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Sled dogs have been pulling sleds for thousands
of years. The purpose of the sled is to carry people and supplies over the
snow. The traditional materials for sled construction included wood, bone,
sinew, and rawhide. Steel bolts came later, and were followed by plastics,
aluminum, and today, materials like Kevlar and carbon fiber. Regardless of
the materials, all modern dog sleds have certain common
characteristics.
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These characteristics include:
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 Runners--the
skis that slide along the snow and support the rest of the sled.
Runners traditionally were made of wood or wood laminate, but aluminum and
other composite materials are becoming popular. Contemporary dog sleds
have plastic on the bottom of the runner. This provides a slick
surface and reduces drag. The plastic slides on and off easily, facilitating
quick changing.
-
Cargo Bed--the portion of the sled designed
for carrying the load. Most sleds have Sled Bags which
are placed on the cargo bed and serve as "backpacks" to hold and
protect equipment and supplies.
-
Brushbow--the "bumper" of the sled
that deflects trees and brush and takes hits in collisions. The
brushbows were traditionally made of wood and were semi-circular in
shape. Most modern sleds have plastic brushbows that are both stronger
and more resilient, and usually more triangular in shape (as shown in
photos).
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Handle Bar--hey, we've got to hang on somehow!
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Footboards--usually
made of rubber or some non-skid material, these are the narrow boards
mounted on the ends of the runners where the musher stands.
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Brake--again, pretty self-explanatory, but
very important. The brake is an aluminum or steel bar in a
U-shape. Two metal claws hang down from the bar. When the bar is
stepped on, the claws dig into the snow to slow and stop the team.
In addition to these common features, most sleds
also have a few important additional components. These include:
-
Snow Hook--an anchor made of metal used to
keep the team stopped. The hooks are angled so that continued pulling
digs them deeper into the snow. This helps keep an excited dog team
stopped. (See photos for shape and design of snow hook.)
-
Track or Drag--a rubber mat that is dragged
between the runners. This is a second braking mechanism. The
advantage of a drag is that the resistance it supplies is much more uniform
than the resistance supplied by a regular claw brake. This is because
the track drags over the top of the trail to slow the team while the claw
brake digs into the trail. Many tracks contain bolts that stick about
an inch into the trail to give them extra "bite."
-
 Snubline--a
rope that is used to secure the sled and team to a tree or other stable
object. This is very handy when hooking up a dog team, or when
stopping for extended periods. Most snublines also contain a
quick-release snap, which eliminates the need to tie knots to secure the
sled.
Two basic types of dog sleds are in use today. The older,
more traditional version is the Basket Sled (shown below), which has a
cargo bed (or basket) raised off the top of the runners by about 6 inches.
The cargo bed is often made of wood slats that run parallel to the
runners. The advantage to the basket sled was that the basket did not drag
in the snow when the trail had fresh powder on it.
About thirty years ago, the Toboggan Sled was
invented. As the name suggests, this type of sled is very similar to a
toboggan used for sledding on hills. Rather than a raised cargo bed made
of wood slats, the toboggan sled has a plastic sheet for a cargo bed, and the
bed is attached directly to the top of the runners, not suspended above
it. The above photos show a typical toboggan sled used in races like the
Iditarod. The advantages to the toboggan sled were that the cargo was
lower, making the center of gravity lower, and the solid plastic bottom allowed
the sled to "float" on top of deep, unpacked snow.
In the past few years, a hybrid of the two styles has been
developed. This style is known as the Raised Toboggan because it
has a solid plastic bed, but the bed is suspended 4 to 6 inches above the
runners. This style of sled has become very popular as it combines the
advantages of both basket and toboggan sleds into one very functional and rugged
model.
Control
and Steering of Dog Sleds
Dog sleds actually drive themselves fairly well as long as the
trail is straight and flat. However, no steering system exists for corners
and tricky trail conditions. Instead, mushers lean from side to side in a
fashion similar to downhill skiing to steer the sleds. Leaning in on
corners is especially important because the sleds tend to skid to the outside on
corners, especially very tight corners (think of the Far Side cartoon entitled
"Crack the Whip"). The brake and track also aid in
steering. By applying the brake or stepping on the track, the sled is
slowed and pulled to the inside of a corner. By not braking, the sled will
swing more to the outside of a corner. The wheel dogs (dogs at the very
back of the team) also play a big role in control of the sled. A
combination of leaning, braking, and good wheel dogs can be used to successfully
negotiate any trail.
Some sled designs incorporate more flexibility into the
sleds. This flexibility allows mushers to move the handlebar side to side,
which moves the stanchions and then causes the runners to tilt on the
snow. By tilting the runners to the right, the sled moves right, and vice
versa. This aids in steering, but isn't sufficient by itself on sharp
corners.
A final important note on sled control is that the sled is most controllable
whenever a force is being applied to it by the dogs. While this seems
trivial, imagine a steep hill. If the sled is not slowed enough on the
hill, the dogs really are doing no work on the sled. When this happens,
the sled doesn't necessarily follow directly behind the dogs or stay on the
trail. By using the brakes and maintaining some resistance, the sled is
much more controllable, and the dog team itself is much more under control.
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