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Ice pitons.—There are about as many designs as there are users, most of the designs obviously being the product of little thought. The shaft should be about 1/4 X 5/8 X 7—10 inches, with real teeth—not nicks—on the thinner sides. These will hold one's weight after the shaft itself has loosened, as it will under pressure or in mild weather and sunshine. The ice piton owes its security to the soundness of the ice into which it is driven and its angle to the ice surface, but particularly to regulation after it has been driven. The smooth, hollow-tubed U.S. Army variety is light in weight, shatters the ice least, and has held a pull of 2,000 pounds parallel to the shaft at temperatures of 10-20° F. But it remains to be seen how well a toothless tube will hold in the field without freezing temperatures to help it. The recently developed ice screw is much superior to the standard designs, developing exceptional holding power parallel to the shaft. |
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