"Tank Destroyers" Topic

the Tank Destroyers had a doctrine of containing and destroying enemy tanks after they had broken through the infantry line.

From what I've read, that was also the German and Soviet policy as well. The "pak front" (main line of anti-tank guns) was set up well behind the front lines, out of artillery range of the enemy. The job of the infantry in the front line was, with artillery support, to strip the attacking infantry from the attacking tanks, so that any tanks that broke through would encounter the AT guns without infantry or artillery support.

Mark;

I think Don Lowery has answered the key question as to why there was no push by the infantry to upgrade AT guns, they had become all but superfluous by the time the of fighting in Northwest Europe. And the reason they were not needed was the attachment of the independent tank battalions on a regular basis to US infantry Divisions. You mention the TD battalions and the US tank divisions but not these workhorse units.

AT guns can be valuable on defense when one has the time to adequately deploy them or where a unit has been on the defense for a period of time. Otherwise they become rather cumbersome. It was not unusual, when an infantry division took casualties, to take personal out of the AT gun units and use them as replacements.

Army FM 17-33, 19 December 1944 codified the mission of these units. Among their roles were:
To support by direct fire the advance of light tanks, other medium tanks, and ground troops.
To serve as a reserve for exploiting a success or breaking up a counterattack against the supported unit.
To fight enemy tanks when necessary.

I highly recommend Harry Yeide's "Steel Victory" as a good, compact discussion of these units.

The infantry didn't want the antitank guns they already had: by late '44 they were disbanding the 57mm platoons and turning them into riflemen across many divisions.

Artillery and lots of it was what the US Army had in spades, and pretty good and breaking up German armored assaults. The towed TD's proved an expensive waste as they were so easily outflanked (e.g. as at Stoumont): unable to quickly withdraw or redeploy, they died where they stood. The era of the towed antitank gun was over.

What the infantry did want was a more effective shoulder fired weapon which didn't arrive in any numbers until the shooting war in Europe was over. YouTube link

What the infantry did want was a more effective shoulder fired weapon which didn't arrive in any numbers until the shooting war in Europe was over. YouTube link

How are we to relate the statement to the video in the link?

Is the suggestion that the M20 75mm RCL gun was "a more effective shoulder fired weapon" for AT work?

It is true that deployment of the M20 did begin at the end of the war. But it was not a shoulder-fired weapon. Weighing in at something more than 100 lbs, it was not even considered a man-deployable weapon. Also, its anti-armor performance was not significantly different than the 2.36in bazooka. In the Korean war, both the M20 and the bazooka were considered ineffective against the T-34. I find it hard to believe that the M20's reputation against late-war German armor would have been better.

The M18 57mm RCL gun was man-portable and could be shoulder fired. But it's anti-armor performance was less than the bazooka. I doubt it would have earned fans in an anti-armor role.

The US Army's best shoulder-fired anti-tank weapon of the end-of-war period was the M20 3.5in "Super" Bazooka. But this design, while completed at the end of the war, did not go in to production until the Korean war.

-Mark
(aka: Mk 1)

No Mark, the suggestion is what they were looking for was smaller, not bigger along the lines of the panzerschreck, not the Pak43

I think you might have confused the 57mm RCL which was indeed inferior to the Bazooka with the much more effective 75. Not considered man deployable? The standard ground mount was the same tripod used by the Browning M1917 machine gun!

Yes, it's a heavy beast to schlepp around, but a heck of a lot lighter and easier to conceal than the 3 inch M5 or something preposterously bigger! Not to mention being air portable without needing it's own dedicated glider aircraft.

I'm pretty sure have a 20 pound HEAT projectile smack into your armor plate is going to do more than scratch the paintwork.

link

The infantry didn't want the antitank guns they already had: by late '44 they were disbanding the 57mm platoons and turning them into riflemen across many divisions.

This is true.

