The Sledge (also known as 'sled' or 'pulk')

The sledge is your portable stomach, wardrobe and home: although it can be a source of unthinkable misery, it must be treated with care.

1. Sledge Design

While the terrain you will cover can be quite varialble (e.g. bare ice, dry snow, wet snow) the sledge is not adaptable and must therefore have a generalized design. Generally, the sledge should be rather long, around 2 meters or so, in order to distribute its weight over a large area, on the principle of skis and snow-shoes. The aids in preventing the slege from sinking too deeply in loose snow or slush, as well as distributing the weight over a large area and thus making crevasse-bridge crossing more safe. The travelling surface of the sledge should have several keels which are intended to retard the sledge from sliding sideways, or downhill, when you are traversing steep slopes. Keels also aid considerably in keeping the sledge on a straight and resistance-free course behind the sledger on flat, though very slippery, terrain, such as bare ice. The sledge hull should be tapered at the ends, as with some sailing vessels. A tapered bow prevents the front of the sledge from snagging on projections while it is being towed, and the tapered stern allows the rear to slide down obstacles rather than dropping off suddenly. Sledges tapered at both ends are rather rare: most have a truncated stern. This is not critical (though it _is_ critical that the bow be tapered), and until new models are produced we must do with what is available.

2. Protection and Efficient Packing

In any areas where you may expect rain (this basically excludes only Antarctica, the North Polar region and the interiors of some icecaps), the sledge must be equipped with a waterproof cover, and items packed in the sledge must be packed in waterproof bags or cases. Water can damage food supplies, wet clothing, cause rust and generally ruin all sorts of gear, so this is an important point. The sledge cover should have a zipper ('waterproofed' with a wide velcro flap) which travels the length of the sledge, making it easy to access any item without, for example, having to unload an entire duffel bag to get one item. Sledges should be packed with this longitudinal zipper mind. You may choose to use several layers of thin plastic, or heavier single-wall plastic containers (such as the watertight canoeing and kyaking gear bags) for items inside the sledge. In wet areas, be sure to empty any standing water in the bottom of the sledge every day. If it rains at night, consider tipping over the sledge to prevent water from entering.

3. Towing the Slegde: Poles, Attachment and Harnesses

The sledge is towed with ropes or poles. Ropes are lightweight, but give the sledger very little control of the sledge, which can be very dangerous, particularly in steep and / or crevassed terrain. Poles, in contrast, allow you to guide the sledge through difficult sections, rather than vice-versa. Poles must be strong but somewhat flexible. Many materials have been used for sledge poles (also known as 'traces'), including wood, metal tubing and fiberglass. In my 1995 Alaska expedition my partner and I used bamboo traces roughly 2.5 meters long and about 3cm in diameter. These were lightweight, flexible and strong, an ideal combination. Sledge traces are attached to points on the bow of the sledge, at least 30cm apart in order to give more lateral control. This attachment should be rather flexible, such as with carabieners on the sledge clipping in to slings fixed to the poles, as a rigid attachment would likely break immediately under a heavy twisting load, such as when the slege rolls over on its side on steep terrain. The other end of the trace is attached to a sledging harness or the base of ones' backpack straps; again, many configurations have been used, but the most practical is on in which the poles are securely attached to the harness but may quickly and easily detached. Clipping in with carabieners works well. A sledge harness should distribute the strain between the waist, chest and shoulders. A single strap around the belly will quickly give you problems. One of the best solutions is to reinforce the straps of your backpack (which _must_ have a chest strap) and clip directly into the strap where it leaves the bottom of the pack and ascends to your shoulders. With some adjustment you should be able to obtain a fit which allows you to lean into the work with your upper body, a great commodity when overcoming steep sections.

4. Pulling the Sledge

Only when the the sledge is properly packed and fitted with traces it is ready to be pulled. Dont' attempt to begin pulling with poorly equipped traces or a messy packing job: you will only have to stop to deal with these later (for example, items strapped haphazardly to the outside of the sledge as a result of laziness, _will_, eventually, fall off...) and it is best to have everything squared away before setting off.

When you're ready to pull, keep in mind your strongest assets. Choose your path wisely to avoid obstacles, rather than simply putting your head down and dragging. You will expend less energy in avoiding obstacles than in overcoming them. Remember that your legs are far stronger than your arms, so use them as much as possible, rather than leaning over-strenuously on your ski poles; using arms and legs in unison, as well as leaning forward with a well-adjusted harness, you will be able to overcome many small obstructions. In dangerous terrain, crevasse fields, keep close to your partner so that you may help each other if needed, but not so close that you are in danger of falling into the same crevasse. Use the rope and have your rescue gear neatly clipped to your harness for immediate access.

Slopes

Depending on the surface and the efficiency of your sledge keels, slopes may be tacked head on or traversed. Traversing an icy slope with poor keels will immediatly result in the sledge swinging downslope and threatening to drag you down. In this situation, crampons and a course directly perpendicular to the slope are the best strategy. On a steep slope with deep snow, however, it will be less strenuous to make a rising traverse, taking advantage of the keels and preventing you from having to pull up a steep slope in deep and loose snow, which is extremely fatiguing.

Surfaces

A wide array of the continuum of possible surfaces is perceptible to the sledger. Wind crust, bare ice, deep dry snow, slush and deep wet snow are only a few of the surfaces you will encounter. It is important to use the most efficient footgear -- for example, skis with skins, crampons, or boots alone -- to deal with the prevailing conditions. Postholing with boots alone while your skis ride the sledge behind you is a complete waste of energy. Similarly, using skis on bare ice can be dangerously clumsy. Use your brain and be efficient. Take the time to _adapt to the prevailing conditions_; this is the key to efficiency -- not to mention survival -- in any situation.

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