Category Archives: Support Weapons

Tank Turret Rotation in WWII

a rollin foxholeLet’s adumbrate about tanks again. Fascinating things, although we always took Willie and Joe’s words to heart: a movin’ foxhole attracks th’ eye. (Alas, the only version of that classic we could find does not embiggen). Anyway, our interest has been more, shall we say, historical curiosity than professional.

To put it another way, we’re all about studying them, but we’re just as glad we spent our career under the sky and stars rather than under some inches of cold-rolled.

The nature of tank war is the nature of all war, in general, with some specialized details particularly adapted to the idea of fighting a mobile machine, and units of these mobile machines.

In armored warfare as in any other, the ability to fire the first shot is the guarantor of life. The ways you can get the first shot include:

  1. Seeing the enemy first. This has some impact on tank equipment as well as tactics. Some tanks are ill-equipped for observation in a 360º plane, making them very vulnerable for an off-axis attack. Of course, the crews train to fight the tank they have, and will develop methods to minimize this weakness.

    M26_Fireball

    T26 Pershing named “Fireball”. The 88mm mantlet penetration killed the tank and two of the five crew. Germany, 1945. They probably did not see the Tiger 100m ahead that hit them, but they were backlit by a fire. The Tiger also hit their muzzle brake with another shot.

  2. Concealment and firing from ambush. As many an infantry school instructor has crowed to students at once excited and aghast: “Ambush is murder and murder is fun!” This rewards a tank that can fire from concealment, without making a lot of noise that alerts the enemy’s dismounted scouts, without a lot of movement to betray the position. In addition, there are great advantages in the defense to be able to fire from a hull-down position. (And to a small turret, which complicates the enemy’s target solution).
  3. Outranging the enemy through superior accuracy or terminal ballistics. The components of accuracy are optic, gunner, gun, and integration. While it’s obviously important to hit the enemy first, it’s also important not to hit the enemy at a range beyond that where you can kill him. Otherwise, you’ve exposed yourself and blown your first-shot advantage for nothing.
  4. Getting on target faster. Here optics — including a good field of view for the gunner — and superior speed and control of main gun aim are the objective. If your turret slews very fast, that’s good, but not if the fast slew can’t produce fine control.
  5. Having more tanks, so that the enemy was servicing another target when your first shot kills him. This is a production and reliability play, but also rewards commanders for ingenuity in bringing their forces to bear in greater numbers at a decisive point.

The next best way to win the fight was having the first effective shot because your tank was harder to hit (or, harder to kill). This is clearly a less desirable position to be in than the one where you drop your tungsten calling card into the enemy’s brisket when he still was unaware you were there.

By World War II (and still today, apart from some unusual vehicles in both cases) the design of a tank was stabilized as a rear-engine vehicle with a rotating armored turret carrying primary and (most) secondary armament. The gun was placed on target in elevation by the gunner raising or lowering the barrel, and in azimuth by the gunner (with direction and sometimes assistance from the commander) slewing the turret.

Caught in the open: fate of many a tank and crew.

Caught in the open: fate of many a tank and crew.

In a textbook illustration of the principle of convergent evolution, WWII tanks of all nations were more alike than they were different. But different nations’ main battle tanks rotated their turrets differently — and some were effective despite a much slower rotation than their peers, which seems illogical.

  • British and Russian tanks rotated electrically. If you ever owned a ’60s British car, you have to have some sympathy for the grimy crews and mechanics struggling to keep the ancestor of Lucas electrics humming. British tanks used spade grips for the controls to rotate the turret. The British had a mode switch which let the gunner control traverse on a “coarse” or “fine” setting. The T-34 used electric for coarse and manual for fine traverse. The T-34/76 used separate wheels for electric and manual, attached to the same traversing gear. In the T-34/85, though, the same handle was used as a lever for electrical control and a crank for manual — ingenious! Rather than explain a T-34’s system, which used the same controls for manual and electric traverse, we’ll let the Military Veterans Museum show you in this 1-minute video:

  • Germans used a hydraulic system, driven by power take-off from the main engine. This was a mechanically simple and reliable system, but it had a key deficiency, as we’ll see. The Germans used foot pedals to slew the turret — left pedal went left, right pedal, obviously, right. The gun was then laid with final precision using a manual handwheel.
  • American tanks used a hydraulic system, but drove it electrically. Instead of a PTO from the main powerplant, like a tractor, the hydraulic system was energized by a pump driven by an electrical motor. Also, only the Americans applied stabilization gyroscopes to tank main armament, beginning with the M4 Sherman (on the early Sherman, in elevation only). This gave the tank a rudimentary shoot-on-the-move capability, and perhaps more usefully in tank fighting, reduced the amount of displacement needed to get on target after moving. When hydraulic system production threatened to constrain tank production, some American tanks were fitted with an electrical system also. The electrical substitute system was designed to have similar performance. American tanks used hand controls to slew the turret, and a foot pedal to fire the armament.
  • Most Japanese tanks had manual traverse only. Indeed, some light tanks and tankettes simply had a machine gun turret where the gunner moved the turret by leaning on the machine gun! While Japanese artillery and naval guns often featured bicycle pedals for traverse, the larger tanks had crank wheels to traverse the turret for coarse position. For fine position, the gun itself usually had a few degrees of traverse, and separate hand wheels. While Japanese naval optics led the world, their tank and AT optics lagged, as did most other aspects of tank development. Late in the war, electric traverse was incorporated in the Chi-Ha and Chi-Nu tanks; early Chi-Has, the bulk of those encountered by the Allies, were manually operated.
  • Some early and light tanks of many nations had manual rotation, and almost all power-rotating turrets had manual as a back-up. For example, the Panther had not only the gunner’s fine-tuning handwheel, required because of the lack of precision in the hydraulic system, but also a hand-lever for the gunner and a separate wheel for the loader. Having backups like this was important, because reliability of the systems on WWII tanks was not all that great. Engines, which were often modified or derived from aviation engines, lasted a few hundred hours before an overhaul was required, and hydraulic or electric motors were scarcely more durable. The tanks used at the peak of the war in Europe were war babies, designed once combat was underway and designed and manufactured with all due haste. They hadn’t had a long debugging cycle. Wartime memoirs are full of tales of operating with one or more systems degraded.

While in theory any system can be engineered to give you any rate of rotation, the German approach of shaft-driven hydraulics had a weakness: the turret could only power-traverse if the main engine was running. For the fuel-critical Germans, this was always a problem. This approach also meant that the speed of rotation depended on engine speed. You only got full-speed rotation at full throttle; at anything less, it was degraded.

How fast could turrets rotate?

