A Copper Head is a a piece of
equipment used in
Aid Climbing.
I have never aid climbed and I have
never used
a copper head, but from what I hear I have come to the
opinion that they are both
evil and
insane.
When a blank section is reached in an Aid climb
with a faint seam or some dimples in the rock
a copper head may be called into play.
It is a small (fingertip sized) barrel of copper
wrapped around a wire. The copper head
is placed against the seam and a hammer is applied.
This sqashes the copper. It deforms and enters
the seam/dimple. The climber then pulls up on
the wire all the time hoping that the copper head
will not slip off the rock.
It is also knon affectionatly as a mashie.