"Tank Destroyers" Topic

I was wondering about tank destroyers. If they're better at destroying tanks than regular tanks are, why not build nothing but tank destroyers? What exactly do regular tanks do that tank destroyers can't?

Destroy things other than tanks?

This is what the US Army thought on the subject:

link

This isn't necessarily the approach taken by other users.

Let's guess you mean US TD specifically.
They had thinner armour and usually worse he effect than a Sherman 75.
Armour is pretty handy when you're attacking and encounter something that's hidden ( like an ATG ) and shoots at you unexpectedly.
A roof on your turret looks pretty handy if someone starts shooting mortars in your direction or pretty much anything from a higher elevation.

The US Tank/Tank Destroyer doctrine was badly flawed. It was developed in the wake of the German's stunning blitzkrieg successes in Poland, France and Russia. The Americans took those examples and came to some bad conclusions. First they decided that tanks were not supposed to fight other tanks. Tanks were like cavalry. They were supposed to beat up on infantry and break through into the enemy's rear areas and cause panic and confusion. They should AVOID fighting enemy tanks. Thus American tanks had large but short guns, good for HE, but not good against armor, relatively thin armor, and lots of machine guns.

To deal with enemy tanks they came up with the idea of the tank destroyer. A large powerful gun mounted on a fast, but lightly armored chassis. They were expected to be used in large masses. When an enemy panzer breakthrough was feared, whole brigades of the TDs would be rushed to the area where they would destroy the enemy tanks from ambush.

The theory must have seemed reasonable to someone, but the reality of it was very different. First off, by the time the Americans got into the war, the Germans had shifted over to the defensive and weren't doing much Blitzkrieging anymore. There were very few opportunities to deploy brigades of TDs to wipe out masses of German armor. For most of the war the TDs got split up into platoon-sized formations which mostly supported infantry.

The biggest fallacy, of course was the notion that the Germans would COOPERATE and not engage the American tanks with their own tanks. It was a ridiculous idea from the start and as a result, you had the tragedy of American tanks routinely facing German tanks which were bigger and more powerful.

Even after the tankers in the field realized the flaws in the doctrine, the generals back home just wouldn't get the message and continued to send under-gunned and under-armored tanks to the front.

No idea about the Allied reasons, but was a lower cost / greater ease & speed of manufacture not a factor in the Germans' prolific use of TDs?

DG – Correct, in part. On the eastern front as the war went on, the decision also frequently involved the fact that getting a larger more powerful gun into a chassis without a turret was much easier than getting it into a turret. Also moving that chassis around with just the big gun required less engine and transmission than if you added the additional weight involved with a turret. And of course this also had fuel impacts as well.

Combine these factors with ease of production and Self Propelled guns became attractive for the bigger, higher velocity guns to use as tank destroyers.

Actually, not one of you is even close. Here is an excellent discussion of why tank destroyers vs tanks in the US Army.

YouTube link

Mike Bunkermeister Creek
bunkermeister.blogspot.com

Hard to take someone seriously who claims attack helicopters are equivalent to TDs.

US tank doctrine was when German tanks were encountered during and advance, pull back and let the air force and/or artillery hit them.
Repeat as often as needed. US tanks were not to engage in tank duels.

American tank destroyers were open top making them easier targets to artillery and air attacks than tanks.
The tactical role of TDs was one of defense,s so they did not present themselves as good targets as often as tanks in an advance would.
My father in law was in the VA nursing home and his roommate was in a TD company in Italy. He was very interesting to talk to. TD crew did not want to be in tanks because of the tanks tactical advances. They were happy to sit of the defense and take the first open shot. He said that in his platoon, they did not lose a single crewman until 1945. Even then they only lost crewmen to mines. That was also how he had good wounded.
I had one uncle killed by a mine driving a truck and another wounded. So I do not think mines are covered enough in WW2 rules.

It seems important to note that Soviet & German tank destroyers were fundamentally different from American tank destroyers. Lumping them into a single discussion seems odd.

US TDs were open-topped to give the crew better situational awareness. Even the armored roofs had a ~4" gap above the turret top to let the crew see.

They were lightly armored because that was the best way to give the speed needed.

Hard to take someone seriously who claims attack helicopters are equivalent to TDs.

Same role and similar operational setup.

The WW2 US Army TD doctrine required a very fast-moving vehicle. What experience proved was that no ground vehicle could move fast enough to respond to tank breakthroughs. But a helicopter could.

Ive always thought they'd have done better in the Desert. big gun and open top for max vision seem more advantageous there than in Europe.

Obviously no one in France in 1944 sent word to 1941 America that the decisive fights would in in a temperate zone against Germans on the defensive. That sort of message gets lost all the time, and it's really frustrating.

I notice also everyone is talking US TDs vs tanks, and not TDs vs towed AT. During the Bulge, TDs turned out to be a much better deal than towed AT guns. And no one's mentioning that Creighton Abrams turned down a tank gun with greater armor-piercing capability because it came at the expense of high explosive, which was what he needed to support infantry.

