Stay At Home Storytelling: meet my SRT kit

I was a caver at university. Have I mentioned that? Well, in these isolated days of little new material for travel and adventure blogs, I thought I’d show you my SRT kit.

Sometimes you need to climb up or down a rope. Big caves in mountain ranges across Europe make this, plus several miles of rope, essential. I only ever did this underground once or twice, which is why my kit is still in pretty perfect condition. Carrying this stuff is a bit of a pain – for anything under about forty feet, you’d use a ladder and clip onto your battery belt for safety.

If you’ve ever abseiled, you’ve probably used two ropes – the one that’s actually technically doing the work and the one you’re handling to create the illusion you’re lowering yourself. In caving, no one’s carrying an extra safety rope into nature’s 3D hell-maze so instead we take a harness and metalwork. This is called SRT, single rope technique. I’m not here to teach you. I never entirely mastered it. I’ve got a bit of rope at home from the morning I had to be cut free from a bridge while practicing. But basically, you use two jammers to allow you to climb in two movements frog-style – arms up, then body up – and a bobbin descender to slide down. The art is in the changeover. Practice is inevitably done from the bottom so when you’ve climbed up, you have to unclip the jammers and wind in the descender without either removing everything so you fall, getting everything tied together or – and this is the number one mistake – trapping your upper jammer against the knot.

Me practicing my SRT in a tree, somewhere around late 2003 or early 2004. I'm attached to a length of rope, I'm about four feet off the ground. My hands are on my top jammer and my feet are in my footloop. I'm about to push the jammer up and then stand up in the footloop.
Me practicing my SRT in a tree, somewhere around late 2003 or early 2004.

By the way, where I’ve put any of this on the rope, it’s on a length of beautifully coiled orange dynamic climbing rope. I’m not uncoiling it because it’s too beautifully done. It’s also dynamic rope which has a certain amount of stretch in it to absorb shock in the event of a fall. SRT should be done on static rope which has minimal stretch (although my experience of SRT is that the ropes still bounce like crazy!). Static ropes are usually white but occasionally black.

Let me show you the kit.

SRT bag - a small blue caving bag with a drawstring top and a yellow webbing cross-body strap.

The harness

Petzl Superavanti caving sit harness. A simple harness made of red webbing with reinforcement on the leg loops. It's exactly as uncomfortable as it sounds.

The harness is a little different to a climbing harness. It’s all webbing, no padding and adjustment is done before you put it on. It’s fastened with a d-shaped maillon – like a karabiner but with no hinged part. It sits around your hips rather than your waist. The lower the better because it allows you to make bigger steps when you’re climbing. Yes, it’s supremely uncomfortable and yes, if you turn upside down, you will fall out of it. Hence…

The chest harness

Caving chest harness. It's a length of red webbing, mostly rolled up, with a black buckle at one end.

I’ve seen fancy chest harnesses used in climbing and high ropes. The caving version is a single long strap wound round you in a particular way that takes ages to learn to do yourself. Mine is a length of red webbing from Hobbycraft with a buckle sewn at one end although most people buy a professionally made one. You pull it tight once you’re on the rope, tuck five feet of spare webbing away somewhere and then discovered you’re a curled fœtal creature with a huge humpback once you come off the rope.

The Croll

Petzl Croll chest jammer. A gold jammer with a toothed cam.

Croll chest jammer being attached to a loop of rope. The cam is pulled back by its black handle and hooked out of the way so it can be installed on the rope.

Petzl Croll on a rope. I'm pulling at it to demonstrate that it won't move downwards because of the teeth on the cam.

Croll is the model name of the Petzl chest jammer but that’s what we always called it. The bottom hole goes on your harness maillon and your chest strap goes through the top hole. This thing has a toothed cam inside it. Thread the rope in and when you move up, the rope glides through. Try to move down and the teeth bite in and you’re not going anywhere. Once this one is on the rope, you don’t have to think about it.

The hand jammer

Petzl Ascension hand jammer with cords. It looks like the Croll but it's blue and has a handle. The cord is yellow and coiled up loosely next to it.

