This is one of those questions where you can have a very simple short answer, or, a very long and complex one, with both being equally valid. I’ll give you both.
The short answer
Having hauled pulks of various designs over hundreds of miles, up and down mountains and glaciers, forest, field and road, the simple answer is that just about any set-up will work, from a strand of bailing twin to a dedicated solid glass fibre set up, but what you should really focus more on how you pack the pulk. This is pretty simple: just imagine you’re packing a canoe that’s heading out into a choppy sea, i.e. keep the weight as low as you can for stability, and towards the rear, so the front floats and the whole thing does not flip.
To these ends, you’re often better having two smaller pulks in sequence with the load divided and as flat as possible, rather than one classic exped built up pulk pilled high with mats and tents.
This is because although fine on the flat, and by flat I mean a snow-covered road or path, anything higher than the sides of the pulk is going to increase the risk of flipping the pulk the second you hit any kind of bump or sastrugi. Also, when talking about weight, that includes all weight, not just fuel bottles, so everything heavier than a sleeping mat. This means tents, down jackets, your water bottle, everything that weights something should down kept low, ideally below the level of the pulks rim (not always possible, but try). This is one reason why you want a very secure method of lashing down the load, as any weight that’s at all high in the pulk, such as a tent strapped on top, is going to cause it to flip unless the weight below it (the ballast) is considerable.
When pulling two pulks in sequence, you will find that the rear pulk will also tend to stabilise the front one, and will resist it flipping, with the rear pulk then riding through the tracks of the first, the overall depth the pulk will sink also reduced (this is important in really soft snow).
Once you get the weight and bulk down of the two pulks, or you’re descending, you can place one pulk inside the other (as long as they’re the same model), or even place them side by side to make them more stable in descent (and also increase the drag). If you’re travelling light then you can also just strap your pulk on your pack, but I’d be probably carrying it facing with to bottom into your pack so that if you fall over you won’t take off!
As for the tracers (the connection between you and the pulk), if your pulk has holes in the front then you could just rig up some cord through the central hole, like on a kids sled, and clip it into your harness or pack, and it will pull along behind you fine on flat terrain, or even medium angles terrain just fine.
If you want to get a little more out of it, then you might want to have a duel tie in from either edge of the pulk, going to a central knot, as this will make the pulk a little more stable, and keep the front more inline.
Such a tie in can be further improved by moving the connection to the side, and down a little from the top edge, as this will put the pulling force lower, and so help to keep the nose of the pulk a little higher (depending on the throw of your tracers). In very soft snow you sometimes want the tracers to be shorter, so you give a little lift to the nose, as well as place all the weight near the back (in super deep snow the pulk will not flip as it tends to be riding in a trench!).
Length of tracers comes down to all sorts of factors, including the weight of the load, snow conditions (or ice), angle, and how you’re attaching it to yourself. But as a rule, if you’re in technical terrain, where you want maximum control over the pulk, then 2-metre distance is ideal, as you can more easily control it with both your body and your hands, but on glacial and open terrain, 3 to 4 metres is better, as this will give you a nice flat pull on the pulk, and also reduce the chances of the pulk being pulled into a crevasse (all rope work should be designed around securing your pulk in case of a crevasse fall, as well having the skills to deal with it if you do!).
If connecting the rear of the pulk to your rope via a Prusik, then make sure it’s connected to both a strong point on the pulk, as well as into the pulk compression system and maybe into the pulk bag (generally a big holdall). On some expeditions, surviving a crevasse fall but losing all your gear might be equally as life-threatening (losing your tent and sleeping bag, and perhaps all your coms, stove and shovel might be a death sentence). You should always remember this whenever you’re clipping in and out of your pulk, as they have a very nasty habit of sliding off when your back is turned!
As for connecting them to yourself. A dedicated pulk harness is always the most effective way of pulling a pulk, even a lightweight DIY one made out of webbing, although Aiguille Alpine and Ice Trek make very good harnesses. Wearing a harness allows you to put all your kit in your pulk on easy ground and will also work when wearing a pack.
The alternative is to clip it into the hip belt of your rucksack, into the side stabilising straps, or into the bottom of the shoulder straps where they’re sewn into the waist if using a two-point system, or into an ice axe loop on the back. These methods should be changed if the pulk is not connected to the rope, as a 100 kg pulk falling onto any part of your pack may rip it off. My prepared rucksack method is to tie a long loop from your hip belt/shoulder straps (a stronger connection), that hangs down near your ass, but allows you to clip a single line tracer in and out more easily than fiddling with karabiners clipped directly into a pack.
As I said above, if you’re going to the greater ranges and plan on travelling on glaciers with pulks, you need a bombproof system that you all understand and have tested at home (go down to your climbing wall and practice with a pulk, pack, skis etc!).
That wasn’t so sort, but I’d say it’s important not to overthink pulk set-ups too much, or in the wrong way, as often this will lead to something too complicated, heavy, expensive, that will either break, fall apart, or prove impossible to use at - 30 degrees C.
But saying that here’s a more effective bit of overthinking it.
Although a simple system above, formed out of cord or even climbing slings will be 90% effective, the extra 10% where it is not working, will probably drive you crazy and both spoil your days as well as make things more out of control and dangerous.
