PIAT - Design

Design

The PIAT was 39 inches (0.99 m) long and weighed 32 pounds (15 kg), with an effective direct fire range of approximately 115 yards (110 m) and a maximum indirect fire range of 350 yards (320 m). It could be carried and operated by one man, but was usually assigned to a two-man team, the second man acting as an ammunition carrier and loader. The PIAT launcher was a tube constructed out of thin sheets of steel, and contained the trigger mechanism and firing spring. At the front of the launcher was a small trough in which the bomb was placed, and the spigot ran down the middle of the launcher and into the trough. Padding for the user's shoulder was fitted to the other end of the launcher, and rudimentary aperture sights were fitted on top for aiming; the bombs launched by the PIAT possessed hollow tubular tails, into which a small propellant cartridge was inserted, and hollow-charge warheads.

To fire the weapon the trigger mechanism, which was essentially just a large spring, had to be cocked, and to do this was an extremely difficult process. The user had to first place the PIAT on its butt, then place two feet on the shoulder padding and turn the weapon to unlock the body and simultaneously lock the firing pin to the butt; the user would then have to bend over and pull the body of the weapon upwards, thereby pulling the spring back until it attached to the trigger and cocking the weapon. Once this was achieved, the body was then lowered and turned to reattach it to the rest of the weapon, and the PIAT could then be fired. Users of a small stature often found this difficult to achieve, as they did not have the sufficient height required to pull the body up far enough to cock the weapon; it was also difficult to do when lying in a prone position, as was often the case when using the weapon in action.

When the trigger was pulled, the spring pushed the firing pin forwards into the bomb, which ignited the propellant in the bomb and launched it out of the trough and into the air. The recoil caused by the detonation of the propellant then blew the firing pin backwards onto the spring; this automatically cocked the weapon so it could be fired.

Training for using the PIAT emphasized that it was best utilized from a slit trench with surprise and concealment on the side of the PIAT team, and where possible enemy armoured vehicles should be engaged from the flank or rear. It was possible to use the PIAT as a crude mortar by placing the shoulder pad of the weapon on the ground and supporting it with a monopod, giving the weapon an approximate range of 350 yards (320 m). The PIAT was often also used in combat to knock out enemy positions located in houses and bunkers.

Despite the difficulties in cocking and firing the weapon, it did have several advantages; its barrel did not have to be replaced or require high-grade materials that were expensive to produce, there was little muzzle blast that could give the user's position away, and the size of the barrel meant it could accommodate relatively large calibre munitions. However, the weapon did have drawbacks. It was very heavy and bulky, which meant that it was quite unpopular with the British and Commonwealth troops who were issued with it. There were also problems with its penetrative power; although the PIAT was theoretically able to penetrate approximately 100 millimetres (4 in) of armour, field experience during the Allied invasion of Sicily, which was substantiated by trials conducted during 1944, confirmed otherwise. During these trials, a skilled user was unable to hit a target more than 60% of the time at 100 yards (90 m), and faulty fuses meant that only 75% of the bombs fired detonated on-target.