This article describes how to construct a sitsling for SRT use, which, whilst not only one of the most comfortable things you've ever strapped around your buttocks is also sparing on the old green and crinklies.
The design is based on an obscure make of French baudrier which I picked up in Gay Paree and caved happily on for several years. Recently I became rather uneasy with the thin, rusty bits of wire which did most of the load carrying so I attempted to reconstruct it using sturdy British (hooray) components. The results were very successful and are described below.
The major feature of the Buttockhugger is that it consists of just one piece of tape threaded in intricate patterns through various buckles. There is no stitching, there are no knots and F = u N is all that stops you from descending the quickest way. This has immense advantages: for a start it enables you to build a sitsling safely yourself from two-inch tape and when the tape wears out you just buy another 3.5m and rethread it; an immense economy over buying a whole new unit. It's relatively cheap, mine cost just under nine pounds, and it even seems to be safe.
The worst thing about the Buttockhugger is building it. Working out how to thread it makes solving a cube look simple. The second worst thing is working out how to put it on, but we'll come to that later.
You will require the following:
Figure 1 Components
|No. required||Item||Ref. on figures 1 and 2|
|2||Belay 'D' ring||1|
|2||Black-coated bent 3 bar buckle||1|
|2||Flat plated steel 3 bar buckle||3|
|(All buckles for 2" tape by Troll)|
(Polyester or nylon tape depedning on your cell type. 3.5m is enough for my 34" beer gut)
|Optional||1m of 5/8" tape|
|Needle and stout thread|
Figure 2 Tape Route Diagram
The best thing to do now is to simulate the topology shown in figure 2. Once you've got the thing in front of you it makes a bit more sense and you can adjust it.
First you find the middle of the tape, point A on figure 2. Preserve symmetry about this point. Thread on the 'D' rings and two buckles as shown in figure 2. The assemblies should be around 700mm apart when pulled tight. This length forms the belt part. Go on down the ends about 80mm and form the leg loops with the bent buckles. Lay the whole thing flat on the floor with the tape on edge and bring the two loose ends up out of the leg loops and run them both into the last buckle. Hey Presto! Fini, as the French would say. Now comes the awkward bit; by studying figures 3 and 4 you will eventually achieve the intellectual leap which enables you to work out how the various straps relate to your body. Then it's just a case of tediously pushing tape through the buckles until it fits. The leg loop buckles should come just below the hips and the belt should be fairly high up on the back. The buttock strap should provide light support in the sitting position. With a krab or even better a triangular Maillon Rapide between the 'D' rings you now have a viable sitsling.
One final optional mod for a really deluxe job. You will find that when
you crawl the leg loops drop. This can be prevented by using that piece of
5/8" tape as a kind of suspender from the middle of the
back belt. I have only shown this on figure 4 to avoid confusion. Stitch or
knot this into place.
Figure 3 As laid on the floor:
The Buttockhugger takes your weight mainly on the leg loops and so is very comfy. I have tried it in the NPC testing lab and underground and consider it quite safe.
All the components are rated at around two tonnes so things shouldn't start to ping until your ropes and krabs start to do likewise. Your natural position in it is upright and even if you do turn upside down you do not fall out.
If by any chance one side should break you are still secure and capable of carrying out all SRT functions although rather uncomfortably. The tape shows no tendency to slip through the buckles even under shock loads.
Figure 4 How it goes on
In use the major wear occurs on the tape in the buckles on the hips, but since tape replacement is cheap you can do this as soon as any severe wear shows.
A final warning, do make sure that you are very familiar with the way that the various loops relate to the various parts of your body, since once tangled it's rather awkward to work out what goes where. It would be very embarrassing to be rescued from the bottom of a big pitch because you couldn't put your sitsling back on.