↓RECREATION
@PopularMechanics _ March 2019 39ILL
US
TR
AT
IO
NS
B
Y^ J
EF
F^ L
OW
RY
PLYWOOD MOUNTAIN Learning the
elementary skills of mountain climbing,
schoolchildren in Kent, England, practice
holds and techniques on a portable wooden
device called an “instant mountain.”
Made of plywood and stringers, the
20-foot climbing board can be dismantled
into two sections and is easily carried by
four men. Blocks of wood in various shapes
and sizes duplicating hand- and footholds
found on real mountains are attached to
the plywood surface. A separation between
the two sections simulates a rock shelf,
and the surface of the upper section is
divided to simulate a crevice for practicing
counterpressure holds.Solid ice panels
are made in forms
shaped like sandboxes
by pouring water
around coolant pipes.
The panels are then
stacked to wall height.
Bonus: The pipes can
cool the wall during
competition in warm
weather.T
HE SPORT OF ICE CLIMBING, in
its truest expression, traverses the
frozen waterfa lls of Hya lite Canyon
outside Bozeman, Montana, or the
face of Mt. Pisgah overlooking Lake
Willoughby in Vermont: Climb-
ers use crampons and ice axes to
ascend forms sculpted by precipitation, wind,
gravity, and other natural phenomena. But for
competition, nature is far too unpredictable.
So for this month’s world championships in
Denver, the American Alpine Club is build-
ing the largest ice-climbing structure ever
made in the U.S.
It will be 48 feet high and 80 feet wide
and support two types of climbing routes.
Lead routes, which use angles and over-
hangs to test technical ability, ascend to
the structure’s high point. They’re made
mainly of plywood, covered sparingly with
handholds like those at a climbing gym. But
they also include free-hanging hunks of ice
made by freezing a chain in a barrel of
water, then removing the barrel. On a pair of
41-foot-tall ice speed walls, competitors race
straight up. Both routes mount to a steel
superstructure that is strong but lightweight,
meaning the speed walls, at about 17,000
pounds each, do more than just get gored by
athletes: They ballast the whole competition.
Typically, in structures built for winter
sports, ice is a load, not a structural mem-
ber. (Think of a snowboard half-pipe, whichsupports snow and ice but is made of con-
struction materials.) With good reason: “If I
know the grade of steel, I know its flexural
capacity, I know its tensile capacity, and a
number of different mechanical properties,”
says A ndrew Savage, an engineer w ith Clark
Reder Engineering, the company build-
ing the speed walls. “With ice those things
change depending on what temperature it
is.” Savage has two techniques for building
the walls, depending on the weather (see
below). That’s a lot of engineering for some-
thing athletes will scale in fewer than ten
seconds, and it’s pretty far removed from
nature. But it’s worth it to give the sport the
biggest showcase the country has ever seen.In which ice stands in
for steel, and plywood
stands in for ice.
/ BY KEVIN DUPZYK /The Biggest Ice-
Climbing Wall in
American History
The challenging
technical routes
on competition
ice-climbing
walls mix ice with
plywood and
rock-climbing
handholds.Chipped ice
is poured into a frame
and compacted; then
water is poured over
it. Once it’s frozen, the
frame is raised and the
process repeated. Voids
from the compacting
process can yield insta-
bility in warmer temps,
so this is plan B.TWO WAYS TO BUILD AN ICE WALLFROM^
—THE—
ARCHIVES
(^1963!)