Half-mast
| Half-mast | |
|---|---|
|
|
| Type | Fuse |
| application | dynamic fall protection |
| Ashley No. | 1171-1173, 1797 |
| English | Cheerful hitch |
| List of nodes | |
The half hitch is a node which, when climbing to roping and dynamic securing is the climbing partner. The backup method using this node is called half-mast backup, or HMS for short.
history
The origins of this knot go back a long way to ancient times. The Phoenicians probably already used this knot to loose ships. It appeared in mountaineering in the 1930s when Russian climbers used it. From 1966 at the latest, the German Armed Forces taught this knot in the army mountain guide course in makeshift mountain rescue under the name of "rope cross brake". Since it was only used for abseiling.
The knot came into the climbing world only towards the end of 1967. At that time, the disadvantages of static securing methods came more and more into focus and the need for dynamic techniques became greater. Franz Ruso suggested a method under the name of “Karabiner-Bremsschlinge”, which is identical to today's HMS. Ruso's proposal went under, along with the multitude of other techniques that were developed during the paradigm shift. A few years later, at the UIAA conference in Trento in 1971, the Italian delegation showed an identical method that was developed around 1969 in the Aosta Valley. The Austrian delegate refused it, however, because apparently rope would rub against rope. In 1973 the Italians presented the security again at the UIAA conference in Andermatt. The DAV safety group around Pit Schubert determined the braking values in the laboratory and finally the commission recommended the new "UIAA safety". From then on, the half-mast developed into one of the most important knots in mountaineering. Its use has resulted in a significant improvement in security technology.
The name "Half-mast protection" came about in a conversation between Pit Schubert and Werner Munter also at the conference. Back then, Munter had proposed a new technique in Trento, which he called "carbine shoulder protection". This used the half-mast hitch, but also led the brake cable over the shoulder to increase the braking force, thus eliminating the advantage of dynamic securing. Since the HMS was recognized, Munter had tried again and again to associate it with his name. It is therefore often mistakenly assumed that Munter is the inventor, and in English the knot is also called “Munter Hitch”.
application
The half-mast throw is used for dynamic securing when climbing. A fall would be fatal if an inelastic rope would suddenly brake the fall. That is why climbers use dynamic climbing ropes , which reduce the impact force through their elongation, and, if necessary, a dynamic safety technique in which some rope runs through the safety device and is braked by friction.
With the half-mast protection, the rope runs through an HMS carabiner and enables the belayer to give the climber as much rope as he needs to move on the rock. If the climber falls, however, the belaying partner holds the brake rope tight so that the knot tightens and the rope clamps itself and dynamically brakes and stops the fall.
The brake hand must always enclose the brake cable for safe handling. Too loose or too late would let the rope slip and lead to burn injuries to the hand and possibly to the partner being let go and falling. When lowering the rope, the angle can be better regulated than with hand rubbing. The smaller the angle between brake and load rope, the greater the braking effect. The hand should hold the rope at a sufficient distance from the carabiner so that it is not pulled into it in the event of a fall. Likewise, the belayer must ensure that nothing else gets into it, such as clothing or hair.
For a long time, the German Alpine Club (DAV) believed that the brake hand should stay up so that the brake cable runs parallel to the load cable. When you follow up, you have to change hands briefly. At the Austrian Alpine Club (ÖAV) the braking hand down method is common and the movements are equivalent to securing with a tube . The braking effect differs only insignificantly. If the braking hand is positioned down, however, there will be more kinking. The DAV safety research therefore recommends the use of a tri-lock carabiner to minimize the risk of the rope being unintentionally unhooked.
Nowadays the HMS is being largely supplanted by backup devices . In DAV and KLEVER climbing facilities, it is only represented with 1% (as of 2018). In alpine climbing , however, it is still part of the basic knowledge. Especially on multi-pitch routes, it is ideal for two-person rope teams, as the fall can take place from any direction and therefore does not have to be rebuilt when changing guides, the HMS has good braking values and does not require any special equipment.
In addition to sport and alpine climbing, the half-mast throw is also used in the area of height and cave rescue and as fall protection for the fire brigade .
The DAV safety circuit determined braking forces of the HMS at the fixed point between 1.7 and 3.0 kN depending on the manual force of the belayer with single ropes (10 to 11 mm) and a fall factor of 0.4. When falling into a standing position with a fall factor of 2, the determined braking forces were between 2.0 and 4.8 kN. With this braking force, it is also possible for weak people to keep a fall.
Knot
Half-mast protection when climbing
When climbing, the half-mast throw with an HMS carabiner is used to secure the half-mast throw.
Half-mast holed
HMS carabiner
Clip the carabiner under the rope that comes from the climber
An eye set
The carabiner in
latch the eye
Draw in
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Half-mast laid
Lay an eye
Engage the carabiner from below through the loose end of the rope and the eye
Tighten
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Half-mast hooked
First a simple trip is inserted into the carabiner . The rope is then inserted again in the opposite direction.
Half-mast cast in seafaring
Loads are easier to control when placed around a bollard than with a round trip . To do this, lead the rope around the bollard, wrap the loose part around the standing part and lead it again in opposite directions around the bollard.
If the bollard is very wide, you can create a bay and walk around the bollard. Then the loose part is put through the bay. You only have to go around the bollard once. This shape capsizes into the shape described above when under load.
Modifications
To block the half-mast cast, the DAV recommends the grinding knot and the ÖAV the sound of water . If the grinding knot is backed up with a blind stitch, the mountain rescue knot is created .
If the loose end is wrapped around the fixed part again and passed through the carabiner, the double HMS is created (ABoK # 1195). Its braking effect is stronger than that of the ordinary.
Individual evidence
- ↑ a b Pit Schubert: Who is the inventor of the half-mast protection system? In: Mountaineers . No. 1 , 1999 ( PDF ; reprinted in bergundstieg 2/2005 [accessed on July 24, 2015]).
- ↑ A little history of half-mast protection. Retrieved on July 24, 2015 (reprint from HDv 347/1 “Military Mountaineering” from 1966).
- ↑ a b Hans Wölcken: The history of the half-mast protection system . In: mountaineering . No. 2 , 2005 ( PDF [accessed July 24, 2015]).
- ↑ Hands up . In: DAV (Ed.): Panorama . No. 3 , 2005, p. 83–85 ( PDF; 531 kB [accessed April 23, 2018]).
- ↑ Climbing hall accident statistics 2017. DAV, accessed on August 12, 2019 .
- ↑ Emanuel Wassermann, Michael Wicky: stood. rope up. come. In: mountaineering . No. 2 , 2007, p. 52–58 ( PDF [accessed November 17, 2015]).
- ↑ Walter Würtl, Peter Plattner: Alpine climbing. A recommendation. In: mountaineering . No. 3 , 2009, p. 70 ( PDF [accessed November 17, 2015]).
- ↑ Chris Semmel: In search of the best exercise routine . In: mountaineering . No. 2 , 2006, p. 67–73 ( PDF , 3.06 MB [accessed June 30, 2015]).
- ↑ Clifford Ashley: Ashley Book of Knots . Number 1797.
- ↑ Andreas Trunz: The importance of the mountain rope in alpinism. (PDF) October 29, 2004, p. 13 , accessed November 17, 2015 .
Web links
- Munter Hitch in YouTube and quick version "shot"