Category Archives: Crew-Served

Tank Secondary Armament Through the Years

While we’re talking tanks — we’ve recently covered armor protection in WWII and rates of turret traverse, and the technical considerations that went into them — let’s talk a little about secondary armament.

Most tanks have had, since the 1930s, a main gun that’s primarily designed to fire anti-tank ammunition, but is also capable of firing high-explosive general-purpose shells, and secondary armament of machine guns. This has come to be accepted as the norm, but it wasn’t always so.

The first tanks deployed by the British Army in 1915-16 were laid out differently from modern tanks. Their automotive equipment (a Ricardo engine and drivetrain) was contained with most of the crew between the tracks, which wrapped around the periphery of the lozenge-shaped tank. Armament was exiled to sponsons which hung off the sides of the tank, outboard of the tracks. These tanks came in “male” and “female” versions, which was defined by their armament. The “male” tank had a small artillery piece in the front of each sponson, and a machine gun in the rear; the “females” had machine-guns all around and were intended to provide support against close-in infantry for the male tanks.

Later, Germany’s first real production tank, the Panzer I, was armed only with machine guns (initially, 2 x MG.13, later 1 x MG.34), as were some inter-war light tanks of Britain, America and Russia, and even the first version of the US M2 Medium Tank, America’s most important inter-war tank. But at the war’s outbreak, and through to war’s end, most tanks were conceptually similar to modern tank: a main gun, a coaxial machine gun that shared the main gun’s aiming systems, and one or more guns atop the turret for antiaircraft use. (One thing WWII tanks almost all did have, which now almost no tanks have, is a bow machine gun aimed by a crewman sitting beside the driver. This gun station was deleted from postwar tanks worldwide).

Secondary Armament Trends as Illustrated by the US Example

The trend in the 1930s and 1940s was for fewer machine guns. This photo from Aberdeen Proving Ground’s museum shows what we believe to be one of only two surviving M2 Medium Tanks (an M2A1). Apart from its primitive, riveted hull of face-hardened armor (a weakness that would persist into the early models of its replacement, the M3), you can see four of its seven fixed machine gun positions in this view.

OLYMPUS DIGITAL CAMERA

 

Each sponson, at the four corners of the fighting compartment, hosted an M1919 Browning machine gun. In addition, two more MGs were fixed to fire forward through the glacis — you see their places left and right of the national insignia. A co-ax in the turret brought the 1919 count to seven; with two AA machine guns added, which could be on the turret or firing through roof hatches in the main-hull fighting compartment, this late-1930s monstrosity could have nine MGs on board, plus the puny 37mm (1.5″) main gun.

Here’s an interior shot (from this page) of the back of the other surviving M2A1’s fighting compartment, showing the two aft sponson MGs, and one AA MG. These rear guns had a unique special-purpose application on the M2: they could be fired at 45-degree “bullet deflectors” above and behind the rear fenders, and would deflect the stream of bullets down — this was to help the tank to kill any infantry it rolled over in trenches.

m2a1int

Seven to nine machine guns are a lot of secondary armament, and one of the problems with that is that it required a large crew to run all the guns. The M2 required a crew of at least 6, although internet sources are all over the ballpark with claims from 4 to 9.

M3 with 6 of its crew in North Africa

M3 with 6 of its crew in North Africa

The M3 that replaced it (called “Grant” and “Lee” by the British, depending on which turret the tank had) had more firepower (a 75mm gun based on the old “French 75″ that was the cornerstone of American gunnery, set in a right-side superstructure sponson) and fewer machine guns (only 2, a co-ax in the 37mm turret and an MG in a small commander’s turret in US-turret versions or an AA/GP flexible gun with the British turret). It got by with a crew of 6 (UK) or 7 (US, adding a Radio Operator). And the M4, which had replaced the M3 by early 1944, went to war with only 3 machine guns (bow, co-ax, and AA/GP atop the turret) and a crew of 5.

There were real benefits to a smaller crew. These were primarily logistical. If you could save one man from a crew, you could get a bonus 16-20% more crews from the same number of recruits, and have to supply proportionally less water, food, and all items for which headcount is a cost driver, to any given number of tanks or tank units. But there is also a benefit in that a smaller crew makes for easier intracrew communication and coordination.

 

The colorful (if over-compressed in the archive.org copy) summer, 1941 propaganda video, The Tanks Are Coming, celebrates American tanks, and includes the M2 Medium; M2, and M3, Light tanks; and White armored scout cars. (Unfortunately, it’s too big a file to embed here, so we’ll just send you to the Archive.org page).

https://archive.org/details/TheTanksAreComing

Note at the 8 minute mark some of the simulators used to train tank gunners, including a sort of air-driven tommy gun and a “wobble platform” designed to make gunners proficient in firing the main armament from a tank moving cross-country. Later in the video, they show an incredible new vehicle, the “Blitz Buggy” — we’ve come to know it in the decades since as the Jeep!

You can see the M3 tank (in the version the British called the “Lee”) in the 1943 movie Sahara with Humphrey Bogart.

The Importance of Secondary Armament in Combat

While much of tank training and gunnery tables assume tank-versus-tank combat, much of armor strategy involves hitting the enemy with your tanks where his tanks are not. That’s where secondary armament comes to the fore. Machine guns are necessary in this tank-vs-enemy-logistical-trains and rear-echelon-units warfare; they are what takes a tank breakthrough of the enemy’s hard-shell combat line and turn it into a rout.

The next most important use of the secondary armament is in tank-vs-tank or combined arms combat, in keeping hunter-killer groups of infantry of one’s own and one’s unit’s tanks. In the Pacific, for example, both Japanese and American tanks were more likely to be lost to infantry attacks than to tanks or dedicated anti-tank artillery. Infantry methods of tank-killing ranged from prying a hatch open and shooting the crew to, later in the war, specially developed infantry anti-tank weapons with hollow-charge warheads.