Maybe at Armor School they all have to recite "the best anti-tank weapon is another tank" but has anyone considered that they might be just a wee bit biased? No doubt there were a number of bad ideas in WWII. There usually are in a war. But the American TDs seem reasonably defensible.

Another perspective:
link

The M18 Hellcat found its element in the race to the German frontier after the Normandian breakout. Their biggest feat was achieved around Arracourt, North-Eastern France, where the 704th TD/4th Armored helped to chew up several German armored brigades between 18th and 22nd, Septermber, 1944. The division caused 75 tank losses for the Germans in 4 days. The foggy weather helped to compensate for the weaker guns of the Americans against the Panthers, and the hastily formed, straight from the armored school Panzer brigades lacked infantry and artillery support. These green troops rode into the crossfire of hull-down American tanks and TDs, and were decimated accordingly. The mad dasher Patton's Third Army prefered the nimble M18s over the old M10s. The crews were confident that they had the best kind of vehicle for taking out German heavy armor by flank shots and for avoiding punishment. The 76 mm gun had the same ballistic limits as the 3 incher. One M18 was tried with the turret of the M36 TD and the 90mm M3 gun at the end of the war. The Hellcat could take the 90 mm, and plans were made for field conversion of the existing vehicles in Europe, but V-day and the arrival of Pershing tanks put and end to the TD developments. Bradley's 12th Army Group was more for the well-tried M10s. The Hellcat's mobility was somehow overrated; the M4A3 medium tank could keep up with the M18s off-road.

Tactical advantage, better crew expertise, and combined arms is the way to fight. It's not always about individual stats.

Wolfhag

Harry Yeide explores US tank destroyer doctrine(s) pretty thoroughly in: The Tank Killers: A History of America's World War II Tank Destroyer Force.

Higher command had an ever-shifting view on what to do with them. Sometimes using them as emplaced artillery firing from sloped emplacements (about the best use that could be made in the slug-fest of Italy). Sometimes flinging them in as if they were tank battalions (eek). Sometimes actually letting them do their job.

By the end of the war, they had actually faired pretty well, racking up a high kill rate with pretty low losses.

The primary aim of tanks is not to destroy other tanks but rather to destroy the enemy infantry and anti-infantry weapons (and anything they can find in the enemy rear lines).
YouTube link
Tank destroyers don't advance and take ground.

This seems to be an odd thread. The Germans made lots of TD they did not call them that. Proably the most famous is the Stug III anbd IV. They did not have turrets but were the same defensive type weapon. They were able to carry a gun capable of eliminating a heavy tank where it was considsred that a heavier gun was not possible to fit.

It is interesting to note that the Brits did not go for Tank destroyers but by D-Day about 1 in 3 Shermans were Fireflys and these were proably the most capable gun on the allied side until late in the war. Now that may not be the sole reasom for the diffrence, the US were more concerned with tanks supporting infantry so that would colour there view.

Open topped vehicles are by no means ideal as they are much more vulnerable to artillery, and so hideing an open topped vehicle is paramount else it can be taken out by mortars.

Brits did have M10, Achilles, Archer and Challenger, but saw them more as a way to get AT guns into position more quickly to support inf and tanks.

You have to understand what they really meant when you toss out the claim "Tanks have no business fighting tanks."

AGF seriously considered using tanks to counter enemy tanks, but they realized that if you do that, you're potentially wasting an offensive weapon on defensive operations, you're decreasing the availability rate and making it harder to set them up for their primary job.

"Tanks shouldn't be forced or bogged down fighting enemy tanks." is a better reading of this idea.

Hence the TD was born. After a few interim models like truck and half-track mounted guns they came up with the M10, which while not perfect did have some advantages, the open turret gave vastly improved situational awareness and allowed the crew to operate more effectively than in the confines of a buttoned-up tank.

It also had an advantage over German TD that it had a fully rotating turret, the downside was that it unpowered, manually operated.

The TD was meant to be held in reserve and used to counter enemy armoured assaults, freeing up the tanks to do their job of attacking and disrupting enemy forces.

In reality the TD's were attached to divisions and used as tanks. It was a huge boost of morale to any soldier to know something with better armour than an M1 bucket and a bigger gun than your average M1 Garand was backing you up. When US troops were in retreat a sarge exclaimed "Why are we retreating, the TD's are here !" And then promptly turned around and attacked.

The doctrine wasn't perfect, but it differed very little from the one the Germans started with. Tanks were meant to break through enemy lines, avoiding being stuck in firefights with enemy armour (if possible), anti-tank forces would carry out that job, be it towed guns, infantry with AT weapons, panzerjaeger and other jagdpanzers, artillery and aircraft.

Even post war, most armies retained AT capability on a wide range of vehicles from the West German Jagdpanzer, the British FV 102 Striker or the US M901 ITV and arguably weapons like the Apache helicopter.

The TD ran into a huge problem, by 1944, the Germans no longer could operate the way they had done in 1940 and 1941 lest they be shot to pieces as happened at Arracourt.