The vaunted Panther tank had, in its first iteration (Panther Ausführung D), one of the slowest-turning turrets in the war, taking a full minute to traverse 360º. The gearing on the turret was changed in the Ausf. A, the next version, and all subsequent Panthers, giving the tank a competitive 15-second full-circle. But that didn’t last; a November, 1943 decision to govern the engine to a lower max RPM reduced slew rate to 18 seconds on Panthers from that point forward — if the crews didn’t learn about and adjust the governors. This was done to try to increase engine reliability: more Panthers were being lost to breakdowns than to Allied gunfire.

What’s interesting is that even though the early Panther turret was quite slow, it was still fast enough to track all but the fastest-moving tanks. All greater speed than a circle-a-minute buys, then, is ability to change targets, or get on a sighted target, faster.

The American system spun a Sherman turret 360º in fifteen seconds, too. The system in the M36 tank destroyer had the same performance, also. (Not surprising as the automotive  gear in the tank destroyers was lifted from the Shermans).

The undisputed slewing champ of WWII tanks was the Russian T-34, which could bring its turret all the way around in 12 seconds.

We couldn’t find any credible information on the slew or traverse rate of Japanese tanks.

The final lesson in all of this brings us back to convergent evolution: despite the different approaches taken by the major tank producers of the era, their performance was roughly similar (excluding the lagging Japanese, who deemphasized tank development and production because of their limited production capacity, and overwhelming naval requirements).

Sources

Directorate of the Armored Forces of the Red Army. T-34 Tank Service Manual. Translator unknown. Retrieved from: http://www.allworldwars.com/T-34%20Tank%20Service%20Manual.html

Green & Green, Panther: Germany’s Quest for Combat Dominance. pp. 107-120.

Military Intelligence Division. Japanese Tank and Anti-Tank Warfare. Washington: War Department,  1 Aug 1945. Retrieved from: http://usacac.army.mil/cac2/cgsc/carl/wwiispec/number34.pdf (bear in mind that as a wartime intelligence document, this is not fully-processed history!)

Zaloga, Steven J. Japanese Tanks 1939-45. Oxford, England: Osprey, 2011.

Zaloga, Steven J. M4 Sherman vs. Type 97 Chi-Ha. Oxford, England: Osprey, 2012.

The cat, or the importance of the smallest indicators

It is a tradition in the great militaries of the world that between wars, sniping becomes a neglected art. It’s neglected because it’s hard, because training for it is costly, and because the principal product of your snipers, actionable intelligence, is little appreciated in the peace time army.

The following story from the First World War illustrates all the reasons this art should not be neglected.

—————————————— I ——————————————

THE two snipers of the Royal Midlandshires, the shooter and the observer, were comfortably in their post. The shooter was longing for a cigarette, which regulations forbade lest the enemy – two hundred yards away – should see the smoke issuing from the concealed loophole; but the observer, Private William Entworth, was studying the parapet opposite.

Suddenly he spoke: “Line of water-tower. Red sandbag. Left. Two feet.”

WWI enfield sniper

Pattern 14 Enfield rifles were adapted with telescopic sights for British snipers. The British program was a reaction to German sniper successes. This rifle was sold by a British dealer recently.

Saunders’ eyes picked up the water-tower in the distance, ranged to the parapet, found the red sandbag, then swung to the left of it. Yes, something moving. He cuddled the stock of his rifle, and brought the pointer in the telescope to bear. Then slowly he began to squeeze the trigger.

“Don’t shoot.”

Entworth was only just in time.

“Why not, ole son?”

sleeping cat“It’s only a cat.”

“A ’Un cat! ’Ere goes.”

“Come off it. If you get shootin’ cats outer this post Mr. Nowell’ll – Besides, it’s rather a nice-lookin’ cat. Tortoiseshell colour. We ’ad one in Ferrers Street ’e reminds me of. … There, ’e’s climbin’ up on the bloomin’ parados, curlin’ round and goin’ to sleep just as if there wasn’t no war. Shall I enter ’im?”

“Wot’s the good?”

“Dunno. Shows we was awake. ‘Time 11.25 Ac. Emma. Cat (tortoiseshell) at K 22.C.35.45. Action taken: None.’” So wrote Private Entworth with laborious pencil. As he finished a voice sounded outside.

“Who’s in there?”

“Private Entworth. Private Saunders.”

“Shut the loopholes. I am coming in.”

“Well, seen anything?” questioned Mr. Nowell, the Sniping and Intelligence Officer of the Battalion.

“They’ve been working on the post at K.22. D.85.60.”

“Seen any Huns?”

“Only a cat, sir. I’ve entered it in the log-book. It’s sunning itself on the parados now, sir. Line of water-tower. Red sandbag.”

“Yes, I have it,” said Nowell, who had taken the telescope.

“Shall I shoot ’im, sir?”

“Why should you?”

“’E probably kills rats and makes life brighter-like for the ’Un, sir, by so doing. There’s a glut o’ rats on this sector, sir.”

british_unit_war_diary_page_wwi“The cat looks very comfortable. No, don’t shoot, Saunders. Entworth, give me that log-book.” The officer turned over the pages. “I wonder if anyone has ever seen that cat before? Hullo, yes. Private Scroggins and Lance-Corporal Tew two days ago in the afternoon. Here’s the entry: ‘3.40 pip emma K.22.C.35.40. Cat on parados.’”

Nowell’s eyes showed a gleam of interest. “Note down whenever you see that cat,” said he.

“Yes, sir.”

“And keep a bright look-out.”

“Yes, sir.” Once more the loopholes were shut, and Nowell, lifting the curtain at the back of the Post which prevented the light shining through, went out. His steps died away along the trench-boards.

“Think we’ll see it in ‘Comic Cuts’” (the universal B.E.F. name for the Corps Intelligence Summary). “‘At K.22.C.35.45, a tortoiseshell-coloured he-cat.’ I don’t think!” said Saunders.

“Shouldn’t wonder. The cove wot writes out ‘Comic Cuts’ must ’a bin wounded in the ’ed early-on. Sort o’ balmy ’e is.”

—————————————— II ——————————————

Meantime we must follow Mr. Nowell down the trench. He was full of his thoughts and almost collided round a corner with a red-hatted Captain.

“Sorry, sir,” said he, saluting.

“Righto! my mistake. Can you tell me where I shall find the I.S.O. of this battalion?” asked the Staff Officer.

“My name’s Nowell, sir. I am the Sniping and Intelligence Officer.”

“Good. I’m Cumberland of Corps Intelligence.” Nowell looked up with new interest. He had heard of Cumberland as a man of push and go, who had made things hum since he had come to the Corps a few weeks back.

