Climbing Nut (also known as a chock).
The climbing nut (see schematic below),
is an
asymmetric piece of
metal
through which a metal
loop of wire is threaded.
When
climbing the
climber
looks for a
crack in the rock which
narrows
downwards. The nut can be
slotted
into the crack from the top
and hopefully
the nut will
jam in the crack.
The climber clips a
carabiner
through the loop in the wire and the
rope
through the the carabiner.
This piece of climbing equipment
originated from small pebbles
that climbers in the
1930's would carry with them.
They would slot the pebble
into the crack and tie
a piece of rope
around the pebble and the rope
they were climbing on.
This was not a very safe piece of equipment
Post war climbers soon developed
more sophisticated equipment such as that
shown below (yeah really sophisticated huh?).
These pebbles were originally called
chock stones which is where the alternative
name for the nut comes from.
Several climbing companies manufacture
their own line of nuts, notably
DMM, Wild Country and Black Diamond.
They come in a range of sizes
generally from 00 - 10.
A number 10 is about half the size
of a fist, a 00 is about the
size of your little fingernail.
After some time climbing one can look at
a crack and recognise which
sized nut will fit into it.
Before this skill is developed a lot of time
can be wasted "fiddling with your nuts".
The second's most important job
is to remove the nuts from the cracks
that the leader has placed.
insert nut
V
side view
------ \ |
\ _ | \ |
\ \|| \ | ----
\ | | | crack in
\_| | | rock
I | |
I | | (looking
I | | face on)
I \ |
I | |
I \ |
I \ |
I \ |
I \ |
I I ^
I I. nut
I I will wedge here
I
V direction
front view of gravity
------
| |
| |
| | -- metal head
|_____|
I
I ^
I direction of
I climber
I -- metal wire (mostly)
I
I
I
I
I I
I I. --loop through which crab is clipped
I I
I
top view
------ A --
| | G | climber who
| | H V didn't know
------ h how to place
h a nut.
.