Stored energy – dislodged pin causes injury

What happened?

During disconnection of a structure, a securing pin became stuck and could not be removed by hand. A hydraulic jack was employed to eject the pin which resulted in the pin being released under load directly into someone’s face. A team of four persons were removing a structure. This involved the removal of four securing pins, each weighing around 10kg. The task has been done numerous times and was usually accomplished with a hammer and drift. On  this occasion, one of the pins became stuck and could not be removed. The work team decided to use a hydraulic jack to force the pin out. Initially this did not work; one of the workers moved directly into the line of fire to obtain better sight of the restriction. The worker tapped on the adjacent plate with a hammer and the pin came loose and ejected with force, hitting the worker in the face. The pin hit the bridge of the person’s safety glasses causing a laceration to the forehead. They were treated onshore and returned to work soon after the incident.

What went wrong

• The task risk assessment (TRA) for this task did not consider the use of a hydraulic jack for removal of the pin, nor did the toolbox talk (TBT) before starting work;
• A change was then made during the task (introduction of the jack), but the new risks were not thought through at all. Nobody in the work team thought to intervene and stop the job due to the change in method and equipment;
• During the operation of the jack, one person decided to switch positions to get a better view and to try and release the pin. That person got directly into the line of fire. There was significant stored energy now pushing behind the pin and that risk was not recognised.

Actions and lessons learned

• Our member noted that lessons were not being learned from previous incidents involving getting in the line of fire. A fresh review on the line of fire risks was initiated, considering all the potential energy forms, including release of stored energy;
• If something changes during a task – stop the job, and reassess;
• Stop and think – take the time to think things through;
• An engineering solution was proposed to remove the line of fire risk while removing these pins. A proposed design of cages or catchers on each pin was put forward, such that the pins can be controllably released into an area without potential for people to be harmed.

Members may wish to refer to:

• LTI: fractured finger during anchor handling
• Lacerated chin caused by flying wedge
• Leg injury when struck by rebounding hammer
• Finger injury while using a crowbar to try to shift a large shackle
• High potential stored energy incident: inner buoyancy module clamp failure during removal