Finally, the armor branch, perhaps because they are a more-technical crowd, less shy of innovation than the tradition-bound infantry, have been a proving ground for new machine-gun concepts over the years. Some, like the US M73 and M219, were complete failures, as was the attempt to adapt the M60 to tank use. But the M1 tank’s adoption of the superior M240 machine gun laid the groundwork for that gun to replace the M60 for the infantry, for which blessing every grunt ought to buy the next tanker he meets a beer.

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.

The “Proximity Fuzed” RPG that wasn’t

In Russia, the improved RPG-7 replaced the RPG-2 in 1961, but it took years for the improved antitank weapons to filter to the Soviet Union’s client states and it took even longer to get to Soviet-supported terrorists and insurgents, even the ones that the USSR recognized militarily, like North Vietnam. When the new AT weapon emerged, it was immediately a threat to American and Republic of Vietnam aircraft, especially low- and slow-flying helicopters.

Here’s the story of a Air Force special operations helicopter gunship pilot’s nerve-wracking experience, while covering a South Vietnamese Air Force recovery of a Vietnamese reconnaissance team. The RT came from TF3AE, the command that replaced Command and Control South in Vietnam. We draw the story from Fred Lindsey’s fantastic doorstop, Secret Green Beret Commandos in Cambodia. (We’ve mentioned the book before). You can find it on page 670-671, and it’s worth reading for the adventure of it, before we start discussing dry RPG facts.

03/26/71 Recon, TF3AE ARVN RT Rescued With Air Support by 219″ VNAF Kingbees and
20th SOS Gunships: AC CPT Charles D. Svoboda DFC (2OLC) with co-pilot LTC Harmon
Brotnov; AC CPT Jim Schuman SS.
The only details of this event are from the remembrance of CPT Svoboda’s and [his] DFC citation. In his written recollection he notes:

It was on my first week on the mission as an aircraft commander. My copilot was my brand new squadron commander, Lieutenant Colonel Brotnov, who was on the mission for the first time, and my gunners were this new “student” gunner and a highly experienced instructor gunner. Jim Schuman was flying lead, and I was flying on his wing. We were called out for
a team taking extremely heavy fire. We arrived at the location, and were briefed by the FAC on where the team was (we certainly don’t want to hit our own troops). We saw a very unfriendly situation, with a rather large landing zone, with the team on the south, and Charlie on the north. Unfortunately. Charlie was ensconced on a long, low ridge, overlooking the LZ and the team. We hated going below the enemy, as we could not fire upward through our own rotor blades. If we flew high, we were sitting ducks. If we flew low, with Charlie on a ridge, above us, we could only make short bursts of gunfire in his direction by banking the aircraft in the opposite direction, and raising the rotors above the path of our own minigun bullets.

Jim (Gunship lead) directed that we make an ‘aggressive’ entry, meaning that we would dive toward the LZ, and toward the enemy, firing rockets and miniguns at maximum rate of speed (4.000 rounds per minute). Jim was checking out a new pilot, allowing him to fly, and the new pilot lost the target, forcing his bird to cease-fire. He told me of this, and I told him that I still had the target, and would assume flight lead, so that he could then roll in on my rockets and become my wingman.

We made an aggressive dive, after which the FAC radioed “Cease Fire, you’re hitting the team.” We always feared this! Guns firing 4,000 rounds per minute each, along with rockets, can tear up a group of soldiers ferociously. And my new commander was my copilot!

I ordered both birds to cease firing, and we began flying “cold” passes over the LZ, between Charlie and the team. We did this several times, and I could see what appeared to be cigarette lighters flashing in the shadows on the ridge. I could also hear static on the radio, which we had learned was caused by the static field of many closely passing bullets. But we continued to hear explosions, with the FAC yelling for us to hold our fire. Damn it, we WERE holding our fire, and we were hanging ourselves out doing it. I spoke to Jim, and said we had better silence the ridge or it would silence us. He agreed, and despite the directives from the FAC, we shot the hell out of the ridge. But they were everywhere. As I cleared the LZ on one pass, below many of the trees, I fired a couple of rockets. One does not usually fire rockets so low, because there is no time to achieve stabilized flight, allowing one to aim. Therefore, they frequently zoom off into oblivion. But we had learned to “lob” rockets by pulling up on the collective just before firing. This would cause the rocket stabilizing fins to hit the air with an upward load, causing causing them to fly upward initially, then to arc downward because of the aerodynamic load on the fins.

My copilot appeared to be mesmerized by his first combat action, about as hectic as one could be. I called for him to flip the weapon selector switch from guns to rockets (they could not fire simultaneously, because the one trigger activated whichever weapon was selected for firing). He was frozen, so I had to take my eyes off the horizon for a millisecond and change the setting. This was hazardous because we were flying through the trees, dodging around the higher ones, trying to keep from being shot down. One minor mistake would be fatal for all. We tried to avoid passing over the same spot on succeeding passes, to keep Charlie from drawing a bead on us, but because of the ridgeline, we were forced to repeat ground tracks. We passed around one taller tree a couple of times, and I cursed the tree. On the following pass I fired a rocket to keep the bad guys’ heads down, and it knocked the tree down. Colonel Brotnov was flabbergasted, as was I. To this day I wonder if he really believes that I did that intentionally!

