Creating Abalakov thread (V-thread)
Monday, February 2nd, 2009 21:59 by
juho Print this page
Abalakov thread, named after great Soviet climber Vitaly Abalakov, is one of the great mountain safety inventions. It’s also known as a V-thread. Generally speaking Abalakov thread is fairly easy to create, doesn’t require any expensive gear to be left behind and, when created and used properly, it’s safe.
Here’s a short introduction to Abalakov thread in a way I’m used to do it. I’m doing it just a bit differently than it’s usually been though; in particularly I’m using pre-cut-pre-tied prusik loops, which, in my opinion, makes it faster and easier to create Abalakov threads. This is actually something, which I would hope that some of the more experienced climbers would comment on. Unfortunately I don’t have images of the procedure yet, but they will be added later on.
- 1-2 meters of >7mm prusik cord or something else with similar strength. The length depends on how you use it. If you use it traditional way, you need about 1 meter. I’m using mostly pre-cut readymade prusik loops, which require longer cord, but on the other hand provide easier and faster creation of Abalakov thread. A narrow dyneema sling will do also, but is far more expensive.
- At least one long, >19cm, sharp ice screw. If you have longer screws, use the longer one. Length of screw adds security.
- Abalakov threading device, either improvised or commercial. You can improvise one from any stiff enough wire. I’ve been very happy user of Grivel Candela, which is great for cleaning screws and cutting rope as well.
- Knowledge to create double fisherman’s knot (see images at the bottom), or other dependable knot according to material you’re using.
- Select location with solid ice and remove all excess ice from area of 20-40cm in diameter.
- Use your ice screw to drill horizontal hole at roughly 45 -50 degrees compared to the surface of the ice.
- Measure a suitable distance for the second hole (15-20cm), you can use your ice screw as a guide. Note that wider the gap between holes, stronger Abalakov you’ve got. Roughly spoken 10cm gap, will result strength of 6-7Kn, 15cm gap 10-11Kn and 20cm gap 11-12Kn.
- Drill second hole to the ice with similar angle, so that the two holes meet as deep inside the ice as possible. If you put second ice screw or the Abalakov threading device in to the hole, it’s easier to aim in to right spot.
- Put the cord (or in my case prusik loop) in to one of the holes as deep as it goes.
- Use Abalakov threading device to pull the cord trough from other hole. In case of candela and prusik loop, it’s very easy to do, just move the wire part below the cord, twist your candela a bit and voila, it’s trough.
- In case of prusik loop or sling, you’re ready to put your abseiling rope trough, in case of untied cord; you need to do a double fisherman’s knot to be ready.
- Place the screw in to ice about 50-70 cm away from Abalakov you’ve just did and use a runner to create a backup for first one to abseil (last one will remove it and abseil with out backup).
- Run half of your rope trough the cord loop you have. Now the first one to abseil can prepare him/herself to go down. First one should carry most of the heavy gear.
- Watch carefully while going down to observe behavior of the ice for fractures and prusik loop for possible slippage (it won’t slip though, if you did the knot right).
- Once first one is down, he/she can start creating the Abalakov for next pitch, while the second one removes the backup and abseils.
As said, I’ve noticed that it’s much easier to use prusik loops instead of untied cord. First of all, it’s easier to hook out with Abalakov threading device and perhaps even more importantly since you don’t need to tie anything you don’t need to remove your gloves (yes I know one should be able to do it with gloves too, but that’s soooo slow). I have a feeling that a loop is easier to stuff in to first hole, since the rope doesn’t make as many curves inside the holes.
In case you don’t have good enough ice available, you could use two Abalakovs instead of one and create a sort of a balanced abseiling point. This being said, I would heavily consider a possibility for other route down in this type of circumstances.
- Incorect selection of ice (not solid enough)
- Incorrect placement of holes (too close to each other or too early interconnection)
- use of improper cord (not strong enough)
- improper knots (either selection of wrong knot, or inproper tying).
Update 5.1.2011: As I wrote another article that concerns testing of a sliding x -type of configuration with V-threads I decided to give a short update on our current V-thread / Abalakov procedures. First of all we’re now using over hand knot while tying the prusik cord. It should be almost as secure in this context as double fisherman’s, but is much simpler to tie and can be tied gloves on. The second change is that we’ve abandoned the use of ready made prusik loops; mainly because the overhand knot is so much simpler to tie – i.e. the reasons for using the loops have disapeared.
Few images about creating Abalakov thread:
Double fisherman’s knot in images:
VN:F [1.9.22_1171]Creating Abalakov thread (V-thread),