CHAPTER 14
ORGANIC SUPPORT WEAPONS: 60-MM MORTAR
AND AT4
The mortar is perhaps the oldest type of firearm
one- or two-piece baseplate that allows it to be fired
in any direction.
known to mankind, and its existence dates back as
early as the fourteenth century. At that time, it was
A variety of shells and fuzes have been developed
nothing more than a shallow steel pot filled with
to make the 60-mm mortar a versatile weapon. It can be
gunpowder and rocks that was aimed in the general
used as either an offensive or a defensive weapon.
direction of the target and fired by touching the
powder with a red-hot iron rod. As you can guess,
it was very inaccurate; however, it did possess one
GENERAL DESCRIPTION AND DATA
extremely important characteristic that is just as
The mortar is a smoothbore, muzzle-loaded,
important today as it was then. This characteristic
high-angle-of-fire weapon. It consists of a mortar barrel
is the high angle of fire that enables it to be fired
with a baseplug and a fixed firing pin for drop firing.
over obstacles, such as hills, forests, walls, or other
The mount consists of a biped with traversing and
defenses. As you can see, this is very important.
elevating mechanisms. A spring type of shock absorber
The weapon can reach and destroy targets beyond
absorbs the shock of recoil in firing. The baseplate is a
the capabilities of flat trajectory weapons, such as
unit that supports and aligns the mortar. For firing, the
a rifle, but the crew firing it is also protected from
baseplug of the barrel is seated and locked into the
enemy observation and fire by these same
baseplate with the barrel passing through the yoke of the
biped mount and secured to the shock absorber. For
The modern mortar is an extremely accurate and
transporting, disassemble the mortar into three groups:
effective weapon that has an adjustable biped and
barrel, biped, and baseplate. This weapon may be
telescopic sight (fig. 14- 1). The modern mortar has a
transported by one crew member without disassembling
it.
The mortar is fired by inserting a complete round
into the muzzle, fin assembly down. The elevation of the
barrel causes the round to slide toward the base of the
barrel. On reaching the base, a propelling charge on the
round is ignited by the firing pin. The pressure of the gas
produced by the burning propelling charge drives the
round up and out of the barrel. The fin assembly
stabilizes the round in flight.
The mortar can deliver fire at ranges up to
approximately 3490 meters. The sustained and
maximum rates of fire are related to the type of round
and charge being used.
The complete mortar weighs 46.5 pounds in the
conventional mode and 18 pounds in the hand-held
mode. This includes the cannon (14.4 pounds), the biped
(15.2 pounds), and the M7 baseplate (14.4 pounds) and
the M8 baseplate (3.6 pounds). The overall length is 40
Figure 14-1.--The 60-mm lightweight mortar (M224).
inches.
14-1