Chainsaw operator's vein ruptured by flying fragment of birch sapling

Tuesday, November 20, 2007

What happened?

An experienced, certified cutter was felling a tree under normal conditions. As the tree was falling, it bent and snapped a small birch sapling, catapulting a fragment of wood about 19 millimetres (3/4 inch) in diameter and 46 centimetres (18 inches) long toward the cutter. The cutter saw the stick coming and tried to get out of the way, but it struck him in the upper arm. There was no apparent injury, so the cutter continued to work until lunch, when he realized that he could not fully bend his arm. He rolled up his shirt sleeve and found a large blood blister and swelling on the inside of his elbow. An examination in hospital determined that the vein in his arm had been ruptured, causing internal bleeding. He was off work for a month.

Why did it happen?

A cutter never has complete control over all the circumstances associated with a falling tree. That’s why it’s essential to plan a specific escape route from every tree that’s being cut and to use that route to get safely away from the immediate area of the tree’s fall. In this case, the cutter was close enough to be seriously injured by flying debris.

How can it be prevented?

The Professional Chainsaw Operation training course is very specific about the two things a cutter has to do before starting to cut a tree. First, clear away any debris or underbrush that prevents solid footing or obstructs access to the tree. Second, choose and clear an escape route by which the cutter will retreat safely from the falling tree.

The safest direction of retreat is back and away from the tree at a 45-degree angle to the left or right side, choosing the side to which the tree is least likely to fall if anything goes wrong. The cut should be planned so that the cutter is on the escape-route side of tree when the backcut is finished. The cutter should then immediately retreat along the escape route, maintaining control of the chainsaw with the brake on — or leaving the saw behind if the tree begins to fall unexpectedly.

The idea behind the escape route is to enable the cutter to be far enough from the falling tree to be out of range of any falling or flying tree branches or fragments. Even if the cutter doesn’t manage to retreat entirely out of the impact area, his distance will allow more reaction time to see and avoid any flying debris that might be headed his way. After the tree has fallen, the cutter must always check for overhead hazards such as hung-up limbs before returning to limb the tree or cut another tree.

In some cases, depending on circumstances such as terrain and the position of the tree to be cut, the cutter should plan a second escape route in case the tree starts to fall toward the primary escape route.