But in reading accounts from the time, one comment that seems to travel with the accounts of re-assigning the AT Gun crews was that the US 57mm AT gun M1 was considered nearly useless against German armor anyway, so re-assigning the gun crews to be riflemen was getting some use out of them.

There was no push on the other direction, to get a more useful AT gun for the infantry. Rather, there was push to use other assets to provide AT defense for the infantry. The reaction to the M36 tank destroyer illustrates this point. The appearance of this vehicle was VERY well received by division commanders, as it finally gave them a tool that could stand up and trade blows with Panthers and Tigers. That tactical approach, standing up in the line and trading blows, was what the infantry wanted. But it was exactly what the TD board did NOT want. And quite frankly they would have been better off with a towed AT gun if they wanted something to stand and trade blows … the 90mm gun of the M36 indeed had enough penetration to take on Panthers frontally, but it did not have enough armor to withstand much in the way of return fire. An towed gun would have been both more effective and lower cost as a solution to stiffening the line.

AT guns can be valuable on defense when one has the time to adequately deploy them or where a unit has been on the defense for a period of time.

From 1939-1942 the Germans demonstrated again and again that towed AT guns could be used aggressively as part of the advance in mobile/maneuver warfare. They provided the base of fire around which other units maneuvered.

The British experience demonstrated it clearly. Some within the British army called it out, but the Army overall seems to have had trouble digesting the implications. British armored commanders screamed for two years about how they were out-matched by the Panzers, when it was in fact the AT guns that were doing most of the killing. British tank designers took a LONG time to get the message that a good HE round would do more to improve the success of their armor than anything on the AP front.

The US Army came to recognize this in Tunisia. That's why the towed tank destroyer formations were formed. But the gun they created for this role, the 3-inch M5, was 1,600 lbs heavier and 2 1/2 feet taller than a Pak 40. It was totally out-sized for it's performance, and would have been quite impossible for the infantry to use. A better gun could easily have been developed -- all the tools were in place, and only needed a program to put them together. But there was no push for such a program.

I think you might have confused the 57mm RCL which was indeed inferior to the Bazooka with the much more effective 75. Not considered man deployable? The standard ground mount was the same tripod used by the Browning M1917 machine gun!

I assure you I have not confused the issue.

… the suggestion is what they were looking for was smaller, not bigger along the lines of the panzerschreck, not the Pak43.

This was how I had understood the commentary, and why I asked how we might interpret the link to the M20 that followed the commentary.

The 75mm RCL M20 weighed in at 114 lbs, and was some 6 ft long. Please reconsider before you suggest this was, in any case or circumstance, a shoulder-fired weapon like the Panzerschreck.

The M20 was a weapon that was transported, along with its crew, by a vehicle. The fact that it could be dismounted and placed on a tripod was useful for emplacing it (although usefully emplacing an RCL is a challenge unto itself). But this was not a weapon that was man-portable by the infantry as they advanced.

I'm pretty sure have a 20 pound HEAT projectile smack into your armor plate is going to do more than scratch the paintwork.

The 20 pounds you quote was the full round: projectile and cartridge. The projectile itself weighed in at something less than 14 lbs.

Any HEAT round fired from a rifled gun, recoilless or not, will have less armor penetration than an equivalent caliber rocket-propelled HEAT round of equal competence. (This last comment is because the skill levels in designing HEAT projectiles varied greatly over time and from one nation's ordnance teams to another).

This is due to two factors. First, a projectile from a gun must always have a larger portion of its weight dedicated to the projectile walls and base. Guns fire at higher chamber pressures, and rifling puts additional stress on the firing process, requiring sufficient wall strength and increasing the pressure by means of the added friction as some portion of the projectile momentum is converted to spin rather than forward motion. A typical 14-15lb 75mm HE round would have perhaps 3 to 4lbs of explosive filler, not more. A typical HEAT round must necessarily have less, as it must devote space to the "hollow" in order to get a shaped charge effect.

