Ice screw

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An ice screw. Some modern screws like this one now have a handle to assist entry and removal, whereas early models did not. Ice screw.jpg
An ice screw. Some modern screws like this one now have a handle to assist entry and removal, whereas early models did not.

An ice screw is a threaded tubular screw used as a running belay or anchor by climbers on steep ice surface such as steep waterfall ice or alpine ice during ice climbing or crevasse rescue, to hold the climber in the event of a fall, and at belays as anchor points. [1] [2]

Contents

Design

Development of ice screws for the period 1924-2000 EishakenSchrauben.JPG
Development of ice screws for the period 1924-2000

Ice screws may come with one or more of the following: an in-built or separate ratchet mechanism to speed up placement, conical centre-hole to aid removal of ice cores, different lengths, different numbers of cutting teeth, different cutting angles, different surface finishes, and different size clip holes. Price and durability are usually design considerations too, as a usable rack of ice screws will be a significant financial investment for many climbers. Many titanium ice screws were initially made in the former Soviet Union using Cold War-era missile technology, but were generally too brittle, and so the majority of ice screws are now made of chromoly steel.[ citation needed ]

The strongest and most reliable type of ice screws currently available are the modern tubular ice screws which range in lengths from 10 to 23 cm. The approximate strength rating on a modern tubular ice screw is around 7  kN, and it has been found that short ice screws in good ice hold about 7-8 kN, no matter what the fall factor or configuration is. [3] The International Climbing and Mountaineering Federation drop test specifies that when multi-pitch lead climbing and the leader has only placed one screw (typically merely clipping one of the anchor screws) before climbing up a couple of meters and falling (a fall factor of 2), the screw must hold. [4] The dynamic ropes used in climbing can mitigate failure of an ice screw by keeping the impact forces low, especially if using a new rope that has not had any previous falls. It is rare that an ice screw fails in fall factors of 1 or less, if placed in good ice.

An older type of screw that is rarely used today is a pound-in ice screw, such as the 'snarg' and the 'warthog'. Instead of screwing these into the ice one would pound them in with a hammer from the ice tool, and then screw them out with the pick of an ice axe. The pound-ins have been largely replaced by modern tubular ice screws that are stronger and easier to use, although warthogs are being manufactured in Britain again for use in creating an anchor in frozen turf when no alternative anchor or placement is available. [5] [6] [7]

The latest ice screws incorporate replaceable tips, thereby increasing the useful life of the screw and enhancing placements. [8]

Placement

It was once thought necessary or beneficial for ice-screws to be placed horizontally or with the hanger up for optimum hold. However, it has since been found experimentally that a screw placed with the tip angled up often holds as well or better. This surprising result is thought to be due to the previously underestimated role of the threads in holding the screw in place. However, horizontal placements are usually recommended.

Some climbers use tape slings to "tie-off" long ice-screws that have not been fully screwed into the ice, to reduce the leverage of a fall, which might bend or break the screw. There is some risk that such slings may move or be sliced by the screw's hanger. Some novel ice screws include a hanger that can be moved down the shaft, instead of using a sling. Placing a shorter screw is usually the preferred option, hence various lengths are available.

Other uses

Long ice-screws are now often used to create V-threads. By making two ice-holes that intersect, an inexpensive but strong cord (typically static climbing accessory cord or tape) can be threaded through, making a relatively safe and cheap anchor. This can be an attractive option at belays and when ice screws are in short supply. V-threads can be particular useful as rappel or abseil points where it is often necessary to leave the final anchor behind. A piece of wire - typically a piece of old coat hanger shaped for the purpose - or a stiff flexible purpose built tool with a small hook at one end and a hanging loop at the other end, is often used to aid threading of the cord.

In the Rosetta project, the European Space Agency equipped its lander with multiple ice screws to obtain stability on comet surface, but they failed to hold, and the lander bounced a significant distance from the initial landing site.[ citation needed ]

Related Research Articles

<span class="mw-page-title-main">Climbing wall</span> Artificially constructed wall with grips for hands

A climbing wall is an artificially constructed wall with grips for hands and feet, usually used for indoor climbing, but sometimes located outdoors. Some are brick or wooden constructions, but on most modern walls, the material most often used is a thick multiplex board with holes drilled into it. Recently, manufactured steel and aluminum have also been used. The wall may have places to attach belay ropes, but may also be used to practice lead climbing or bouldering.

Climbing protection is any of a variety of devices employed to reduce risk and protect others while climbing rock and ice. It includes such items as nylon webbing and metal nuts, cams, bolts, and pitons.

