U.S. WWII Tank Destroyer Doctrine.

[tar]

I received the following link to a US Army Leavenworth papers study on tank destroyer doctrine in WWII:

Leavenworth Papers No. 12

Seek, Strike, and Destroy: U.S. Army Tank Destroyer Doctrine in World War II

by Dr. Christopher R. Gabel

Combat Studies Institute

U.S. Army Command and General Staff College

Fort Leavenworth, Kansas 66027-6900

September 1985

http://www-cgsc.army.mil/carl/download/csipubs/gabel2.pdf

[JasonC]

A hatchet job by pure armor types and a crock.

Tunisia is supposed to show the idea unworkable, then for the rest of the war they pound straw men and point out the failures of towed ATGs.

Every time the actual performances or crew reports or unit reports are mentioned, the SP TDs are doing beautifully, yet the narrative continues to portray everything as a failure.

The after war survey work finds each battalion accounted for its own number of enemy tanks, at much lower losses. (And while performing all manner of additional useful side missions). But it is just ignored what an outlier success that is, among allied weapon systems.

There are also numerous egregious errors throughout, on matters of simple fact. E.g. the Tiger I is said to be invulnerable beyond 50 yards, which is poppycock. The Panther is said to require side hits, when turret worked. Shatter gap is not mentioned nor its remedy, tungsten. Instead the 90mm is presented as the only effective AT weapon. In fact the only mention of tungsten is as ammo for the Panzer IV in Tunisia (lol).

The Lehr counterattack in Normandy never happened. For Mortain, only the towed battalion directly in the attack's path is mentioned, not the 2 battalions that fire brigaded to the scene just as doctrine called for. For Lorraine, M18 successes at Arracourt get passing mention, then they try to tarnish even that by pointing to one M18 platoon that lost 3 guns (while killing 15).

The higher level glosses of the Bulge pretend the TDs weren't successful or as intended, but has to admit they KOed over 300 German tanks and scored heavily in the most of the decisive engagements. Since that can't be allowed to pass, failures of towed ATGs are given more space.

I think the real reason TDs were hated is they were not employed in a manner that helped the careers of senior officers. Tunisia gave them a bad name, unjustifiably (they had no equipment yet, but still exchanged off when used properly). Once actually equipped, they worked just fine, but at company scale and below, where reps are only made for Lts and Cpts.

The men who actually served on them are a far better guide.

[YankeeDog]

Jason --

I'd be curious to hear your opinion on the following, as it is a thesis I often hear bandied about:

The shortcoming of US TD Doctrine and technological development in WWII was not so much that TDs were poor anti-armor weapons, but that they were only marginally better in this role than the multi-role tanks they fought alongside, and also were only marginally cheaper to produce than a comparable medium tank.

Furthermore, on the real battlefield, it was often difficult to ensure that the TDs engaged enemy armor; they just as often ended up being used in a more standard medium tank role, against infantry, ATGs, etc.

As such, the US would have been better off concentrating development and production on better-armed M4 mediums, and getting the M26 Pershing into combat, rather than devoting time and resources to developing and producing TD designs.

I don't know enough about the details of US armor doctrine and technological development to make an make a fully informed opinion about this myself, but I am inherently wary of "could have done it better" theses like these, that rely heavily on hindsight.

As a purely speculative exercise, though, it is interesting to try to estimate how much earlier than July 1944 the US could have gotten 76mm M4s into combat (which seem to render the M10 pretty much unnecessary), and how much earlier than February 1945 they could have gotten 90mm-armed Pershings into combat (which seem to supercede the need for M36 Jacksons), had they made fielding these systems a priority from the get-go, focusing efforts on these improved multi-role tanks, rather than on the TDs.

Cheers,

YD

[ June 05, 2007, 01:36 PM: Message edited by: YankeeDog ]

[JasonC]

Yeah, that is the crock in question.

It functions by a slippery sort of evasion, in which half a dozen disparate charges are all supposed to point to the same conclusion, when they don't, most of them are false, and the conclusion is not available.

TDs are supposed to fail against armor because they are insufficiently protected. But actually they succeed because they have sufficient firepower.

TDs are supposedly no better than the tanks around them, but then the tanks around them are supposedly hopeless because they don't have the guns on the TDs, and the TDs are supposed to be to blame for that.

So to the realities and real possibilities. The US produces about 650 M10s by the end of 1942. Meanwhile, before an American sees a German on the ground (OK, a little later, I mean Kasserine), about 10,000 75mm Shermans have been produced.

All those 75mm Shermans are not going to be dropped in the drink. They were made when nobody knew they'd need a more powerful gun and all the field reports were saying the Sherman addressed all the difficulties on the Grant, and from El Alamein on that it was the best tank on the field. (And it then was, in North Africa anyway). So there was never any prospect of nobody going to war in a 75mm Sherman if they had skipped the TD idea.

