PIAT: Britain’s Answer to the Anti-Tank Rifle Problem

The British began World War Two with the Boys antitank rifle, but like all antitank rifles it rather quickly became obsolete. The replacement for it was adopted in 1942 as the PIAT – Projector, Infantry, Anti-Tank. This was a unique sort of weapon which fired a 3 pound (~1.35kg) hollow charge projectile using a combination of a massive spring and a firing charge much like a rifle grenade blank cartridge – a spigot mortar, really. The large (3.25″, 83mm) projectile was able to defeat almost any tank that would be developed during the war, as it could burn through 3-4 inches of hardened armor. However, it had a terrifyingly short effective range – 110 yards on paper and more like 50 yards in practice.

The PIAT would recock itself upon firing, but the initial cocking was something like a crossbow, requiring the shooter to brace their feet on the buttplate and pull the body of the weapon upwards, compressing the 200 pound (90kg) mainspring. When fired, the weapon has a pretty harsh recoil, although it did not have any flash or backblast like the American Bazooka did. By the end of the war more 115,000 PIATs had been made, and they would serve the British military into the 1950s, when they were replaced with more traditional rocket launchers.

 

81 Comments

  1. Does anybody have any ideas on why it took so long to develop the recoilless rifle? Was it just ignorance of newtons laws? Were there any recoilless cannons in the black powder era?

    • While looking for data about Greek fire, some authors assumed rocket launching tubes could have been already known since antiquity.

      • 1. Rockets were first developed in China, about the mid-12th Century AD. They seem to have been developed from fire arrows largely by accident; somebody made one with the new incendiary, black powder, in its package, packed it a bit too firmly, lit the fuze and loosed it from the bow, and when the fuze burned down instead of going BANG it took off under its own power.

        2. “Some authors” assume a lot of things. Siphons for Greek Fire (an incendiary containing naphtha, turpentine, and both phosphorus and quicklime to make it self-igniting on contact with air or water) were used by the Byzantines in the 6th Century AD. Earlier fire weapons, like Archimedes “boat-burning ray” were mainly based on using mirrors to focus the sun’s rays like a burning glass.

        Tubes for launching rockets were a Western innovation, used in naval warfare beginning in the 14th Century. They were quickly superseded by cannon, which were less likely to set the ship on fire due to lack of backblast. The Chinese used boxes and baskets as rocket launchers, often on carts allowing as many as 200 arrow-sized rockets in a single launcher.

        See; History of Rocketry and Space Travel, by Wernher von Braun and Frederick I. Ordway;

        https://www.amazon.com/Space-Travel-History-Update-Rocketry/dp/0061818984/ref=pd_cp_14_1?_encoding=UTF8&psc=1&refRID=NPYMM6V5ZSFT9MJJ12XJ

        cheers

        eon

    • The Davis gun was the first recoilless gun, developed and used during WW1 as an aerial weapon against submarines & zeppelins.

      It is important to remember that recoilless guns’ muzzle velocities are lower than similar sized regular gun. Blowing large portion of the charge backward to blanch the projectile and what left of the charge forward moment come at a cost. As a result most recoilless guns relays on explosive projectiles rather than kinetic kill, it make more sense to use the gun only to deliver the shell to target than to deliver it into the target.

      As for black powder, I believe the black powder have even lower muzzle velocities so recoilless black powder gun make even less sense.

    • The first true “recoilless” gun was the Davis Gun in WW1;

      https://en.wikipedia.org/wiki/Davis_gun

      It was mainly used from RNAS and U.S. Navy flying boats to shoot downward at surfaced U-boats.

      As I’ve stated here before, the 1860s Armstrong and Whitworth breechloading cannon could have been made into recoilless guns fairly easily, if you could have put up with their appetite for black powder.

      Since field guns of that era were used almost exclusively in the direct-fire role, and rate of fire was the primary objective, a recoilless gun along those lines might not have radically changed artillery tactics, but it would probably have made things a lot messier for anybody on the receiving end. A 12-pounder Napoleon fired two round a minute partly due to being muzzle-loaded, but mainly due to having to be horsed back into position after rolling back about eight feet under recoil with every shot. A recoilless gun doesn’t have that problem.

      As for backblast, artillery crews back then were trained no to stand behind the gun anyway, to avoid being “run over”. So the drill wouldn’t have changed very much at all.

      cheers

      eon

    • As has already been noted: the Davies Gun was the first recoilless gun used in service. Was needs to be bourn in mind is that the Davis used lead shot fired backwards as the ‘equal and opposite’ reaction.All(?) recoilless weapons since have used gas as the opposing reactant, helped by a venturi. That’s why they all have massive rounds; the propellent has to propel the round forward and enough of it’s own gas backwards to equal the forces.

    • @hyperboloid – The whole point of a recoilless rifle is to have a very light weight piece of artillery. The metallurgical technology to make the light thin steel barrels for them didn’t exist until the late 19th century. The first recoilless guns were used in WWI. That isn’t that long of a development gap.

      To put it another way, it was steel making technology, especially being able to make single homogeneous billets of steel large enough to be useful for artillery, that what the hold up in advancing the technology of artillery. Smokeless powder was available before the metallurgical technology ability to make full use of it was.

    • It’s mostly down to materials. For an effective recoilless weapon, you need really good machining, the material to machine, and that material has to be capable of withstanding the heat and erosive effect in the venturi area for multiple shots. That sort of material was in the realm of science-fiction, insofar as mass production went, until the WWII era. Which, not coincidentally, was when we first started to see mass-issue recoilless on the battlefield.

      Recoilless was a thing much like caseless; the basic idea was there, but the enabling materials technology simply wasn’t up to the task. Especially in a production environment during wartime–Look at what happened to the Gerlach squeeze-bore stuff during the course of the war, for another example.

    • Rockets need “hollow charges” to be effective and that was a secret weapon until 1940. The Germans who attacked Fort Eben Emael in 1940 used massive hollow charge demolitions which they hadn’t even been allowed to see in real action before the attack. The holes they made in the fort are still visible.

      • “Rockets need “hollow charges” to be effective and that was a secret weapon until 1940.”
        I can’t agree with it without adding: Rockets need “hollow charges” to be effective against armour.
        Fragmentation and incendiary rocket can be crafted without such technology.

