radius of 1.53 m/kg1/3, fully 76% larger than the
predicted scaled radius in snow. The equations de-
The sizes of craters we measured during these
veloped by Mellor (1986a) for predicting the scaled
tests were all larger than predicted from previous
radius from experimental data greatly underesti-
data for static spherical explosive charges set on the
mate the radius of craters in layered snow and ice
snow or ice surface. The mean scaled apparent ra-
produced by artillery projectiles. On the other hand,
dius of the craters formed by 105-mm point-detonat-
the scaled depths of the artillery craters were similar
to or less than the predicted depths; 0.25 vs. 0.4
and 0.24 m/kg1/3 in snow and ice for the 105-mm
crater in snow and 50% greater than predicted for
ice, 1.07 vs. 0.87 and 0.71 m/kg1/3. The mean scaled
apparent radius of the 81-mm point-detonating pro-
and ice for the 81-mm mortars, and 0.33 vs. 0.40
jectile craters was 1.17 m/kg1/3, 34% larger than the
m/kg1/3 in snow for the 60-mm mortars.
predicted scaled apparent radius in snow and 65%
The shapes of the craters formed were influenced
larger than the predicted radius in ice. The 60-mm
by the multiple-layered medium of snow, ice and
mortar projectiles produced craters confined to the
frozen ground into which the firing took place (Fig.
shallow snow layer, with a mean scaled apparent
14). The greater-than-predicted radii of the craters
a. Typical 60-mm mortar crater.
b. Typical 81-mm mortar crater.
c. Typical 105-mm howitzer crater in shallow ice.
d. Typical 105-mm howitzer crater in thick ice.
e. Typical 105-mm howitzer crater in a floating ice sheet.
Figure 14. Typical crater cross sections.