In 1943 they make 6000 M10s and twice as many Shermans. If they had made 76mm Shermans instead, would they have had more vehicles? No. More 76mm vehicles? No. Fewer.

Because the 76mm turret for the Sherman wasn't ready. It was based on the T23, a tank design meant to replace the Sherman completely but never adopted, largely due to suspension problems but also because it offered no real advance over a Sherman, other than the new gun. So it was decided to put its new turret on the Sherman chassis to make the 76mm Shermans. Adapting it took design time.

So the first six months of 1943 were not available for 76mm Shermans in any case. You make M10s or you get no 76mm vehicles. You kinda need a force structure and doctrine to make and use M10s, though. If you don't have one, you get more 75mm Shermans and wait for 76mm Shermans. So, in 1943 you'd wind up with 3000 fewer 76mm guns, not more, in return for 3000 76mm Shermans earlier.

In 1944, they aren't making Sherman 75s anymore, really. A few thousand from the last production lines to switch over. Most of the production in 76mm Shermans, and the new 105mm Sherman (which the men considered their most effective all around weapon, incidentally). You also get 2000 M18s and 1400 M36, the last arriving by September.

If you have extra M4A1 76 in Normandy, does the fight go way better? No it does not. Because they discovered shatter gap only during the Normandy fighting. The equations told them a 3 inch would hole a Tiger at 2000 yards with plain AP. It was more like 400 yards in reality, due to rounds failing and breaking apart on the face hardened German plate.

The solution to that was tungsten, and they had plenty, but had not see it coming (the need I mean), so shells hadn't been made and shipped. It is the fall before the APCR shows up.

By then you have Sherman 76s either way. The ADs that arrive in the late fall wave come with 100% 76s from the states.

Could you have had no 75s left? No. As mentioned, too many 75s already built and moved to theater before battle is even joined and any of these needs become apparent. They are not going to be junked.

The Brits have Fireflies in Normandy, but still find it extremely costly to attack superior German armor. US 76s without tungsten are weaker by far.

You also can't find any occasion where the TDs fail due to their modestly weaker armor. The reason is obvious - the times you need a 76 rather than a 75 is when you are facing a Tiger or Panther (US part of the front, a Panther), and those have monster guns themselves that are going to hole you if they hit you, either way.

A late model (W armor) Sherman might shrug off some 75L48 rounds at sufficient range. But the ranges in Normandy are close, and most enemies with that gun vulnerable themselves.

The tankers are complaining that the Panther is better than their own tanks, pretty much. But that can't be remedied in Normandy, on any decision you make. Best you can do is have more 76mm and 105mm weapons, and if you have great foresight, more APCR for them. As it is, the Panthers get creamed when they try to counterattack (both Lehr in July and Mortain), by TDs in particular.

OK, what about after Normandy and the chance to have Pershings sooner? It was possible to accelerate the Pershing. If it were top priority, they could have had 1000 or so by the end of 1944. Note that they did make nearly 2000 during the war, they were just all still stateside. There could have been time to get some of them to theater sooner.

But they were teething. They were still in teething in Korea. They were underpowered, and their mechanical reliability in drive train terms was never really corrected. The M-48 Patton was the solution to both problems. So you would have had mid hundreds of them running, best case, with others still in pipeline and the states, and in the shop.

In return, you give up 1400 Jacksons fielded by the end of 1944. Plus the 2000 M18s and the 6500 M10s, by now with tungsten. You have in return maybe 500 running Pershings and maybe 4000 extra 76mm Shermans (the M18 really was cheaper, 20 tons etc). Not what I call a good trade.

A Pershing can dominate a StuG or Panzer IV, which is certainly useful. Against the German heavies, though, its far heavier armor still isn't nearly heavy enough. Panthers and Jagd-70s are throwing sledgehammers, and the Tigers are Kings throwing lightning bolts. They had 250 Jumbos, were those decisive? No. Twice as many Pershings aren't going to be either.

It is quite obvious to me that a larger portion of upgunned vehicles is dramatically more useful. The reason is, it simply does not make sense to go for uparmoring, when the German guns are so awesome. You won't make it, anyway. Eggshells with hammers is a better bet, simply because you can't make thick enough eggs (in time, in any quantity, etc - I mean yeah there are 250 jumbos etc).

Now, were the turreted tanks more useful outside the dedicated tank vs tank role? Sure. But the TDs did a lot better there than many seem to think. They were excellent bunker busters from better AP performance. They developed a whole indirect fire system in Italy, during the periods of their underutilization from lack of German armor to fight.

The men loved them, and thought them highly effective. Not something you can say of the Sherman in general. They had far lower loses than the full tanks, despite less protection, mostly due to their less offensive doctrinal role. They killed their own number on average, without losing all themselves, which is outstanding for any weapon system.