      • Those charges used at Eben Email were so large that a single soldier couldn’t carry one so the Germans split them in half. Two soldiers each carried one half and connected them together on top of the artillery turrets. Then they got as far away as they could before the blast. And these troops came in gliders and parachutes.

  2. The ATF removed the PIAT from NFA registry ago. It is still classified as a curio and relic, and can be transferred like any C&R rifle.

  3. Some interesting bits about the PIAT.

    1. The Blacker Bombard was a 29mm (rod diameter) spigot mortar on a four-legged mount weighing almost 400 pounds all-up, that fired an even bigger “bomb” than the PIAT. (NB; The British refer to the projectiles of mortar type weapons as “bombs”, which can cause some confusion.) It had about the same range (100 yards “according to the manual”), and its bomb was well capable of blowing the turret entirely off most 1940 tanks with a hit on the turret ring;

    https://en.wikipedia.org/wiki/Blacker_Bombard

    There are still abandoned Bombard dugouts all over the south of England even today.

    2. Actually, it was kinetic energy that the spigot mortar imparted to its projectile, not inertia; that was the bomb’s resistance to the kick in the rear that launched it (Newton’s first law). But that’s kind of academic because it’s the hollow-charge warhead that does the work, regardless of velocity.

    3. The PIAT bomb’s effectiveness was due to its warhead containing almost a pound of RDX (Cyclonite), a primary high explosive normally only used in the explosive train (“gain”) in detonators, and then only in very small amounts. RDX is hideously shock-sensitive, and in the PIAT bomb hollow-charge it was only partly tranquilized by mixing it with paraffin (canning/sealing wax). Mainly to avoid it going off if somebody dropped it while loading it (a not infrequent “fumble”).

    5. The odd “bubble” sight was entirely separate from the direct-fire sights for a reason. It was to allow the PIAT to be used as a primitive mortar. By extending the monopod all the way and turning the shoulder rest a quarter turn, it could be rested on the ground and fired in a high arc, like a modern-day “commando” mortar.

    In the bocage country of France during the breakout from the Normandy beachhead, my uncle who ran a Sherman company saw this done quite often, with the PIAT being used to shoot over the hedgerows at ranges up to 250 yards to drop the powerful hollow-charge bomb onto the thin top armor of German panzers. Today, some of the most advanced ATGWs in the world, like the U.S. Javelin, are designed to do the same trick, known as “top attack”, because it’s the surest way to kill any tank with a man-portable AT weapon.

    6. Yes, you could jam a PIAT round into a tank by hand, and it would detonate, killing the tank and you both. The Japanese had a weapon deliberately designed to be used this way, called a “lunge mine”;

    http://i16.photobucket.com/albums/b24/hybenamon/LAND/MISC/Ultra%20Close%20Killing%20Of%20Tanks/lung.jpg

    As Ian Hogg said, no nonsense about time or impact fuzes with this one.

    7. Logs and lengths of track were common “augments” to armor on American and British Shermans in 1944-45, mainly due to the German Panzerfaust 30. General Patton was opposed to this, because the extra weight put more strain on the M4A3’s already over-stressed vertical volute spring suspension (VVSS), with the narrow track. The wide-track horizontal volute spring suspension (HVSS) on the M4A3E8, aka “Easy Eight”, was mainly to solve this problem by allowing heavier armor in the welded-plate hull.

    8. The lack of backblast meant that the PIAT could be fired from inside a structure without injuring or killing its operators. This made it both a good weapon for urban combat, and one well-suited to use by resistance forces. (Over 200 PIATs were delivered to the French resistance by SOE via’ airdrop in the three months before D-Day for this exact reason.)

    In such ambushes, the range was rarely over 50 yards, and often under 20, so the range restriction wasn’t really a big problem. The main thing to remember was that when shooting from a second-story window, the bomb could slide out of the front end trough if you tilted the “muzzle” down a bit too much.

    After the war, only the German Armbrust and the French MAS 50 hollow-charge ATG launchers were purposely designed to eliminate backblast when fired.

    9. Never, ever “dry-fire” a PIAT. That spring is quite capable of breaking through the front end cap and launching itself if there isn’t a bomb up front to provide a recoil effect to recock it. Anyone who has ever seen an M60 MG recoil spring go off into the distance during a botched field-strip knows what I’m talking about.

    10. The failure to recock on recoil was due to not holding the beast tightly enough against the shoulder. It not only failed to recock, but the recoil generally knocked the operator flat on his backside, often with a very sore shoulder. Incidentally, the size of the PIAT’s trigger was due to it generally requiring at least three fingers to exert enough force to sear off the spigot against that 200-pound spring’s resistance.

    11. The full cocking distance of the PIAT is 14 inches. But if you don’t get just the right stance, it usually bends you over like a hairpin. As Ian Hogg says, anyone less than five-feet-seven was laying himself open to a back injury trying to cock a PIAT. An even more amusing pastime was trying to cock it while lying in a trench.

    12. The Infantry School at Hythe ran the last PIAT course in 1959 (!) It was still considered a useful adjunct to the 3.5in Bazooka because it was both more compact and could be fired “from indoors” if need be. Both it and the Bazooka were superseded in 1962 by the Carl Gustaf 84mm recoilless gun, and the Energa AT rifle grenade associated with the L1 (FN FAL) 7.62 NATO self-loading rifle.

    Thank you for whatever interest has kept you reading to this point.

    cheers

    eon

    • “Japanese had a weapon deliberately designed to be used this way, called a “lunge mine”;”
      Its warhead seems similar to German Hafthohlladung
      https://en.wikipedia.org/wiki/Hafthohlladung
      which was applied to enemy tank by usage of magnetic forces and has normal delay fuse, so at least giving user chance to escape. Having such weapons apparently lead to fear that enemy will use similar weapon, which was reason for covering own tanks with Zimmerit. However in reality enemies did not deploy magnetic AT mines, additionally captured vehicles covered with Zimmerit were examined and though to be applied:
      – for increase fire resistance (protection against Molotov cocktails and flamethrowes) by Soviet: http://www.tanks-encyclopedia.com/articles/tech/zimmerit-in-soviet-tests/
      – for enhancement of camouflage by British: http://www.tanks-encyclopedia.com/ww2/british-work-on-zimmerit/
      none of them used magnetic AT mines, though British delivered some magnetic CLAM Mk III mines for Resistance forces in Europe, but this was not AT mine, rather saboteur mine – it contained only 227 g of TNT (for comparison Soviet РПГ-40 has 760 g of TNT and is said to able to pierce 20…25 mm of armour), additionally it accepts so-called time-pencil as detonator, which according to: http://www.timelapse.dk/timepencil.php existed in few variants differing in time, with shortest being 10 minutes

    • “It was to allow the PIAT to be used as a primitive mortar”
      In its low-trajectory-high-trajectory duality it somewhat similar Soviet NONA family, one of members of it is NONA-S: https://en.wikipedia.org/wiki/2S9_Nona
      It is based on БТР-Д after which it inherit following traits: swimming, air-drop-able, is armament is 120 mm caliber rifle пушка-гаубица-миномёт (cannon-howitzer-mortar, if I translated it correctly) which can fire great range of various projectiles (see table in Russian wikipedia query), HEAT shell (3БК19) able to penetrate 600 mm of armour.

