Figure 12. Tree slash caught in tracks during cornering.
Figure 13. HEMTT stuck in wooded trail control section, station
struction (after approximately 20 passes of
Appendix H summarizes the soil conditions
fully loaded 5-ton trucks).
for the NOGO situations encountered on the
Control section 7+00 to 8+20 on the wooded
trail became impassable after only 15 passes
of the HEMTT (it was not a problem with the
tank) due to rut depths exceeding vehicle
DECISION AID AND
ground clearance (Fig. 13).
GUIDELINES FOR SELECTING
Control section 2+50 to 3+50 threatened
NOGO on the north end of the wooded trail
when it filled with chunkwood after pass 25
All techniques used at Fort McCoy improve
of the HEMTT due to severe rutting.
the condition of the trail. The best technique de-
The tire mat section on the corners became
pends on a variety of criteria. Table 6 can be used
impassable after 25 passes of the M60 because
as an engineering decision aid for selecting sur-
of the mats catching in the tank track and
facing techniques. These criteria (e.g., training,
being thrown out of position. The mats were
cornering, etc.) can be used as guidelines for rat-
moved aside for the remainder of the passes.
ing stabilizing surfaces listed and can be readily