“Anything you want?” continued Cumberland. “You’ve been sending through some useful stuff. I thought I’d come down and have a talk.”

Nowell led the way to his dug-out. He had suffered long from a very official Corps Intelligence G.S.O., whom Cumberland had just replaced. Under the old regime it never really seemed to matter to the

This RE. 8 was typical of Great War reconnaissance planes.

This RE. 8 was typical of Great War reconnaissance planes.

Higher Intelligence what anyone in the battalion did, but now Cumberland seemed to take an interest at once. After a quarter of an hour’s talk Cumberland was taking his leave. “Well,” said he, “anything you want from Corps, don’t hesitate to ask. That’s what we’re there for, you know. Sure there isn’t anything?” “As a matter of fact there is, but I hardly like to ask you.” “Why not? “It’s such a long shot, sir.” “Well, what is it?” “I’d like aeroplane photos taken of K.22 squares C. and D. opposite here. New photographs, sir.” Cumberland was about to ask a question, but looking up he caught the slight flush of colour that had risen in Nowell’s face. “Righto,” he said easily. “We rather pride ourselves on quick work with aeroplane photos up at Corps. I’ll have the squares taken to-morrow morning if visibility is pukka. And the finished photos will be in your hands by five o’clock. Good afternoon.” Cumberland strode along the trench, and Nowell stood staring after him.

“Never asked me what I wanted ’em for,” he muttered. “Taken in the morning; in my hands by afternoon. Why, in old Baxter’s time such efficiency would have killed him of heart-disease. Well, let’s hope that cat’s playing the game, and not leading a poor forlorn British Battalion Intelligence Officer to make a fool of himself.”

—————————————— III ——————————————

The next afternoon the aeroplane photos duly arrived, together with a note from Cumberland:

“Dear Nowell,

“Am sending the photographs of K.22.C. and D. taken to-day, also some I have looked out of the same squares which were taken six weeks ago. It would appear from a comparison that a good deal of work has been put in by the Hun round C.3.5. It looks like a biggish H.Q. I have informed C.R.A. who says it will be dealt with at 3 pip emma to-morrow, 18th inst.

“C. Cumberland,

“Capt. G.S.”

—————————————— IV ——————————————

It is five minutes to three on the following day, and the bright sun which has shone all the morning has worked round behind the British position.

In the morning two gunner F.O.O.’s have visited the trenches, compared certain notes with Mr. Nowell, and gone back to their Observation Posts on the higher ground. Nowell himself has decided to watch events from the O.P. in which was laid the first scene of this history. He hurries along to it, and calls out: “Who’s in there?”

“Private Saunders. Private Entworth, sir.”

“Shut the loopholes. I’m coming in.” He goes in.

6_inch_30_cwt_howitzer_muzzle_view_IWM_Duxford“Move along, Entworth, and I’ll sit beside you on the bench and observe with my own glass. Get yours on to the spot where the cat was. Got it? Right. Two batteries of 6-inch Hows. are going to try and kill that cat, Entworth, in a minute and a half from now. Zero at three o’clock. Nice light, isn’t it?” At these words of Nowell’s several thoughts, mostly connected with his officer’s sanity, flashed through Entworth’s rather slow brain, but long before they were formulated Nowell rapped out:

“Here they come.”

Sounds just like half a dozen gigantic strips of silk being torn right across the sky were clearly audible in the Post. At the same instant through the watching glasses heaps of earth, tin, a stove-pipe, were hurled into the air. There were other grimmer objects, too, as the shells rained down.

Fifteen minutes later, Mr. Nowell having gone, Private Entworth was speaking, though his eye was still glued to his glass.

“Direct’it right off and right into a nest of ’Uns. There was ’ole’Uns and bits of ’Uns in the air, I tell yer, Jim Saunders. Loverly shooting, ’twas! I doubt there’s anything at C.35.45. left alive. There is, tho’! By ––– there is! There goes that ruddy-coloured cat over the parados like a streak, and what ’o! for Martinpunch!”

—————————————— V ——————————————

And finally an extract from “Comic Cuts,” the Corps Intelligence Summary of the next day:

“A cat having been observed by our snipers daily sleeping on the parados of a supposedly disused enemy trench at K.22.C.3.4. it was deduced from the regularity of its habits that the cat lived near-by, and – owing to the fact that the German trenches at this point are infested by rats – probably in a dug-out occupied by enemy officers. Aeroplane photographs were taken which disclosed the existence of a hitherto unlocated enemy H.Q., which was duly dealt with by our Artillery.”

Hesketh-Prichard, H. (2012-07-01). Sniping in France: With Notes on the Scientific Training of Scouts, Observers, and Snipers (Kindle Locations 1760-1833). Tales End Press. Kindle Edition.

About Sniping, a Few Observations

  • Sniping is ultimately a psychological operation.
  • This is not the best-known sniper memoir (that would be MacBride’s, probably) but as Hesketh-Price stood up and ran the sniper school, it carries considerable weight.
  • As this story shows, the whole book is well written and is a fun, fast read.
  • This story is the best capsule illustration we know of why a sniper’s greatest worth to you is not in his trigger pulling — however good he is at that.
  • Count on the British to have no qualms about blowing large quantities of “Huns” away, but take delight in the survival of the little Hun cat.

The British only developed a sniper school and culture under pressure from German snipers. Like most democracies, Britain would let this tribal knowledge fade out during periods of protracted peace. And have to learn it all over again under pressure from German snipers within a couple decades.

What’s “RHA” in Penetration Specifications?

Anti-tank, anti-armor, and armor-piercing ammunition needs to have a specification describing its penetration. Now, any scientific test would be buried in disclaimers and details. What muzzle velocity, what distance, what angle, what atmospheric conditions. But there are certain norms.  It’s customary to convert ambient temperature and pressure during the test to an international standard atmosphere, 59ºF and 29.95 inches of mercury. It’s customary to convert slanted armor to its thickness equivalent along the axis of the shot. And it’s customary to describe penetration as distance, millimeters or inches, in a specific medium, RHA.

The Armor of this Russian T-34/76, with armor thickness and obliquity noted. All armor was RHA.

The Armor of this Russian T-34/76, with armor thickness and obliquity noted. On this specific model, nearly all armor was RHA (the 52mm thick turret front may have been cast).

RHA is Rolled Homogeneous Armor and it’s the most common of three types of steel armor that was commonly used in World War II. The others were Cast Homogeneous Armor and Face-Hardened Armor. In general RHA was the gold standard at the time, with CHA and FHA used for specific purposes. There are some terminological differences, of course: the British called RHA machineable armour, because it could be practically cut with machine tools; FHA was very difficult to cut on its armored face, due to heat-treating giving it a very hard, but brittle if overstressed, surface. RHA, conversely, is strong but ductile, which enables it to shuck off more and harder hits. The British breakout of FHA, which Americans call face-hardened armor, is flame-hardened armour.