    • There was no risk of the bomb sliding out of the trough. The trough has two clips at the back which can be seen at 2:25 and the bomb has a small disc at the base by the fins which slots into the two clips. If the bomb falls out you havent loaded it properly. Recoil is stout but really no worse than firing a heavy sports rifle such as a Wetherby .300 magnum or a Rifle grenade, not particulary pleasant but not life threatening. I was lucky enough to fire a practice round some years ago and the tank Museum at Bovingdon has a simulator you can fire.
      As for the velocity and range its about the same as a 2.36inch Bazooka M1 but without the flash and smoke turning you into a bullet magnet.

      • This particular PIAT seems to be fitted with a tray to launch training projectiles. These inert projectiles looked like a German stick grenade and were reusable by replacing the blank cartridge..
        Regarding the limited range, this was fairly common a the time. Bazooka, Panzerfaust and panzerschreck had realistic range from 30 to 60 meters.

    • Thank you eon for adding to the history of what, must be, the most important forgotten infantry weapon of the last world war.

      Anyone interested in the Blacks Bombard should watch the below Time Team dig on Shooters Hill, SE London. They excavate a pit, as described by eon, and reveal a guerrilla co-ordination bunker that astonished all the experts, and which had communications that were uncommon in British homes until the 1970’s

      https://www.youtube.com/waåtch?v=Z4J-iIrtVocå

    • Eon,

      Just caught this point on a re-read. RE: Point #3. Your information on RDX is quite a bit off. RDX is actually one of the more stable and least shock-sensitive explosive compounds out there. As a matter of fact, that’s why it’s used in so many different compounds–It requires a detonator. Set it on fire, and it just burns. RDX is the primary explosive component of C-4, and was chosen as such due to this stability.

      I’m not sure where you got your information, but it’s a little off.

    • The assessment about trying to recock it while lying in a trench reminds me of it being described as looking like you were having rough sex with the weapon.

  4. I can see utility of this device while fighting in close quarters, definitely in open field. Hitting tank from side or back would be the best bet. You definitely did not want to stand in front of tank when machine gunner (from either hull of turret post) can spot you and make mince meat out of you. The fact of non existing smoke trail was definitely helpful.

    This brings me to testimony of one British man who was too young to serve as regular trooper at the time. He told me couple of things how Britain was preparing for its last stand; it was o edge of despair. Luckily for them and thanks to valiant effort by RAF it did not happen.

    • “I can see utility of this device while fighting in close quarters, definitely NOT in open field”
      However, this can be applied also to most other man-portable AT weapons of that era. It should be remembered that all were in fact less-or-more last chance weapons, if you need to use one that mean all others method of destroying enemy tanks failed.

      • I am not sure if it is true, but I have heard in past that Soviets used against German armour REAL close quarter means – magnetic charges applied by individual soldier to tank’s belly. Allegedly Germans countered with magnetic-proof coating.

        Another one, almost prohibitively risky when we consider power of Animal Protection Lobby, is that they were supposed to train dogs to deliver explosive charges close to a tank. Using known Pavlov’s reflex, dogs were trained by being fed from tank. After a while dog was in tune and understood he will get his/her “menage” there.

        • “is that they were supposed to train dogs to deliver explosive charges close to a tank. Using known Pavlov’s reflex, dogs were trained by being fed from tank. After a while dog was in tune and understood he will get his/her “menage” there.”
          Dog-tanks hunters entered Red Army service in 1935, some were used during Great Patriotic War and at least few tanks were destroyed, however such dogs were at least problematic in use. Due to loud sounds of battlefield some dogs tended to search for cover, also as Soviet tanks were used in training such dogs some try to go into such tanks. [Germans and Soviets used different greases so their tanks smells differently to said dogs]

  5. I forgot to mention, this is an useful contribution to small arms/ infantry firearms history. They are not just pistols, rifles and machineguns. While we look at these early devices we can observe tremendous progress made by this category of arms; probably more than any other. As we all know, the current generation of anti-tank missiles can knock out any tank in blink of eye, as has been proven in battlefields of Syria and Iraq.
    Excellent show, Ian!

    • “tremendous progress”
      Proportional to development of tanks and other AFV. In that AT weapons seems to be similar AA weapons.

    • “(…)battlefields of (…) Iraq”
      At same time older pattern of AT weapons can be encountered.
      For example РКГ-3: https://en.wikipedia.org/wiki/RKG-3_anti-tank_grenade
      hand-thrown HEAT grenade, adopted by Soviet Union in 1950s, phased out in 1970s in favor of РПГ-18 «Муха» (fly [meaning insect]) disposable launcher, yet it was observed in usage in 2000s.
      РКГ-3 can penetrate either 170 mm or 220 mm of armour (depending from version) at angle of 30° (Soviet-style measurement, 0° = vertical plate), rather poor value against most modern tanks, but usable against non-tanks (like APC) and with lucky hit able to pierce older pattern tanks.

      • This is first time that I read about Soviet/ Russian anti-tank grenades. Their application certainly required utmost level of dedication to the cause which soviet soldiers were famed for.

        During my service time in CSLA we had in inventory recoilless canon vz.59. It may be interesting for you to read about (there are also basic data in English)
        http://forum.valka.cz/topic/view/12584/CZK-vz-59-vz-59A-82mm-bezzakluzovy-kanon

        I never came to actually firing one but in armorer’s course I became sufficiently familiar with it. I am not sure if it was exported to Syria/ Iraq. Perhaps Soviet weapons of this kind were more prevalent in that theater.