The reason they succeeded - and they did - is clearly first of all just their firepower. Which was excellent, particularly so for Jackson and Achilles of course, but also for the others once tungsten was available. They were versatile. Despite all the doctrinal kerfluffles, in practice they were used in a survivable fashion and generally well supported by recon-intel and other arms.

One man's opinion...

[ June 05, 2007, 03:15 PM: Message edited by: JasonC ]

[Sgt Joch]

well speaking just in game terms, I find the M10 much more useful than 75 sherman.

The M10 give you one-shot/one-kill capability against any german tanks, including Tigers/Panthers out to 500-600 meters, if setup in a good firing position.

500-600 meters is usually the limit of your effective LOS in a typical CMAK Italy/NWE scenario.

The 75 Sherman can hold his own against Mark IV's but struggles to kill Tigers/Panthers at ranges over 200 meters.

One shot from a Mark IV/Panther/Tiger will kill either a M10 or 75 Sherman, so the Sherman's better armour protection offers no practical advantage.

[Guest Mike]

Except against 50mm ATG's - I recall playing a scenario with mixed tanks and TD's & a bleedin' 50mm got 2 TD's while another bounced off teh front of a Sherman.

[Bert Hamoen]

Since this thread is sliding towards a whole different subject I add my two cents: the HE capabiltity of a Sherman 75 is enormous compared to any TD.

Of course the 90 mm of the Jackson gives a bigger bang, but the TD's carry a lot less shells ! So, in CM, as in real life, you really cannot do without either of them.

Although, in a small points battle (ME), I would choose the Sherman 75 over a TD because it is more versatile in my opinion and the chance of encountering a Tiger or Panther in a small points game is very small because of the price of the german tanks. Besides: it is difficult for a Sherman 75 to knock out a Tiger, Panther or, for that matter, one of the big TD's, but not impossible.

[JasonC]

Well in QBs, the single most versatile and affordable type is in my opinion the Sherman 105, M4A3 model. Runs you 167 points, the same as a 75W Sherman, 25 points or so more than a weak armor 75. About as much less than a 76W Sherman. The HC is limited but when you are only facing a single opponent, typically enough. ROF is lower it is true. But the HE certainly gets the job done.

In CMBO I like the Jacksons best. They cost only 135 points or so and dealt with beasties, while also having strong HE, if not really enough of it. Weaker MGs weren't as much of an issue because MG fire in general was so weak in CMBO. In AK, they just aren't available. Even the Hellcat isn't available until 1945.

The Hellcat is a bit too thin, given all the light gun threats the Germans can have for very low prices, and the super accuracy of light Flak in CM in particular. The cost is low, but unless you know you are facing infantry and armor only, the vulnerability is too much.

This isn't a problem with the M10. Yeah, 50mm can bounce from Sherman fronts. HC from leIGs and Stummels is another borderline case where a bit thicker armor helps. But the really light stuff doesn't work and that is most of what you need.

In moderate sized fights, I like to take 1-2 M10s and the rest Shermans. In a fight small enough that I only get 1 piece of serious armor, the Sherman 105 is my weapon of choice.

Incidentally, the Priests are as afforable as the M10s, and have great ammo depth and HE firepower. I usually avoid them, though, because they have one vulnerable front plate as weak as the Hellcat, and encounter the same problem with hidden light guns.

The item to never take given the pricing as it is, is the 75W Sherman. Take the el cheapo early ones, or take the improved 105s or 76s. With the 75W you pay about as much, for their marginally better armor and full MGs and HE load, without getting anything in the way of useful heavy AT ability.

Kinda a shame from a realism perspective, though, because that was actually the most common type in Italy.

[Other Means]

Achillies, 105's and Churchill XI's. Gotta love playing the Brits.

[MikeyD]

"Shatter gap is not mentioned"

I don't think I've ever read a contemporary overview that so much as mentions shatter gap. That topic was considered a small technical aspect to a larger doctrinal argument. As another example, I understand that Germans weren't fully aware of the effects of switching to homogeneous armor and basically lucked-out on later Stug armor protection!

And another thing about 'contemporary' documents. Factual details inevitably have to catch up with them later. I recall one after-action report about St. Lo that had every German tank and anti-tank gun as an 88! And apparently every Brit on the Western Front feared the dreaded German 'Spandau' mg. These documents are mostly useful as a snapshot for what people were seeing and thinking at the time - and for driviing the OCD gamer crowd crazy.

[JasonC]

Except it is reissued 1973.

And they found empirically that they needed APCR in Normandy, and fielded it.

The article knows enough to cite tungsten for the German 75L48 on the Panzer IV, because it is trying to present German tanks as in every way superior to US ones. That they didn't have any APCR ammo is not mentioned. That the US TDs did is also not mentioned. This is bias, pure and simple, because they are grinding an axe not giving an objective assessment.

