About 50-60 cm long and about 5 cm wide saw with usually very large teeth (1) - compare with the frozen-food knife - with which snow blocks are cut to build an igloo. The length of the hand tool is decisive for the size of the blocks that can be sawn; the width to be able to exert enough force when loosening those blocks (2). Not infrequently, the snow saw is made yourself (3). [MOT]
(1) Although long knives without teeth are also used.
(2) HAGEN: 56-59.
(3) For example PRATER: 82: "use a piece of tempered aluminum alloy about 1/8-inch thick, 2 inches wide and 26 inches long. Attach a wooden handle to one end, leaving 20 inches for the cutting blade. Hacksaw serrations in it for the cutting teeth."