It turns out that the rockets into the team which were blamed on us were actually new shoulder-mounted Rocket Propelled Grenades (RPG’S) being fired at us as we passed over the LZ between the team. The original RPG’s were designed for light armor and infantry, and had contact fuses. This new version was designed for helicopters, and had contact AND proximity fuses. Luckily, none must have passed close enough to us to detonate, but many passed by us, exploding among the team we were protecting. A few also exploded in the LZ, causing the tall elephant grass to catch fire. The flames were about as high as we were flying, and were spreading out in ever increasing circles. On one pass over the LZ, when I passed through the smoke, the other chopper was coming directly at us, only about 50-100 feet away, with closure speed of over 200 mph. Luckily we both broke quickly and in opposite directions, and the gunner said he thought he could reach out and touch the belly of the other chopper. Finally, the firing from Charlie cut down, and we called the slicks to come in for a pickup.

We said they would have to wait awhile because of the fires in the LZ. All of a sudden the team ran THROUGH these very high flames, leaping into the smoking ash left by the expanding fire. The slicks came in, one at a time, landed in the smoking ash, raising a huge, black ashen cloud, and picked up the team. We escorted them out of the area. Then, as the slicks headed for home, Jim and I returned to the site, expending the remainder of our rockets and ammo on the ridge line.

CPT Svoboda was an Air Force officer, a gunship pilot in the 20th Special Operations Squadron. The “slicks” were Sikorsky UH-34s, obsolete piston-powered helicopters flown by the South Vietnamese Air Force’s 219th Squadron, “King Bees.”

A gathering of SF RT guys and their air support guys is always interesting, because the aircrews think the recon teams were nuts to do what they did, but the RT guys know the copter crews were nuts to come get them.

Now, this is a very stirring story of action and audacity. You can almost smell the shellbursts of the RPGs. Thing is: RPGs don’t have proximity fuzes. (There is a Chinese “airburst” round for use against infantry, but it bounces off the ground before it detonates, and it postdates the war). So why did Captain Svoboda think they did? It goes back to a fundamental difference between the RPG-2, or B-40 as it was known to most during the Vietnam War (from the Chinese export stencil on the ammo), and the improved RPG-7. The RPG has become one of the most universal systems in war; there’s even a US-made, Westernized version we provide to allies under MAP.

But the initial mass-produced version, the Ruchnoi Protitankoviy Granatomyot-2 (“Hand AT Grenade Launcher”), was a reusable improvement of the German Panzerfaust and like its disposable ancestor, its designers’ watchword was simplicity. Indeed, US Army intelligence manuals on the Soviet Army at the time described it only as an “antitank weapon of the improved Panzerfaust type,” and lacked any photo or sketch of it.

It had no optical sights, just a flip-up pair with a front bead and rear ladder. It was a straight tube with sights and a grip piece, no shoulder rest, blast shield or cone. The RPG-2 was made in Russia from about 1948 to 1961, and in China from about 1956 to about 1970. And — important from our point of view — the warhead, which showed its later Panzerfaust ancestry, had a simple contact fuze and no self-destruct mechanism.

The RPG-7 was introduced to the Soviet Army in 1961 and into the Vietnam War sometime in 1967 or 68, although it remained outnumbered by RPG-2s until the last, 1975, offensive. It had iron and optical sights and considerably improved range (we’ve hit stationary tank-size targets on the range at 800m; practical combat range on moving armor is probably half that). Most interesting for our present purposes, the PG-7 warhead has not one, but three means of initiation:

  1. Piezoelectric contact fuze in the warhead nose (“1″ in the illustration);
  2. electric contact fuze between inner (“2″) and outer (“3″) cones of the warhead;
  3. pyrotechnic timed self-destruct mechanism (“8″).

pg-7v_of_rpg7_sect

All three fire the charge (“6″) from its base, creating a Munro Effect jet made up of hot gases and the molten copper alloy charge liner (“4″). The self-destruct mechanism detonates the round if it hasn’t hit anything in five seconds, by which time the round has covered 900-920m.

rpg7 training aid

That’s what was happening to CPT Charles Svovoda, his copilot LTC Harmon Brotnov, and his wingmen and the other US and RVN airmen on this mission. Airbursts of RPGs around them certainly seemed like the proximity fuzes they knew from enemy 37mm and 57mm anti-aircraft artillery.

It is possible that the airbursts’ threat to the rotorcraft was coincidental, but it is also possible that the NVA were deliberately using the self-destruct mechanism for its airburst effect; this is something Islamic terrorists would develop into a fine art in the nineties and the oughts, but it would certainly be consistent with what we know of the leadership and initiative of the North Vietnamese forces that they could have been doing this 20 years earlier, over Cambodia.

We can’t blame them for thinking they were facing “a new version, made for helicopters.” In any event, we concur with Fred Lindsey, who wraps up this post by quoting the citation for Svoboda’s Distinguished Flying Cross from this flight:

He was participating in aerial flight as a UH-1N helicopter Gunship Commander near Due Lap, RVN …CPT Svoboda made repeated firing passes at low level in support of a long range reconnaissance patrol which was under heavy opposing automatic weapons fire deep in hostile territory. The extremely accurate and devastating firepower from CPT Svoboda’s helicopter allowed the rescue of the entire patrol…

per Hqs 7th Air Force Orders dtd 09/24/71.

Captain Svoboda survived the war; along with the DFC, he received 10 Air Medals for combat missions in 1970 and 1971.

For more information on the RPG, look at this previous Weaponsman post, or this quite excellent history by Dan Shea in Small Arms Defense Journal. We cannot overstate the quality of the Shea article; it’s really good and accurate.

