AN operator broke his arm after it was caught between a shattered timber post and the hammer of a mechanical post driver. 

The individual was erecting fencing along hard ground when he tried to use one post as a brace and another for the fence, only for the wood to break and shear when he drove the Protech EVO down. He was still holding onto one of the pieces of timber at the time. 

READ MORE: BSW Group announces sweeping changes to its board

His arm became trapped between the bottom of the post cap/gripper plate and both the top of the machine's rock spike and the top of the broken timber post.

The operator managed to lift the hammer and post cap off his arm and free himself. He then contacted one of his work team members on his mobile phone, who was working further down the fence line. The work team used the work site Morooka to transport the injured operator to the works vehicle and then drove him to the nearest accident and emergency department. The operator’s arm was set in a protective cast. He is expected to make a full recovery.

A safety bulletin from Scottish Woodlands read: "The operator has over five years of experience operating this machine type.

"The operator was working as part of a four-man team. The ground the fence line was being erected on was hard, the operator had been using the rock spike to create pilot holes along the line for the timber posts. 

"A number of the timber posts had broken as they were being driven.

"The operator could not achieve the required depth for one post, so was setting out another post next to it, to act as a brace.

"The operator swung the post spike out from below the hammer and set the post into the top of the pilot hole.

"He lowered the post cap plate/gripper plate on to the top of the post. The hammer and post chain connection length was in the region of 10-15 cm.

"While still holding the post, the operator allowed the hammer to fall this distance onto the post cap plate to allow him to remove the connecting chain, intending to then raise the hammer up the mast to its full fall height.

Forestry Journal: The safety bulletin details the incident The safety bulletin details the incident (Image: Scottish Woodlands)

"As the hammer fell onto the post cap/gripper plate, the top of the post broke and sheared, allowing the hammer and post cap/gripper plate to fall further than anticipated, trapping and crushing the operator's arm between the bottom edge of the post cap/gripper plate, and the top of the rock spike." 

What can we learn? 

The report noted:

  • The work team’s emergency response and support arrangements worked well. If elements of your work task require you to work alone, ensure you set up regular contact times with your colleagues.
  • If you are using the rock spike to create pilot holes, always move it completely clear of your work area before you commence driving a post.
  • Ensure the connection chain is the minimum length to minimise any potential hammer fall while setting the gripper plate into the top of the post.
  • Ensure the spikes on the bottom of the gripper plate (the Protech EVO has three) are in place and unworn. They serve an essential function in holding the post in position during the post driving process.
  • Remove your hand from the entrapment/crush zone of the post driver and post/cap/gripper plate, before allowing the hammer to fall any distance.