriately trained and certified.
- Require that technicians and operators of aerial platforms receive regular refresher training courses related to their field of responsibility.
- Include aerial platform safety in your safety meetings.
|The accidents we report are real, and the victims are real. The safety guidelines we provide are to help companies and individuals work safely with hydraulics. All guidelines we provide are general, and are not intended for one specific hydraulic system or machine.
WHEN YOU PURCHASE HYDRAULIC-POWERED MACHINERY AND/OR EQUIPMENT, WE HIGHLY RECOMMEND THAT ONCE YOU DETERMINE THAT IT CAN DO THE WORK YOU WANT IT TO DO, YOU THEN DETERMINE HOW MUCH SAFETY HAS BEEN BUILT INTO IT BY THE MANUFACTURER. IN ADDITION, WE RECOMMEND THAT YOU, WITH THE INPUT FROM YOUR OPERATORS, MECHANICS, ENGINEERS, PRODUCTION PERSONNEL, AND SAFETY DEPARTMENT, FORMULATE A LIST OF MINIMUM SAFETY STANDARDS FOR THE EQUIPMENT YOU PURCHASE. ALTHOUGH WE LIKE TO BELIEVE THAT MOST MANUFACTURERS ARE CONCEREND ABOUT SAFETY, SOME BELIEVE THAT CERTAIN SAFETY MEASURES ARE AN UNNECESSARY EXPENSE. WE FURTHER RECOMMEND THAT ALL THE SAFETY STANDARDS AND RECOMMENDATIONS THAT YOU DEVELOP SHOULD BE REVIEWED BY YOUR SAFETY DEPARTMENT, ENGINEERING DEPARTMENT, AND BY THE RESPECTIVE MACHINE OR EQUIPMENT MANUFACTURER PRIOR TO MAKING THEM POLICY - TOTAL SAFETY CAN ONLY BE ACHIEVED WITH A TEAM EFFORT.
|The Fluid Power Safety Institute does everything possible to insure that the information and drawings contained in these documents is accurate, and the procedures are deemed safe and reliable. However, these are general recommendations only and might not be applicable to all situations.
You MUST have your engineering department and service department read these recommendations and make the necessary changes for your specific application.
The Fluid Power Safety Institute is not responsible for actions taken by untrained and/or unauthorized persons. ALL hydraulic system service, repair, and troubleshooting should be done by trained, authorized persons ONLY.