Friday 30 March 2018

PIAT: An Odd Fellow

The British PIAT grenade launcher, a combination of a medieval crossbow and a modern HEAT grenade, became one of the more unusual examples in its class. Heavy and uncomfortable to use, the PIAT went through many fronts of the Second World War in the hands of Allied soldiers. However, its subsequent career was not long. The weapon did not survive competition from the simpler and more reliable RPG.

British infantry was armed with two types of anti-tank weapons at the start of WWII: the 13.97 mm Boys rifle and the No.68 rifle grenade. Experience in France showed that these weapons could defeat German light tanks, but were ineffective against the medium PzIII and PzIV. The army needed a new anti-tank weapon that was compact but still capable of sufficient penetration. In pursuit of this weapon, British engineers had to resort to some unusual methods.

History of creation

In 1930, Stewart Blacker, a young British officer, patented a light infantry support weapon that was a further development of a spigot mortar. These weapons were rather common in WWI, and fired shells with hollow tails that were inserted onto a spigot. In 1937, the Parnell aircraft company produced a prototype of Blacker's weapon, which was named "Arbalest". It took part in a tender for a light platoon level infantry support weapon, but lost out to the Stocks 51 mm mortar.

The German Blitzkrieg in France revived the interest in Blacker's weapon. Now it was no longer a weapon that fired a fragmentation grenade for anti-personnel use, but as an anti-tank weapon. In 1940, Blacker, already a Lieutenant Colonel, was appointed to the MD1, the "irregular warfare" section. The fruit of his work was the Blacker Bombard: a massive weapon serviced by three or four men that fired 9 kg HE bombs. The Blacker Bombard was approved for service and put into production in early 1941, but it was never used in real battle, as the maximum range was only 100 yards. A few thousand Blacker Bombards were transferred to the Home Guard, which was formed in anticipation of a German invasion of the British Isles.

Realizing that the Blacker Bombard was not what the army needed, attempts were made to reduce the size of the launcher and make it serviceable by one man. A prototype of a smaller bombard was ready by mid-1941. Thanks to a lighter HEAT projectile, the weapon was much more compact. Now it could be fired from the shoulder. This design included a "half-barrel" directing pipe. However, trials of the mini-bombard were disappointing. Misfires were common. Even the grenade did leave the weapon, the target still survived, as the fuse did not work even once. Major Millis Jefferis was tasked with further development. Taking the miniature bombard as a starting point, he quickly produced an improved design, initially called the "Jefferis Shoulder Gun", later renamed to PIAT (Projector, Infantry, Anti-Tank).

Overall view of the PIAT grenade launcher.


The American bazooka, German Panzerschreck, and other RPGs all have a simple design: a tube, open from both ends, that has sights and a trigger attached to it, as well as additional equipment such as a protective shield or a bipod. The British PIAT was much more complicated. It consisted of a tube, 83 mm in diameter, which had a directing semi-tube in the front. The semi-automatic mechanism was housed inside the tube. From the front, the body of the launcher was covered by a cap with a spigot in the center. The grenade was placed upon the spigot during loading. The striker was contained inside the spigot. The striker was a hefty steel cylinder with a firing pin on the front. The rear of the striker was up against a spring, with a slot cut in it to lock in place. A butt with a rubber pad was attached to the rear of the body, and a trigger mechanism inside a rectangular guard to the bottom. The sights, consisting of a collapsible front sight and a rear sight, were attached to the left of the barrel. A bipod or telescoping monopod could be attached below.

A fully disassembled launcher.

How did the PIAT fire? The process was very similar to how a medieval crossbow was used, and consisted of two steps: the winding and the loading. The gunner turned the butt to unlock it, and, bracing against it with his feet, pulled the trigger guard (this required significant force). The spring compressed, and the striker retreated to the firing position. The grenade was then placed upon the spigot. The weapon was ready to fire.

Upon pressing the trigger, the striker was freed, and was launched forward, impacting the primer. The expanding gases propelled the grenade forward and recoiled the striker, which compressed the spring and locked in place. Subsequent shots could be fired after only inserting a new grenade. Because of this, the practical rate of fire of the PIAT was quite high: 8 RPM, compared to the American bazooka's 4-5 RPM.