        • “During my service time in CSLA we had in inventory recoilless canon vz.59. It may be interesting for you to read about (there are also basic data in English)”
          Could you explain what mean JOF and JPrSv in Ammo Used?

          “Perhaps Soviet weapons of this kind were more prevalent in that theater.”
          Closest Soviet equivalent is probably Б-10:
          https://ru.wikipedia.org/wiki/82-мм_безоткатное_орудие_Б-10
          with disclaimer it is substantially smaller (barrel length is 1910 mm against 3771 mm, mass is 86 kg vs 386 kg) and has lower muzzle velocity (320 m/s vs 565 m/s), time-wise it is quite close as it was adopted in 1954 that is 5 year earlier. Available shells are: HEAT, HE-FRAG.
          This gun was also produced in China as Type 65.
          Query in Russian wikipedia list following operators:
          Algeria (120 examples in 2016)
          Angola (sum of 400 examples of B-10 and B-11 in 2016)
          Bulgaria (license production since 1958)
          Vietnam (Type 65)
          Guinea-Bissau (still in inventory as of 2016)
          Iran (still in inventory as of 2016)
          Cambodia (still in inventory as of 2016)
          China (license production as Type 65 and Type 65-1)
          Namibia (still in inventory as of 2016)
          Nicaragua (still in inventory as of 2016)
          North Korea (1700 examples in 2016)
          Mozambique (still in inventory as of 2016)
          Togo (Type 65)
          Poland
          Syria
          Ethiopia (still in inventory as of 2016)
          Equatorial Guinea (still in inventory as of 2016)
          Also adopted by: Egypt, North Yemen

          • I could not find clear definition for mentioned types and my memory does not go that far. In text they mentioned that two types of ammunition were intended for vz.59 – one of anti-armour shaped warhead and other of high-explosive fragmentation type.

            Equivalent of “shaped” in Czech terminology was “kumulativni”.

          • “Looks like cozy affair, at least in pictures”
            After seeing this pictures, this weapons size-wise seems to be closer to Б-11 (107 mm) rather than Б-10 (82 mm) recoilless gun
            https://en.wikipedia.org/wiki/B-11_recoilless_rifle
            it weight is 304,8 kg and it has 3,383 m barrel, muzzle velocity is 375 m/s, available shells are: HEAT (penetration 380 mm) and HE-FRAG

        • “This is first time that I read about Soviet/ Russian anti-tank grenades.”
          Mainly used types of AT grenades of Soviet production during WWII:
          RPG-40 – this wasn’t HEAT yet, it contains 760 g of TNT, overall mass 1,2 kg, armour penetration 20…25 mm
          RPG-43 – first HEAT, mass also was 1,2 kg, contains 612 g of TNT, penetration 75 mm
          RPG-6 – improved HEAT, designed for easiness of productions, mass was 1,1-1,13 kg, contains 580 g of TNT, penetration up to 120 mm

  6. Well… Here we have a perfect exemplar for what Ian and Bloke on the Range were discussing about “Annoying Gun Myths”, the other day.

    At about 6:45, Ian is talking about the “hollow charge”, and how it works. He says something to the effect that such a charge “burns through” the target’s armor plate, and… Well, crap: One of my favorite authoritative sources for things firearms-related just stepped into my wheelhouse, and then kinda-sorta stepped in it.

    A “hollow charge” is essentially a shaped charge. The usage may vary, in that you’ll occasionally find folks saying “hollow charge” for shaped charges that have no liners, and rely solely on explosives for the effect, but when you hear “hollow charge”, think “shaped charge”.

    And, manifestly, what is going on with a shaped charge is not “burning its way through the target”. There isn’t time for the material to melt under something like a glorified oxy-acetylene torch. At all–What you see as a “melt effect” in the material, post-impact, is instead what happens when you expose the armor or other material to the immense pressures created by the shaped charge and the penetrating rod of material from the liner. Under those pressures, the material flows like a semi-solid liquid, and the results appear as though it melted, when in fact it did not. The apparent heat residual makes you think “this melted”, when in actuality, you can’t impart that kind of heat that quickly to make a hole under those conditions.

    What is actually happening is that when the shaped charge is detonated (always from the top dead center of the back of the charge, BTW…) the blast wave moves forward along the column of explosives, converting solid to gas along a wave front. When it encounters the blast liner, or the cavity, that blast wave does two things: One, it refracts on itself, due to the void, and then it takes whatever liner there may be, and basically pops that liner inside out and drives it into the target like some sort of giant super-velocity spike. No melting required, no melting taking place–This is happening on a scale of micro-seconds, and there simply isn’t time for a charge to “burn through” as though it were some sort of giant welding torch. As well, the amount of energy present in the explosives that make up the charge is simply not sufficient. Were you to take a ball of C4 equivalent to the amount in an improvised shaped charge, and then burn it on top of the plate, you won’t get a hole–Just a hot piece of metal plate. Build yourself a little improvised shaped charge, and you’ll penetrate that armor easily.

    Shaped charges simply don’t work that way, no matter how many supposed “smart people” will try and tell you otherwise. The “burning” and the “melting” are illusions, produced by the immense pressures produced using these techniques. On the scale of time that these events take place, and with the energy available in the explosives, melting simply ain’t going to happen. What is happening is plastic deformation of the material in the target, which can look a lot like it was burned through, when the reality is quite different.

    This sort of thing is important, when you are trying to understand what is going on with your weapons, and make use of the effect in combat. Explosive Reactive Armor works because the “counter-blast” that is triggered when it is hit with a shaped charge jet basically disrupts the jet, scatters it, and “de-focuses” the blast wave from the shaped charge. As well, if you understand the way the warhead works, it becomes a lot easier to analyze why it may have failed, and then be able to adjust your targeting accordingly.

    In short, shaped charges manifestly do not “burn” through anything. What they do is make use of the blast wave as it propagates through the explosive material, focus it in a specific direction, and then drive a liner through the target in the form of a jet. No melting, no burning, just pure force. You can think of the shaped charge as being a chemical atlatl, a hammer, driving that cone of copper or other material through the armor, and you’ll be a hell of a lot closer to what is really going on than by thinking of it as some sort of superfast oxy-acetylene torch.