Panther mantlet penetrated by US 90mm gun in Aberdeen testing.

CHA Panther mantlet penetrated by US 90mm gun at 800m in Aberdeen testing. Only some guns and some specific projectiles could penetrate here.

The US transitioned to mostly RHA early, as did the USSR (all T-34 hulls were entirely RHA, and both RHA weldments and CHA castings were used for turrets). British and German tank production started the war using face-hardened armor, and changed midwar. All armies used cast homogeneous armor for some purposes. For example, the Germans used it in the commander’s cupola and in the mantlet or gun shield of all Panzer V Panther tanks. The US made Shermans with cast turrets and with both cast hulls and welded RHA hulls.  The initial Panther model, Ausführung D, was made with face-hardened armor for the hull and turret (apart from the two cast parts mentioned above). In July 1943, they changed to RHA for the glacis (the upper front plate), and a year later they began using RHA on the sides.

As a rule of thumb, RHA is the best of these steel armors, with the best protection from penetrating and HE attacks, but it has some deficiencies. It is hard to form in anything but flat plates. CHA can be cast in almost any shape.

Heat treating is used to bring RHA to a specific hardness. The hardness of steel armor is measured on the Brinell hardness scale. As a general rule, the thicker the armor the lower the Brinell scale value, and therefore hardness of the metal, will be. The FHA plates of WWI armored vehicles, which were 1/8 to 1/4 inch thick, had a Brinell hardness of 420-650. The RHA for the WWII generation vehicles ranged from 220-390 or so. For example, these are the German specified values (for both RHA and CHA):

Thickness Range (mm) Brinell Hardness

16-30

309-353

35-50

278-324

55-80

265-309

The reason for this decline in hardness with increase in thickness was the state of the production art, and it was fairly universal across the belligerents’ RHA armor. The Russians’ armor was the hardest by Brinell measurement.

Penetration of a Panther glacis. This may have been FHA, judging from the Greens' analysis of these Aberdeen tests.

Penetration of a Panther glacis. This may have been FHA, judging from the Greens’ analysis of this series of Aberdeen tests.

FHA was hardened to a higher level (Brinell in the 500 range), but only a few mm deep. The idea was to have more resistance to penetration on the surface, but more ductility in the rest of the armor to prevent brittleness and fractures, or spalling of chunks off the inside of the armor. Spalling was the kill mechanism of the British HESH (High Explosive Squash Head) round of late-war was designed to produce. The US later produced a version called HE-Plastic or HE-P.

The more you study armor penetration, the stranger it gets. For example, a long rod penetrator like the APFSDS rounds used in modern tank guns can actually perforate armor thicker than it can penetrate, by causing failure in the armor plate; it can also perforate the armor deeper, through that failure mechanism. That’s completely counterintuitive, but penetration and perforation curves from live testing demonstrate it.

Late in the war, shaped-charge warheads became a problem. Using WWII-era understanding of lining materials and explosives, effective shaped charges tended to be larger than most tank main gun calibers. Instead, they were deployed by short-range rockets like the German Panzerschreck and the US 2.36″ rocket launcher, and other infantry weapons, such as Russian drogue grenades, the British PIAT and the Japanese lunge mine (which is exactly what it sounds like, a shaped charge on a stick for a suicidal human attack on tanks. They were used on Okinawa and were made in the hundreds of thousands for the anticipated defense of the home islands).

armor-penetration-table

Penetration curves like this are typical of kinetic-energy penetrators, like these US 90mm shot types. Shaped charges do not depend on kinetic energy for their penetration, and thus, their effect on target is range-independent, as long as the delivery system can deliver the shaped charge to the target. The same shaped charge will work the same in a 3000-m ATGM or at the end of a 1.5 meter lunge mine.

The hardness of armor had much less influence on shaped charge penetration. But as a shaped charge has an optimum standoff distance, detonating it early reduces its ability to burn its way through armor. This led to various kinds of appliqué armor, some factory and some improvised. The Germans were a step ahead here. They had already added stand-off plates called Schürzen to many combat vehicles (including the Panzer III, IV and Panther) as a countermeasure against Russian anti-tank rifles. The Schürzen were homogeneous, but not very hard — only Brinell 105 or so. Schürzen were ineffective against conventional tank and antitank guns, but would sometimes fragment or deflect the steel or tungsten-cored 14.5mm Russian anti-tank rifle projectile, which otherwise could penetrate the side armor of those tanks at close ranges (~100m). The effectiveness of Schürzen against shaped-charged warheads was an unexpected but welcome bonus.

As we said, armor penetration is a weird science. The Schürzen, for instance, had almost zero effectiveness against the 14.5 if struck absolutely square on, at a 90º angle, but got much more effective as the angle increased even a few degrees.

Sources

Farrand, Magness, and Burkins. Definition and Uses of RHA Equivalences for Medium Caliber Targets. Interlaken, Switzerland: 19th International Symposium of Ballistics, 7–11 May 2001. Retrieved from: http://ciar.org/ttk/mbt/papers/symp_19/TB151159.pdf   (That site has the whole proceedings of the symposium).

Green, Michael & Gladys. Panther: Germany’s Quest for Combat Dominance. Botley, Oxford: Osprey, 2012.  (A very worthwhile book, rich in technical detail, with excellent notes and index and a wealth of photographs).

Uncredited, Armor-Piercing Ammunition for Gun, 90-MM, M3. Washington: Office Of The Chief Of Ordnance, January 1945. Retrieved from: http://www.lonesentry.com/manuals/90-mm-ammunition/index.html  (Lone Sentry is a former W4, and is highly recommended for this sort of period material).

Numerous other sources were used en passant but the bulk of the information in this post is from Farrand et. al. and the Greens.

Weapons Term that Stumped Us: “Pronock”?

We don’t often run into a word referring to weapons that’s completely unfamiliar to us. Even more rarely, we can’t even track the word down. That’s what happened to us in reviewing a 1952 document by the Operations Research Office, a now-defunct FFRDC1 operated by the US Army at the time.

Even generals got in on the tank killing. Of course, this one wound up a POW, out doing a corporal's job with a bazooka.

Even generals got in on the tank killing. Of course, this one wound up a POW, out doing a corporal’s job with a bazooka.

The document reviews the performance of US tanks and tank units in the first year of the Korean War. It was originally classified as SECRET, and the second of two volumes does not seem to have survived. The lost (?) second volume comprised Appendix K to the fundamental document: surveys of some 239 North Korean T-34 tanks examined by American ordnance experts. Fortunately, some conclusions from those surveys made it into the first volume.