<span class="mw-page-title-main">Traditional climbing</span> Style of rock climbing

Traditional climbing is a style of rock climbing in which the climber places all the necessary protection gear required to arrest any falls as they are climbing, and then removes it when the pitch is complete. Traditional bolted aid climbing means the bolts were placed while on lead and/or with hand drills. Traditional climbing carries a higher level of risk than bolted sport climbing, as the climber may not have placed the safety equipment correctly while trying to ascend the route; for some of the world's hardest climbs, there may not be sufficient cracks or features in the rock that can accept protection gear, and the climb can only be safely attempted by bolting as a sport climb.

This is an index of topics related to climbing.

<span class="mw-page-title-main">Ice axe</span> Winter mountaineering tool

An ice axe is a multi-purpose hiking and climbing tool used by mountaineers in both the ascent and descent of routes that involve snow, ice, or frozen conditions. Its use depends on the terrain: in its simplest role it is used like a walking stick, with the mountaineer holding the head in the center of their uphill hand. On steep terrain it is swung by its handle and embedded in snow or ice for security and an aid to traction. It can also be buried pick down, the rope tied around the shaft to form a secure anchor on which to bring up a second climber, or buried vertically to form a stomp belay. The adze is used to cut footholds, as well as scoop out compacted snow to bury the axe as a belay anchor.

<span class="mw-page-title-main">Glossary of climbing terms</span> List of definitions of terms and concepts related to rock climbing and mountaineering

This glossary of climbing terms is a list of definitions of terms and jargon related to rock climbing and mountaineering. The specific terms used can vary considerably between different English-speaking countries; many of the phrases described here are particular to the United States and the United Kingdom.

<span class="mw-page-title-main">Ice climbing</span> Activity of ascending ice formations

Ice climbing is the activity of ascending inclined ice formations. Usually, ice climbing refers to roped and protected climbing of features such as icefalls, frozen waterfalls, and cliffs and rock slabs covered with ice refrozen from flows of water.

<span class="mw-page-title-main">Rock-climbing equipment</span>

A wide range of equipment is used during rock or any other type of climbing that includes equipment commonly used to protect a climber against the consequences of a fall.

<span class="mw-page-title-main">Abseiling</span> Rope-controlled descent of a vertical surface

Abseiling, also known as rappelling, is the controlled descent of a steep slope, such as a rock face, by moving down a rope. When abseiling the person descending controls their own movement down the rope, in contrast to lowering off in which the rope attached to the person descending is paid out by their belayer.

<span class="mw-page-title-main">Aid climbing</span> Style of climbing

Aid climbing is a style of climbing in which standing on or pulling oneself up via devices attached to fixed or placed protection is used to make upward progress.

<span class="mw-page-title-main">Sport climbing</span> Form of rock climbing

Sport climbing is a form of rock climbing that relies on permanent anchors, permanently fixed into the rock for climber protection, in which a rope that is attached to the climber is clipped into the anchors to arrest a fall; it can also involve climbing short distances with a crash pad underneath as protection. This is in contrast to traditional climbing where climbers must place removable protection as they climb. Sport climbing usually involves lead climbing and toproping techniques, but free solo and deep-water solo climbing on sport routes is also sometimes possible.

<span class="mw-page-title-main">Belaying</span> Rock climbing safety technique using ropes

Belaying is a variety of techniques climbers use to create friction within a climbing system, particularly on a climbing rope, so that a falling climber does not fall very far. A climbing partner typically applies tension at the other end of the rope whenever the climber is not moving, and removes the tension from the rope whenever the climber needs more rope to continue climbing.

<span class="mw-page-title-main">Lead climbing</span> Competitive discipline of sport climbing

Lead climbing is a climbing style, predominantly used in rock climbing. In a roped party one climber has to take the lead while the other climbers follow. The lead climber wears a harness attached to a climbing rope, which in turn is connected to the other climbers below the lead climber. While ascending the route, the lead climber periodically connects the rope to protection equipment for safety in the event of a fall. This protection can consist of permanent bolts, to which the climber clips quickdraws, or removable protection such as nuts and cams. One of the climbers below the lead climber acts as a belayer. The belayer gives out rope while the lead climber ascends and also stops the rope when the lead climber falls or wants to rest.

