Quick and Safe V-Thread Descents

Most alpine climbers use V-threads (Abalakov threads) occasionally (if you don't know how to do a v-thread you may want to google that before reading further), but not many choose to set out on a climb planning to use them to descend many hundreds of metres down a large ice face. I used to think of V-threads as something for ice cragging and occasional use in the mountains but I'd never considered that a steep ice face could actually be a sensible, safe and fast way to get off a big peak.

That all changed when one of my climbing partners came back from spending the winter in the Canadian Rockies and suggested that the best way off our late autumn ascent of the Swiss Route on the north face of Les Courtes near Chamonix would be to abseil the grey, late season ice of the NE face. My initial thought was that it would take forever to do the 14 or so abseils required, but after considering the alternative of having to carry our overnight gear up the mountain and descend the hugely crevassed Talefre glacier I decided to give it a go. As it turned out the system he showed me was simple and efficient and we were back at our kit within a couple of hours of starting the abseils. The system: It's important to have a system to keep you organised and efficient and minimise the chances of making a dangerous mistake when descending at the end of a long day. For the sake of explaining the system I've assumed that the descent starts with an abseil into the top of an ice face off a rock anchor or V-thread you've already set up. The system described below is one way of doing things and you'll probably want to modify it to suit the conditions and equipment you have with you.

1. Gear up – Decide who is going to go first (leader). They should take all the ice screws (ideally you will want at least four sharp screws for maximum efficiency) and a couple of long extender quickdraws. The second can carry the tat, knife and v-thread tool. Both should have daisy chains or similar and prussics.

2. Leader abseils – The leader abseils down using a prussic as a back up. If the ice is variable they will need to aim for the densest, hardest patch of ice they can see, otherwise simply go to within a couple of meters of the end of the rope.

3. Leader places single screw belay – After checking that the prussic can hold them (if necessary backing it up by wrapping the rope round their leg) the leader uses both hands to place an ice screw straight in and clip their lanyard on to it. Sometimes it may be necessary to smash cruddy ice off the surface to get to more solid ice to place the screw in. If working with a smallish good patch of ice then this first screw is places at the top to leave room for the V-thread diagonally below it. If the ice is bomber then you can use a shortish screw for this belay to save time.

4. Bounce test belay – Once clipped on the leader abseils until their weight comes fully onto the ice screw. Remaining attached to the ropes the leader bounces their full weight on the static lanyard attaching them to the ice screw.

5. Second starts abseiling – Assuming the ice screw holds with no sign of weaknesses appearing in the ice around it, the leader trusts it and unclips from the ropes so the second can start abseiling.

6. Leader starts V-thread – working with both hands the leader quickly places a medium or long ice screw at a 45 degree angle at about chest height. They then back the ice screw off but leave it in the hole so they can line up the second screw. If the ice is cruddy make the V-thread as deep as possible but otherwise it is quicker to go slightly shallower as it means the screws don't have to line up quite as perfectly.

7. Second helps - generally I find if you're working efficiently the second gets to the belay around the time the leader is starting to place the second screw. Once they get there they check there prussic is holding and start to help make the V-thread. This can involve helping line up the screw, then cutting the tat to the required length and getting ready to thread it. Once the second screw is started the first screw can be removed and cleaned (e.g. by tapping the back of the screw onto an ice tool - never tap the sharp end of the screw or the threads as this will blunt the screw). Make sure the cleaned screws are returned to the leader.

8. Complete V-thread - I find poking the tat down the second hole and hooking down the (usually slightly longer) first hole is quickest, but it doesn't really matter. Tie the tat off with an overhand knot leaving reasonable tails. When tying the tat include the rope end you are going to pull within the loop so it is all ready.

9. Bounce test thread - Once the thread is complete the second clips in and bounce tests the thread before coming off the ropes. I usually back up the thread to the single screw with a slack extender quickdraw. If you have concerns about the thread after bounce testing it a separate thread can be added above and the two equalised, although this is rarely required. Bounce testing is important as I have managed to get V-threads to fail on a couple of occasions.

10. Pull ropes - The second pulls the ropes and the leader feeds them through the tat, once the knot is reached the leader can put his belay onto the ropes. One of the nicest things about abseiling down an ice slope is there is generally very little risk of the ropes getting stuck. The second rope usually falls cleanly past the belay without tangling.

11. Leader abseils and second removes single screw belay - once the leader is off the belay and abseiling it should be fine to remove the screw - you've bounce tested the thread so trust it. 12. Repeat - If you're working efficiently you can get this down to around 5 mins per rope length – around 700m an hour…