So the TD which was primarily a specialist defensive weapon was pressed into service as a tank, because if it quacks like a duck, it's a duck and it will be used as a duck.

TD's were too much like tanks and ended being used up as such, which led to the understanding that if TD's were going to be used as such, they might as well have used proper tanks and they switched the AT role to other units which could focus on the job and not be used as ersatz tanks.

TD's were too much like tanks and ended being used up as such, which led to the understanding that if TD's were going to be used as such, they might as well have used proper tanks and they switched the AT role to other units which could focus on the job and not be used as ersatz tanks.

As many have noted … it's more about employment, doctrine and tactics, in WWII. As the war went on. Regardless, generally if either a Tank or TD saw a target. They'd engage most likely, as always based on terrain and situation …

And again, in most/many cases … who gets off the first well aimed shot "wins" as so many of the historical stats have noted. Which makes sense to me …

Hard to take someone seriously who claims attack helicopters are equivalent to TDs.

Again, here it is more about employment, doctrine & tactics. As we see with the US military. E.g. some of the earlier UH-1s packed AT missiles IIRC, the SS-11(?). Then the AH-1 the TOW AT missile and later the AH-64 the Hellfire. All those missiles were designed to kill AFVs(and about anything else they could hit ! The Predator & Reaper Drones today, IIRC frequently pack those as well.) As the West knew if the USSR/WP crossed the IGB. They'd have a flood of AFVs rolling thru the countryside.

The tactic similar to a point to WWII AT/TD tactics. The Gunship would ambush the AFV(s). Firing from a covered and concealed position. As we see sometimes WWII TDs did. The modern Gunship would hover low behind a ridge, tree line, structures, etc. Then "pop-up" fire it's ordinance at the oncoming AFVs. Then go back down under cover. Possibly move to an alternate/supplemental position. Then pop-up again, fire, etc., etc., repeat … Again, something like a WWII TD would/could do. But the Gunship has a number advantages over most/many TD/AT weapon systems …

E.g. My Mech Inf Co,'87-'89 had 2 M901 ITVs organic to it's TO&E. Plus every Inf Sqd had an M47 MAW = 9 total. Again to kill AFVs … and again kill anything else if need be … Depending on terrain & situation …

Something else to note. E.g. FA can fire directly, but generally it is almost always used to fire indirectly. However, there were a number of times FA had to fire directly, again based on terrain and situation. E.g. :

Berlin or Manila in WWII.

Korea when NoKo T34/85s overran US positions in 1950.

Vietnam US FA in Fire Bases had to fire directly as VC/NLF/NVA forces attempted to overrun the Fire Base.

The post-war sitation is very different from the one in 1940.

Back then the only good antidote for an enemy tank was an AT gun. They were supposed to be small, easy to hide and cheap to make. By the end of the war, they were everything but that. Guns had grown so big that there was little or no alternative but to put it on some kind of vehicle (though some armies did persist in using large AT guns for many years)

After the war, the rapid development of missiles meant that infantry now had access to a weapon that could be crewed by one or two men and still be highly effective. This meant that from then on all branches of the armed forces now had anti-tank means rather than have to rely on a specialist branch like the TD. As a result the TD merged with the tank and new opportunities rose to improve vehicles such as armoured cars and troop transports to have a greater anti-tank ability and able to support infantry more effectively.

If there was a problem with the TD doctrine it was the fact that it was considered a separate branch and was not integrated into combat units the way other weapon systems were. That and the flawed "Battle Need" concept, the idea that a weapon would not be introduced until there was a clear demand for from the field. The problem was that the combat forces didn't have the time or expertise to figure out what they "needed" quickly enough to ensure to a new weapon system could reach them before the next enemy development cycle, if they were able to come up a clear battlefield need and demand in the first place.

Another problem was that when some needs did reach AGF they were the final arbiter. This could result in them making a false assumption and underestimate the reports coming from the front, such as underestimating the ability of the Germans to mass-produce the Panther and use it as their main tank rather than stick with the Panzer IV. And there was no guarantee that the demand was interpreted the right way. Some used it to push their own pet projects like the concept of a super-fast TD (the M18 Hellcat) or the idea that the 3-inch/76mm was preferable to the 90mm, you just had to get more of them to the front lines etc. Perhaps the best example was Mc Nair's sudden Road to Damascus moment when after the heavy losses in Tunisia he saw British reports that lead him to conclude that well-emplaced towed guns would always dominate tanks. What he failed to understand is that while the British had some success with towed guns, they also understood that putting them on a mobile chassis was clearly the way forward. So while everyone struggled to upgrade their towed guns into AFV's, McNair was taking M10's away from the TD units and forcing them to use the poorly designed 3-inch AT gun, which was too heavy and too big to be used efficiently. The combat effectiveness of these units plummeted while that of the M10/M18/M36 equipped units only increased and this policy was eventually reversed.

The trouble with U.S. tank destroyers was that they were a defensive weapon, but the U.S. was on the offensive. But they did pretty well anyway.

The post-war sitation is very different from the one in 1940.