The Best Example of the Worst US Machine Gun

Technically, this isn’t exactly a US machine gun. Although it’s true that this French-made light machine gun, commonly called the Chauchat, was issued to the American Expeditionary Force when it arrived in France. It was probably the first machine gun ever designed to be manufactured cheaply and rapidly using stampings, sheet metal and steel tube, and simple screw machines with the barest minimum of time, and set-ups, executed on traditional lathes, shapers and milling machines. Many of the automotive industry techniques that were applied to the Sten and the M3 grease gun were not yet available in 1915, so the manufacturing technology that went into this gun is even more remarkable.

Chauchat 1

The evolving conventional wisdom is that the 8mm version was not all that bad; the true disaster was the American attempt to Bubba it to fire the .30-06. But the bad reputation of the Chauchat ensures one thing: you can get an example for quite short money for a transferable machine gun. This excellent-condition example is the best we have seen, and it’s on GunBroker right now with a buy-it-now of $7,500!

That is a bargain for a transferable, historically significant machine gun, and right in time for the centennial of the Great War. Here’s the other side, just to prove we’re not showing you the star’s best side:

Chauchat 2Now, the beauty of the Chauchat is kind of an acquired taste. It’s pretty rudely functional, in a way that few polished, blued, walnut-stocked service weapons of the day were. That’s one way in which this old poilu is a harbinger of modern times. But it was an early example of a shoulder-fired, bipod-equipped, single-gunner (with one a/gunner making a crew of 2) light machine gun.

The Chauchat, called by its reluctant doughboy operators the “Sho-Sho Gun,” was formally the Fusil Mitrailleur Modele 1915 C.S.R.G. from the initials of the members of the committee that brought it forth. Mechanical engineer Col. Louis Chauchat and hands-on machinist Charles Sutter were the designers; Paul Ribeyrolles wasthe production engineer who prepared it for industrial mass production, and Gladiator, Ribeyrolles’s velocipede and motorcar factory in suburban Paris, was where the bulk of them were manufactured (a second factory came on line late in the war).

The Mle. 1915 was a revision of a 1907 Chauchat-Sutter design that was manufactured by more traditional methods. While France only built 100 of the Modele 1907 C-S, zero of which survive, they were able to produce hundreds of thousands of the 1915 CSRGs in two converted automotive plants, enough that they had them to spare for their Allies like Belgium and the USA, and a Chauchat diaspora carried the guns as far as Russia and Greece after the war.

It is a long-recoil design, which means that the bolt and barrel remain locked until the assembly has recoiled the entire length of the cartridge — for the 8 x 50 Lebel, 70mm or about 3 inches — and then the barrel returns forward when the bolt is held back. The empty is ejected from this rear position, the feed system (here, a 20-round, half-moon curved box magazine) pops up a fresh round, and the arrival of the barrel forward trips the release of the bolt, chambering and firing (if the trigger remains depressed) the next round. This is the system of the Browning Auto-5 shotgun and the Remington Model 8 rifle (essentially Browning’s rifle version of the same action), but the Chauchat is the only successful application to automatic weapons that we’re aware of. (This is the point in the article where Daniel E. Watters is invited to correct us if we’re wrong!). Recoil is boosted by the conical booster that many have mistaken for a flash hider; it’s actually there for the same reason the MG42 has a similarly conceived muzzle attachment. The long recoil action yields long movements of heavy parts, and therefore, potentially more dispersion than comparable weapons, at least partly offset by a lower rate of fire.

This brief video, from our friends at Forgotten Weapons, shows you the cyclic rate of an 8mm Chauchat.

The bizarre half-moon magazines, unique to the Chauchat, were required by the rimmed 8mm Lebel cartridge, which is dramatically tapered: 16mm at the rim and 8.3mm at the case mouth. Some people have concluded there is a solid type of magazine (see the one in the gun on the left side picture), and another version with large cut-outs, but in fact, all mags we’ve seen have one smooth side and one cut-out side. We don’t know whether the cut-outs were meant to lighten the mags or to allow round counting; We do know it was a rotten idea for a gun used in the gooey muck of trench warfare. But at least one intended employment of the CSRG was as a lightweight gun for aerial observers, where your fate was more likely to be a long fall, or burning to death, than mud, trench foot and typhus.

This example is also extremely well accessorized, with AA sights (visible on the gun and a spare set in the accessory shot below), and spare mags and carriers. It hasn’t been fired in years, but the seller says it worked when it last was put to the test.

Chauchat 3

The starting price of the auction is $5,750, but there’s a reserve. As mentioned above, the Buy-it-now is $7,500. Here’s the seller’s blurb:

This is a splendid condition Chauchat with numerous accessories. 8 m/m Lebel, C & R and fully transferable. Model of 1915 by C.S.R.G. 5 Magazines, Anti-Aircraft sight installed, spare set of anti-aircraft sights, very rare musette magazine bag, even more rare wooden magazine case, bipod, original sling. Can supply about 1000 rounds of ammo with gun, extra price. This is a high quality Chauchat that when last fired about 8 years ago, ran like a top. Even with English manual.

It’s really a rare chance to add a museum-worthy, historically significant firearm — the wellspring of all light machine guns and squad automatic weapons! — to your collection.

Of course, if you’re inspired with desire for one of these unusual French ticklers, but shrink from spending quite so much, there’s a less minty Chauchat that Ohio Ordnance is offering for a starting bid of $4,500 and no reserve. Certainly the minty one is the better investment-grade gun.

The seller of the minty Chauchat, WDHaskins, has quite a few other enticing rarities, including a 1909 Hotchkiss Portative (English Army version of what the US called the Benet-Mercié Machine rifle, a Japanese Lewis aerial observer’s gun, and a really nice collection of English double guns — shotguns and rifles. This link goes to all his current auctions.