In addition, the act of spinning the projectile (the job done by the rifled barrel) dissipates the focus of the shaped charge, further reducing it's penetration.

By the end of WW2, a typically competent rifled HEAT round might penetrate 1.2 to 1.3 x it's diameter. This general statement is consistent with the results of the M20, which is generally given credit for about 100mm of armor penetration capability.

That is about the same as the late-war projectiles fired by the 2.36in M9 bazooka. The 3.5in M20 "super bazooka" was rated as penetrating up to 275mm of armor. Rather better than the 75mm RCL could ever achieve.

The disappointing performance of the 75mm RCL M20 in Korea was the driving reason that the US Army moved up to the 105mm / 106mm RCL calibers. 75mm in a rifled gun barrel was not enough for a useful AT capability.

That is not to say that the infantry didn't want man-portable, shoulder-fired AT capability at the company or platoon level. They did want it. The path was through weapons like the super bazooka. Not through RCLs.

RCLs were battalion or higher-level support weapons. They were organized into batteries, transported by vehicle, and had dedicated crews. Good enough to replace towed AT guns, being less capable but more flexible, by about the mid-1950s. But in 1944, not so much.

-Mark
(aka: Mk 1)

Wow. Lots of good stuff here. But some misses the mark as well. First many have focused on the US in NW Europe from Normandy through The Bulge. Six months in one Campaign out of a six year war. Need to look at the overall picture. Back to the basic question or my paraphrase it "what was the difference between a tank and a tank destroyer"? The fundamental answer goes back to the classic dilemma of tank design the trade off between armor, speed and firepower. Today's Main Battle Tanks have all three so we don't see TDs running around anymore. But the technologies available at the start of WWII required trade offs. Hence light tanks which were fast with weak armor and guns. Heavy tanks which lumbered along. Perhaps the two closest examples of the modern MBT concept were the T34/85 and Panther. Outside of those two examples most designers were still thinking Light Tanks, Cruiser Tanks, Infantry Tanks and in this mindset it was logical to have a Tank Killer Tank or TD specialized for that role alone. All you need to do is look at late war post war models. The best Soviet TD was the SU 100. When they stuck the 100mm gun on a tank, the T54, they stopped developing TDs. When the Brits figured out how to get a 17pdr in every tank, The Comet, they gave up on TDs. And the Americans stopped production of the M36 when they stuck the 90mm in a Pershing. So the real answer of why Tank Destroyers has more to do with Technology than doctrine. As soon as Technology allowed designers to make tanks that had big guns, good armor and fast speed the tank destroyer became obsolete. Cheers!

M36 90mm gun motor carriage – a 90mm gun on a Sherman chassis ….. finally.

B

The Comet didn't mount a 17pdr. The Challenger did and was very much a TD not a tank.

I agree the MBT concept killed off all the specialty vehicles over a few years. It seems such a logical concept but in the early years of WW2 the tech just wasn't there yet.

I think the Pz IV H is also a candidate as an early MBT though not by design – it just evolved into one. The armour was just a little too thin and couldn't be upgraded without slowing the tank down. I don't think they ever looked into doing that, having the Panther in production anyway.

What was the first true MBT? The Centurian? They got into the ETO but not into action in 1945. The T-54 was obviously later.

The discussion has focused on the ETO in 1944-45 for very natural reasons. When you say Tank Destroyer we all think US TDs, thought the Soviets, Germans and Brits also used them.

One of the main reasons towed ATG guns fell out of favour with the US and also the UK&C forces is that on the attack they are less useful and in addition German tanks were becoming very rare by then. Most GIs probably never saw a German tank or even a StuG. In certain areas and time periods they probably saw plenty of them. But in quieter sectors when the Germans were on the defensive tanks and AFVs of all kinds would be more or less absent.