    • I am glad someone eventually put finger on it. Indeed, there is no time to “heat-up torch”. Burning of metal is subsequent effect of pressure wave concentrated to small area. It turned into liquid and partly gas.

      I recall reading somewhere that the material of liner is critical as is that cone angle.

      • Denny–I’d add “The apparent” in front of your third sentence, and that would make it entirely accurate.

        The “Munroe Effect” is what we call it in the US, and there’s a bunch of semi-hysterical stories about it, if you enjoy the comedy that is ordnance procurement here in the US.

        The effect is named after one Charles Munroe, a gentleman who was working for the U.S. Navy at one of the torpedo stations back in 1888. He noticed that you could imprint a leaf onto a piece of steel by the simple expedient of placing it between that block of steel and a charge of guncotton. This was a well-known parlor trick in the explosives world, but nobody saw a usage for it until the Germans came up with the charges they used on the forts at Eben Emael during the opening of the 1940 campaign. At that point, everyone was thinking “secret weapon”, and when a Swiss gentleman named Andres Mohaupt came to the US with that “secret weapon”, demonstrated it, and then offered it up for sale, the US military was going to pay big money to get it. Then, the lawyers got involved, did a patent search, and discovered that Munroe had done much of the basic research back before WWI, and… Mohaupt didn’t make his fortune, the way he thought he would. Possibly the one time where the lawyers did some good, actually…

        The grenade Mohaupt sold the design for eventually became the warhead for the first bazooka, and he went on into the oil industry, where his little shaped charges were used in well-drilling operations, and are indeed still a part of fracking. Mohaupt wound up making his fortune in the oil industry, BTW, and probably made more money than if he’d stuck to weapons.

        So, from the US perspective, the shaped charge is a bit of an embarrassment–We are the folks who discovered the effect, played with it, abandoned it as a toy, and then had to have the Germans rub our noses in it before we went “Hey… This might be useful…”.

        There were a bunch of European experimenters who contributed, as well, but Munroe was apparently the first. Or, at least, the one with the best publicity, sort of like the Wright brothers.

      • And, yes, the material of the liner is a critical element in what the charge can do. Higher density, shape, angle of the cone, and the rate of detonation all play a role in what the shaped charge is capable of.

        The big shaped charges used in demolition work, for example, all have glass liners instead of metal, because you want the jet to be big and to break up relatively quickly–There’s no use in creating a charge hole that’s thirty feet deep, and an inch or two wide, when you only want to pack explosives down around the six- or eight-foot level, and then tamp them. Likewise, in anti-armor work, a glass shaped charge liner is simply not going to be as effective as a metal one.

        So, horses for courses.

        It is a fascinating area to study and work in, but rather expensive to play around in. You really need either government sponsorship, or be working in an area of industry which uses these things routinely, like oil-well fracturing.

      • “I recall reading somewhere that the material of liner is critical as is that cone angle.”
        Article https://ru.wikipedia.org/wiki/Кумулятивные_боеприпасы give following formula crafted by М. А. Лаврентьев:
        b=L*(Pc/Pп)^0,5
        b – depth of penetration
        Рс – density of penetrator material
        Рп – density of penetrated material
        L=R/sinA
        R – radius of shell (cone)
        A – angle between axis and wall of cone
        With disclaimer that it is only for cone-shape and liner of uniform thickness. It says that modern HEAT shells which does not conform for that can pierce up to 9 times of own diameter.

      • Generally, early HC liners were mild steel. Lead and iron were tried by Matthias and Mohaupt in Switzerland, but they made shallower holes than a steel liner did.

        The critical factors are melting point and tensile strength. Ideally, you want a material which will only partly melt or vaporize, with the rest of it being forced through the cratered hole made by the blast and acting rather like a shotgun blast inside the vehicle, while the pieces retain enough heat to ignite or even detonate vulnerable materials, like fuel or ammunition. Their high velocity is what makes them really lethal to the crew.

        The liners in the warhead of the U.S. M72 LAWS 66mm, and the TOW 1 ATGW, were made of a tantalum/osmium alloy. This seemed to give the best performance.

        In most respects, a hollow charge with a liner acts very like a self-forging penetrator, not a blowtorch.

        cheers

        eon

        • “tantalum/osmium alloy. This seemed to give the best performance”
          This converge with formula which I quote, with all other values fixed, bigger density of liner mean bigger penetration.
          Steel density vary between 7,75 and 8,05, when Tantalum is 16,69 and Osmium is 22,59.

      • So… In simple(r) terms… You gents are basically saying that the “shaped charge” warheads of, say, Soviet AT hand-thrown grenades, the U.S. Bazooka, the PIAT just examined by Ian, the Panzerschrek und Panzerfaüste 30 klein, 30, 60 und so weiter, the Japanese “lunge mine,” the U.S. “super bazooka” also reviewed not-long-ago by Ian, the Soviet RPG 2/ “B40 rocket” and Soviet RPG7 are all basically creating “self-forged projectiles” before “self-forging projectiles” of copper were added to road-side bombs, i.e. “IEDs”? Or have I missed something obvious?

        So, the Japanese relied on someone filled with ideological indoctrination to use a “lunge mine” even underwater should Coronet and Olympus have taken place in November 1945, or like in Burma, sitting in a hole in the road straddling a huge bomb with a hammer to hit the fuze until it went… While the Soviets had various hand-thrown AT grenades, the Brits had an enormous and heavy machine, the PIAT to chuck the things at least fifty yards from outside their rubble fighting position, the Americans their “use only outside” Bazooka, and the Germans their expendibles with hand *placed* charges, magnetic AT mines, or the odd Hitlerjugend oder Volkssturmman with a Panzerfaust to deliver a blow against a Soviet tank…?!!

        Any odds on surviveability in each of these scenarios? I mean, didn’t the Panzerfaust simply fire a huge black-powder charge like the LDV/Home Guard Northover Projector, albeit open at both ends instead of just the one, incinerating anything behind it with its back-blast, revealing the firer’s location, and launching a “shaped charge” warhead/grenade to something like 50 yards against a Soviet tank with various extemporized “appliqué” armor like spring mattresses attached?

        • Dave;

          The difference between a shaped-charge jet and the slug from a self-forging fragment or explosively formed penetrator IED is fairly large, although there is something of a continuum from one to the other.