<span class="mw-page-title-main">Nut (climbing)</span>

In rock climbing, a nut is a metal wedge threaded on a wire that climbers use for protection by wedging it into a crack in the rock. Quickdraws are clipped to the nut wire by the ascending climber and the rope threads through the quickdraw. Nuts come in a variety of sizes and styles, and several different brands are made by competing manufacturers. Most nuts are made of aluminum. Larger nuts may be threaded on Dyneema cord instead of wire, but this has become unusual.

<span class="mw-page-title-main">Rock climbing</span> Sport in which participants climb natural rock formations

Rock climbing is a sport in which participants climb up, across, or down natural rock formations. The goal is to reach the summit of a formation or the endpoint of a usually pre-defined route without falling. Rock climbing is a physically and mentally demanding sport, one that often tests a climber's strength, endurance, agility and balance along with mental control. Knowledge of proper climbing techniques and the use of specialized climbing equipment is crucial for the safe completion of routes.

<span class="mw-page-title-main">Prusik knot</span> Type of knot

A Prusik is a friction hitch or knot used to attach a loop of cord around a rope, applied in climbing, canyoneering, mountaineering, caving, rope rescue, ziplining, and by arborists. The term Prusik is a name for both the loops of cord used to tie the hitch and the hitch itself, and the verb is "to prusik". More casually, the term is used for any friction hitch or device that can grab a rope. Due to the pronunciation, the word is often misspelled Prussik, Prussick, or Prussic.

In rock climbing, an anchor can be any device or method for attaching a climber, a rope, or a load above or onto a climbing surface—typically rock, ice, steep dirt, or a building—either permanently or temporarily. The intention of an anchor is case-specific but is usually for fall protection, primarily fall arrest and fall restraint. Climbing anchors are also used for hoisting, holding static loads, or redirecting a rope.

<span class="mw-page-title-main">Dynamic rope</span> Rope designed to stretch under load

A dynamic rope is a specially constructed, somewhat elastic rope used primarily in rock climbing, ice climbing, and mountaineering. This elasticity, or stretch, is the property that makes the rope dynamic—in contrast to a static rope that has only slight elongation under load. Greater elasticity allows a dynamic rope to more slowly absorb the energy of a sudden load, such from arresting a climber's fall, by reducing the peak force on the rope and thus the probability of the rope's catastrophic failure. A kernmantle rope is the most common type of dynamic rope now used. Since 1945, nylon has, because of its superior durability and strength, replaced all natural materials in climbing rope.

<span class="mw-page-title-main">Belay device</span> Mechanical piece of climbing equipment

A belay device is a mechanical piece of climbing equipment used to control a rope during belaying. It is designed to improve belay safety for the climber by allowing the belayer to manage their duties with minimal physical effort. With the right belay device, a small, weak climber can easily arrest the fall of a much heavier partner. Belay devices act as a friction brake, so that when a climber falls with any slack in the rope, the fall is brought to a stop.

<span class="mw-page-title-main">Abalakov thread</span>

The Abalakov thread, also known as a V-thread, A-thread, or 0-thread, is an ice protection technique named after its innovator, Soviet climber Vitaly Abalakov. The Abalakov thread is a common method of protecting oneself while ice climbing because it is easy to create, does not require the sacrifice of expensive gear, and can be very safe when used properly. An Abalakov thread is often used in multi-pitch ice climbing routes. Because of its safety and convenience, the Abalakov thread is considered one of the most significant innovations in ice climbing. It significantly expanded the scope of possible routes and abseiling safety.

References

  1. Cox, Steven M.; Kris Fulsaas, eds. (September 2003). Mountaineering: The Freedom of the Hills (7 ed.). Seattle: The Mountaineers. ISBN   0-89886-828-9.
  2. Semet, Matt; Mike Tea (2011). Climbing Dictionary. Seattle, USA: The Mountaineers Books. p. 124. ISBN   978-1-59485-502-3.
  3. Beverly and Attaway
  4. http://www.theuiaa.org/upload_area/cert_files/UIAA101_DynamicRopes.pdf [ dead link ]
  5. Ryan, Mick (December 2007). "The Warthog Rises Like A Phoenix From The Ashes". www.ukclimbing.com. Retrieved 5 December 2015.
  6. "Mountain Technology Warthog Turf Screw". www.needlesports.com. Retrieved 5 December 2015.
  7. "Snarg ice piton/screw". www.smhc.co.uk. Scottish Mountain Heritage Collection. Retrieved 5 December 2015.
  8. "E-Climb: Ice Screw Replaceable Tips". Archived from the original on 2011-07-10. Retrieved 2020-01-21.