But the original document is full of fascinating insights. One of them was that napalm was hugely successful against Nork T-34/85s, and was potentially a threat to American tanks. Napalm is mentioned nearly 60 times in the 308-page report. The mechanism of destruction wasn’t completely certain, but it appeared to be that the nape set the tanks’ solid rubber road wheels on fire, and the burning wheels got hot enough to cook off the rounds in the tanks’ sponsons. FOOM! End of tank, or as tankers say now, “catastrophic loss.” In 1952, the term was “loss, unrecoverable.” That described the situation where the burnt-out hull was here, the insinerated turret was there, and both of them had small, carbonized cinders of what had been the crewmen.

Unknown what killed this tank, but napalm is a possibility. It appears to be buttoned up, but still burning. Tough luck for the Norks inside.

Unknown what killed this tank, but napalm is a possibility. It appears to be buttoned up, but still burning. Tough luck for the Norks inside.

On the basis of limited evidence, air attack accounted for 40 percent of all enemy tank losses in Korea, and 60 percent of all enemy tank losses caused by UN weapons.

On the basis of limited evidence, napalm was the most effective antitank air weapon thus far used in Korea. (p.2).

The difference between all enemy tank losses, and enemy tank losses caused by UN weapons is presumably the same thing that caused a lot of US/UN losses: mechanical failure. A table on p. 36 bears this out, and is discussed on p. 35:

On the basis of this record, the greatest single cause of loss in NK T34’s would seem to be UN air attack, which accounted for 102 out of 239, or about 43 percent of the total losses.

Napalm appears to be the most effective weapon of all, accounting for 60, or about 23 percent of the total count. Abandonments, in most instances without any visible evidence of cause, accounted for 59, almost another 25 percent of the total count. Tank fire was the third largest single cause, knocking out 39 tanks, or about 16 percent. (p. 35).

This led to a discussion of napalm’s effects:

Napalm as a weapon to defeat armor must be given rather special consideration. It is essentially a weapon of an accidental nature. With the possible exception of the relatively rare occurrence of a direct hit, napalm does not of itself destroy or seriously damage a tank. However, it is fully capable of starting a chain of events which may bring about the loss of the vehicle. A napalm bomb, if a hit is registered sufficiently close to the tank, will splash its burning fluid on the tank. Because of the fire, the crew may suffer burns or be induced to abandon the tank. However from the prisoner of war interrogations it appears that tank crews usually had sufficient time to get clear before the fire had spread (see Appendix D). However, the abandonment of the tank ultimately led to its destruction, for the napalm from the first or successive strikes had sufficient time to ignite the rubber on the road wheels, heat the ammunition to the point of detonation, and set fire to the fuel. Any or all of these factors brought about the loss of the tank. (p. 37).

Amplified, and considered in terms of US tanks in this partly redundant passage:

From a general examination of US tanks, the Air Force Operations Analysis tests of napalm against T34 tanks (FEAF Operationr Analysis Office Memo No. 27, prepared jointly with Deputy for Operational Engineering, FEAF, 30 October 1950) and the ORO tank survey (see Appendix K), it is belleved that napalm- caused tank fires are essentially “accidental” in nature, i.e.,
the napalm itself does not have enough energy to set ammunition or fuel afire by bating a tank, but it does have enough effect to set afire rubber bogie wheels , which In turn can fire the tank bilge or amnunition and thus kill the tank. Also, napalm entering through the air intake of a tank can set the bilge afire, again firing ammunition and killing the tank. It appears that both of these “accidents” can be eliminated by minor tank redesign or by fire extinguishing techniques. (p. 59).

Not clear what killed these tanks, but our guess is that the Nork crewman in the foreground suffered a terminal case of amall-arms projectile sickness.

Not clear what killed these tanks, but our guess is that the Nork crewman in the foreground suffered a terminal case of amall-arms projectile sickness.

The USSR may conclude on the basis of the Korean campaign that napalm is a very effective antitank weapon. This possible conclusion can be vitiated by minor redesign of US tanks to reduce effectiveness of “accidental” fires. In future attack on Soviet-manufactured tanks, napalm may remain effective, but the types of fluid filler–such as “G” agents, chlorine trifluoride, or pronock — in improved napalm-type tanks may be even more effective. (p. 60).

There’s the word “pronock.” What is it?

But first, let’s continue our digression into the Korean War tank effectiveness report. The unexpected effects of nape on tanks got the ORO thinking. Some of the thoughts probably explain why the report was classified so highly in the first place:

On the basis of the burning of the rubber on tank road wheels with napalm, resulting in the destruction of the tank, tanks appear vulnerable to 40-kt atomic-weapons attack up to a distance of 2,500 yards on a clear day, and 2,000 yards on a hazy day. (p.3).

Er… yeah. T-34s were vulnerable to destruction by nuking. We’ll accept that.

Original caption: Napalm Bomb Victims.  Mute testimony of accuracy of close support missions flown by Fifth Air Force fighters are these Red Korean tanks, blasted out of the path of advancing 24th Infantry Division units near Waegwan, Korea. AIR AND SPACE MUSEUM#:  77799 AC

Original caption: Napalm Bomb Victims. Mute testimony of accuracy of close support missions flown by Fifth Air Force fighters are these Red Korean tanks, blasted out of the path of advancing 24th Infantry Division units near Waegwan, Korea.
AIR AND SPACE MUSEUM#: 77799 AC

And then there was a list of things that the US ought to develop, based on combat experience with tanks in Korea:

Support a vigorous and expanded research and development program to provide a balanced family of antitank weapons without, however, either overemphasizing or neglecting the role of heavy gun tanks such aa the US T43. This program should emphasize:

a. Development of an effective long-range antitank gun for use by the infantry. This gun should be capable of being moved over rough and unfavorable terrain, preferably in a light, highly mobile vehicle.

That, of course, is the paragraph that gave birth (by a circuitous route, it’s true) to the US M40 106mm recoilless rifle. The M40’s immediate ancestor, the M27, would be rushed to Korea and tested in combat.

b. Development of a family of lethal, influence-fused antitank mines s with sterilizing and arming devices, suitable for remining by rockets, artillery, and air.

Simultaneous development of corresponding mine-detection &vclearing devices.

That stands to reason.

d. Research and development on new types, of air and ground munitions utilizing liquid fillers, such as napalm, chlorine trifluoride, pronock, and G-agents.

That’s the strange use of the strange word, “pronock.” What is it? Napalm is well known. G-agents are nerve agents originally developed by the Germans: Tabun, Soman, Sarin, and Cyclosarin, known in the US/NATO coding system as GA, GD, GB and GF respectively.

