Using the Sliding Barrel sledge

My first XC sled was a bought fibreglass 'pulk', a streamlined bathtub-type device with long aluminium tube towbars and a padded waist belt. These can still be seen heading out onto the snow from Alpine resort lodges carrying infants or the packed lunches for a day out. As long as the snow is firm, the route is straight and the load is light these are good sleds, and a downhill run with the pulk pushing behind is high excitement.

In the real world the troubles started. If you do not stay at resorts (I don't) there is no cleared road up into the snow. If you own a 4WD (I don't) you can push your way up the mountain roads until the snow is a respectable depth, then put your pulk on the snow. If you are out for a few days, a fast thaw can clear the snow off sections of your return route, making big problems. Sooner or later rocks scrape up the fibreglass on the base of the pulk, and in soft new snow the front of the pulk pushes snow ahead of it rather than gliding, and progress is slowed to an exhausting and exasperating crawl.

I made a conversion with a lightweight wheelbarrow wheel so the pulk could be converted from sled to wheelbarrow in about ten minutes, and this dealt with the disappearing snow problem. I used the 'wheelbarrow pulk' for quite a few expeditions, but the other problems remained.

I made up a multipurpose ultralight handcart for a winter trip to England via Canada. This device had to pack into airline baggage with an all-up camping weight of 30 Kilos, carry the full weight plus skis on wheels towed by a hiker or a bicycle, and convert on reaching the snow to a sledge that could be towed on skis. To my great surprise everything worked overseas, and it towed on the snow with a couple of ropes substantially better than the towbar-fitted pulk.

The new sledge would not need to be carted by air, but had to fit inside a 650 cc twin cylinder Subaru hatchback. It had to ride properly when rope-towed on many varieties of snow, be immune to scrapes on rocks or short thawed sections, and instantly transform to a wheeled cart if the snow cover ran out. The Sliding Barrel was the result.

Instant wheels

Look back at the top photo. If you flip the sledge over so the wheels are on the ground, the front tips of the aluminium tube runners drop into your (gloved) hands on each side of you. The device is now a pull-cart, and all you have to do is somehow secure your skis and poles to the runners, which are now upwards. An elastic hook strap is ideal. The sledge has been pulled on wheels across country, and down many a muddy, slushy, rocky trail. The sledge weight is not balanced over the wheels, leading to some load on the arms, and a need to stop for a few moments every two hundred yards to prevent shoulder overload. This weight distribution assists hard hauling, and keeps vital kilos off the back wheels when you need to charge through an unmelted drift of snow rather than flip the device back to a sledge. If the snow at your location is completely reliable (lucky you!) the wheels and support arms may be left out, cutting weight, bulk and cost, and lowering the centre of gravity. The process is not as pleasant, but hauling the sledge on wheels is significantly faster than towing it on skis.

Tube runners

45 millimetre diameter aluminium tube 3 millimetres thick is used for the runners, and the total running length is two meters, since the bend ahead of the sledge body is very shallow. The tube is on the heavy side, but this lowers the centre of gravity, stops any chance of rocks denting it, and allows for the inevitable slow abrasion as rocks score the surface. Really rough scratches on the tube may be sanded smooth. When the sledge is towed over soft, compactible snow there is a continuous series of nice-sounding 'crumps' as the snow compacts under the runners, but the forward motion remains smooth since the compression angles are right. Pulk designers please note. In really low-density snow the runners sink in until the actual drum contacts the snow in the middle, and this part of the drum is waxed. This adds a wide centre 'runner' to the configuration. Snow light enough to start the front of the drum pushing snow has not yet been encountered, but true powder is rare in Australia.

The runners add nothing to the strength of the sledge. They fix to the strong frame with four stainless-steel hose clips. A close-up of one of the rear mountings is below.

The mobile cupboard

Half the fun of a conventional pulk or sledge is firmly lashing all your gear to it and trying to snow and rain-proof the assembly to resist bad weather and sledge rollovers. There is no such enjoyment here. All the gear pushed into the big blue drum is hermetically sealed until camp is once more pitched. I carry a reasonable pack load comprising food, drink, odd clothes, snow shovel, tent and the closed cell mat used on the permaflate. In rain or falling snow I pitch the tent using the backpack contents, remove the sledge runners and dive into the comfort of the tent. I can now reach out to the sledge body and slide the cap end into the door of the tent. In shelter the wheeled cap is removed and discarded, and all the drum contents required are transferred to the tent, remaining dry all the way. It is as easy as emptying a larder. I push the mobile cupboard away when leaving the tent on outside trips, but apart from that it stays docked with the tent door. Overnight I pack food, drink and oddments back in the cupboard to form a bundle that resists freezing, clearing the tent floor at the same time. On a bad weather or cold morning (most mornings are cold) I breakfast and put on clothes inside the sleeping bag, then clear the entire tent contents apart from the backpack into the cupboard. When I finally stagger outside the empty tent, I know I will be on skis and towing within half an hour.