Back then the only good antidote for an enemy tank was an AT gun.

Very true … the tactics, doctrine, etc., evolve almost synergistically with tech generally as it appears sometimes. But of course there are always exceptions. E.g. Poor leadership can't/won't defeat the enemy. Even if with tech superior and/or numbers.

Arguably a good example is the France '40 Campaign. The German dogma, tactics, techniques, etc. was more effective, efficient, etc. Than those of the UK, France, etc. generally. As was the case thru out most of Western Europe in first few years of the war. For the most part. The armies there were basically "out classed" by the "Blitzkrieg", etc.

British reports that lead him to conclude that well-emplaced towed guns would always dominate tanks. What he failed to understand is that while the British had some success with towed guns, they also understood that putting them on a mobile chassis was clearly the way forward.

Something else we see that developed very much during WWII. Mobility is an important/paramount factor generally in modern(and even in unconventional at times) warfare. It's about a war of maneuver, as again the Germans demonstrated, in the very early years of WWII.

U.S. tank destroyers was that they were a defensive weapon, but the U.S. was on the offensive. But they did pretty well anyway

Yes, I think that is what I was somewhat trying to say. In some of my posts above. Regardless, again based on terrain & situation. You are there to kill the enemy. And with/use the weapons you have to do it no matter the original intent based on dogma, etc.. in some cases. E.g. FA firing direct, TDs being used in the same or similar manner as Tanks(or what we call today MBTs) in WWII.

At least the US army went to war with a decent AT system.

Military planners in the 20s and 30s assumed that tanks would be confined to supporting infantry operations. They expected to face infantry divisions, that's why they were well equipped to deal with infantry and anti-tank measures were almost an afterthought, figuring that a company of AT guns would be enough to deal with the company of tanks that would accompany a division, the rest would be dealt with by artillery and if necessary armoured counter-attacks.

This didn't go well when the Germans pooled all their tanks into armoured divisions and used them to smash through the frontage of a pair of reserve divisions. Hundreds of tanks with only a handful of AT guns on the other side …

Units simply didn't have the means to stop them. Even the Germans underestimated the threat of tanks, when the French and British counterattacked they were hard pressed to bring up their own AT assets and found them thoroughly lacking. It was sheer luck and some clever thinking to use artillery and 88mm flak in direct fire mode to cause the attacks to stall and fail.

Had the French and British lacked the infantry and artillery support to properly support their tanks.

The Germans increased their AT assets, but this wasn't enough. In 1944, a German infantry division tried to stop the Polish armoured division in the same spot they had defeated the French four years earlier and were defeated in a matter of hours. Properly trained and experienced, with the right doctrine and equipment they made short work of German resistance, despite that division having far better AT equipment at their disposal than their comrades in 1940.

This kind of topic frequently brings out old wives' (old NCOs'?) tails.

No, US doctrine was NOT "tanks don't fight tanks".

Now to answer the OP, "what exactly do regular tanks do?" That can also be found in doctrine. At least, the theoretical answer. What tanks (or any other force of arms) actually did on the battlefield often differed from doctrine, but at least we can look to doctrine to see what the tanks were supposed to do.

What is doctrine? How can you find out what the doctrine was (or is)? Is doctrine what a guy said on a History Channel program I saw once? Is it what someone wrote in a novel or a memoir?

The thing is, it isn't doctrine if it isn't used by the organization in question. When we are speaking of organizations of hundreds of thousands or millions of people, you don't get doctrine by giving an interview. Doctrine, for armies, is what they write down and issue to their soldiers and officers while they are training. That means field manuals, long winded documents that guide the mass of soldiers and officers in how and what they are supposed to do.

So if you want to know what US Army doctrine was with regard to what tanks were supposed to do, or whether tanks were supposed to fight other tanks -- look at the field manuals!

To wit:

FM 17 ARMORED FORCE FIELD MANUAL, November 1941, p. 23:

The objective of armored attack is to destroy the enemy. This is effected by breaking through his defenses and surrounding all or parts of his command.

Hmm. Seems that US Army doctrine for tank warfare was looking for more than just a specialist vehicle. Attack and destroy the enemy, break through his defenses, surround his forces. Nothing there about only shooting at soft targets or only support the infantry, or sit back and snipe at enemy tanks …

But more specifically to the question of tanks fighting tanks:

FM 17 ARMORED FORCE FIELD MANUAL, November 1941, p. 31, 32:

When enemy armored units are met during a march, attack will be made from march column. The tank units lead the attack. Missions and objectives for subordinate units will be immediately ordered by the division and column commanders. The tank destroyer units well forward in the column may be used to attack and delay the enemy.

Once an enemy armored force is in position to intervene in the battle, its destruction is the main task of our own armored units. The enemy armored units must be attacked and destroyed by all available anti-tank weapons … even if this entails the abandoning of a previously assigned mission.

OK boys, here is a multiple choice question:

In 1941, when enemy tanks were encountered, US doctrine said that US tanks were to:
a ) Withdraw and let the tank destroyers take care of things.
b ) Engage immediately, and lead the attack on enemy armor even if tank destroyers were present, even if it meant foregoing other mission priorities.