[JasonC]

Other Means - fair points. I think the Churchill VIII is already sufficient, and is available earlier. Not early, though. The Achilles is good for AT but seriously weak in infantry killing (very little HE and 3 minutes of MG ammo). Sometimes it is worth paying the extra 60 or so to get a Firefly instead. (Of course, if the 95mm Churchills do HE for you...)

[Harry Yeide]

Originally posted by tar:

I received the following link to a US Army Leavenworth papers study on tank destroyer doctrine in WWII:

Leavenworth Papers No. 12

Seek, Strike, and Destroy: U.S. Army Tank Destroyer Doctrine in World War II

by Dr. Christopher R. Gabel

Combat Studies Institute

U.S. Army Command and General Staff College

Fort Leavenworth, Kansas 66027-6900

September 1985

http://www-cgsc.army.mil/carl/download/csipubs/gabel2.pdf

I like Gabel's study more than JasonC does, but what struck me immediately when I started looking at the TD story was that doctrine is the wrong focus--conditions anticipated by doctrine occured on a largish scale only a handful of times during the war. In those cases (e.g., El Guettar, Anzio [sorta], Lorraine), SP TDs did what they were supposed to do. But most times and most places, armor, infantry, and TD officers tossed the doctrine out the window and did what seemed to make sense at the time.

I have no insight into the "what if they had built more of these thingies than those thingies" question. As Rummy said, you go to war with the army you have. The infantry wanted tanks to support them with 75mm guns, and I have never once seen an infantry account that said, "If only the tanks had had a 76mm gun...." The infantry also liked tank destroyers. If a division could get a battalion of each, which was typically the case from Salerno on, everybody was happy. The armored divisions happily mixed TDs in with tanks where needed; it wasn't doctrine, but it worked. On balance, the army had just the right equipment to win the war.

I will say that SP battalions were much more effective on average than towed battalions. They could go where the enemy was instead of waiting for him to come to them. SP TDs could withdraw when the enemy overan the infantry line, and towed guns frequently could not. Towed guns are swell antitank guns, but lousy TDs.

Must take out the trash now.

Cheers.

[coe]

ahhh a return to the TD doctrine...

here's a few questions...

1. how do you think the U.S. TDs would have faired in the Russian front (lets say circa 1943-1944) where the tank battles could occur at far greater ranges?.

2. are there any circumstances where the TDs were used as an offensive role rather than the defensive doctinal role (i.e. go in against armour on defense, create the breakthrough

3. are there instances where TDs failed in their defensive role

4. The germans made their TDs turretless destroyers (StuG, JadgPanzer, JadgPanther etc.)

I know part of this was due to lack of parts, production constraints - they had pretty good success - do you think the benefits of open turrent vs. turretless (why didn't the U.S. build turretless TDs).

5. Can the German success and failures in the use of their own TDs support or not support the TD doctrine or were the German TDs too different to afford proper comparison? (actually on that note, what was the actual German doctrinal use of TDs?)

[Corvidae]

Tank destroyers were perfectly good for their role as first shot tank killers.

Please stop beating on the M4 sherman

M4 Shermans were perfectly good general purpose tanks. Their guns were not ideal for AT work, But they could do it if they had to.

the 75/L38s were adequate although a tad short, this limited them somewhat.

The 76/L25s also had shortcomings.

However as a general purpose tank they were effective. They could kill any common enemy tank from any angle at medium ranges. they could also kill or dissable most enemy Uber tanks from the side or rear.

They had good armor and once wet amo stowage was adopted their flamability problems were pretty much solved.

These are of course not the specialized AT weapons that modern tanks are.

But the fact that shermans are still in service in several countrys ought to say something

[Other Means]

I think you'll find no one so far in this thread is a critic of the M4. An all round excellent tank. I've recently surprised an opponent by duelling long range with his PzIV's and winning. The little extra armour on the M4 making all the difference.

Originally posted by JasonC:

Other Means - fair points. I think the Churchill VIII is already sufficient, and is available earlier. Not early, though. The Achilles is good for AT but seriously weak in infantry killing (very little HE and 3 minutes of MG ammo). Sometimes it is worth paying the extra 60 or so to get a Firefly instead. (Of course, if the 95mm Churchills do HE for you...)

True, but it's just so gratifying after having to skulk around for years with JS2 against PzIV's, just to be able to roll right through them with the Churchill XI and kill their big brothers frontally with the Achillies is great fun.

None of these are Swiss army knife of the Tiger but with a little scissors/paper/rock handling you can get great results.

[JasonC]

coe,

You ask excellent questions. I will try to address each in turn.

US TDs on the eastern front -

In 1943 they would mostly do quite well. First, that era they have to be M10s. But the Germans opposite that are giving the Russians trouble are almost all in 80mm front vehicles, in the form of late model Panzer IVs and StuGs. These gave the Russians serious trouble because their main weapon against them could only penetrate them at 500 yards (in CM, can't, but Pz IV turret hits easy and effective partially makes up for it).