 

Physical Security: 6 Facts about Safes

vault-door-family-imageHaving just been through the rodeo of safe-buying, and about to do it again, we came away with some wisdom we’re willing to share with you. If you learn from our pain, you will experience less of your own when you do this, so we’re putting it out there.

  1. An expensive safe is usually better, but a cheap safe now beats a perfect safe in the indistinct future.
  2. The best safes aren’t “gun” safes, but commercial safes that might be too heavy for your floors.
  3. A safe that can be walked off with is not a safe, it’s a gift basket for your burglars.
  4. How you install the safe is as important as the safe itself.
  5. Electronic locks are a single point of failure.
  6. All safe manufacturers lie about their products’ capacity. A lot.

Also: customer service counts, and it might not be where you expect to find it. Make sure you know, in muscle memory, the combination. And once they’re locked up inside, don’t put your guns out of mind. We’ll also tell you which accessories we like best.

An Expensive Safe is Usually Better, But…

If you have no safe now, go out and buy the biggest one you can reasonably transport, and then come back and read this article. Very cheap safes don’t seriously deter or slow down burglars, and provide minimal fire protection. There are ways to save money on a safe. For example, summertime is usually good, as dealers have incentives to move last year’s model. Craigslist can be a source of old safes, but most of the safes we’ve seen there are home-store junk. Some brands make only junk. For example, Stack-On sells nothing but crap under their own name. They make higher quality safes under house names for some sporting-goods chains, like the anti-gun gun store, Dick’s (Dick’s brand is “Field and Stream 1871″. These are Stack-On safes, but better built than the ones Stack-On puts its own name on).

An old jewelry-store or bank safe can sometimes be found at business supply store or antique shops. These may or may not provide the burglar and fire security one hopes to gain from a safe, but in most cases will actually be better than a new “gun safe.” To understand why, read this website: http://gunsafereviewsguy.com/.

The Best Safes Aren’t Gun Safes.

Two things have been driving the design of gun safes for years: relentless competitive pressure to lower prices, and customer demand for more volume and lower weight. This adds up to thin sheet metal safes that burglars can brute force in minutes. The commercial safes that jewelers, for example, have long relied on, provide much better security. But a long-gun-sized one may be hard to install in a home — their weight can be reckoned in tons.

A Safe That Can Be Walked Off With isn’t a Safe.

Imagine you’re a burglar, and you are looking through YOUR house for whatever can most rapidly be turned into the largest quantity of heroin and meth. (The last thief to steal to feed an orphan was Jean Valjean, and he’s a fictional character. Since then, thieves steal to stay stoned, and because they’re too lazy to work). A burglar that finds a safe is sure he is having a happy day. IF that safe can be physically removed, that’s what he’ll do with it, to work on opening it at his leisure. There are several ways to make sure the safe is still there when you come home:

  • Make it heavy. Your typical burglars work solo or in small crews. You do not want a safe that three men can remove, loaded, using the tools available in your building and grounds. They may be stupid but they’re sly and cunning and very creative when it comes to the TTTPs of stealing. So on top of the weight of the guns, some heavy weights (for example, discarded gym weights) in the bottom of the safe can complicate the burglar’s target solution.
  • Anchor it down, and make it impossible to get a pry bar in, attack the sides, or knock over the safe. More on this in the next item.
  • Welding is your friend. Three safes in a row? Tack ‘em together. Just one? Put it on two eight-foot sections of railroad rail — and weld it to ‘em. Now they have a safe they can’t get out the door, unless the burglar is also a dab hand with your welding/cutting gear.

Remember, the strength of the safe is in the time and effort burden it imposes on a burglar (and the time and temp resistance it offers a fire).

How you install the safe is as important as the safe itself.

Just about every gun safe on the market comes with a couple of bolts and instructions on how to bolt the safe to the concrete floor of your basement. Hardly anybody does that. That’s a mistake. When you bolt down the safe, you limit the burglar’s options. He now has to break it in situ, or give up.

Your installation can also create other limits or complications to his ability to remove or attack it. Corners are good because he now can attack only two sides. Installed in a narrow passageway (or maybe one created by two facing safes), he now can’t get a very good mechanical advantage with a lever. This also limits his ability to attack it in situ. Burglars are lazy men; otherwise, they’d get a better living by working. So keep any or your tools that might help them break in well out of sight of the safe.

If your collection will not fit in one safe, consider multiple safes in multiple locations. Burglars know to hit certain locations first — like the master bedroom and associated closets.

Finally, there’s camouflage, concealment and deception. Given the size of the typical gun safe, and the need for regular access, any sophisticated concealment is not an entirely practical option for most people, but at an irreducible minimum you do not want your safe visible from a window. When we’re going to be away, a parachute canopy goes over the banks of safes, and moving boxes full of papers and old clothing are stacked in front of them.

Our deception plan includes a small, man-portable safe that contains nothing of value.

Electronic locks are a single point of failure.

These are currently trendy. They were, and are, a bad idea. The better-designed ones fail closed and lock you out of the safe; the worse-designed ones fail open. But sooner or later they all fail. The mechanical lock will fail, too: when it wears out, in 1000 years’s worth of opening. It won’t be your problem then.

What happens when your e-lock fails closed? You call a locksmith or safe-smith and he comes expensively to your premises and drills the safe open. If the safe has the latest anti-theft features, it’s irreparable at that point; if it’s a little more old-fashioned, it can then be repaired. At even more expense.

You don’t want other electronic gingerbread like power outlets, AC-powered lights (battery LED lights are OK, put the batteries on a replacement schedule) or powered dehumidifiers. You don’t want anything that requires a wire to go through the perimeter of the safe. (Where wire goes, fire goes).

All safe manufacturers lie about their products’ capacity.