          Classic shaped-charges came first, following on the initial observations about hollow charges reproducing the cavity in the explosives on the target. Observing that the addition of a liner seemed to enhance the effect, people started playing around with them. I want to say that the whole thing wasn’t very well-understood until a gentleman by the name of Thomer did micrograph work on the issue in Germany, and the transition from hollow charge to shaped charge with liner was made. During this same period, work on what became the explosively-formed penetrator was done, mostly in Europe by Germans and Austrians.

          With the shaped charge, you’re using the blast wave’s passage through the explosive charge to essentially turn the liner into what amounts to a penetrating rod like we use in APFSDS rounds, only you’re doing it in microseconds right at the armor’s surface. Giving the jet time to form and space to do it is critical–Which is why you see those probes sticking out from the nose of shaped charge warheads. If you’re using one in cratering or other demolition work, there’s a bunch of factors that go into calculating stand-off, mostly based off the target material. Rule of thumb, you need to detonate the charge within around two charge diameters distance from the target for optimal effect, although that can vary depending on material in the target.

          It doesn’t take much to disrupt the jet, either–Explosives can do it, and running into a target with different densities within it, like Chobham armor or glacial moraine. You want to really disappoint a crew of Engineer troops, have ’em all excited to be doing live cratering charges, and have the 40-lb shaped charge utterly fail to do squat when fired into the gravelly mass of glacial moraine. No matter what you do with the charge, then, in terms of stand-off and so forth, the guys are gonna be pulling out the shovels and post-hole diggers to get those charge holes dug. And, that’s ever so much fun in the rock/sand/clay mixture of a moraine.

          An explosively-formed penetrator, on the other hand? Not as sensitive to distance, and not as easily disrupted. You can improvise one with plastic explosives and a metallic plate, thus the term “plate charge” or “platter charge”. Ideally, they’re round, preferably concave, and can be guided in a tube like a gun barrel. You plaster the plastic explosives in the proper proportion, detonate top dead-center of the rear of the thing, and what you get is a metallic slug that forms and drives a considerable distance, pretty much through whatever is in front of it. You can do some interesting things to bridge support structure with them, and you can really mess up a vehicle.

          Where you start running into convergence with these things is mostly with the factory-built charges, where you can do spacers in the charge, change the density of it, shape the plate/platter, and all that. When you do that, you sometimes can approach velocities and performance of a shaped charge with a platter charge, but have a much heavier mass doing the work, which means more damage.

          All things considered, I think I’d rather be in a vehicle with reactive armor, and get hit by a shaped charge. The jet stands a pretty good chance of being disrupted, but the same reactive armor really has a hard time stopping or even disrupting the slug from an EFP. The shear mass involved is the reason, as well as the fact that the battering-ram of the EFP isn’t going to give the reactive armor a chance to do much disrupting. Hell, from what I’ve heard, a lot of the time, the EFP just bludgeons its way in, and never even sets off the reactive tiles.

          As to the survivability using these things up close and personal…? LOL. The Germans had a badge they gave out, when you managed to kill a tank using only the weapons available to the Infantry, not inclusive of an anti-tank cannon. Not many guys got the thing awarded while they were alive, although there was someone who supposedly earned the badge five times, and survived the war. He killed his tanks with a range of weapons, from Molotov Cocktail to Teller mine and Panzerfaust. If I remember right, the guy I read about was a Combat Engineer, and he was a certified hard case, surviving multiple years and campaigns on the Eastern Front.

          So… Doable, but likely not survivable for the majority of us. Having done the “guy on ground hunting tanks” routine in training, all I can say is “Thank God they finally bought the damn Carl Gustav…”, because most of the crap they wanted us to do when I was a young Private back in the 1980s was purely suicidal. Google up “Eagle Cocktail”, sometime, and imagine being the dumbass who volunteered to go play “bell the cat” with a thirty- to fifty-ton war machine. As a young man, I’ve concluded that I simply wasn’t that bright, and had obvious problems connecting cause with likely effect. Either that, or I was extraordinarily trusting in my leadership and extremely optimistic about my survival odds, doing the “hunting tanks is fun and easy” BS in the training manuals.

          For the love of God and little green footballs, there was a section in that manual that essentially had you sneaking up on a tank, and sticking a crowbar into the tracks in order to de-track it and make a mobility kill on one. Anyone who’s ever observed the rage and angst a tank crew possesses when they have to put a track back on in the field can imagine what they’d likely do to the idiot who deliberately caused that to happen, likely involving the main gun and a bunch of wasted HE and HEAT ammo…

          • Thank you very very much! Highly informative, particularly for a “rocket science” dunce as myself.

            I was wholly taken in by the “annoying myth” through repetition and unfamiliarity. The very earliest infantry vs. tank history from WWI through the Spanish Civil War and the Russo-Finnish “Winter War” would bear close scrutiny. And an age where the best tank was arguably the T26 vs. what came shortly is swiftly superseded.

            There are images from the “last ditch” period of the Thousand Year Reich’s doomed attempt to forestall unconditional surrender…Or participate in a sort of national mass-suicide catering to the leader’s whims, perhaps: Single speed bicycles used by Volksgrenadier and Volkssturm companies with a large “Teller mine” suspended from the top of the frame, or twin Panzerfaüste clipped to the handle bars alongside the front fork straddling the front wheel…

            Is it accurate to state that the first “shaped charges fired in anger” was when glider-borne paratroops used them to knock out Belgium’s Eben Emael fortress? Or was there an earlier use?

          • Dave,

            Eben Emael was the first use that I’m aware of. Or, so all my sources have it.

            The really amazing thing about that whole deal is just how much time there was between observation of the effect and use of what many saw as a parlor trick. You would think that trench conditions and siege work in WWI would have gotten some people thinking about using it at places like Verdun, but no.

            It just indicates how bad we are at some of this work. Ever wonder why such an obvious development as the Claymore mine wasn’t around for WWII or Korea? All it is is essentially a factory-made portable fougasse, of course, and it’s something the Corps of Engineers should have inferred was necessary after WWI, with its mass infantry attacks. Took until the late 1950s, though…

          • “why such an obvious development as the Claymore mine wasn’t around for WWII or Korea”
            Red Army deployed more-or-less similar in effect devices: ФОГ-1 and ФОГ-2 during Great Patriotic War: http://warsite.ru/load/oruzhie_sssr/protivotankovoe_oruzhie_minomety_ognemety_vremen_velikoj_otechestvennoj_vojny/fugasnyj_ognemjot_fog_1_fog_2/7-1-0-25
            they were flame-throwing mines (stationary flame-throwers) expelling liquid by means of powder charge. They were one-shot and could be equipped either with single (directional) exhaust or quintile (star-like) exhaust, depending on liquid used single give range of 59-60 m or 130-140 m and quintile have zone of hitting with radius 45-50 m or 90-100 m.