An M10 with plain AP has no trouble against those at range.

Now, against Panthers and Tigers, which become significantly more numerous by 1944, the US TDs had trouble due to shatter gap. But as soon as you experience that for a month or so, tungsten starts being made to solve it. There is a lag from first encounter with significant numbers of them, before you can expect to actually get tungsten. Once you have it, though, US 76mm becomes an effective "animal killer". There was no great tungsten shortage for the allies, it was purely a matter of figuring out the stuff was needed. In a long continuous fight, they'd find that out by late summer of 1943 at the worst, and solve it a few months later.

At that point, they are at least as effective as SU-85s. As T-34/85s become available, still useful but less critical.

On offensive use of TDs, you ask about creating breakthrough against defending armor. TDs were used offensively, but mostly against infantry, gun, and bunker defenses. The Germans mostly attacked when they had significant armor, locally, in the west. Arguably this was dumb on their part, a result of an overly aggressive doctrine about what armor is for. Yes they sometimes defended with armor but usually after it had already been quartered in numbers, and then in penny packets as fire brigades behind the lines etc.

There is no (large, operational) occasion of massed German armor standing on defense, attacked frontally by specificially TDs leading. The Brit portion of the Normandy front is the clearest case of the Germans standing on defense in the west with massed armor.

The Brits attacked them with HE inundation tactics followed by mixed tanks, including their Fireflies. They did quite poorly, did exchange off some German armor but at quite unfavorable rates. This was mostly due to overly aggressive driving forward with massed armor.

TDs would work better by gradually picking them off. Meaning, continual probes of all arms (arty first, infantry supported by a few tanks, etc) with TDs (or Fireflies) on overwatch, taking one's time about it. In other words, precisely *not* attempting immediate *breakthrough* (which tries to get it all over with quickly and get through before they react), but instead consciously attriting as many as they can feed into the area.

The other offensive use made of TDs against defending armor was the US practice of attaching penny packets of TDs to armor task forces. Basically, ADs typically had a TD battalion and farmed it out to the combat commands in companies. They then either worked with armored cav and light tanks (elements short on AT firepower themselves, but highly capable against infantry), or were just shoved down to each battalion in penny packets.

Especially before Sherman 76s became numerous, this gave some local stronger hitters if German heavies were encountered. Helped most when it was just a penny packet on the other side, though. (I mean, 4 M10s won't help much if you run into a whole Panther battalion). They just become a specific tool to remove single "blockages" by the occasional well placed Panther.

As for instances of failures of the TDs on defense, the closest case is Anzio. The Germans launched serious armor attacks against the Anzio beachhead in February 1944. There were TDs within the beachhead and the attacks were halted. But the TDs actually peformed poorly, and it was largely HE inundation tactics that really stopped the Germans.

There is one instance of an entire company of emplaced M10s destroyed in a single afternoon, essentially without loss to the Germans. The tactical use was poor. They just tried to dig the guns in thoroughly and used them as static defenders near the front line. This was motivated by the limited space in the beachhead (no fall back room or depth of defense zone to operate in) and by the poor state of the ground - a muddy crater field, which made off road mobile linebackering seem impractical. The Germans also held higher ground with superior observation, making stealth tactics essentially impossible.

What actually stopped the Germans at Anzio was continual use of naval gunfire and medium bombers in saturation attacks. As in raids by nearly 200 B-26s at a time. Artillery in the beachhead also contributed. Overall, the allies were using their logistic superiority to deluge the battlefield with HE. This stripped the German tanks of infantry and made the countryside impassable (with help from the late winter mud), as well as attriting a few of the tanks directly. The Germans moved to night infiltration tactics by infantry, with armor limited to following up in daylight against the places already cut off.

Since TDs took serious losses and were unable to meaningfully contribute to stopping the German armor on that occasion, I would call it a failure of the TDs. Arguably, only superior armor fronts would have been helpful in such conditions. I mean, with off road mobility limited and enemy observation good, the only way an AFV is going to dominate is if it can shrug off enemy AT fire (until they get close, perhaps). See the next on why that wasn't likely to be achieved, though.

On the German preference for turretless TDs and the benefits of turrets, the Germans wind up turretless because they are searching for maximum firepower, and secondarily (later on) due to uparmoring. In engineering terms, you can essentially always put a bigger gun or more armor on a turretless vehicle.

There tends to be a lag in these things, and ability creeps up from the low end first. By that I mean, it is first the lightest turreted tanks that are found to be useless, for lack of an adequate gun. If the vehicle is too small to take a better gun, the turret is dispensed with and a truly capable gun used in a fixed mount.