The main type of ammunition was the Bomb H.E./A.T. In addition, three other types of grenades were used: the dummy Bomb Drill/A.T. used to practice loading, the single use Bomb Practice Inert/A.T. and the multi-use Shot Practice/A.T.

Drawing of a grenade for the PIAT.

The hull of the grenade was made from thin tin. A 340 g explosive charge was held in the front, with a HEAT cone. A ballistic cap contained the F.P. No.425 instant fuse. The impulse from the fuse was passed on by a detonation cord to the detonator in the center of the explosive charge. The rear of the grenade consisted of a tube with four stabilizer fins, protected by a ring. The tube contained a brass casing with a primer and 2.7 g of nitrocellulose gunpowder for launching the grenade. The projectile weighed 1.2 kg.

Grenades came from the factory with the launching charge already installed. The fuse came in a tin case attached to the stabilizer ring. Its slot was covered with a cork. Grenades were packed into a container made from three greased cardboard pipes. A 41x34.4x10.7 cm contained with three grenades weighed 6.4 kg. Three containers were packed in one wooden crate.


The PIAT took a long time to develop, so it did not come in time to fight in North Africa. Production of the first batches began in August of 1942, and it was only issued in the middle of next year, right in time for the Allied landings in Sicily. 115,000 PIATs were made by 1944, and production continued until the end of the war (over 7.5 million grenades were made).

Loading training.

The PIAT quickly became the infantry's main anti-tank method. The infantry battalion TO&E distributed the PIATs in the following way:
  • Infantry company: 3
  • Reconnaissance platoon: 4
  • 3" mortar platoon: 3
  • 4.2" mortar platoon: 1
  • Machine gun platoon: 1
  • Quartermaster platoon: 3
One battalion had 21 PIATs in total.

A fully equipped PIAT operator.

The PIAT had no dedicated crews. All infantrymen trained with it. The commander of the company or platoon assigned PIAT crews directly before the battle. Even though the PIAT was developed to be serviced by just one soldier, practice showed that one man cannot carry the hefty launcher and ammunition at the same time. An ammunition loader was assigned to aid him, carrying two containers with grenades (six grenades in total). Gunners were instructed to open fire from as short a range as possible, as the maximum range of a PIAT was only 115 yards. The PIAT could also be fired indirectly. In this case the maximum range increased to 320 yards, but the precision left much to be desired.

The PIAT was used to support assault teams as well as to fight against armoured targets. The assault team manual suggested that 2-3 PIATs be assigned to each group. Of course, the grenades were powerless against stone walls, but they could suppress enemy positions in windows and portholes. British troops used the PIATs in this way during the Normandy landings. Sergeant Stanley Hollis received the Victoria Cross for the destruction of an enemy artillery position with one. There were also plenty of successful applications of the PIAT against armour. For example, during Operation Market Garden in September of 1944, British paratroopers destroyed several StuGs that attacked their positions.

PIAT from 2/10th Australian battalion, Balikpapan, July 1945.

The PIAT appeared on the Pacific theater of war in late 1943. The Australians called it PITA (Projector Infantry Tank Attack). The grenade launchers were issued to "jungle divisions", with one launcher per infantry platoon. The main target for the PIAT was not so much Japanese tanks, which were rather rare, but enemy strongholds. Sometimes the PIATs were used in their intended role. For instance, Private Ganja Lama of the 1st Battalion 7th Gurkha Regiment used his to great effect at the battle at Ningtouhonga on June 12th, 1944. When his company was pinned down by heavy fire, Lama crawled up to a range of 30 meters with his grenade launcher and destroyed two tanks. For this heroism, the brave soldier received Britain's greatest honour: the Victoria Cross.

The USSR received a thousand PIATs and 100,000 grenades, but details of their use are unknown. A large number of launchers was also dropped by parachute in occupied Europe. For instance, the Polish Armia Krajowa was sent 530 launchers and nearly 9000 grenades between September of 1943 and February of 1945. It is known that PIATs were used during the Warsaw Uprising, as well as by the French Maquis and Yugoslavian Partisans.

