They think it will take an hour to chip a foot of ice out of a 10-foot diameter hole.

The churn drill is a large drilling machine that bores large diameter holes in the ground.

Cut this waste in half and cramp it to the opposite corner of the block, and drill a 1-1/4in diameter hole where the pieces meet.

A similar technique, called plug and feather, involves driving wedges into lines of small diameter holes that have been drilled in the rock.

The exits of the funnel are multiple 1ft diameter holes or tubes, projected parallel to the ground, and spaced equally around the bottom.

A specialist hinge has been developed which uses the walls of a 30 mm (1-3/16") diameter hole, bored in the particle board, for support.

In large diameter holes (from 200 to 400 mm.)

They also produce a much larger diameter hole in comparison to a shaped charge and hence produce a far more extensive behind armour effect.

"They'll dig a small diameter hole in the rock if you use the HEAT rounds."

Each of the impacts caused a small diameter hole and he stopped when he had six.