Thus is it first the Pz II and Pz 38 chassis that move to Marders. Then the Pz III chassis to StuGs. Not until 1944 are Jagds produced on Pz IV chassis (though a few Nashorn in 1943 use those). The Russians dispense with T-70s to make SU-76s. Fundamentally this is about getting useful firepower vehicles out of the low end of the available production lines.

The German move to uparmored, dedicated TDs comes after all of that, basically in 1944 only. (The Elephant foreshadows this earlier, but was a limited-run special case based on a Tiger design that was not accepted). That is when Marder use of 38 chassis gives way to Hetzer use of them, Pz IVs are foregone to get Jagds with better armor slope, or Jagd-70s to get Panther level firepower and protection out of a IV chassis, a few Jadgpanthers for long 88s instead of a few Nashorns, etc.

This was driven largely by Russian upgunning and to a lesser extent armor improvements and a desire to stay ahead of them, to restore the range edge enjoyed in 1943, etc.

Guderian lamented the diversion of production from turreted tanks. He felt the offensive power of the panzer force was being sacrificed, and that turretless TDs were only good for stiffening infantry defenses, tended to be penny packeted, etc. But the development was probably sensible, and it is quite doubtful the Germans would have been better off with fewer of these special types and more turreted Panzer IVs. Perhaps in maintenance and logistic terms (the plethora of types was hard to manage).

It is reasonable to ask whether the Americans could have or should have copied this ungunning then uparmoring strategy. The US used turretless SPA to get larger guns on existing medium chassis - the Priest and a handful of 155 SPA - but not SPAT. The low end chassis, the Stuart, was used for HMCs with short 75 but not for serious TDs. (Just a handful of ad hoc field versions, using US 76 or captured PAK 40).

It was clearly pretty useless to still be fielding lots of Stuarts in 1944. They were OK vs. pure infantry, about the best that can be said. But the US was not chassis production limited like the Germans were. So it would have made more sense to just replace the light companies with TD companies or assault gun companies with Sherman 105s, using the manpower and abandoning the M5 chassis.

The Chaffee was a half way replacement and not really a success. Clearly more useful than a Stuart, but still underpowered in AT terms. In Korea they fare quite poorly against T34-85s. The US finally got an upgunned light tank in the Walker Bulldog, finished after Korea. Never really used it themselves, though. They were used in Vietnam by ARVN and were effective. Unless you are going to get the like much earlier, the US light tank tradition has to be judged a much clearer failure than the much more successful TDs.

Could the US have fielded upgunned vehicles on medium chassis, without turrets but with better guns? Earlier, perhaps. I mean, in the M10 era they might have put 90mm on the same chassis without a turret. Later the Jackson manages it with one, so it was possible. But how were they supposed to know they would need 90mm so soon? The ordnance equations said the 76mm would suffice against Tiger Is to 2000 yards; they hadn't seen shatter gap yet. When they do, they already have over 6000 M10s built. Clearly it is better to make those effective with tungsten, instead of trying to ditch the 76mm and remove turrets to mount a 90mm etc.

Achilles gets the best Brit gun along with a turret, and Jackson the best US one along with a turret. The serious high end question, then, is whether it would have been better to field these as turretless vehicles not with still bigger guns (they were the best available and sufficient clear to the war's end and beyond), but with thicker armor. Jagd-70 or SU-100 style, in other words.

Argubably that would indeed have been better. But there is a higher bar for US or UK uparmoring to be effective, than for German. Why? Because the German gun mix is monstrous from quite early on. I mean, you can take something as tiny as a Pz 38 and uparmor it to a Hetzer, and get something that is meaningfully more armored, because the guns it is facing include large numbers of short 75s or Russian 76s. But if the guns you need to defeat are 75L70, that is clearly a taller order.

Still, the Brits had the late Churchills and the US a few Jumbos. It was clearly possible to get front armor sufficiently thick to make many German guns ineffective. It just took around 6 inches of armor, or 4 inches well sloped. And it is clearly easier to get uniform well sloped in a turretless design.

So yeah, the US might have fielded "SU-90s" and the Brits a 17 pdr TD, turretless, perhaps on the Churchill chassis. They would have been late war critters with middle hundreds to low thousand production runs, but they were technically possible and would have been superior to the fielded allied TDs in armor protection. They would have been highly useful in the Bulge, and might have acted as overwatch vehicles in assaults against German armor.

As for comparing German and US TD doctrine and effectiveness, the Germans were blessed with a weaker enemy gun mix faced. That is the main less than comparable point. This is true from mid 1943 on - before then the Russians (and Brits in the desert) faced a German tank mix still light enough in gun firepower that meaningful uparmoring was well within reach. Once they field uniform 75L48 or better, though, even a KV tank of 45 tons is no better protected than a Sherman or plain T-34, effectively.

