The accident: During a water main installation, a crew member entered a newly dug lateral excavation, preparing to install pipe. Using a quick coupler, an excavator operator changed buckets and swung the machine over to the trench to continue digging on the main line. The bucket detached and fell into the excavation, killing the man in the trench.
The bottom line: While quick couplers allow instant attachment changes, users should always inspect them to ensure they have been properly engaged and locked prior to use.
According to OSHA, at least 15 accidents involving unexpected bucket release from quick couplers occurred within the past six years, with eight resulting in fatalities.
As a result, most quick coupler manufacturers now provide retrofit locking pins, which insert behind the coupler’s front or rear levers to avert unintended release. Other manufacturers offer newly designed coupler systems, and include safe use instructions and operating procedures.
Yet, OSHA says unintended bucket releases continue to happen. Two reasons: not all workers who use quick couplers realize the risk or they continue to use older coupler models, not knowing of manufacturers’ corrective actions. Often, users fail to retrofit with locking pins, while others lack adequate installation or inspection training. If you have questions regarding your quick coupling device, immediately notify your employer. Contractors can also contact their manufacturers to get the most current information.
In the mean time, protect yourself and your co-workers by:
- Securely latching attachments before work begins.
- Thoroughly inspecting all quick couplers for unexpected release hazards, such as older couplers requiring locking pins or another retrofit method.
- Choosing newer quick coupler models specifically created to prevent unintended attachment release.
- Asking for and installing manufacturer recommended retrofits when necessary, such as positive locking pins or other manually installed devices.
- Using a manual or automatic independent secondary system to prevent bucket slippage, in the event of a primary system failure. Also, make sure the secondary system includes an attachment verification procedure.
- Following quick coupler maintenance and inspection procedures per the manufacturers’ recommendations to prevent a malfunction.
- Making sure you do visual and operational inspections on all machine components and controls before operating the machine.
Information for this Safety Watch was gathered from OSHA and NIOSH. It is meant for general information only. For more information, visit www.osha.gov or www.cdc.gov.