If you have 16 guns, you think an 18-gun safe gives you room to grow. But that’s because you’re unaware of how safe manufacturers figure guns. In their world, long guns have no scopes, magazines, or bolt handles. You can get 32 guns in a 32-long-gun safe if they’re 32 H&R Toppers (single shot break-action shotguns). If they’re anything else, rotsa ruck. An “18-gun” safe is probably good for 8 to 10 guns. As a rule of thumb, deflate the manufacture’s claim by 50%.

Capacity isn’t all that the manufacturers lie about, either. You’ll notice that no gun safes have a GSA rating, and very few of them have an Underwriters’ Laboratories rating. That’s because the manufacturers don’t submit them to testing. This may be because the testing is expensive, and few buyers look for these certifications.

But it may also be because the manufacturers know their safes would not pass the stringent GSA or even the looser UL standards.

Some Closing Comments

We went to Famous Shooting, Hunting and Fishing store, complete with a pickup and tie-downs, for a safe.  We didn’t want to buy something so major online, and the store offered attractive discounts on last year’s safes. We thought for sure we’d be better off with this place’s renowned customer service. But that was not the experience we had.

In fact, on a slow weekday, in a store teeming with workers, we couldn’t get anyone to talk safes. “Not from here, it’s that department,” they offered with a desultory wave in no particular direction. After talking to four workers and a manager, we concluded they just weren’t in to selling the $2k safe we’d selected, and we went elsewhere. (And bought a less expensive safe, in keeping with Fact About Safes #1 above). Remember: secure enough and now is better than loose now and more secure next month, maybe.

There are ways to recover a lost combination, assuming your safe maker stays in business. But the best way is not to lose it, and the way to do that is to drill it into your muscle memory. All of the Schools of Education in the USA insist that drill is unnecessary and kills motivation; all of the football coaches at those same schools’ universities insist that only by drill does learning become real. Who has the better of it? Simple to answer, is a typical state university better known for its Ed.D output, or its team’s gridiron performance? So practice with the combination until you get so your fingers work the lock intuitively. (This gets harder to do when you are older, and have lots of safes). Then, open and lock the safe frequently to make sure you don’t forget. You should be doing this to inspect the firearms, rejuvenate moisture-removing silica, etc, at least weekly.

Accessories we have found useful include a canister of silica (you can refresh it by baking out the moisture, using your kitchen oven) and battery-operated LED lights. Many other accessories are crap.

The whole point of a safe or safes is to keep your property safe (what else?) and secure. A good safe should cost you about what a year of homeowner’s or renters’ insurance goes for. And keeping your guns out of criminal hands might just save a life.

Haunting video of Japanese World War II Tanks

Some of them have been reclaimed by the jungle. Some, shattered by American fire. Some, parked in rows and left at war’s end. Some lie where salt water is reducing them to iron oxide day by day. Most of them have been looted, and some defaced by graffitti.

You may find the new-agey music with its Bolivian wind instruments and whatnot fitting, or you may like it. Personally, we’d have gone with something with traditional Japanese instruments, but then, we’re not making the video,it churlish to squawk about the decisions of the guy who actually made it.

The split, shattered armor of some of the tanks is mute testimony to the fate of the crews. Most Japanese families have a story of men who went to war, and whose fate is unknown, except that they did not return. Apart from a few prominent war criminals who faced the gallows at war’s end, the price of expansionist Japanese militarism was paid mostly by conscripted private soldiers on all sides.

Japanese tank technology was about where European tank tech was in the years running up to the war. The Japanese were engaged for a decade in China before taking the USA on, and their tanks, based on 1920s Vickers designs (which were world-leading at the time) and similar to English, Italian or Russian machines of the era, didn’t need much improvement to be effective against Chinese infantry and cavalry forces.

Most of them were only equivalent to the early-war US M3 Stuart light tank, if not outclassed by it. The best common Japanese tank, the Type 97 Chi-Ha, was outgunned and outarmored by the American M4 Sherman, a tank that was marginal in the ETO. It also didn’t help the warriors of Nippon that they had few anti-tank guns, and those were of inferior calibers. Lacking the evolutionary pressure of the tank battles of the ETO, Japanese tank development stagnated. Had the Home Islands been invaded, they’d have been helpless against Pershings.

They’d have rolled out anyway, fill of fight and Yamato damashii. It’s just as well that war was never fought. How many of those doomed tankers went on to have creative jobs and happy families in the postwar State of Japan?

The Japanese forces, scatttered across specks of islands in the vast Pacific, fought with immense bravery, but struggled always with logistics. The reason many of these tanks were captured intact is not that the Japanese ran out of fight, but because they ran out of fuel and/or ammunition.

 

On this Day in 1962: Infantry Nuke Test

The USA fired its last above-ground nuclear test at a test site in Nevada on this day, 17 July, in 1962. The operation was a culmination exercise that brought together nuclear warhead tests (code-named Little Feller, as a nod to the W54 warhead’s light weight and low yield) and nuclear weapons employment maneuvers code-named Ivy Flats.

Screenshot 2014-07-17 12.50.48

The test was a pretty-much full-spectrum test of an actual tactical nuke, and a very unusual one — a nuclear infantry weapon called the Davy Crockett. A lot of tripe is written about the Davy Crockett, including that it could not fire a projectile further than its blast radius, but most of that tripe is written by people who either apply unreasoning fear to all nuclear weapons (something that was encouraged during the Cold War by the Soviet Union and its witting and unwitting agents of influence), or by the sort of uninformed juicebox mafiosi that become “national security” writers for Wired. Even more-respected anti-nuclear campaigners often got it wrong, like some of the details on this basically solid page at the Brookings Institution. In fact, this test demonstrated that the weapon was safe, within its limits, and effective.

