1978 A new camming device has been developed

An article about Ray Jardine's Friends, written by Ian Wade, published in Off Belay, June 1978.

Is Your Nut a Friend?

By Ian Wade

The introduction of new technology into climbing equipment has historically caused three major reactions; an outcry from traditionalists that adventure has been removed from the sport, an upsurging of standards as the most adventurous climbers push this new piece of equipment to its limit, and finally a general elevation of climbing standards. This reaction has been observed in the development of pitons in the first decade of this century, with the introduction of crampons to the Alps in the l89O's, and, going way back to the early years, when some utter cad first began using a rope.

A new camming device has been developed which promises to elicit this cycle of reactions. These critters, Friends by name, now regularly used on the hardest Yosemite climbs. First ascents of five of the seven 5.12's currently completed in Yosemite involved the use of Friends. The advantages of these new camming devices include easy insertion and removal with one hand. They are much faster and simpler to place than any present protection device. They work in parallel-sided cracks, in cracks with flares of up to 25 degrees or more, and can rotate to align themselves with the direction of an applied load in a good placement, thus making them safer than any present generation nuts.

Friends are a rational development in a long line of camming devices and represent an application of scientific principles to cam design in a way which has not previously been undertaken. After five years of testing in Yosemite, they could now become the next generation of climbing protection.

Scottish climbers of the early 60's were perhaps the first to use the cam principle for protection. Pieces of hard wood, of various lengths, with a through hole drilled close to one end were wedged across cracks for use in aid climbs.

These crude camming devices illustrate the basic principle upon which all other cams rely. The loaded cam exerts a force perpendicular to the sides of the crack and this increases the friction between the cam and the rock, adding to its holding power. The angle of the cam may be varied up to some maximum angle which depends on the friction between the rock and the cam material. Thus any one cam can fit a range of crack sizes. An armlock is an interesting example of a free climbing application of the cam principle to the human body.

The next applications of the cam principle involved various aluminum shapes. These covered a greater range of sizes than the pieces of wood employed by the thrifty Scots. Lowe Alpine Systems, CMI, and SMC all make camnuts of this type, and the Chouinard hexentries include limited range camming as one of their modes of placement.

The latest application of the cam principle is the work of Ray Jardine who used the mathematical and engineering experience he gained while working in the aerospace industry to design and product Friends. The major innovation here is the four separate cams attached to a central axle. The cams are loaded via a stem which hangs from the axle. Each cam moves independently, conforming to the shape of the crack. The cams are shaped to contact the rock at the same angle throughout their range. Maintaining such a constant contact angle in varying width cracks was obviously not possible with the old wooden cams, although it is a design feature of some, but not all of the currently produced metal cams. Extensive testing was done to determine the ideal angle based on the amount of friction between aluminum and various types of rock. The cam angle for Friends was chosen to correspond with the slickest rock normally climbed on - limestone.

Each of the cams is spring loaded to ensure it grips the rock when placed. An early prototype of a Friend had no mechanism to release the tension on the springs and required four hands to remove! A trigger release was added which now allows the Friend to be placed and removed easily with one hand, making it by far the easiest to place cam-action nuts.

The wedging force of Friends is considerably lower than other nuts (reference OFF BELAY 29 and 31). The wedging force factor is 1.1, based on a cam angle of 25 degrees. This makes a Friend much less likely to expand a flake under load. Also the spring loaded cams will automatically expand to accommodate any widening of the crack.

Because the four cams move independently, the unit can be used in irregularly shaped cracks, the kind which heretofore had been impossible placements. For example, outward and even downward flaring cracks, with up to 25° flare, can be used with minimal loss of holding power. An unforeseen by-product of the four-cam design is its tendency to "walk" deeper into the crack, rather than out into the "great void," when the climbing rope jiggles the stem back and forth.

Test Data

The maximum impact force which can be generated by a modern kernmantel rope is in the region of 1300 lbs., making the maximum load on an anchor in the neighborhood of 2600 lbs. With this criteria in mind, Friends were designed to withstand loads of at least 3000 lbs. Static tests were performed on the prototypes which showed strengths of 5700 lbs. Production models were then redesigned to save weight. Testing of the production models is not yet complete. However in the first tests, the loop of 1 inch webbing broke at 3300 lbs. The manufacturer estimate the yield strength will be over 4000 lbs.

Some interesting field testing of the prototypes has been done. A 100 lb rock tied to a 10 feet length of low-stretch rope was dropped from 10 feet above a Friend placed upside-down in a parallel sided crack. This was an exceptionally severe test because the low-stretch rope absorbed little of the shock. However, in no case did the Friend fail. They simply rotated 180 degrees and held the 20 foot static fall!

ln the five years of their development, Friends have held over 200 actual falls during climbs. Kris Walker holds the current record, a 30-footer.

Placement Tips

Placing Friends, as other protection devices, requires an understanding of their design and possible limitations.

A parallel sided crack is the optimum placement, unlike regular nuts where a pocket provides the best placement. A Friend, placed in a pocket, may be hard to remove.

Horizontal cracks can be utilized but do not afford as reliable a placement because of the possibility of bending the stem. As the manufacturer states one may "develop a bent Friend". Shallow cracks in roofs can be used but there is a risk of the rock crumbling at the point of contact with the cam.

In principle, Friends can also be used with some sort of spacers in wide cracks without loss of holding power. It is unlikely that they actually would be used in this manner but this illustrates why Friends do work well in rotten cracks. Flakes of rock behave like spacers and are compressed between Friend and rock with little affect on the holding power. It is possible that Friends may also offer good placements in ice coated cracks, using the same reasoning but this is still unproven.

The factor that will most significantly affect the use of Friends is undoubtedly their purchase price. With twenty-seven separate components and over one-hundred manufacturing operation, Friends are not cheap. They are presently being manufactured in England as production costs in the U.S. were prohibitive. They will be available on a mail order basis only initially.

-Ian Wade, Portland, Oregon

"Friends can be ordered from Jardine Enterprises. Prices and availability are as follows:

Include $0.50 per order for shipping."

[Captions]

Left: A properly rigged "Friend" in a flaring crack. Note the independently determined positions assumed by each cam in repsonse to the changing crack dimension.

Below and title page: Ray Jardine uses his invention, "Friends," to protect a difficult Yosemite climb.

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