First reports from Leyte tell of increased use of land mines by the Japanese defenders.
As had been anticipated from the trend of previous operations, U.S. troops landing on
Leyte found that the Japanese had made practical and extensive use of minefields and booby
traps in the planned defense of the island.
Preliminary reports indicate that although a decided effort at mining had been
attempted, improvised mines were used more often than standard enemy demolitions. Chief
of these were aircraft bombs set into the ground with an armed nose fuze
exposed as the detonator. A haphazard use of bombs in this manner was encountered
before by Sixth Army troops in several Southwest pacific operations.
On Leyte, the principal minefields were found on the air strips at Tacloban and
Dulag. Here 63-kilogram aircraft bombs had been planted in groups of three at intervals
along the length of the runways—an obvious attempt to destroy aircraft
which might try to land on the strip. Bomb mines of this type were planted
also on the beach which runs parallel to the nearby Tacloban airfield and
which was a logical vehicle route. Near Dulag, armed bombs, which could be
detonated by a truck tire brushing against the fuze, were laid on the
surface along roads and camouflaged with grass.
|Tacloban air strip. Dots indicate the approximate location of
Japanese bomb mines found buried on the runways and the nearby beach.|
In addition to the bomb mines, the Japanese on Leyte employed two types of
improvised mine that have not been found in general use in past operations. These
were the so-called "coconut mine," and an improvised box mine.
The coconut mine was a simple but not particularly effective device. The
Japanese had taken a large quantity of coconut shells, hollowed them
out, and then filled them with black powder. A Model 91 hand grenade
was imbedded in the powder, with only the grenade's 5-second pressure
detonator exposed. These makeshift antipersonnel mines were used as pressure
detonated booby traps, and were easy to camouflage in natural surroundings. An
observer has reported that these improvised demolitions also served the enemy
as hand bombs when whirled and thrown at the end of a 3-foot fiber
rope. On detonating, they made a terrific explosion, but did little damage.
|Japanese Coconut Mine|
Crude, improvised box mines were found to be a fairly common device. Constructed
in several sizes, these mines consisted of a wooden box filled with picric acid
or ammonium picrate explosive blocks. Like the coconut mine, these demolitions
were detonated by a Model 91 or Model 97 pressure-detonated hand
grenade which was set into the explosive, but with the armed fuze exposed. Many
of these mines were found hidden in the grass along roadsides, or set as
booby traps beneath staircases and floorboards in houses where the Japanese
had been storing ammunition.
|Japanese Improvised Box Mine|
Many different sizes of this box-type mine were found constructed for time-fuze or
electrical detonation. On the Maintez River the retreating enemy attempted to
demolish a bridge with eight of these mines bolstered by 21 cases
of 75-mm shells. The electric caps used were of a type similar
to U.S. manufacture.
Although improvised mines were most common, many standard Model 93 (tape-measure),
Model 99 (magnetic), and Model 3 (pottery) mines were found stored in
ammunition dumps or emplaced along roads as antivehicle
demolitions. Some Model J-13 antiboat mines also were found
on A-day near the landing beaches ("A-day" for the Leyte
operation was the equivalent of the familiar designation, "D-day").
At one place a tank trap consisting of a ditch 20 feet wide and 10 feet deep was
located 100 yards inland of a landing beach. This trap was discovered to be heavily
mined with this hemisphere antiboat mine. The enemy had made no attempt
to place these mines according to a definite pattern. Some were buried
completely, some half buried, and others lay exposed above-ground. But all were
scattered haphazardly throughout the barrier.
Although indications on Leyte are that the Japanese have tended to use mine
warfare to an extent greater than has been encountered in the past, preliminary
reports indicate the Japanese are still lacking in adequate land mines and
minefield doctrine. However, as the enemy improves his technique with
time, U.S. troops must be prepared for more effective antipersonnel and
antivehicle mining by Japanese units.