After many rehearsals, including a live-fire of an actual warhead suspended three feet above the ground (Test Little Feller II on 7 Jul 62), a Davy Crockett crew fired their weapon at a simulated enemy force 2,852 meters distant. They launched the projectile in front of trench-covered friendlies and — much further back — bleachers full of observers, including such VIPs as Robert F. Kennedy (then Attorney General) and Army Chief of Staff Max Taylor. (This test was Little Feller I, even though it was 10 days after Little Feller II). The weapon functioned flawlessly. Within half an hour, military units advanced through the blast zone. The entrenched troops were 1600m from the detonation; the Army calculated that the low-yield W54 would produce immediate casualties from radiation only within 250m, and delayed casualties only within 350m, of its impact point. These radiation effects were much more long-ranged than the heat and blast effects of the .02 kiloton warhead. A tank 100m from detonation would be usable, apart from the effects of radiation, which would have killed its crew.

Here’s a video of the test. We tried to find the original because this one has too much compression and a lot of video artifacts, but sometimes you have to take what you can get:

The actual burst is at about the half-way point, about nine minutes in. Other reports suggest that its yield was later calculated to be 0.018 kt, a little lighter than the 0.022 produced by the confusingly earlier Little Feller I test. As none of the surviving documentation suggests that this yield variation from the nominal 0,02 kt setting upset anyone at the time, it suggests that variance of plus or minus two-thousandths of a kiloton was considered nominal.

It’s interesting to see the other equipment the troops, from the 4th Infantry Division then at Ft. Lewis, Washington, have: Garand M1 rifles, M48 tanks, a Hiller UH-12 helicopter.

The Davy Crockett was actually an ingenious weapon, and for its time, an effective one, if only psychologically. How effective? Decades after it was retired, it was still taught to Soviet tank officers as a battlefield threat to be feared and targeted. When the weapon was withdrawn (due to further miniaturization allowing longer-range and more-accurate delivery of tactical nukes), the GRU managed to convince itself, and the Soviet General Staff, that the withdrawal was all a ruse by those perfidious Americans.

Here’s how it worked: the DC came in two versions, the M28 and M29. The “light” DC had a 2000 meter range, and the heavy 4000 meters. The caliber of the main recoilless gun was different: 120mm versus 155 mm, and even the caliber of the spotting gun, which was used to check trajectory before firing, differed: the “light” Davy Crockett has a 20mm recoilless spotting gun firing the M101 spotting round, and the “heavy” had a 37mm. Because the gun was recoilless, it and its tripod could be light. Both versions could be carried by Jeep or M113 Armored Personnel Carrier, and the M28 could be broken down into manpack loads (if heavy ones) and carried by its own crew.

davy crockett jeep

When XM101 spotting rounds were found in Hawaii, the media went haywire. Typical of the products of their “layers and layers of editors” was this graphic.

davy crockett

What’s wrong with it? Count the legs on the tripod.

The projectile, the M388, was roughly the size and shape of a prize watermelon, and could contain conventional explosives or a W54. It worked with both guns because it was a “supercaliber” projectile. (Imagine a watermelon-sized rifle grenade). A different piston was used in the smaller and larger guns. They also fire two non-nuclear (or simulated nuclear) Davy Crockett rounds.

A war in which battalion commander had their own nukes would have been… interesting. Army planners expected the US warhead stockpile to grow to over 150,000 warheads to support their Pentomic Division warfighting scheme. (That was about five times its actual 1967 peak).

The dummy version was of the M388 the M421. Almost all surviving documentation shows these weapons as non-type-classified, “XM” weapons (i.e. XM388, XM29, etc).

FM23-30-Davy-Crockett-warhead

Authority to deploy the Davy Crockett was devolved almost as low as nuclear weapons commit authority ever got: the battalion commander had full authority to use the weapons as he saw fit, once a general release was granted.

Most Davy Crockett launchers were allocated only one or two warheads, plus several conventional high-explosive ones; this was because the system’s survivability on a tactical nuclear battlefield was somewhat constrained. It had to be fired within field-gun and mortar range of the targeted enemy (4,000m max), it was an unprotected weapons system, and it was

The launch produced a considerable backblast, and would have exposed the firers to enemy retaliation. This gave a small advantage to the light weapon, which was usually fired from its jeep. The heavy weapon had to be dismounted from a charmer personnel carrier or truck and fired from the tripod every time. Then, after exposing its position, it would have to be reloaded before the crew could skedaddle.

The Davy Crockett had a short service life; it was an interim weapon before warheads could be miniaturized into standard gun artillery weapons.

Because the M101 spotting rounds contained depleted uranium, which is now managed as a hazardous material, we’ve learned that 75,318 rounds of spotting M101 were produced. Some 2000 were expended in lot qualification tests at the factory, 44,000 were destroyed by firing into a containment after the weapon was scrapped, and a max of 29,000 were fired from the deployed launchers at a variety of field sites. Apart from the Ivy Flats/Little Feller I test on 17 Jul 62, no Davy Crockett was ever live fired. (There were warhead live tests earlier, during development).

Both versions of the Davy Crockett used the same projectile, the M388.

At the end of FY 62, the USA had 25,540 operational warheads in its stockpile, and growing. About 2,900 of them were Davy Crockett warheads. At the end of 2013, we had 4,804 total warheads, and shrinking. Among the entire classes of nukes that were eliminated were small-yield nukes like the Davy Crockett warhead, and battlefield nukes — like the Davy Crockett warhead.

The old V3-position of Hermes-Lampaden

V3 luxemborg

This appears to be of the Ardennes type but it may have been a test unit in Miedzyzdroje, Poland.