Warsaw resistance fighters from the "Czata 49" battalion with PIAT launchers.

The PIAT's post-war career was short. The British army abandoned it in 1951, replacing it with ENERGA rifle grenades and American M20 "Super Bazookas". The Australians continued to use the PIAT alongside the M1 Bazooka until the Korean War, but both weapons were quickly displaced by the Super Bazooka. Some number of PIATs fell into the hands of the Haganah and was used during the first Israeli-Arab War of 1948-1949. The IDF retained the PIAT until the late 1950s.

Haganah soldier with a PIAT.

Advantages and drawbacks

The Canadian army performed a questionnaire among its combat officers in 1944-45 to establish which infantry weapon was the most effective. The PIAT took first place of 31 weapons (the Bren gun came second). The officers' subjective feelings seemed to agree with operational research. 7% of enemy tanks knocked out in Normandy fell to the PIAT. To compare, ground attack aircraft were responsible for 6%. However, after German tanks and anti-tank guns began using HEAT shields in large quantities, this percentage began to decline.

The first warning bells rang during the fighting in Sicily. Complaints were made about the low precision and reliability of the PIAT grenades. Trials gave disappointing results: only 60% of the shots from 100 yards hit a stationary tank. A quarter of the grenades that hit their target did not explode. On the battlefield, it would seem that the PIAT's high rate of fire would be key to engaging the enemy successfully.

One advantage of the PIAT compared to the Bazooka or Panzerschreck was a lack of a gas stream coming from behind the barrel. This made the launcher safer for the crews, made it possible to fire from indoors, and made it easier to hide. However, that concludes the list of advantages. The launcher was very heavy. The PIAT weighed 2.5 times more than the M1A1 bazooka. It also took significant effort to wind it up, about 90 kg. While it was quite possible to wind it up while standing, only the strongest soldiers could do it while prone or sitting down. The 1 meter length of the PIAT was another factor that made it difficult to use for short soldiers. The Bazooka and Panzerschreck had no anthropomorphic limitations, especially not the Panzerfaust, which was effortlessly used by teenagers and old men of the Volkssturm.

The range of the PIAT was also insufficient, only 100 meters. The range of the Bazooka was 275 meters, but the British still considered that insufficient for the open spaces of North Africa. The mountain ranges of Italy, bocages of Normandy, and urban areas of Western Europe were much more suitable for its use. Crews could fight from ambushes, and enemy tanks were restricted in mobility.

Another drawback was the recoil of the PIAT. If the soldier did not press the butt of the launcher against his shoulder tightly enough, then the automatic mechanism would not function, and the spring would not wind up. The PIAT would have to be wound up manually, which would reduce its rate of fire advantage. It's not surprising that the original idea proposed by Blacker and Jeffris was not developed much further and that the PIAT's career was quite short.


  1. Strikes me that they should of developed more HE warheads for this weapon. Furthermore after the German's developed spaced armor it would still make a handy light artillery piece for Universal Gun carriers. Overall the PIAT was a perfect example of British old school ingenuity.

  2. I find myself wondering why they bothered to build it at all. Just ask the US for extra bazookas. US units fired enormous quantities of bazooka rockets. The weapon was so cheap and simple I would guess they could have produced enough to cover british needs also.

    1. One can't always wait for the American's to deliver a weapon. Plus this weapon fired 83 mm Grenades, without a blast to give oneself away or fringe oneself when used in tight quarters.

    2. There's also the detail that the Bazooka wasn't yet available when the developement of this thing started, and it was still having some serious teething problems when the PIAT started coming off the assembly lines in useful numbers. Plenty understandable why the Brits might have felt it better to hedge their bets, and TBF the rocket tube's main practical advantage was lighter weight - the accuracy of dumbfire rockets being what it is the actual effective ranges of the two weapons were more or less the same and as mentioned the spigot mortar did boast the perk of having no backblast/exhaust issues.