Pulk pain is the frustrating kind in which the pulk flips constantly, is constantly getting stuck, or shoots off on its own mission while trying to drag you with it. Such a pulk will feel like a liability on steep terrain as if it really has a mind of its own, and in descent, or when trying to weave through tricky terrain, such as ice fields, debris or rocks, it will break you before you break it.
Ideally what you want from your tracers is control, but at the same time have a set-up that adapts itself to both the movement of the pulk, the terrain and the person pulling.
Imagine you go with two tracers going from the front edges of the pulk to the left and right hip of the climber, a system that’s quite common (with both rigid and rope systems). If you’re on flat ground it works Ok, although you might see the pulk cock backwards and forwards as you walk, but if you hit a steep section where the climber must sidestep, you’ll find all the weight goes onto one strand, pulling from one hip to one side of the pulk, which will probably see the pulk start to track at an angle, and then flip.
What you really want is a system that adjusts and gives an equal pull at all times, and at both ends, no matter what angle either of you is at. This can be created by having a Y hang that is not fixed at both ends, or a single point joined to an adjusting Y hang.
Ideally, you want a system that can be adjusted on the fly, which with a rope system can be achieved by simply tying knots into your tracers, or even extending them with slings (usually 120 cms). Generally the further away the pulk is from you, the less twitchy it will be, but the less control you’ll have.
On tricky ground, it’s vital that you be able to easily manipulate your pulk by hand, which means you need a tracer set up that either features some extra knots, or a cross cord set up (this set-up also stops the pulk from being lost of any of the karabiners/connectors come adrift, as it creates a closed-loop).
On some tricky terrain, such as moving around crevasses, you will often stop and pull the pulk manually behind you, park it, move on, and then repeat. On steep traversing ground (such as moving around Windy Corner), you may even move with the pulk’s tracers being controlled in your hand, not your hips, allowing the pulk to be pulled along, like walking a big dog, reducing the risk of a dangerous swing and yank on your waist.
When pulling heaving loads (which could be up to 200 kg on a big multi-month trip), you should add in some shock absorbency, as this will reduce a sudden dead stop, which can be jarring. By placing some looped 5 mm or a single loop of 10mm bungee cord in your system (tied in a knot, or crimped with Hog rings), you will feel the pulk begin to slow, allowing you to increase the force, which will generally see the pulk pop over the obstruction. When using a shock cord link you should always have some form of back-up, otherwise, you might lose your pulk (a pulk, sliding backwards, could go several miles before it decides to stop!).
One thing to avoid is stupid little fiddly karabiners or connectors, where your $1000 carbon fibre pulk has been fitted with 30 cent keyhole karabiners, whose gates not only stick open in the cold but also are so sharp they rip your gloves apart, not that you can even use them when wearing gloves!
Make sure all connectors can be handled with big mittens on and will not stick open. Avoid screwgates on any connection that you wish to be able to operate constantly (primarily your harness), but go for a 100% secure option on any single point connections where failure would result in total loss. This does not mean at the pulk or harness end, as you’re never going to find both karabiners/knots coming undone, but rather in the middle, or when you have only one connection. Ideally, a 100% secure option should be a knot, a screwgate, rapid link, rap ring, soft link, or screwgate (screwgates are never 100% safe).
On a polar trip where every gram counts, then you could probably just secure all your tracers directly to pulk and harness, or use soft shackles, and just remove the harness when you need to.
On the subject of karabiners, in order to avoid them unclipping due to the cord pulling across the gate (it happens), consider always larks footing cord into the karabiner, or use barrel knots, so they’re fixed in place.
The loads on your pulk when climbing will be minimal, and even with a fall into a slot, 5 mm or 6 mm Perlon cord is fine (you can easily rig up a pulk with a cordelette). For bigger trips where strength and weight are important, then using spliced 4 mm Dyneema is ideal, as splicing will allow you to do away with many of the knots, and give you a very lightweight system. If the tracers are made up of different parts, then ideally they should be colour coded so they’re easier to sort out and untangle (tangles have to be high on the list of causes of frostbite).
What about rigid tracers?
Rigid tracers have several advantages over rope tracers if your focus was on skiing, and you can buy commercial rigid tracers for about the same price as making your own (once you take into account time). The main advantage is that when going downhill they keep the pulk behind you, and so don’t catch you up and wipe you out (or over take you!).
In reality, if you fit a brake rope (loop of knotted cord that goes across and under your pulk), your pulk will generally stay behind you as long as you know its moods, and by extending several extra metres, or placing two side by side for stability, and packing them well. Some good skiers can also ski with the pulk beside them then you will probably be ok (you should only be going down a ‘green’ run pulling a pulk, not black). You can also use your ski poles to try and cobble together rigid tracers (clip the baskets to the pulk), but the downside is that you’ll have rigid tracers and no ski poles.
Another option is for the person behind to control the speed of the pulk in front via the rope (if you’re tied together).
The downside of rigid tracers comes on technical ground, as it’s very hard, or impossible, to turn sideways, or turn and face your pulk, and it’s also always fixed away from you. If the pulk is heavy and rolls sideways it’s easy to break the shafts (most are made from fibreglass), and on the two trips I’ve done with rigid tracers, we had multiple broken pole sections, which can only be taped up.
There’s a book worth of info on the actual pulk and associated pulking kit and accessories, but generally, just try and keep it simple, safe and practical, and only overthink the important stuff!
If you have any questions about this article (more detail!), or other questions you’d like me to cover in detail, then message me, and please share this article on social media.