As for German doctrine and actual practice with TDs, the doctrine was to use them in full battalions but the practice was to distribute them in companies at most, and more often in platoons, sometimes even single vehicles. Use as singles is continually being condemned by the brass and was no doubt wasteful (too easy for the enemy to employ teamwork flanking tactics), but brass doesn't lecture the men not to do things they aren't doing. The motive was always to get some AT protection for the infantry.

In pure attrition terms, the best use of TDs is to focus on armor killing, not the integrity of the infantry defense. The best place to engage is within the defense zone, after the enemy has already penetrated somewhere. But the men typically try to engage farther forward, at the FEBA, in order to protect their comrades in the poor bloody infantry from enemy tanks.

That tendency was seen in the US TD force too, but when the Germans seriously attacked with armor they generally broke in quickly. So the US TDs mostly engaged in the right spot, by prior German success. (Anzio is an exception, some of the desert fights with wide open LOS likewise).

The Germans also pressed TDs (StuGs mostly, occasionally Jagds) into attack roles in place of tanks, particularly late in the war, for want of enough Panzer IVs to fill all the PDs (the source of Guderian's complaints). They were not generally pleased with the results. Partially this reflects doctrinal differences - the right way to use turretless TDs is on overwatch well within a probing infantry formation, which the StuGs knew and did - while tanks more often lead or operate immediately behind small scout groups of Pz Gdrs etc.

It cannot be said that the German TD forces stopped every allied armored breakthrough. Mostly this reflects scarcity on the ground and enforced penny packeting. It also reflects use too far forward, too often. (A typical case is a mobile StuG company "linebacker", used once the right way from reserve, but remaining too long on the line after first commitment, and out of position for the next threat or attrited in place before it, etc).

Still there is little doubt the TDs stiffened the German IDs considerably, and contributed to their legendary tactical toughness on defense.

[Redwolf]

Originally posted by coe:

ahhh a return to the TD doctrine...

here's a few questions...

1. how do you think the U.S. TDs would have faired in the Russian front (lets say circa 1943-1944) where the tank battles could occur at far greater ranges?.

2. are there any circumstances where the TDs were used as an offensive role rather than the defensive doctinal role (i.e. go in against armour on defense, create the breakthrough

3. are there instances where TDs failed in their defensive role

4. The germans made their TDs turretless destroyers (StuG, JadgPanzer, JadgPanther etc.)

I know part of this was due to lack of parts, production constraints - they had pretty good success - do you think the benefits of open turrent vs. turretless (why didn't the U.S. build turretless TDs).

5. Can the German success and failures in the use of their own TDs support or not support the TD doctrine or were the German TDs too different to afford proper comparison? (actually on that note, what was the actual German doctrinal use of TDs?)

If you allow me to crosspost from this simultaneously going thread here:

http://www.armchairgeneral.com/forums/showthread.php?t=51843&page=2

If you mean "would the American TD concept would have worked for the Germans or Soviets on the Eastern front?", there are separate cases to be considered:

* Early Eastern Front German: nope, the Russians weren't capable of coordinating "Sedan-style" breakthroughs with tanks, much less doing much damage if they did. So no need for the Germans to have tank hunters for "active" hunting.

* Early Eastern Front Soviet: they could have used them, but in all likelyhood they wouldn't be able to find the broken through German tank units. Both because there is too much terrain to search and because coordination is lousy. Plus why bother with turreted TDs when the T-34 already has a better gun, a turret and enough mobility?

* Late war Soviets: they ignored the German tanks anyway. German tanks bother you? Attack elsewhere.

* Late war Germans: they were better off with the Jagdpanzer style vehicles (no turret, strong shield) because for them it's more important to hold the line in the first place. When a breakthrough was achieved by the Soviets there were so many Soviet tanks streaming through that a thin TD won't do, because you cannot avoid getting hit under huge numerical inferiority. The Tiger battalions as firefighters were the only thing suitable.

The latter point is important. U.S. tank destroyer doctrine doesn't only specify a vehicle and how to use it. It also relies on bringing at least about as many TDs as you have broken through tanks - which in France 1940 would have been realistic. If that is given you can live with thinner armor since the number of hits from return fire is obviously proportional to the relationship of number of vehicles involved on both sides.

If you bring fewer than the opponent vehicles you must be able to take hits.

[JasonC]

Oh, I should mention one other doctrinal-institutional weakness of the German use of their uparmored late war TDs. Basically, the only people who got the best ones were the PDs, SS and Heer, who already have serious AT ability in tank form, Panthers around, etc. Because the IDs were "poor cousins" throughout.

Arguably, the people who can make the best use of a Jagd-70, say, are IDs on defense who would love a Panther powered vehicle, used with stealth etc. But they got StuGs, late war occasionally Hetzers, when they didn't have to settle for Marders. Most of them killable by even the lighter enemy guns, though sometimes outranging e.g. a T34-76.

The heaviest TDs were used in separate heavy TD battalions treated as army level assets, but generally supporting a panzer corps. (E.g. Jadgpanthers in the Bulge). As such they were used in areas where the Germans had Panthers around as well, and often in places they were attacking, tactically.

