1. INTRODUCTION
In the British Army, troops of all arms are instructed how to deal
with road craters and road obstacles when prompt action is required
in an emergency. The following is an extract from a British Army
document on this subject:
2. CRATERS
First, look for antitank mines, antipersonnel mines, and booby traps, within
or around the craters. Then look for a detour and use it if possible, cutting
down fences and ramping all low banks. If a suitable detour exists, it will
nearly always be more advisable to use it than to repair the crater.
If it is necessary to fill in the craters, slightly different methods will be
used for dry and wet craters.
a. Dry Craters
Trample down all loose earth inside the crater.
Start filling the crater with all the loose soil available. As soon as the
depth has been sufficiently reduced, a tracked vehicle should be driven across
the crater to consolidate the soil, and this procedure repeated at intervals. Where
brushwood is available, alternate layers of brushwood and soil should be laid. The
brushwood will help to consolidate the soil, and at the same time distribute the
load. Any rock, stone, or gravel thrown up by the explosion should be saved, and
used later in making the road surface.
Continue filling until the depth of the crater has been reduced to 3 feet. As
a rule, any filled-in craters of this depth will be passable for tracked
vehicles, 3/4-ton trucks, and even 1 1/2-ton trucks.
If it is essential to make a passage for all military vehicles, cut ramps on
opposite sides of the crater, and shovel the soil from these two cuts into
the crater. If each ramp is cut 10 feet long, enough soil will be made available
to reduce the depth of the average crater so that it will be passable for
all vehicles.
The surfacing of a filled-in crater should be completed before
any but the most essential vehicles are permitted to cross, unless
the crater is completely dry and likely to remain so. Otherwise,
vehicles crossing over will churn up the soil and soon render
further crossing impossible. The surfacing should consist of the
stones and gravel which have been reserved for this purpose or of
fascines [brushwood bundles]. A maintenance party will be
needed to look after the surface until an engineer repair
party can take over.
The following table may be used as a guide to indicate the
time and labor required for crater filling. If a party of
20 men, equipped with picks, shovels, and axes, go to work on a dry
crater 25 feet in diameter and 7 feet deep, in medium soil, they
can make it passable for
tracked vehicles | _ _ _ _ _ _ _ _ _ _ _ |
|
in 30 minutes |
"4 x 4" (all-wheel-drive) trucks | _ _ _ _ |
|
in 35 minutes |
3/4-ton trucks | _ _ _ _ _ _ _ _ _ _ _ _ |
|
in 40 minutes |
all vehicles except buses | _ _ _ _ _ _ _ |
|
in 75 minutes |
all vehicles | _ _ _ _ _ _ _ _ _ _ _ _ _ _ |
|
in three hours |
b. Wet Craters
If a crater contains water, a modification of the above procedure
will be necessary.
If rocks and stones are available, use them to fill the crater up
to water level. If there are no rocks or stones at hand, fill the
crater bottom with earth. Cover this with two layers of empty sandbags
to form a seal. Lay 9 inches of brushwood, and then 9 inches of
earth. Repeat this sequence of empty sandbags, brushwood, and earth
until the depth of the crater has been reduced to 3 feet. Layers should
be laid so that they slope upward toward the center of the road to allow
for consolidation of the center.
After this, follow the procedure outlined for filling a dry crater.
Water-filled craters naturally take slightly longer to improve than dry craters.
3. OTHER ROAD OBSTACLES
Hastily contrived road obstacles—such as farm wagons, the wheels of which
have been removed, or felled trees—will often be fairly easy to destroy
or move. However, it should be taken for granted that they will be liberally
bobby-trapped. There will seldom be enough time to wait for skilled engineer
personnel to locate and neutralize these traps. Therefore, the first troops
to arrive on the site will find it necessary to set off the traps by using
hand grenades or by tying ropes to the obstacle and, from a safe
distance, hauling it off the road. It must also be remembered that
antitank mines will probably have been laid in the road underneath the
obstacle for this reason, an extremely careful examination of the road
surface is a necessity.
Finally, it is strongly emphasized that if any possible detour exists, it
is normally much quicker to go around an obstacle than to remove it. It must
be expected that detours or obvious turnouts will be imaginatively mined and booby-trapped.