Ascenders are very useful devices, they are basically uni-directional rope clamps. Locking in one direction, while sliding easily in the other. Ascenders are mainly useful when situations arise that were not intended. Such as the second falls off the overhanging and is hanging free in space, thus the rope has to be climbed to regain the rock. Or one climber gets hit by a falling block and is knocked unconscious, then they will need to be hoisted up, or the other climber will need to escape the system. In all these situations an ascender would be invaluable.

The ascenders mentioned below are not really designed for usage like a handled ascender. For instance they are not designed for long fixed rope ascents or caving. The problem being that they would become uncomfortable to hold over an extended period. They are also more likely to be dropped.

All devices are super strong, so this is not the limiting factor to the weight they hold. the limiting factor usually comes down to the strength of the rope. Most devices use a camming system, to change the downwards pull into a pinching force. So as the loading increases, the rope can get damaged and can even completely fail.

Prussik loops were the original method of ascending a fixed rope. 5mm prussik loops tend to work best.

French Prussik

This is simply when the prussik loop is passed round the rope and the ends are clipped together. The number of times it goes round the rope, varies the friction and holding power. It can be used as an ascender but is not generally used as such. This is because it doesn't lock solid. But it is good as a safety backup for an abseil, by clipping it to a leg loop. So if you get something caught in the abseil device or you simply let go of the rope, you do not go anywhere. This can be tied with slings as well, the friction is just as good.

Prussik

This is the original ascending knot. Which is simply a double or triple larks foot round the rope. The number of times it goes round the rope varies the friction. It is a little difficult to use as it can lock very tight, and is thus difficult to move in either direction. But it is strong, reliable, light and cheap. If it is only for emergency situations than it is very good. But it would be impossible on longer ascents.

Petzl Tibloc : 39g, 8-11mm

This is the simplest ascender ever devised, as it has no moving parts. It looks a little weak but it really isn't, also it is only a little heavier than prussik loops. It is not good as an abseil protector, as the teeth are fairly aggressive, and would badly pick the sheath. But as ascending goes it is very good, but does tend to pick the sheath, but thus does not squash the core as badly as camming ascenders. At over £12 it does seem to be a little expensive.




Wild Country Ropeman MK1 : 62g. 10-11mm

This was one of the first micro ascenders, and now has two versions, the MK1 and MK2. The MK2 has a slightly redesigned cam with conical pins which allows it to work with smaller rope diameters. The Mk1 runs up the rope smoother than any other device I have used, and as thus is quite good for abseil protection. The cam is apparently the least rope friendly, but is by far the most sheath friendly, due to the large teeth. I think it is the best micro ascender available, although the price seems a little high at over £18.