Anyone? Hmmm? Ferris?

That was in 1941. That was the doctrinal baseline as the armored force was built up, the armored divisions were formed and trained, and the Sherman was designed and taken into service.

A little (not a lot) later we can find more.

FM 17-10 ARMORED FORCE FIELD MANUAL, March, 1942

From the Opening Paragraph:

The role of the Armored Force and its components is the conduct of highly mobile ground warfare, primarily offensive in character, by self-sustaining units of great power and mobility, composed of specially equipped troops of the required arms and services. Combat elements of the Armored Force operate in close cooperation with combat aviation and with large units of ground troops in the accomplishment of a mission.

What the US Army wanted was a highly mobile offensive striking force. That's what the Armored Divisions were designed and trained to do. They were not the sit back and defend force, not the occupy and consolidate force, not the support the infantry force. They were the offensive force of sustained mobility and power.

Drilling down a bit on this, from p. 2, Paragraph 3, we find the 4 Part Doctrine of Armored Warfare, still used today:

CHARACTERISTICS–The characteristics of Armored Force units are:
a. Mobility.—All combat units are mounted in armored motor vehicles.
b. Firepower.—Through a multiplicity of weapons mounted on the vehicles.
c. Armor protection.—All combat vehicles are protected by armor of varying thickness, capable of withstanding at least rifle fire.
d. Shock action.—Accomplished by the combination of the other characteristics and by the weight and crushing power of the major vehicles.

So tanks, and everything else in the armored divisions, were to be very mobile, have high firepower, be protected, and be capable of shock action.

No where does it say sniping.

To the question of tank vs. tank action, on p. 91 we find:

Medium tanks also protect … against the attack of hostile tanks. When the enemy is composed of mechanized troops, a large medium tank component, if available, is held in the reserve.

The mission of the tank destroyer with the armored division is to assist either by offensive or defensive action in the protection of the division against hostile mechanized forces.

Another pop quiz:

In US Army doctrine, who had the primary role (vs. the supporting role) when an Armored force met enemy tanks:

a ) The light tanks
b ) The medium tanks
c ) The tank destroyers
d ) Chuck Norris

And now the last doctrinal statement from the WW2 period, written after the combat experiences of Tunisia and Sicily at least.

From: FM 17-100 ARMORED FORCES FIELD MANUAL, January, 1944

Under the Missions of the Armored Division, item "j" reads:

Attack to destroy enemy armored units when forced to do so as a matter of self-preservation or when hostile tanks threaten seriously to disrupt operations of other troops.

So we have much of the doctrine laid out for view. Tanks were mobile, high firepower, protected weapons for offensive action. Enemy armor was to be a priority target when they appeared, even to the detriment of other missions. Medium tanks had primary responsibility for engaging enemy armor in the area of operation of an Armored Division, with any tank destroyers playing a supporting role.

Can we please be done with the "American doctrine said tanks don't fight other tanks" bit? You don't have to rely on talking heads on the History Channel, or guess and assume. You can go read the doctrine yourself.

-Mark
(aka: Mk 1)

Nice post Mark but I'm afraid the subject will rear its ugly head again in 6 months.

Wolfhag

Six months ? Someone with a king-size brass-bound edition of Belton Cooper's "Death traps" will come along any moment to hit us all over the head with it telling us with unwavering certainty that it was Patton who personally held back tank development, that the Pershing could have been available in 1811, that TD doctrine was a failure as in "FEYLUR !" and that Cooper has a thousand times the street cred of any historian and actual military archives because he spent the war scraping dead tankers from the inside of tanks and that it was all confirmed by the History Channel !!! Now load that in your 75mm and smoke it !!!

Well let's hope they do it without the patronising 'pop quizes'.

Yes, Mark I agree … and I was basically taught & studied the same things you posted based in WWII US ARMY doctrine, etc. As I said :

"Regardless, again based on terrain & situation. You are there to kill the enemy. And with/use the weapons you have to do it no matter the original intent based on dogma, etc., in some cases" …

" Mobility is an important/paramount factor generally in modern(and even in unconventional at times) warfare. It's about a war of maneuver" …

How come this so quickly became a "US TD" centric thread? Or was it originally intended as such?

I was basically taught & studied the same things you posted based in WWII US ARMY doctrine ….

I think this is key to understanding the mis-understanding that seems so pervasive whenever the subject of US armor and the Tank Destroyers comes up.

Wargaming tends to drive our thinking and understanding to the tactical level. What's my armor penetration? What's my cross-country speed? If your primary goal is to joust with Panthers, Shermans don't make much sense.

But if we think in terms of operational terminology and the doctrine, it is easier to understand.

Mobility
Firepower
Protection
Shock Action

In this I think the higher unit-level games provide somewhat better insight. Even though I prefer the one-to-one unit scales for my own gaming, I recognize that it is easier to understand the differences between Armored Force doctrine and Tank Destroyer doctrine when looking at assembled companies and battalions that have capabilities rolled up into ratings on protection or mobility or firepower that take a variety of details into consideration, assembled into brigade and division-sized actions covering several dozens of Km.