Petzl Ascension with cords spread out. The attachment cord is on top and the footloop is at the bottom - it's not stretched out as far as it could go because it won't fit in the picture otherwise.

This works just like the Croll in that it has a toothed cam but it has a handle. It’s attached to the middle of a narrow rope. One end attaches to your harness. It’s arm-length, no more. Can’t push it up higher than you can reach. So you push it up and then you stand up in the foot loop tied in the other end. Up goes the jammer, up goes the loop, up you step. The Croll catches you after each step, enabling you to push the hand jammer up again.

The descender

Petzl Stop with braking karabiners. The Stop is three bobbins with blue front and backplates. It's attached to an oval locking karabiner and has an oval straight-gate karabiner next to it for braking.

Rope threaded through Petzl Stop. The rope at the bottom goes up and the rope at the top goes down but it's on a loop of coiled rope so it's hard to show. It's purple and orange dynamic rope - you should do SRT on white or black static rope.

We always used the Petzl Stop, otherwise known as the Petzl Go. It has three cams in it and a handle so you can turn one of the cams to squash or not squash the rope and enable you to go or to not. Threading it upside down may well lead to coming off the rope and dying. Hair catches very easily between the bobbins. There’s also a handle-less version if you’d rather have less control.

The braking karabiners

You don’t just depend on the descender. When the rope is wound around the bobbins to add friction, you also put it through two smooth oval non-locking karabiners to add a bit more friction. You’ll probably want that at a climbing wall with your dedicated practice rope but in a cave, the rope is often wet and muddy and a swollen gritty rope provides enough friction that you might have to force it through your high friction descender kit.

The cowstails

Caving cowstails - a length of red rope with a knot tied in the middle and two tails of different lengths. Each tail has a snap curvegate karabiner attached.

If you’ve done via ferrata you might have encountered cowstails. The caving version is different. It’s thick rope and it’s short – the longer one is no longer than arm’s length and the shorter, well, shorter. They’re for safety – besides going up and down, SRT includes manoeuvring around obstacles and sometimes you want to be clipped in while you deal with them. You don’t want to be clipped in to a rope too long to be able to undo it. At each end is a curved snapgate karabiner – locking is obviously safer but the idea is to be able to just smack your cowstail onto something without fiddling to open a karabiner that needs two hands. Mine aren’t properly tightened – you need to hang from them to make sure the knots tighten in advance of using them for real. I have used them for real – I got stuck for nearly an hour at a rebelay and you’d think nearly an hour of swinging and swearing and frustration would get those knots neatened nicely but it didn’t. Once they’re tightened, you can trim the ends, as short as possible. If they’re properly tight, you shouldn’t need a tail to slide through for safety because it should be so tight it’s not going anywhere. But my cowstails aren’t finished.

The spare karabiners

Two aluminium locking karabiners. The gate is blue and the lock is red. They're by far my prettiest karabiners.

I have a spare krab at each side of my harness. They’re not meant for climbing, although I think they’re both suitable in an emergency. They’re just gear loops for hanging stuff on. Caving harnesses don’t come equipped with an entire line of loops along the back. I don’t think I’ve ever hung anything from mine but if you’re doing an expedition, you’d have pitons and the like, Prussik loops and a knife. I never got the caving knife – Petzl do one with a folding blade and a hole in the middle. You can open it one-handed. It’s for rope rescue. I’ve been on the receiving end of rope rescue – that morning on the bridge probably isn’t the only time – but I was never proficient enough to even think of rescuing.

The Prussik loops

I never used these as a caver, I acquired them at climbing instructor caving last year. Basically, they’re loops of cord that you wind in a certain way to create something that works like a jammer – slides up happily but will clamp the rope and refuse to go down. They’re a backup. You don’t use it as your main ascender – well, I can think of one person who might but he suggested free-diving one of the bigger sumps (flooded passageways) in Swildons using a paper bag as a respirator.

Have I missed anything? I haven’t mentioned the everyday caving kit but if you really want a “What to wear to crawl into the bowels of the Earth!” I can do that another time.