Chlorine trifluoride is less well-known, but was a remarkable German “twofer” that produced both incendiary and toxic effects, and that was produced by the Third Reich’s chemical-warfare directorate as “N-stoff” or “Substance N.” The incendiary effect of ClF3 is pretty remarkable — it’s hypergolic not only with normal fuels, but also with water. And it can set asbestos on fire. It does bad things to human beings. It’s never actually been used in warfare (or in most other applications) because containing and handling it is a challenge; Rocketdyne once developed rocket engines that used this stuff as oxydizer with Hydrazine Hydrate as fuel. Hydrazine (N2H4), another Nazi product (as the fuel in the mixture “C-stoff”) used in the V1 and Me163, still has some uses (in the ACES ejection seat, IIRC), but is itself among the nastier things in the hazmat catalogue.

For completeness’s sake, the last of the list of recommendations:

e. Continued development of special amunition, such as shaped-charge and squash-head ammunition, together with improved bazookas and recoilless rifles.

But what in the name of science is “pronock?” It clearly is something that can be used as a tank filler, like napalm, like chlorine trifluoride, like the G-agents. And something that, like those substances, one would rather not have fall on him. Beyond that, we’re stumped. Google was not our friend, either.

Update

Looking for some photos of tank kills definitely attributed to napalm, we found this period article on napalm in Korea which depicts — unfortunately, in a very horribly reproduced half-tone — one of the tests of napalm on a captured T-34. It also describes the thickened gasoline’s composition, and effects on the enemy:

Red tankmen weren’t afraid of diving planes at first, their tough armor would repel 20 mm fire, it was hard to hit the maneuvering tank with rockets, and bombs had to be right on to kill a tank. Napalm was another story. Pilots drop the fire bombs short from low altitude, let it skip to the target. Accuracy is not at a premium. The napalm bomb will cover a pear-shaped area 275 feet long and 80 feet wide. A solid sheet of 1500° fire envelops everything , Killing personnel, exploding ammunition. It is not a flash fire like gasoline alone would be but clings and burns and burns.

… As fast as the Reds moved in tanks to stop the retreat, napalm was dropped on them. They ran out of tanks and weight of phases of the war have seen far fewer communist tanks in action.

The article noted two indirect effects of napalm on the enemy: tanks would be found with the crews inside, unmarked but dead of suffocation, the napalm fires having stolen the very oxygen from the air they breathed. And the psychological effects of the weapon induced many surrenders.

Notes

1. FFRDC: Federally Funded Research and Developmant Corporation. The most famous are probably RAND, which was sponsored by the USAF. The ORO was an Army/Johns Hopkins lashup, that the Army grew tired of and pulled the plug on in the 1960s.

How an Original Tiger Wound up in Fury

One of the most remarkable things about Fury is the presence of a real, running, Panzerkampfwagen VI Tiger 1 on screen. This is the first time a real, live, Tiger, and not a mockup on some other chassis, a scale model, or a CGI digital emulation, was used in a feature film. Here’s a video of how a high-strung thoroughbred war machine from most of a century ago performed before the cameras:

As Tigers belonged to an empire that was crushed to rubble some 70 years ago, the few of them that have survived have mostly come to nest in museums. But one that was captured in 1942 in the Western Desert nation of Tunisia has been running (occasionally) and entertaining visitors at the Royal Armored Corps’s Tank Museum in Bovington, England for some years now. Tiger 131 was shipped to the set (along with some doting caretakers), and the Museum also provided the title character, Fury the Sherman tank.

The Museum now has a temporary exhibit dedicated to the movie, including some of the props they didn’t originally provide, and wargaming stations that let visitors get creamed by Tiger tanks themselves — at least, in the digital realm.

The Tank Museum also posted this video explaining some of the other lengths the movie makers went to, to make Fury as grimly accurate as they did.

We did note the absence of anachronisms on the screen, at least in terms of props and settings. (Some of the language and human expression is more 21st Century than 1945, but what can you do about that?) If you’re planning to see the movie (about which we remain uncharacteristically ambivalent), these videos contain no real spoilers and may help you look for details you’ll enjoy seeing.

About that Keene, NH Bearcat

This is Keene's Bearcat. There are many like it, but this one is Keene's. Without its Bearcat, Keene is useless. Without Keene, the Bearcat is useless...

This is Keene’s Bearcat. There are many like it, but this one is Keene’s. Without its Bearcat, Keene is useless. Without Keene, the Bearcat is useless…

Keene, New Hampshire, is a sleepy college town, left-leaning as NH goes, and the subject of a great outcry two years ago because the police purchased (or rather, had your Federal taxes buy, so maybe “requisitioned”) a Lenco Bearcat armored personnel carrier. We were part of that outcry.

Keene’s justification for the vehicle was that they needed it to defend large gatherings, like the Pumpkin Festival.

This made the entire town the laughingstock of the Western World, and parts of the Old World stretching back to the furthest conquests of Alexander the Great (we concluded, “Somewhere in North Waziristan, Gulbuddin Hekmatayar is laughing his ass off at us.” back in 2012).

Before we bring the story up to date, note that a large number of the inmates of Keene are college students at Keene State, the designated Party School of the NH System. That helps to explain What Happened Next.

So how do the people of Keene demonstrate how the police in their leafy burb don’t need any riot control vehicle? By rioting, naturally.

At the freaking Pumpkin Festival.

We are Not Making This Up®. We’d be ready to go back to that 2012 post and eat our pixels, but…

We just got done talking to a Keene cop, and they used all their resources to control the riot, except one. Which one? You got it: the Bearcat.

A perfect chance to grind patchouli-scented hippies (not to mention drunks in their fourth sophomore year) under the Bearcat’s run-flat tires, and they go all restraint, like. Lord love a duck.

Somewhere in North Waziristan, Gulbuddin Hekmatayar is laughing his ass off at us.

(Not Making This Up® is a registered trademark of Dave Barry. Used without permission -Ed).

 

The Randall Knife

Singer-Songwriter Guy Clark with “The Randall Knife.”

It’s a kind of talking blues/folk/country thing, sentimental if not schmaltzy; not entirely to our taste, but the subject matter redeems it. You know there was a Randall knife in Clark’s house. You know he  knows the feel of the Randall in his hand.

You know his father was, by God, a man.

 

A man can make up a song, but he couldn’t make up this song out of whole cloth.

The Randall wasn’t an SF knife, before Vietnam. Since then, it has been, and both Randall Made Knives and Special Forces have benefited by the partnership. Sure, there’s now the Yarborough knife for SF grads (old-timers who are SF-Q’d can get them, too, although it’s a hair more complicated because your bona fides has to be checked).