At that level, the doctrinal terminology, and the ability (or limitations) of the various weapons to execute on that doctrine, all make sense.

-Mark
(aka: Mk 1)

Dwindling Gravitas has a significant point. US tank destroyers had a problem in that b open topped vehicles are far more vulnerable to artillery fire. Even relatively light tanks are virtually invulnerable to HE in normal concentrations. German tank destroyers ( not mobile AT guns) were fully armourd cap a blend of being buttoned up and usually were limited traverse guns, often better than the equivalent tank. I believe the 38 (t) was one of the last tank destroyers to leave service post war as it's small size made it easy to hide in ambush. Again it was more able than an opened top vehicle to withstand HE.

A thinly armoured open topped vehicle is a poor substitute for a tank in a offensive role. A defensive posture (even as part of an overall attack) is a much better fit for an open topped vehicle that can hide.

Even German TD's though better protected need to be on over watch or in a more defensive role as the in limited traverse was an issue.

Interestingly the Swedes considered the S tank a tank as uniquely it could stop, turn and fire faster than a turreted tank. This of course was before truly effective stabilisation came in for turreted tanks.

All this talk of U.S. doctrine reminds me of comments from both the Germans and Soviets that studying U.S. doctrine was pointless since the Americans never followed it.

UshCha, you seem to be forgetting the Panzerjager I and the entire Marder series of open-topped self-propelled antitank guns.

Indeed I am not forgetting the German open topped vehicles, however they are to me what you describe them to be, mobile anti tank guns, while they move faster and can be emplacement potentially quicker than a towed weapon,they suffer the same tactical limitations of vulnerability to HE as towed guns. This by no means makes them worthless but does limit there range of useful tactical deployments. They need to be deployed where artillery is not a threat before they have served their purpose.

I was just pointing out that German TDs weren't always "better protected."

I am not forgetting the German open topped vehicles, however they are to me what you describe them to be, mobile anti tank guns, while they move faster and can be emplacement potentially quicker than a towed weapon …

This is an excellent description of what the US Tank Destroyer command wanted.

Let me ask: would you consider the Marder to be a lesser solution for the role you describe if it was armored across the back, and could traverse it's gun through 360 degrees?

(Trying very hard to avoid 'patronizing' pop quizzes here -- please note the complete absence of any attempt at humor.)

The Tank Destroyer Force wanted mobile anti-tank guns. They wanted anti-tank guns that could mass quickly, and deploy to key positions in the path of the enemy's mobile tank force with sufficient speed to take and prepare ambush positions.

Please note that the vehicles were not officially called tank destroyers. An M18 was not "76mm Tank Destroyer M18", it was "76mm Gun Motor Carriage M18". They were self propelled guns. It just happened that after the 75mm GMC M3, they decided to put the gun in a mount with 360 degrees of traverse and 360 degrees of armored protection.

I have seen discussions among WW2 tank enthusiasts (and gamers) that articulate and belittle the doctrine that "speed is armor". But that is a strawman -- there was no such thought process evident (to my readings) in the formation of US Tank Destroyer doctrine.

Speed was for assembling a sufficient force of tank destroyers and getting into position ahead of the enemy's tank force. The back-and-forth in the doctrinal development was all about the need to be faster than the enemy's armored force, not faster than their turret traverse or they ability to track a target. And key to this thinking was that "terrain is armor" or "position is armor". Being able to deploy to advantageous firing positions was the key to Tank Destroyer doctrine.

… they suffer the same tactical limitations of vulnerability to HE as towed guns. This by no means makes them worthless but does limit there range of useful tactical deployments.

The risks of artillery fire are somewhat misstated, not so much in the post I am quoting here (mostly to re-introduce the topic) but more so in several other posters' comments.

In my (admittedly limited) opinion the open-topped turret of US Tank Destroyers did not pose a critical risk factor under artillery bombardment, except in limited specific circumstances.

In WW2, a field artillery round (105mm or larger) landing ON you vehicle was going to ruin your day, quite regardless of what vehicle you were in. Shermans, or even Panthers, did not have top armor that could withstand such strikes without highly destructive results for both crew and vehicle. However, direct hits on the vehicle from artillery area fire were rare. Direct hits specifically on the turret from artillery area fire were even more rare.

Far more important was all-around protection from fragments. Near misses were the common danger, and having armor prevented penetration of fragments from all but the closest / biggest near misses. This is what the US Tank Destroyer Board wanted it's vehicles armored against -- HE fragmentation. That level of armor also provided protection from small arms fire, but it was fragmentation that was the driving concern.

Panzerjaegers (Marders, etc) had similar levels of armor across their frontal arcs, but were open to small arms fire, and more importantly perhaps to fragmentation from HE near misses, across the rear arc.

