The Origination of Ice Screws
Ice Screws are descended from ice pitons. They were extra-long, blade-type rock pitons with holes, notches, or bulges to increase their grip on ice. Climbers experimented with new designs after WWII, including a larger shaft area to reduce the load per square inch on the ice and more holes to help the shaft freeze into the slope.
When ice screws were first introduced in the early 1960s, enthusiasts predicted that they would revolutionize ice climbing by bringing safety to the slopes. Critics scoffed, claiming that the screws were no better than the older ice pitons. This was especially true of the lightweight, relatively weak “coat-hanger” ice screw, which is now rarely used. However, ice screws have continued to improve and are now considered reliable leader protection
Modern Ice Screws and their Use
The modern tubular ice screw is the most durable and dependable design. This screw, which is typically 7 to 9 inches long (18 to 23 centimeters), works well in both winter and summer temperatures. Screwing in and out is relatively simple, with some models including a built-in ratchet for faster placement and removal. The hollow design reduces ice fracturing by allowing displaced ice to work its way out through the screw core.
The ice inside the core must be cleaned out immediately after the screw is removed, or it will freeze to the interior, rendering the screw temporarily useless. Some ice screws have a slightly conical interior that allows for easier ice removal. If ice forms on the inside, use a stiff wire to push it out.
The strength of an ice screw is greatly influenced by its shape and size. A large-diameter screw of the same length can support more weight than a smaller-diameter screw of the same length. A tubular screw can withstand more force than a solid screw.
Another type of ice screw is hammered into place before being screwed out. This type, which was created in an attempt to create an easy-to-place and easy-to-remove screw, is available in both solid and tubular forms.
The solid versions are effective in water ice at temperatures below freezing but less so in other ice and at higher temperatures. Melt-out is sometimes rapid due to limited thread displacement, and they tend to shear through the ice under load. They can break if not hammered in all the way, and they can be difficult to remove at times.
Hollow-core versions of pound-in, screw-out designs have the advantage of allowing displaced ice to escape through the core rather than being pushed aside by a solid screw. With its small threads, this design can be installed with a series of light blows and removed relatively easily by unscrewing or levering out with an axe pick. It is most effective on hard ice but can be unreliable in temperatures above freezing.
HOW TO CHOOSE ICE SCREWS
Choose a Variety of Ice Screw Lengths
ICE SCREWS are available in lengths ranging from 10 to 22 cm. The shorter ice screws (10-13 cm) can be inserted into thinner ice without damaging the rock beneath. As a result, most climbers will have at least a couple of shorter screws on hand. A climber may choose to carry more 10-13 cm screws early in the season when the ice is thinner, or if a particular climb is a mostly thin ice.
The meat of a typical ice climbing rack is made up of screws that are 16 or 17 cm long. Screws of this length, when properly installed in good, hard ice, are quite strong. It is not uncommon for a leader to use eight or more of these length ice screws as intermediate protection while climbing a standard ice route.
Longer screws, ranging from 19 to 22 cm in length, are useful when extra security is required because the ice near the surface is not as strong. A longer ice screw can also be used to drill two adjacent holes in the ice to create a threaded anchor.
Choose Ice Screws That Are Easy to Place
It is critical to be able to handle and place an ice screw with one hand while wearing gloves. All modern ice screws have teeth and threads that are meticulously engineered to bite into hard ice. Some ice screws have an unfolding knob or handle from the hanger. Once the first few threads are engaged in the ice, the climber can turn a screw in more quickly and easily.
Some argue that different-shaped hangers are easier to handle with gloves, allow the ice screw to hang in a better position when clipped to a harness, or interfere more or less with the ice’s surface while screwing in. All modern ice screws, in fact, are designed with features that make it easier for a climber to place them.
What Do you Need with your Ice Screws?
A tough, reinforced nylon bag designed specifically for storing ice screws is a good idea for protecting the rest of your pack’s gear from the screws’ sharp teeth and threads. Ice flutes, which are plastic sleeves for the screws, can also be used.
How to Store Ice Screws?
Make use of a fine file (flat file and 3 mm maximum round file). Take care not to damage neighboring teeth with a too-large file. To protect the threads, place the screw in a soft-jawed vice. Only file the outside of the screw.