Towing techniques

The first year I towed with 3.8 millimetre top quality nylon braid. It was too elastic and made it hard to maintain the sledge in constant motion. This year I changed to 6.5 millimetre nylon braid and the sledge tows smoothly. The two tow ropes (and spare) are just under 4 meters long. All three are closely matched for length. There is a smoothed hole on the upper front tip of each runner, and a rope passes through each hole, with a single knot right on the end to stop it pulling through. The free ends are wound three times around the padded hip/belt mounts on my backpack and then tied together at the front of the waist. Both ropes must be the same effective towing length within half an inch or so. A heave to unstick the sledge, and off we go. I use 'snakeskins' on my XC skis since plenty of steady pull is required. On moderately twisting tracks the sledge emulates Mary's little lamb, aligning one runner with one of my ski tracks and following with hardly a backward glance needed on my part. If a change in direction is required I stop, so the sledge sticks and then take off pulling in the required direction. A stuck sledge will slew on the snow before it comes free, so it aligns with my new direction then takes off. Anywhere in the world the ubiquitous petrol-head will have left illegal 4WD or snowmobile tracks just where you are going. This is a fact of life. The Sliding Barrel will drop a runner into one of these tracks and stay aligned with it. A very deep, barely possible 4WD track may tilt the sledge so far over that it rolls onto its side, but this is rare, and the plentiful illegal Canadian snowmobile tracks I saw are shallower.

Sooner or later, as with my mountain ascent, you find a slope that is too steep to pull the sledge up, and it is time for hard work. Undo the tow-ropes from your waist and tie them together. Climb a few yards up the slope, then haul the sledge up to you using the tow ropes. Repeat, repeat, then repeat again. On the way down the sledge will of course take off on such a slope. Hang on to the tow ropes and give it a push, braking it to a stop at the end of the rope. The sledge's ingrained habit of sticking whenever it stops becomes as useful as a handbrake. Repeat ad infinitum to descend. If the slope is open with a runout, take off the ropes and give it a push. This sledge is stable at high speed, and has been seen taking air over a few bumps without coming a cropper. You can tow it down moderate descents. If it starts to overtake, ski to one side. As it passes it will run over the tow ropes and this will slow it to a stop. Extra braking can be preset by tying a short cord loop over each runner so they are swept to the back supports and sit there restraining proceedings.

Weights and measures

The long cylindrical drum used has a capacity of about 180 liters. The bare drum, lid and lid clamp weigh about 8 kilos, and the whole sledge, drum and wheels included, but minus tow ropes weighs about 17 kilos.

Performance update 1st August 2000

For the first time the sledge was manhandled down and across a steep rocky slope on wheels due to vanishing snow cover. On reaching the snowless flat track below I started to tow the sledge on wheels but it 'felt wrong'. The tricky descent had skewed the clamped-down cap of the drum body slightly, and the sledge was no longer perfectly square, resulting in the runner handles sloping to one side as the sledge was hauled along the level. I could sight down the side of the sledge without letting go of the handles and see that the front and back were no longer parallel. All it took was a quick hard yank of the handles in the right direction to shift the back cap once more, and the sledge was back to normal. and remained that way for the long trip back to the car down the track. There is no need for a design change here. I am relieved to see the sledge will twist rather than break in this way, and this may well save its structure one day, when the inevitable downhill crash occurs. If the slip becomes too common, a light coat of Silastic silicone rubber adhesive to the contact faces of the steel band used to clamp the cap to the drum body would no doubt raise the force required at which slip occurred. This may have happened for the first time on this outing because the contact joint between the band and the tapered lips of the cap and the drum was wet, and this would have reduced the normal frictional 'stick'.

For pulling the sledge long distances on wheels a new trick was found. Rather than stopping for a few moments to rest the elbows every two or three hundred yards, I found it possible to lift the sledge up so the front of the runners forming the handles were hooked into the bent elbows rather than held by the hands. This shifted the centre of gravity backwards, reducing the load to lift, and rested over-straightened elbows at the same time. I shifted back to hands after a while, and was able to alternate between the two for miles without any need to stop.