The Jagdpanzers were all sent to the Pz Jgr battalions (occasionally even the Pz Rgts) of the PDs, which they were not sufficient to fill, leaving some of the PDs with StuGs.

As long as a StuG was a superior AFV - before mid 1944 say - the IDs mostly had at best a company of them, the rest of the Pz Jgr battalion being towed or Marders. Independent StuG "brigades" used to support IDs gave them some StuG numbers in ID stiffening roles. Once the IDs started getting more StuGs organic, it was past its prime and the typical enemy vehicles faced could readily kill them at range.

The period and units when the Germans came closest to having mobile linebackers of superior AFVs for pure defense roles, were the independent StuG brigades in 1943. After that they either weren't superior, or were attached to PDs who were only on defensive deployments part of the time and had Panthers anyway. Before that they either didn't have any, or had only Marders again mostly working with PDs.

[Redwolf]

Right, Jason.

The medium "shielded" (Jagdpanzer with thick front plate) german TDs should have formed Infantry Corps controlled anti-tank battalions to seal up penetrations by Russian tanks, just like the heavy TD battalions did for "premium" formations.

Instead the medium Jagdpanzers were given to the frontline Panzer divisions to increase their striking power - which usually meant the TDs were used like tanks.

Protecting the flanks of a German tank strike would have been the better job for the StuGs, which are more useful against infantry and spontaneously assembled counterattackers.

[Redwolf]

Originally posted by JasonC:

The Germans also pressed TDs (StuGs mostly, occasionally Jagds) into attack roles in place of tanks, particularly late in the war, for want of enough Panzer IVs to fill all the PDs (the source of Guderian's complaints). They were not generally pleased with the results. Partially this reflects doctrinal differences - the right way to use turretless TDs is on overwatch well within a probing infantry formation, which the StuGs knew and did - while tanks more often lead or operate immediately behind small scout groups of Pz Gdrs etc.

This is also an often overlooked aspect of StuGs.

For most people a Jagdpanzer is just a StuG with an angled shield, but that is far from the truth.

StuGs are an entirely different thing. They were invented, and stayed throughout the war, infantry supporting artillery, controlled by the artillery, manned by artillerymen, equipped with artillery sights and so on.

The later shift to Jagdpanzers didn't only mean changing the vehicles. It also meant that control passed from the artillery branch to the armor branch, and then offensive use increased. This is partially the result of the armor branch just not having enough tanks or good-gun SPs, so they just use politics to get their hands on anything that can roll with a good gun.

But the result was that Allied penetrations through German infantry wasn't sealed as the remaining low-level TDs and the StuGs were overpowered, and that the actually useful Jagdpanzers were thrown away.

[coe]

thanks for the responses, I should have asked those questions on the previous full blown TD doctrine.

what would it take to defeat the TDs when they are used properly. If they are excessively open top, would the doctrine involve alot of artillery?

And as we got into the one shot can kill anything mode (1944) did it make sense for either side to have really heavy tanks since those could be penetrated.

Jason et al. I find it quite interesting your opinion about that TDs would do well in 1943 on the Eastern front against the Germans. Could I assume that this is because the Russian 76mm Zis or 57mm ATGs were less powerful than the 76mm U.S. canons. In that sense, were the US 76mm easier to score the first hit with than the 75mm L/43 or L40 germans. Essentially you have two forces on the open step approaching...who has the greater max range? I would presume that at this range slower turret is less of a disadvantage. I would assume, all else being equal, if the guns had equal range and penetrating power you might not want to be in the TDs at range because of the supposedly thinner armour (though it appears to me that the late war TDs were pretty much tanks but without the top. Still it would have been interesting if there were a battle when a bunch of panthers come up against TDs at long ranges.

As for the dug in experience at Anzio...was this a case of inability to get the first shot off? Persumably then the TDs had some first shot = kill capabilities. It would make sense that the TDs would be less effective in battle if you knew where they were to begin with (even if they knew where you were to begin with too) since the sloped frontal armor of panthers would be a tougher nut to crack.

[Redwolf]

Coe, are you talking U.S. or German doctrine now?

[coe]

oops well i meant for the question about what would it take to defeat U.S. TDs in their doctrinal role...if they were so successful what is their achilles heel? so to speak.

When you think about it, the U.S. had a pretty good mixture of tanks and TDs and the German big tanks weren't all that invincible as stated. Though how they managed to get such good exchange rates on the eastern front is amazing since the 122mm guns on the IS series and the 85mm gun are pretty good too.

[Redwolf]

Originally posted by coe:

oops well i meant for the question about what would it take to defeat U.S. TDs in their doctrinal role...

How about a couple of mortars

And cost. These things are not much cheaper than a tank which is a much more valuable weapon.