Skarper. Re Comet. The Comet mounted a 77mm which I believe was a shortened 17 pdr barrel firing the standard 17 pdr projectile with a shortened case to lessen recoil so they could fit it into the Comet Turret. Because the ammo could not be used in regular 17 pdr (due to case size difference) it was called the 77mm. So while you are in fact correct the Comet did not mount a 17 pdr by name in practice it was pretty much the same gun.

I understand the focus on NW Europe, I just think the scope of the discussion should be broader. I also think that towed AT Battalions, while called TD Battalions by the US, are really a separate discussion from true Armored TD units equipped with M10, M18, M36 etc.

I find the most fascinating period for Tank Destroyers to be the Desert where the Germans, Brits and US, realizing the shortcomings of towed AT guns. mounted "big guns" on anything that would carry them. The Brits used trucks like the Deacon, the US Halftracks and the Germans obsolete tank chases like the 38t or captured French equipment. And I agree with you this all came about because the MBT concept had not evolved yet.

Cheers!

The Comet 77mm was not as powerful as the 17pdr in the Firefly and later the Challenger. It was I think slightly better than the M1A1 76mm?

The Comet was quite a capable tank, but not a huge leap forward compared to the other tanks in production at the time. Then the Centurian appeared and the Comet became redundant, though because it was in service stayed in British service until 1958 and later with other countries.

The desert theatre is indeed interesting and in many ways a very particular situation. Although it was strategically and politically vital the forces involved and amount of combat was very much less than what follwed in Italy and the ETO.

An informative and entertaining discussion so far!

Re: British 77mm gun (in the Comet) and the 17pdr …

The 77mm gun is frequently described as a shortened 17pdr. In fact the 77mm gun was developed from the British Vickers HV 75mm gun, which never entered service in its original form. This gun was a re-design of the Ordnance 20cwt 3-inch AA gun, using the same cartridge, in a more compact package, and was the gun intended for the Cromwell. But through a tragic spate of mis-communications and/or production priorities, it could not be fit into the the turret that fit in the turret ring that fit into the hull of that tank. And so the Comet … nothing more than a slightly enlarged Cromwell hull with a new turret and gun, became a necessity.

The only relationship between the 77mm and the 17pdr developmentally was the projectile. Since the 17pdr was already in service, it was found to be expedient to use the proven projectiles of that weapon in the new gun. While it is true that the barrel was designed to use the same production tooling as the 17pdr, I don't think it could be said that one was developed from the other, or that the 77mm was just a shortened 17pdr barrel. Might be wrong on that last point…

The actual caliber of the OQF 77mm gun was still 75mm. The name "77mm" was chosen to prevent confusion with the existing OQF 75mm gun already in service. The actual caliber of the 17pdr gun was 76.2mm. The difference was not enough to prevent using the same projectiles in both guns.

Or so I understand.

-Mark
(aka: Mk 1)

The fundamental answer goes back to the classic dilemma of tank design the trade off between armor, speed and firepower. Today's Main Battle Tanks have all three so we don't see TDs running around anymore.

I would beg to disagree.

In the post-war era, up through today, we still see tank destroyers in service in many armies. What we don't see anymore is the TD doctrine of the US Army -- of a separate force of tank destroyers held as a GHQ reserve to provide a mass response to armored forces penetrating the front lines.

A selection of vehicles that I would suggest qualify at Tank Destroyers in the post-war era:
- Sweden: IKV90
- Austria: SK-105
- France: AMX-13/90, AMX-13/105, AMX-13/SS-11, AMX-10RC
- GFR: Jagdpanzer Kanone
- US: M901
- Soviet Union/Russia: BRDM1,2,3 ATGM vehicles, BTR-RD and BKM vehicles

In all cases these vehicles were designed to fill a primary role of fighting tanks, with the firepower to destroy tanks but emphasizing lighter weight, lower cost and better mobility than tanks.

-Mark
(aka: Mk 1)

And I still need to argue for the inclusion of attack helicopters as the "Tank Destroyer" of the 1970s and later.