The risk from above can really be thought of as limited to tree-burst when under fire in forested areas, or from air-burst munitions (very rare in WW2), or from light (infantry) mortar fire or infantry weapons. But when used in their doctrinal roles (ie: not when used as ersatz tanks) there was no significant risk from light mortars or infantry fire.

So when we think of US Tank Destroyers, we can see them largely as one developmental path from the same base as the Panzerjaegers. Early US Tank Destroyers were really very similar to early Panzerjaegers. The further evolution of that platform for the Americans was better mobility, 360 degree traverse for the gun and 360 degree protection from fragments. The further evolution for the Germans was 360 degree protection from fragments, and enhancing the frontal protection against direct fire, but keeping the limited traverse.

-Mark
(aka: Mk 1)

Mark,
I think we are basicaly in agreement. However that meand a TD is a Tacticaly defensive weapon. This limits its use in offence. One reads of US TD's being used as "tanks" which is a long way from ideal. As I understand it Airburst was coming in by the end of the war and overhead protection of all arms from such munitions was becoming more important. You are correct direct hits bt HE even now don't do any AFV much good but they are rare enough in most circunstances to be a non significant factor.

Only the western allies had radar airburst rounds and they were pretty rarely used.
Of course, flak routinely used timer airburst.

A number of allied tankers describe use of the german 88 for airburst.
It seems they felt it was a significant risk to dismounted crew and "up" commanders.

But yes, generally speaking.
An open top vehicle wasn't much more vulnerable to indirect fire.
US TD crews were rather more concerned about direct small arms.
And of course this was considered in the design of half track apc.

I thought Zaloga's point in his balanced discussion of the US TD vs tank doctrine and usage debate in, I think, Armored Thunderbolt and elsewhere, doesn't get appropriate recognition – namely that they never came up with an adequate A/tk gun, however carried, until the 90mm M36 came along.
R.

In WW2, a field artillery round (105mm or larger) landing ON you vehicle was going to ruin your day, quite regardless of what vehicle you were in.

Getting hit by a large artillery round was rather rare. But mortars were far more common. Light or medium mortar bombs won't penetrate the turrets of most tanks. They will do a number on an open turret.

Getting hit by a large artillery round was rather rare. But mortars were far more common. Light or medium mortar bombs won't penetrate the turrets of most tanks. They will do a number on an open turret.

Quite agree.

But the doctrine for the TDs was to operate in friendly territory, to head-off and engage the fast moving Panzer columns after they had penetrated the front line. They were to ambush the enemy when he was on the march, not stand in the line and weather a deliberate assault.

In that environment, light and medium mortars were not likely to be a major concern.

And so they were designed to provide protection against fragmentation from field artillery.

However that meand a TD is a Tacticaly defensive weapon. This limits its use in offence. One reads of US TD's being used as "tanks" which is a long way from ideal.

Quite agree with this as well. I think this is, in fact, the key to understanding the whole issue.

TDs, and the TD doctrine, were developed to address a single risk scenario. That risk turned out to be very rarely evident once the US Army got into action.

The TD vehicles were designed and built, and the TD units were organized and trained, to be a separate force of specialized armored vehicles held in reserve JUST IN CASE the enemy broke through the front lines.

That was the flaw. No front line commander was going to hold such a valuable resource as a significant armored force in reserve just in case…

And so they got pushed forward, in penny packets (since they had no dedicated formation higher than a battalion anyways). They got used as ersatz medium tanks in a variety of roles from supporting infantry attacks to bolstering the AT firepower of medium tank formations to stiffening defensive lines, despite their flaws and sub-optimizations for that role. M10s also served as self-propelled artillery on some occasions. M18s also got used as ersatz light tanks / scout tanks, perhaps with fewer notable shortcomings for that role.

The problem was not that the vehicles weren't useful for the job they were designed for, but that the job they were designed for wasn't useful enough to get its own vehicles.

-Mark
(aka: Mk 1)

I thought Zaloga's point … doesn't get appropriate recognition – namely that they never came up with an adequate A/tk gun, however carried, until the 90mm M36 came along.

This does raise a peculiar issue in the US Army post-1940 doctrinal thinking. Quite aside from the so oft repeated ex post facto fabrication "tanks don't fight tanks", there seems to have been a real doctrinal issue that seems to have misguided development and deployment.

One of the factors that led to the TDs was a doctrinal belief that a concentrated tank force would always be able to break through a primarily infantry defensive line.

This was probably a reasonable belief. With the exception perhaps of Kursk, which I think can be viewed as the extreme case rather than the common planning scenario, concentrated attacks with armor DID break through pretty reliably.

But that does not mean that you don't put capable anti-tank weapons on the front line!!!

This part I don't really get. Why didn't the infantry ALSO demand 3-inch AT guns, and 90mm AT guns?

There really is almost no evidence that the existence of the TD force slowed the development of AT capability in US tanks. Ordnance pushed forward all kinds of tank designs with beefed up AT capability, but the Armored Board had 1,001 reasons to drag its feet, not some much because they had someone else (TDs) to handle the threat, but because they just didn't perceive the threat.