It was just one of those things, like a Seiko or Rolex watch. Like owning a car that would go unreasonably fast, and getting a reputation for going unreasonably fast in it.  Like having access to a veritable petting zoo of the world’s most famous firearms, and still buying your own to plug real or imagined “training gaps.”

What’s After Black Hawk?

We still think of the Sikorsky Black Hawk as a modern helicopter, and the Bell Huey as an artifact of the 60s (it actually first flew in the 1950s as the YUH-40!). But the Marines continue to use Hueys, although theirs have been modified about as far as an aircraft can get. The Army, Navy, Air Force and Coast Guard have all the “new” Black Hawks. But the Black Hawk is itself an old bird: we first saw one at Mott Lake Compound in the winter of 1981 or 1982, about 32 years ago. Since then, we’ve seen what they could do, even in Afghan density models, going into the field in ancient A-models and riding an ultramodern Q-model medevac bird back to Bagram.

Sure, we were still jumping, rappelling and fast-roping from Hueys 10 years after our first Black Hawk sighting, but the UH-60 came in on the UTTAS program of the 1970s (the program that took it to the Navy was, we think, LAMPS). A Sikorsky proposal edged a Bell proposal. Well, now it’s time for a new competition to demonstrate technology, as the first step towards developing a replacement for the Black Hawk, a helicopter that came to be as loved and respected as its predecessor. And the same two firms are going head-to-head again. Here’s what one of the contenders, the Sikorsky SB-1 Defiant, looks like:

Future Helicopter JMR

The contenders are both more than just helicopters. The Sikorsky entry (above), for which the venerable chopper builder teams with Boeing, is a compound helicopter, with a thrust propeller in the back, and counterrotating rotors to handle both torque and the µ-1 problem at high speeds (when the forward speed of the aircraft in air is great enough to reverse airflow on the retreating blade). The first aircraft we know of to exceed µ-1 in level flight was the Carter Copter Technology Demonstrator, a hybrid gyroplane/airplane which used rigid rotors largely unloaded in flight, and small wings suitable for cruise only and stalled at lower speeds. The CCTD concept is unsuited for a military helicopter replacement because it cannot hover, although it can land and take off vertically; military requirements include the ability to conduct sling load and fast rope operations.

The Bell entry is a convertiplane of the tiltrotor type, the V-280 Valor.

Bell-V280

It looks like they have simplified the V-22 concept by having only the rotors, not the entire engine pods, tilt.

It’s a joint program, so maybe the Marines will get out of the 1950s and 1960s, finally.

Both aircraft show that the basic vision is something with a Black Hawk’s interior volume and carrying capability, but faster (and presumably, more-efficient thus longer-range) cruise. The Joint Military Rotorcraft program is primarily an Army one, although if the Army develops worthwhile new aircraft the Navy and Air Force will be right there to join in. The JMR is a technology program only, and the contracts that Sikorsky and Bell now have are for flying prototypes with no assurance of production. Army and Navy have long-term rotorcraft programs that are primarily technological and budgetary at this point.

The basic problem with conventional helicopters is cruise speed: the µ-1 limitation holds them to well under 200 knots. That’s the key problem JMR will try to address. For decades, a wild variety of VTOL aircraft configurations have attempted to address this, and both Bell and Sikorsky have been involved deeply in those experiments, as have a number of lesser-known firms such as Carter, Piasecki (which continued as an R&D shop after selling their tandem-rotor plant and designs to Boeing in the 1960s), Groen Brothers, and others.

SPARTY, Circa World War I

This grainy, moïre-wracked image comes from American Machinist, Volume L (50) Jan-Jun, 1919.

wwi_sp_arty_experiment

It appears in the bound volume of the trade magazine on page 266, and does not seem to be referenced in the text. A few pages earlier, there’s another self-propelled artillery piece, a 9.2 inch howitzer.

wwi_sp_arty_experiment_9-2_inch

The first of these weapons, at least, is well known to specialist researchers. The Holt Tractor Company of Stockton, California made early tracked tractors for agriculture. Their initial models steered not by differential braking or power to the tracks, but by a “tiller wheel” that was mounted out in front of the machine. By World War I their ag tractors were very successful, and their engineers adapted them to military use around the time of the US’s entry into the long-running European war in 1917.

All the military tractors were experimental. The Army Ordnance Department experimented with them, but deployed none of them to France.

The versions included what may have been the first manufactured tank, and at least seven or eight iterations of the self-propelled artillery design, most of which mounted the US 75mm M1916 field gun, a variant of the French 75.

The popular Holt tractor was also adapted in Britain, experimentally, and France and Germany produced tanks based on Holt running gear. The most famous of these tanks was the German A7V, a tank that was outnumbered in German service by captured British tanks.

The Holt company is a trademark you may not recognize today, as the forerunner of a modern giant whose trademarks you definitely know. As the company was best known as the maker of the Holt’s Caterpillar Tractor, it changed its name first to Holt’s Caterpillar and finally, just to Caterpillar. So Holt’s tractor is still with us.

While Caterpillar (and small-c caterpillar) tractors would be successful as artillery prime movers, the company does not seem to have adapted their post-war tractor models into potential military sales. The engineering requirements for tank tracks and suspensions are too different from those needed for tractors, bulldozers and earth-moving equipment. And also, the US didn’t get serious about tanks until it began to seem clear that we’d need to start numbering our World Wars, so there was no money in tank development for an American firm in most of the interwar years.

Cartel Grenades Explode Back into the News

Reanimated M67 training or dummy grenades recovered in Mexico.

Reanimated M67 training or dummy grenades recovered in Mexico.

From the equivalent of the “Early Bird” sent to Federal LEOs earlier this week:

MEXICAN CARTELS USING GRENADES. The International Business Times (UK) (8/18, 173K) reports that ICE officials have observed a “trend increase” in the use of grenades by Mexican drug cartels in recent months. James Phelps, an assistant professor in the Department of Security Studies and Criminal Justice at Angelo State University in Texas, is quoted saying, “The reason you’re seeing so many more [grenades] this year is because much more heavily-armed drug shipments are coming into the United States…With Border Patrol so heavily distracted doing paperwork and watching the mass flood of people coming into the country, they don’t have as much time to do what they used to do — drug interdiction.”

But wait: It’s Not News

The IBT article is here (it was linked in the original, too) but what struck us is not what’s new about this, but what isn’t. Customs and Border Patrol has been seizing grenades on the border for a long time. ATF has been tracking this since the nineties, and has been on it hot and heavy since the early oughts. We have access to a long-ago-leaked 2011 LES presentation on Mexican Drug Trafficking Organization (DTO) use of both surplus and improvised grenades.