          • Fougasse already in use, gosh, say the 16th century?

            Flame fougasses… Well, Greek Fire I suppose…

            And in WWI we get the Livens Large Gallery Flame Projector that is hauled piece by piece through a sapper-dug tunnel into a mine gallery within a few hundred yards of German trenches, and painstakingly reassembled for the dawn of the “big push…” And such flame fougasse type weapons were readied as anti-invasion defences of Old Blighty during the years of the Blitz. In fact, the UK’s “Petroleum Warfare Department” erm, well, uh, “cooked up” Operation Lucid (“Lucifer”) to use flame fuels with modern day “fire ships” to scatter the German flotilla of invasion barges at Boulogne-sur-Mer… Not actually used as intended, but meticulously planned…

            https://en.wikipedia.org/wiki/Operation_Lucid

            And the German concrete bunker designs included a nozzle mounted to the roof attached to a flame thrower for use against attackers with demolition charges and offensive flame throwers. Bloody business certainly.

            You are right that command-detonated shrapnel mines in a “single serving” the size of a smallish notebook, aka. the Claymore mine took a very long time to be deployed if it had to wait until the Vietnam War, or at least the U.S. phase of it, to be used! I do believe the NLF and PAVN aka “Charlie” took to the concept right away after being on the receiving end, no? And even used directional shrapnel mines as anti-heliborne devices unless I’m mistaken?

          • “I do believe the NLF and PAVN aka “Charlie” took to the concept right away after being on the receiving end, no?”
            I am not sure about that, but Soviet Army adopted own such mine about one year after first intelligence data and examples were gathered, Soviet version is called МОН-50: http://saper.isnet.ru/mines/mon-50.html
            and is generally similar but have some difference, most notably it has bit different shapes, as examined captured mines showed too wide angle of launched elements in vertical plane (some fragments flew too high, which was considered waste) thus Soviet one has smaller angle in that plane.

            “Claymore mine took a very long time to be deployed if it had to wait until the Vietnam War, or at least the U.S. phase of it, to be used”
            According to https://en.wikipedia.org/wiki/M18_Claymore_mine
            Following the massed Chinese attacks during the Korean War, Canada and the United States began to develop projects to counter them. Canada fielded a weapon called the “Phoenix” landmine, which used the Misznay–Schardin effect to project a spray of 0.25-inch (6.4 mm) steel cubes towards the enemy. The cubes were embedded in five pounds of Composition B explosive. It was too large to be a practical infantry weapon and was relatively ineffective, with a maximum effective range of only 20 to 30 yards (about 20 to 30 meters).
            So in fact there was such idea after Korean War, but getting viable weapon was not such easy task as it might looks.

            ““plate charge” or “platter charge”. Ideally, they’re round, preferably concave, and can be guided in a tube like a gun barrel. You plaster the plastic explosives in the proper proportion, detonate top dead-center of the rear of the thing, and what you get is a metallic slug that forms and drives a considerable distance, pretty much through whatever is in front of it.”
            Such devices are described as using Misznay–Schardin effect

          • Counterinsurgency–Lessons Learned No. 53 (DJSM-545-66) Viet Cong Improvised Explosive Mines and Booby Traps (U)(U.S. Military Assistance Command, Vietnam APO San Francisco, 29 Sep 1966): “Directional (Claymore Type)” p. 24.

            TC 5-31-1967 Dept. of the Army Training Circular–Viet Cong Boobytraps, Mines and Mine Warfare Techniques (HQ, Dept of the Army May 1967): p.10: g. Directional Fragmentation Mine (DH-10). This directional mine is primarily an anti-personnel mine which also can be used against thin-skinned vehicles or similar items. The concave front or fragmentation face of the mine contains approximately 450 half-inch steel fragments embedded in a matrix, and is backed up by cast TNT. Designed for electrical detonation, the mine is provided with an adjustable frame so that it can be placed on various types of surfaces and aimed in any direction. The single fuze well is centered on the convex (back) of the mine. This mine is often referred to as a VC claymore mine.
            Characteristics
            Type– Dual purpose
            Color– Gray to black
            Maximum diameter– 18 in.
            Width== 4 in.
            Total weight– 20 lbs.
            Filler– Cast TNT.

  7. George MacDonald Fraser (of ‘Flashman’ fame) wrote in his memoir of service on the Burma front of using a PIAT as a mortar against Japanese barge transport. The book is called ‘Quartered Safe Out Here.’
    Worth a look

    • The father-in-law of Jeremy Clarkson (of TV’s Top Gear fame) won the Victoria Cross at the Battle of Arnhem during WW2 using, among other things, PIAT launchers.
      Major Robert Cains VC. Quite a bloke. Wikipedia has details with more elaewhere, well worth a look

    • How much heavier is a recoilless rifle round than a cannon round with the same weight of projectile? I realize that the projectiles will be different but I’m curious about that weight differential. It wouldn’t matter if you’re talking about a jeep mounted recoilless rifle, but what about a man-portable RR? US troops use the Carl Gustaf. It was previously very heavy but just came out in a titanium version. How many soldiers does it take to field that weapon? One to carry it. How many to pack the rounds? How many rounds can one soldier carry, in addition to his regular gear? And what is its useful range?

  8. Weapon of choice scenario:

    Setting: a forest next to the highway somewhere along Grizzly Valley

    Okay, here we are at the ambush point. According to the news and our client, terrorists are heading east with 3 18-wheeler trucks full of weapons-grade uranium. And even worse, they’re being escorted by a bunch of tanks! The good news is that they have no air support and the recent snow blanket is slowing them down. The bad news is that the snow storm is making it impossible for us to get artillery support or air support should the ambush not be successful! Get a weapon and stop them before they cross the border. Just try not to irradiate us in the process!!

