After guiding the gate into the boot, a team member signaled to an operator to boom up and then turned to walk away from the trencher. While booming up a boom hitch pin broke causing the boom to slip free of the anti-roll bracket. The boom was caught by a safety chain however rolled/drifted to the side of the chain striking the team member in the back, head and neck as he was walking away. The team member was taken offsite for evaluation and care where he was diagnosed and treated for a concussion.

Contributing Factors

1. Mgmt. Systems – Improper Maintenance

Boom hitch pins are subjected to extreme vibration and pressure. There was no formal process in place to inspect the pins for damage or wear.

2. Unsafe Conditions – Defective Tool or Equipment

The boom hitch pin broke allowing the boom to slip free of an anti-roll bracket.

A safety chain was only installed on one side of the boom. The chain stopped the boom slipping further however caused it to roll / drift in the direct of the chain.

3. Unsafe Acts – Improper Body Placement

The injured team member failed to step safely away from the equipment prior to giving the operator the signal to boom up.

4. Unsafe Acts – Improper Work Technique

The team member turned his back to the equipment after signaling to the operator to boom up.

5. Unsafe Acts – Unsafe Acts by Others

The operator did not wait for the team member to step away from the boom to a safe distance before booming up.

Energy Wheel Hazard Assessment

Hazard assessments should be performed as part of the work plaining process to identify potential hazards and controls. Utilizing the Energy Wheel this job task presents the following hazards:

✓ Motion – Change in position of objects or substances (boom slipping and swinging in the direction of the safety chain)

o The team member was struck by the boom when it swung in his direction while it was being boomed up.

Hierarchy of Control Considerations

When implementing controls, leaders need to follow the hierarchy of controls (1-6), which are listed from the most effective to the least effective below:

✓ (3) Engineering – Isolate the hazard as much as possible away from team members.

o Consider evaluating the pin to determine if it is appropriate material for the application.

o Consider shortening the safety chains or change location of the chains to prevent the boom from slipping free of the anti – roll bracket.

o Consider installing safety chains on both sides of the boom to prevent it from being pulled in one direction if there is a pin failure.

NEXTERA ENERGY E&C RED EDGE BULLETIN:

GREAT PRAIRIE WIND PROJECT

10/06/2022

✓ (5) Administrative Controls – Change the way team members work to avoid the hazard.

o Consider including pin inspections as part of pre use, monthly, quarterly inspections.

o Consider routine pin replacement at set milestones such as machine hours worked.

o Consider retraining ground personnel on safe work distances to be maintained from operating equipment.

o Consider retraining ground personnel on the importance of avoiding having back turned toward operating equipment.

o Consider retraining operators of the need to ensure that ground personnel remain a safe distance back before operating equipment.

o Consider retraining operators of the need to stop / discontinue equipment operation if ground personnel approach the equipment while its in operation.