See Illustrated Encyclopedia of the American Revolution, Neumann, p.162. where the author points out that, water ways, when frozen in Winter, provided convenient means of travel in otherwise rugged terrain. Crampons, lashed to the boots, assured a sound grip to the ice. This example chiseled from iron stock as imported from England, is 4 1/8” width. Notable is that the strap holes were hot forged with a pin leaving a thickened  “flash” edge.