Tree Trimmer Is Killed
When Boom Arm Breaks

In 1995 a self-employed tree trimmer died instantly after falling 50 feet from a boom truck bucket. The man was using an older aerial lift truck to trim trees with a small chainsaw at a friend’s acreage. The lower section of the hydraulic boom and the hinge area was constructed of metal. The upper section and the bucket were made of fiberglass. The upper section was round and approximately 8 inches in diameter; its rated total capacity was 300 lbs.

The boom arm was in maximum vertical extension above the truck. The man was holding a 60-lb. branch when he momentarily hyperextended the fiberglass boom to clear the truck cab. At this extreme point in its jerky movement, the upper section of the fiberglass boom snapped completely in two at its base. When the boom broke, the bucket remained in a fixed position with the upper arm and inverted when it swung down, propelling the man headlong into the ground.

The boom arm swung back and forth like a pendulum to a resting position, the broken ends held together by cables inside the arms which automatically kept the bucket level with the ground in normal operation. The man was not wearing a hard hat, nor any safety belt or harness. He knew his machine needed repair, but kept on using it despite warnings.

#1 Boom truck operators should wear fall protective equipment -- a body belt or harness and a lanyard!

---The man was thrown head-first out of the bucket as it swung down.

---He may have survived if he was wearing a safety belt and short lifeline to arrest this fall.

#2 Equipment which supports or lifts human life must be maintained in excellent working condition.

---The man had a history of delaying or ignoring needed maintenance and repair on this equipment.

---Friends who were aware of this had said “that machine is going to kill you someday”.

#3 Boom truck owners should never use the boom arm as a crane to move logs, limbs,etc.

---Using an aerial truck as a crane frequently exceeds its rated capacity, puts excessive stress on all machine components, causes material fatigue, and increases the risk of mechanical failure.