But there does appear to have been a complacency on the part of the Infantry, that seems to have been related to the existence of the TDs. I'm not sure how the Infantry Force got comfortable with the idea that better AT weapons would be available once the front line infantry divisions had been overrun. But it seems odd that there was no outcry from the (very politically powerful) infantry. Ordnance new how to make the barrels and (debatably) the ammo. Whey was there no push to put them on towed carriages for the infantry?

This is the doctrinal difference between the German Panzerjaegers and the US Tank Destroyers, both towed and self-propelled. Panzerjaeger formations were PART of the infantry (and panzer) divisions. They were a part of the divisional defense, not something that was to be called after the divisional defense failed.

-Mark
(aka: Mk 1)

While U.S. TD battalions were not, technically, part of any division's TO&E, almost every TD battalion was attached directly to a division most of the time -- in many cases, the same division for months at a time. Almost every infantry division had either a TD battalion or a tank battalion attached, sometimes one of each.

Ive always thought [TDs would] have done better in the Desert. big gun and open top for max vision seem more advantageous there than in Europe.

They did quite well there, but the Americans were late to that party. The typical US TD in the Desert was a 75mm on a halftrack, not the 3" gun on the tracked M10.

And they were both badly outranged by the 88s.

This part I don't really get. Why didn't the infantry ALSO demand 3-inch AT guns, and 90mm AT guns?

Probably for the same reason that the 17pdr did not replace the 6pdr as battalion AT. Its very weight and size meant that it took a lot longer to deploy and was hard to hide. If you are constantly attacking, a heavy towed AT gun that needs hours to emplace properly is not much use, 95% of the time. It is also not much better at hiding than a TD.
The big towed AT guns were important in set piece attacks to reinforce the objective in time for the expected counterattack or if you expected an attack but I doubt that the US 3" gave a big enough advantage over the 6pdr to replace them as integral AT guns, especially after the 6pdr APDS started appearing.

Also bigger guns means more men and vehicles to man and transport them, means less for the infantry platoons.
It would have been very different if US had been on the strategic defence for year.

Probably for the same reason that the 17pdr did not replace the 6pdr as battalion AT. Its very weight and size meant that it took a lot longer to deploy and was hard to hide.

Yeah but … but … but …

The 17pdr I can understand. This was a weapon in the class of the German KwK42 75mm gun (the gun in the Panther).

The U.S. had the 3-inch anti-tank gun M5, which was in fact in about the same size and weight category as the 17pdr. But it was not in the performance range of the 17pdr or the KwK42. Rather, it was in the performance range of the German Pak 40 75mm anti-tank gun.

The Pak40 was a notably smaller and lighter anti-tank gun, which was probably at the edge of what an infantry crew could man-handle, and so also at the edge of what the infantry could productively use. It was the last of the German PaKs to fit the Blitzkrieg model of pushing towed-gun Panzerjaeger batteries forward aggressively as active mobile formations. The Germans did produce some larger Pak guns (long 88mm and even 128mm guns). These were not nearly so widely distributed, and were much more defensively oriented weapons, being of size and weight more like the FlaK than PaK weapons.

The U.S. 3-inch gun M5 was a WW1-era anti-aircraft and coastal artillery gun designed for fortress emplacements, retro-fitted to a WW2 gun carriage. But by late 1942 U.S. Army Ordnance also had the 76mm tank gun M1 available. This was a modern gun designed to duplicate the performance of the 3-inch gun in a lighter, more compact package. If a towed AT gun had been developed from this weapon, it could have been in the size and weight range of the Pak40. This would have been less handy than the 57mm M1 to be sure, but it would have been a substantial improvement over the 57mm in performance.

It seems no one from the Infantry pushed Ordnance on AT guns. It looks to me like they became complacent, just assuming that the Tank Destroyer Battalions or the Armored Divisions would protect them. But the Armored Divisions had a doctrine of defeating enemy tanks that might interfere in the areas of their own offensive operations, while the Tank Destroyers had a doctrine of containing and destroying enemy tanks after they had broken through the infantry line. Neither of those branches had a doctrine of distributing their forces across the front line to protect infantry positions.

Of course that's what the Tank Destroyers were often tasked to do. But their equipment and training was not optimized for the role. It seems that infantry commanders they were attached out to, focused as they were on taking and holding ground, were not terribly enthusiastic about AT assets that could maneuver independently for advantageous fields of fire, nor terribly impressed by AT assets that had equipment and training focused on shoot-and-scoot tactics.

It sounds a bit like I am criticizing and Monday-morning quarterbacking U.S. Army Ordnance and the Infantry. In cases like the USN BuOrd torpedo testing, or the US Army Ordnance AP projectile testing, I might be more directly critical. But in this case I am more trying to understand than to criticize. I just can't figure out, after the experiences of Tunisia (can you say "Kasserine Pass"?), why the Infantry was not more active in pushing for first class AT guns.

-Mark
(aka: Mk 1)

Maybe "they" realised there was a lot to be learnt and were reassured that more tanks would be around in future and they would be used better.