Sure, they're dead meat if you get an AA weapon to hit them. But until the enemy finds his ZSU23s, a Cobra or Apache is going to shred that tank company.

Lion, while I wouldn't disagree that attack helicopters could be considered the modern descendants of TD's I do doubt the effectiveness in that role. A E Curtis who used to be very active on TMP until he sadly died was involved in the US Army's Opfor force (I forget exactly what he did) and his opinion based on the exercises that they run was that attack helicopters were very vulnerable and their chances of having any significant impact on enemy armour were slim at best. It was easy enough to predict where the attack helicopters would try and ambush the armour and push anti air assets into place to hit them as they deployed. You don't need ZSU23's either. GW2 and Afghanistan proved that attack helicopters are vulnerable to HMG's and man pack SAM's.

The reason for the focus of the discussion on U.S. Tank Destroyers is that "Tank Destroyer" was an American term; other nations used other terms, such as "self-propelled gun (SU)," "panzerjager (tank-hunter)," "jagdpanzer (hunting tank)," "sturmgeschutz (assault gun)," etc. So when you say "Tank Destroyer" most people naturally think of the U.S. examples.

The STG was intended to be used to suppress fortifications in infantry assaults. It had a short-barreled 75 as most effective in that role. When the need to oppose Soviet T34 and KV tanks enmass arose they converted the STG to a JAGDPanzer role by mounting a long barrel 75. Then they made the STU42 with a 105 to continue the initial role.

Anyway, I think the self-propelled AT missile launcher took over the role of tank destroyer (lightly armed but capable of taking out MBT's)and yes, the US has them.

With regards to disbanding of 57mm ATG platoons in late 1944 and 1945, bare in mind these guys were pretty much out of a job by this period with most German armour deployed eastwards to face the Soviets.

Your average US infantry division generally had more tanks and SPGs assigned to them than what most of the Panzer Divisions had functional.

The Bulge was the exception (and caught the US unprepared).

@Fred: Yeah, I miss AECurtis, too.

But his/your notes on the problems with helos also apply to WW2 US TDs: Relatively easy to predict where they would attack, and very vulnerable to even "small" weapons (a .50cal or 13.2mm MG would shred an M10 3" GMC, nevermind what a 2cm Flak would do).

But against an opponent who doesn't have Soviet/Russian levels of AA, helos tend to run rampant.

Fred it get complicated quickly. Just as chopper ambush spots are predicable, so to are the likely spots for the Air defense assets. Which is when me and my guns come it. SAAD (suppression against air defense)were one of my favorites to shoot. And they worked out pretty well. Allen and I discussed this a time or two. And unlike tanks ADA if not a hard target, doesn't take much to break radar dishes or missiles.

Owen

I'd agree with the notion of anti-tank helos fitting tank destroyer doctrine circa 1940!

Most of the NATO AT birds in the 1980s were light choppers susceptible even to small arms fire (SA-342L/M Gazelle and Bo-105PAH-1)let alone proliferation of SA-7s etc.

Thus to have any reasonable chance against Soviet armour these would have had to operate in friendly airspace and whack armour that had broken through.

That is very much in line with TD Doctrine as originally envisaged.

Iraqis lost tons of SA-342s in Iran-Iraq (and Iran also lost a lot of better armed AH-1Js). US attempts to use AH-64 offensively were disastrous at Karbala in 2003 with large numbers of AH-64s damaged, 2 shot down, 2 damaged beyond repair and all for a measly 12 Iraqi tanks whacked.

Badger22,

What sort of SEAD are we talking about?

Radar guided systems could be tracked (but these generally tend to be directed at high flyers). These can be targeted by anything that can detect radar as well as being jammed.

Vast majority of AD that can harm helos in a combat zone is infra-red (SA-7/-13/-14/-16 etc) or even manually guided (ZPUs and RPGs as well as various heavy machine guns and even small arms).

These are much harder to detect and can be dispersed easily.