Texas_Improvised_Grenades.pdf

One interesting thing is that not all cartels have good sources of military grenades, hence the back-up of improv ‘nades.

Slide 1

Reports indicate that Los Zetas historically try to seek grenades from sources in Guatemala, due to their control of many areas in that country. The Gulf Cartel has historically attempted to acquire their grenades from Mexican military sources, whereas the Sinaloa Cartel has sought to acquire improvised grenades.

Sinaloa was supported to that end by the ATF’s gunwalking program, which included walking grenade components, as a sideline to the main project of walking guns. The military grenades that the cartels are swapping off tend to be leftovers from 80s and 90s unrest and insurgencies in Central America, plus the Mexican military’s ongoing loyalty problems. The ATF alleges that, “90% of grenades traced in Mexico are over 20 years old.”

grenades_seized_2010But grenades walked by ATF’s cats-paw Jean Baptiste Kingery were used in 2013, along with other weapons which may or may not have been ATF-walked, to murder three officers of the Jalisco State Police in the village of Tepatitlan.  According to an ATF Significant Incident Report by liaison officer Jonathan Ortiz in the Bureau’s Mexico City office, one of ten grenades was attributed positively to Kingery by the Mexican officers, based on unspecified “evidence,” with no information on the other nine available.  Here’s the SIR:

ATF SIR Kingery Grenade 20131010.pdf

Within days of the SIR’s transmission, CBS had a story about it by then-CBS reporter Sharyl Attkisson (caution, autoplay video). It was kept off the evening news, but appeared on a morning show.

More grenades. In this case a mixed bag of reanimated M26 and M67, plus some GI M67s and 40mm rounds.

More grenades, seized by Mexican cops. In this case a mixed bag of reanimated M26 and M67, plus some GI M67s and 40mm rounds.

The history of the Kingery grenades is instructive. Kingery sourced his parts in the USA, then brought them to Mexico for final assembly and delivery. He was under ATF observation (although they thought he was under their control, a very different thing), from 2004 to 2010, when he made aliyah to his Sinaloa pals. He remains in Mexico; he was arrested there but ATF and DOJ has been remarkably uninterested in extraditing him.

The grenades, like the Iron River of ATF-sourced guns, were delivered to the cartels and to Mexico with the approval of Phoenix Group VII (SA’s Voth and McAllister inter alia), and the local US Attorney and an Assistant (Dennis K. Burke and Emory Hurley). The grenade-walking was also blessed by every layer of ATF and DOJ supervision. This included the Phoenix SACs and all management levels up to then-director Kenneth Melson and AG Eric Holder. Particularly responsible, apart from Voth and McAllister, were Phoenix field division SAC Bill Newell and Current Director Byron Todd Jones participated in the planning of the gun- and grenade-walking from his position in faraway Minnesota, as a trusted intimate of Holder.

The objective of the grenade-walking seems to have been to support the gunwalking; the intent of the gunwalking was to produce a series of crimes in Mexico that would justify new anti-gun laws and new powers for the ATF in the USA. The Mexican Government maintained plausible deniability on the operation. Several ATF agents pointed out the likely result: cops being killed in the USA and in Mexico, but those named managers were indifferent to the deaths; after Border Patrol officer Brian Terry was murdered by an ATF-furnished weapon, and first dozens, then scores, then hundreds, of Mexican lawmen were slain, David Voth was “giddy” over the bloodshed.

One wonders if Voth is still giddy, as more and more Mexican law officers keep getting deadened by his work product. (Like most gunwalking figures, except for Melson and Burke, Voth was promoted to HQ after the scandal broke).

How Do the Bad Guys Reload Grenades?

They start with training grenades. These grenades resemble the real thing, but produce a loud bang and a puff of smoke and zero fragmentation.  Because they have a fuze optimized to do that, no frag material (usually), and no filling. The grenades are reusable for training by simply discarding the old fuze and introducing a new one. To prevent too-easy conversion, and give the report of the fuze someplace to go, the training ‘nades have holes in them where the factory grenade has a thick welded-on or cast-in base plug. Training grenades also lack the internal fragmentation liner of most newer grenades (on the old Mk II “pineapple” grenade, fragmentation was supposed to be promoted by the scored lines, and the training grenade is similar to the frag, except for the extra bottom hole).

improvised_cartel_grenadesA normal defensive grenade like the M67, standard from the end of Vietnam on, has fragmentation material (often in a sleeve or liner) and a filling of high explosive (for an M67, Composition B). It has a fuze that contains a percussion cap and hammer mechanism to start the fuze train going, a delay element, and then a cap, gaine or booster which detonates with enough force to produce detonation in the relatively stable explosive filler.

The cartel-improvised grenades always lack the frag sleeve, and usually substitute black powder (or another easily manufactured low-explosive improvised filling) for the HE. (Technically, the difference between LE and HE is the velocity of the detonation front: in HE it is supersonic). As a result, they’re less effective than factory grenades, and are more like offensive grenades than defensive ones. A further result is that factory grenades are preferred to improvised grenades by most cartel sicarios. 

The following picture is from al-Reuters and was one of the illustrations used by the International Business Times in the story picked up by the DHS-DOJ Early Bird. Note that along with a Smith .357 and a Tec-9, this particular cartelitito, bagged in 2012, had nine M67s, three M26s, and eight Mk IIs. Oh, and an M72A2 LAW. These weapons appear to be almost all factory, not improvised (note the safety clips on the spoons of the M67s, something rarely seen on improvised ‘nades).

weapons-seized-zetas-cartel-reutersJust to remind everybody: Mexican law enforcement thinks this kind of thing is caused by the 2nd Amendment, and if we had the strict gun bans that they have, we’d live in a paradise, like they do.

Why Is It In The News Now?

If the cartels’ ‘nades are an old story, why are they in today’s news? For instance, in:

We don’t know for sure, but this sudden reanimation of an undead necrostory from years ago suggests that its battlefield prep by regulators, the administration, and their junior varsity in the media. It suggests an anti-dummy-grenade legislative or, more likely, regulatory initiative is in the works.

The ATF has eased its focus on gunwalking, but it’s never given up its desire for more authority. So you’ll see a spate of stories like those linked above, then editorial calls to unthinking action: Act Now! For the Children! They will certainly never admit that these criminals have these weapons (all, you will note, US military issue weapons) because the US furnished weapons to nations and insurgents with rotten inventory control, and definitely don’t want to mention ATF’s role in gunning up los sicarios. They are unlikely to give up their underpants-gnome theory of criminal organization takedowns, but are still stuck on the bit where the enhanced criminal organization commits more crimes.