One of the most interesting weapons of World War II was the V-3, the little-known third Nazi “vengeance weapon.” It was an ultra-long-range cannon that used multiple breeches or powder-chambers, fired in order as a projectile shot down the barrel, right as it passed each chamber, to overcome the limits of standard artillery. It fired a subcaliber “arrow-shot” (Pfeilgeschuss) and was expected to hit London, accurately, from mainland France.

A site at Mimoyecques, France was the main location for the V-3. Over fifty tubes were planned for this weapon at this site, but the site was destroyed by bombardment by the RAF, using gigantic Tallboy bombs. As a result, the V-3, the “London Gun,” never fired a shot at England.

A German-language web page on the V-3 site at Hermes-Lampaden adds to our knowledge of this odd weapon’s history, because the Hermes-Lampaden V3s were fired in anger, at the allied-held city of Luxembourg. The website provides us with a launch pad to look at this weird weapon.

In 1942 engineer August Coenders, Chief Engineer of the Röchling firm, began to research the idea of the multi-chamber cannon, an idea in existence since the 19th Century. With the multi-chamber cannon principle, side-mounted propulsion-charge chambers were added to a cannon barrel, chambers whose propulsion charges were detonated after the projectile had passed them by, and which therefore brought higher velocities.

Coenders developed a multi-chamber cannon in 1942 under the cover name “High Pressure Pump. Soldiers nicknamed it, due to its unusual form for a cannon, “Tausendfüssler” meaning “Millipede,” or “Fleißiges Lieschen”, meaning, approximately, “Busy Lizzie.” The Nazis named it, in their taxonomy, V3, for the third operational “Vengeance Weapon.” The maker of the barrel sections for the piece was the firm Röchling Steel Works in Völklingen, Saarland, with finishing (final machining?) at Wetzlar.  The arrow-shaped, two meter long projectiles (150 mm caliber) which were designated “Rö Be 42″ were also developed by Röchling.

via V3-Stellung bei Hermeskeil-Lampaden.

Coenders developed versions of his very long, fin-stabilized sub-caliber shell for conventional artillery also — his big idea was to increase penetration by increasing sectional density, and it can be argued that his research led, after the war, to the common APFSDS (Armor Piercing Fin Stabilized Discarding Sabot) round that tanks these days fire at enemy tanks.

The V-3 version of the Coenders round weighed 40 kilograms, of which 7-9 were explosive. It was 100mm with fixed tail fins and used front sabots and a rear sabot/obturator to fit in the HDP’s 150mm bore. The round left the muzzle at about 1050 meters/sec (3445 fps), almost instantly shedding its sabots, at least according to the drawings. Other sources suggest that the round barely broke 3,000 fps in combat applications).

v3ammo

The Mimoyecques installation was destroyed by the RAF’s legendary 617 Squadron in July, 1944, and then soon afterwards overrun. But as the site explains (in the German; translation is ours with notes [in brackets], or you can try the goog thing):

After the Allies captured the Channel coast near Mimoyecques in September 1944, the plan to bombard London with up to 50 HDPs from the bunkers had to be abandoned.  SS-Gruppenführer [~Colonel] [Hans] Kammler, to who the Vengeance Weapons detachments were subordinate, wanted to prove the combat suitability of the V3 beyond question, and sought from Hitler the permission to employ the HDP against the City of Luxembourg during the Ardennes Offensive [Battle of the Bulge].

To this end two shortened versions of the HDP with the designation LRK 15 F 58 (Langrohrkanone) [Long Barrel Cannon] were emplaced in Ruwertal near Hermeskeil-Lampaden. They were put into action by the Firts Battery of the Army Artillery Detachment 705. [This unit was an independent artillery unit that was under the command of the Kammler-controlled Vengeance Division (Division zur Vergeltung)]. The emplacement of the first gun took from 28 Nov 44 to 23 Dec 44, the second needed a little more time. Two steel guns were erected, which were positioned on a wooden substructure. The wooden substructure was half buried in the slope. The barrel elevation was 34°. This shortened version of the High Pressure Pump was no more than 50 m long and was fitted out with 12 side chambers attached at right angles. The cannons had a range of up to 60 km with a dispersion of up to 4 km.

That’s a pretty large group; an online angular size calculator tells us it’s 3.8 degrees, or 229 minutes of arc/angle. We suppose that if your target is, as was the norm for V-weapons, “minute of major metropolitan area,” that accuracy was acceptable.

The Mimoyecques guns had been meant to be 150m long and range 165km; the whole battery was supposed to be capable of firing 300 shells an hour on London. One gun intended for Mimoyecques provided some parts for both Hermeskeil-Lampaden guns, except that the Mimoyecques guns had the auxiliary chambers aligned in herringbone fashion, and the H-L guns had them set orthogonal to the gun’s bore.

The H-L guns, illustrated in this 26 Nov 44 drawing, were set at 34º and were made up of 13 straight sections and 12 cross-sections (where the chambers attached), and they hoped to deliver 3-4 shots per hour.

V3 plan

The V3 bombardment of Luxembourg was irritating and frightening, but of no military consequence. The pair of V-3s fired a total of 183 rounds, of which only 44 were confirmed as hits in the target area.  It’s uncertain whether it was the rounds on target, or the 139 that landed somewhere off target, that killed 10 people and wounded 25 — a pretty pathetic result. The guns were dismantled in February 1945 when the Germans withdrew from the area; the second gun was not taken out of action until the US Army was closing in. In 1945, parts of four HDPs were found at the Röchling plant, and removed to the USA for testing. They were subsequently scrapped.

Here are some links in English on the V3: