Chain Saws.

chain sawing a tree across a track

Prolonged rain has softened the ground and strong winds have then brought this tree down across the track. The tree is supported at both ends so an undercut means that the cut will open under the weight of the tree and not trap the blade.

Undercutting makes the chain saw try to push back of course, so it is comforting to know that this is a well maintained saw with a working chain brake.

The operator has a nice stable stance but he would be safer yet if wearing safety glasses, gloves and ear defenders.