A worker was injured while clearing a log from beneath a slasher which had been attached to a tractor via a three-point linkage connection.
A chain and two D-shackles were used as the top link between the tractor and the slasher to provide a flexible connection for rough terrain. A pin had fallen out of a D-shackle and the slasher dropped onto the worker as he removed the obstruction.
The D-shackle pins had not been secured with a split pin or similar fastening device but had remained secure due to the distortion of the pin caused by the load.
Three-point linkages, commonly used to fit attachments behind tractors, are standardised mechanisms consisting of an adjustable top link centred above two lower lifting links
- The D-shackle pin may have worked loose during normal machine operation, as there was no secondary fastening system in place.
- Never work or stand under suspended machinery unless it is supported by suitably designed props or stands. Do not use wood to support the machinery.
- Replace chain connections with an adjustable bar or some other method, where possible.
- If a chain must be used, secure all D-shackle pins with a secondary fastening device.