Background
On a sunny spring afternoon in the Southern U.S., a water hole, just below a pond dam, had to be crossed to access the remaining portion of a harvest area. A skidder operator placed 11 trees, 18-24 inches in diameter, across the water hole to make a bridge 14 feet wide by approximately 50 feet long. The bridge started on the pond dam and spread across the head of the water hole. A feller buncher operator needed to cross this makeshift bridge to access the remaining trees.
Personal Characteristics
The feller buncher operator was 40 years old, with 20 total years of experience working in the logging industry, the past 10 of which he operated a feller buncher.
Unsafe Act of Condition
As the operator started across the log bridge, he raised the cutting head about four feet in the air so he could see the logs he drove on. From the impressions on the bridge after the accident, it appeared the operator had the right tires of the machine on the fourth and fifth logs from the right, which left three logs as a safety buffer. The left side of the machine drove on part of the pond dam and the far-left logs. As the feller-buncher crossed the bridge, the logs on the right side bowed from the machine’s weight. This caused the machine to lean to the right. Since the cutting head was raised, this significantly altered the center of gravity.
Accident
About half-way across the bridge, the feller-buncher’s left tires transitioned from the dirt pond dam to the log bridge. These logs at the transition point were approximately 20 inches in diameter. The rise in the left tires bumped the machine further to the right. In addition, the trees on the right side flexed downward, and the simultaneous motions caused it to tip over. The feller buncher rolled onto its right side, fell into the water hole, and landed in about four and a half feet of water. This left the machine with about four inches of water over the top of the door.
Injury
A crew foreman passed near the area and saw a tire in the air through the trees. He did not realize the machine was in the water. He drove to the deck and then walked to the machine, where he realized it was submerged. The foreman called the owner, who was on the landing. The foreman then ran to the feller buncher to see if the operator was still inside. The two men pulled the operator out of the submerged machine onto higher ground on the pond dam and contacted emergency medical services, which transported the operator to the hospital. The operator had a pulse, was experiencing shallow breathing, and had a cut on his nose.
The operator suffered severe trauma to one side of his head, most likely occurring when the machine rolled over. He likely was knocked unconscious, leaving him unable to get out of the machine, resulting in drowning. Brain scans revealed no activity, and the following day the decision was made to remove him from life support, and he died. It was difficult to determine how long the victim was underwater, but it was at least five minutes and as much as 15-20 minutes.
When the operator was pulled from the cab, he was not wearing his seatbelt. He was known to normally wear his seatbelt, so it is unknown why he did not have it on at the time of the accident. It is unknown whether the seat belt, being only a lap belt, would have prevented him from hitting his head.
Recommendations for Correction
1. Never use makeshift bridges without ensuring proper structural integrity. Consider using dragline mats or other portable bridge structures. Alternative means of access should also be investigated.
2. Harvest plans should include pre-planned emergency procedures in the event of an incident, including directions for EMS.
3. Never work alone in the woods, especially when operating heavy equipment.
4. Always have a means of communication between employees, such as cell phones or two-way radios.
5. Always wear a seatbelt when operating logging machinery, a multi-point harness being the safest.
Source: Forest Resources Association