    Enemy information:
    3 tractor trailers of weapons-grade uranium
    14 T-34-76 STZ “borrowed” from a hostile neighboring country
    10 pickup trucks of bad guys, including RPG-7’s and PKM’s

    Available weapons at camouflaged ambush point:

    1. 8.8 cm Raketenwerfer 43
    2. PIAT
    3. crate of Hafthohlladung grenades and 5 thermite grenades
    4. 4 crates of surplus AT4’s and perhaps a Javelin
    5. Browning wz.28 and FM 24/29
    6. 8.8 cm PaK 43/41 disguised as fallen tree
    7. M3 Gun Motor Carriage
    8. FV107 Scimitar
    9. 12 cm mortar
    10. Bazooka Jeeps
    11. Get something else!!

    This activity is completely voluntary. You are not required to respond if you do not wish to do so. Please keep any and all criticism humane and free of foul language.

    Thank you.

    Cherndog

    • I want to stop the trucks without spilling the fissionables- I like not glowing in the dark. If there was a bridge on the route I could blow, down it would go.

      AT mines would be my weapon of choice. Deadline a few tanks in the lead escort, the road is blocked. Then blow up a couple at the rear, or at least blow their tracks off, to stop them turning around and going back.

      Kill the semi tractors- without them, the load doesn’t move. Rifle grenades would be good enough for that job.

      Then fade back into the woods and snipe anybody who sticks his head out for a few hours, until the weather clears enough to get some reinforcements and a NEST team in here.

      cheers

      eon

      • And supposing that one of the enemy pickup trucks turns out to be a flak wagon like the 4M GAZ AAA? That truck has four Maxim guns and would make mincemeat of anyone or anything lacking armor. I suppose your answer would be “Shoot truck with AT4 first, ID the truck later.”

        • One of the basic errors of Third World armies is putting “big” guns on “soft” vehicles. They overlook the fact that if the vehicle is taken out first, the “big gun” is useless.

          The Italians learned this lesson the hard way in WW2, with their Autocannoni 90/53, their standard 90mm AA gun mounted on an Ansaldo truck;

          https://upload.wikimedia.org/wikipedia/commons/0/0f/An_Italian_90-53_gun_on_a_truck_mounting_joining_the_rows_of_derelict_Axis_vehicles_and_equipment_jettisoned_by_Rommel%27s_army.jpg

          Intended as a dual-purpose AA and direct-fire AT gun, they stopped production at 57 examples when Western Desert combat showed that in direct fire mode, infantry tended to annihilate the gun crew and drivers with rifle and MG fire before they ever got a clean shot at a British tank. Oops.

          So yes, if it looks like a truck, blow it up with whatever’s handy. You might need an AT4 or etc. for something like one of the old Czech M53/59 Prahas with the light armor on the cab and the gun mount, but keep in mind, the mount is open on top, and once you’re within grenade-chucking range they can’t depress enough to hit you.

          The Russians got it right with the ZSU-23-4. Basically a light tank with quad 23mm autocannon. And of course the American M163, a 20mm Vulcan in a remote-control turret on an M113.

          If either of those were escorting the convoy, I’d want Javelins to do the job. A lot of Javelins. Not so much for armor penetration (AT4 will take out either one) but because I could launch from outside of their effective ground-defense range. See The Last Centurion by John Ringo.

          cheers

          eon

          • “The Russians got it right with the ZSU-23-4.”
            Main reason for Soviet vehicles to have closed compartments was to allow installation of NBC-protection. Such feature was not required from beginning of Cold War, so some early-Cold War era vehicle do not have it (for example BTR-40 and BTR-152), but later it was common.

    • “(…)The good news is that they have no air support and the recent snow blanket is slowing them down. The bad news is that the snow storm is making it impossible for us to get artillery support or air support should the ambush not be successful(…)Get something else(…)”
      For traveling in such environment M29 Weasel might be useful
      http://www.tanks-encyclopedia.com/ww2/US/cargo-carrier-m29-weasel
      it can also swim if there is such need, its armed version carried either 75mm recoilless rifle M20 or 37 mm Gun M3, first can fire HEAT shells which penetration of 100 mm armour, which should work against “T-34-76 STZ”. However if you want to be sure about that, Snow-Trac-Carrier armed with 120 mm L6 WOMBAT recoilless rifle might be solution:
      https://en.wikipedia.org/wiki/File:Wombat-carrier-variant.jpg

    • “try not to irradiate us in the process”
      Then get 9П149: http://weaponsystems.net/weaponsystem/CC02%20-%209P149.html
      which has NBC protection. It is based on МТ-ЛБ prime mover, what resulted in high off-road performance, it can also swim. It carry 12 missile, which are of SACLOS, which mean than operator need to keep target in sights until missile hit. Penetration vary, 9М114 missile can pierce 560 mm, when 9М120-1 is said to pierce no less than 800 mm, maximal range is 5 km for older missiles and 6 km for newer ones. It has no other armament, but can also fire missiles with thermobaric warhead or HE warhead.
      Data from: https://ru.wikipedia.org/wiki/9П149

      • 4 crates of surplus AT4’s and perhaps a Javelin

        And unless I’m entirely credulous, sedulous, and utterly mistaken, is it not the case that the Swedes/ Bofors, etc. have made an AT4 variant, just adopted by the U.S. army, USMC, and oh yes, what there is of a Swedish army, what with conscription belatedly introduced ca. oh! This year! 2017! that uses a highly concentrated saline solution instead of the plastic of the “prototype?” “Armbrust” launcher? Please advise…

  9. The father of a friend of mine was issued with a PIAT in 1945 for his part in Operation Varsity. He didn’t exactly take to the weapon, which was very awkward to use. However, it was useful in fighting in urban areas. Houses are a lot easier to hit than tanks, and it made sense to use the PIAT to discourage any Germans trying to use a house as a strongpoint. I don’t think he was sorry to see the back of the PIAT though, who wouldn’t rather carry a Lee-Enfield?

    • No surprise that guy didn’t like the PIAT. But is there any user-friendly man-portable anti-armor/anti-fortification weapon that WON’T give fiery back-blast?

      • As I remember, his problem with the PIAT was the immense effort needed to cock the thing, as alluded to by Ian. For its time, it was an effective weapon, and I am sure it saved many British and Canadian lives in the fighting in Europe.

        Apart from the problem of cocking it, the PIAT might well have been more useful than the Bazooka, in that it could be fired from inside a building, and used as a mortar, and you can’t do either of those things with a Bazooka.

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