Guns vs Armour

[JasonC]

First, US TDs were not lightly armored. The first halftrack mounted French 75s were, and ever since everyone has repeated it like a mantra, but it simply isn't so. The Hellcat was also lightly armored, deliberately (for speed). The M10 and M36 were open topped, but about as armored as any medium tank. It took a full heavy PAK to KO them etc.

The reason to go turretless is purely to get a bigger gun on a smaller chassis. Whenever it was possible to mount the gun on the chassis with a turret, it was. The US successfully fit a 90mm gun, the largest they fielded for direct fire, in a turreted TD - and the Brits likewise fit their 17 pdr in a turreted TD. Both on common chassis. So why would they go turretless?

Still larger guns were mounted turretless, but weren't ATGs for direct fire - the 25 pdr, the 105, 155s - all went on M3 or M4 chassis as SPA. (The 105 also fit in the turret of the Sherman "assault gun", though).

As for smaller chassis, there was only one really, the Stuart. They mounted 75mm on those open topped but turreted, as the M8HMC.

As for the Germans and "turreted TDs", they were called tanks and they weren't lightly armored.

As for performance with PAK, through midwar the Germans were much more successful with PAK fronts than the allies typically were. But the reason was largely a common doctrinal failing on the allied side - poor cooperation between armor and artillery. Both the Brits and the Russians tends to use armor too much alone, and this increased the strength of a sufficiently thick gun line. The Brits were further hampered by lack of HE (their doctrine was that the MG was used vs. infantry not the gun).

By midwar that cleared up, although close cooperation between indirect fire and armor remained weak in the Russian army. They made up for it or tried to with direct HE fire from tanks and SUs, but that meant those were also vulnerable to replies by PAK.

Still, the evidence is that PAK were considerably less effective over their whole service life than AFVs were. The Germans fielded about as many heavy PAK as they did full gun-armed AFVs. Between them, they averaged about a kill apiece (major German AT system fielded about equal allied tanks lost, and do equal them if infantry kills are taken out), and the AFVs certainly scored higher than the guns did. (Indeed, only the better German types can have scored above unity, average). While occasionally a well placed unit of PAK could KO several times their number, equally often they would be lost to artillery fire or fail to pull out in a retreat etc.

As for the AT effectiveness of allied SP TDs, they did their job whenever there was German armor attacking in strength. That just didn't happen all that often in the west. When it did, the Germans lost 50-100% of the committed armor, typically. The highest scorers were essentially always the SP TDs, with indirect artillery, tanks, and infantry AT all effective supplements. Mines and towed ATGs and airstrikes got a few more but not in the same league as the previous.

For much of the rest of the war, though, the allied TDs were "underemployed" for lack of German armor to fight. They were used as additional tanks supporting general attacks, a task for which they were less well suited (lacking overhead cover vs. artillery fire, light on MGs and HE loads, etc). Sometimes they fired indirect as extra artillery. Some of the foot units were used as artillery and others were disbanded to get extra warm bodies in the foxhole line, as infantry replacements. Many unit cannabilized their 57mm ATGs in particular.

The Germans needed their heavy PAK, and other than using some 88mm ATGs indirect occasionally, did not resort to such things. In the last year of the war, though, infantry AT became a significantly larger portion of their AT defense, and towed PAK a lesser one. Many IDs transitioned to 1-2 companies of SP TDs and 1 of light flak, with only 0-1 companies of towed PAK as division, and a few batteries of it at the regimental level. Even the latter were sometimes replaced by panzerschreck groups (notably in the volksgrenadier formations). The main shortage pushing this was lack of transport. Trucks were scarce and went to mobile divisions, as was fuel.

As for its tactical use, being on defense helped. The Germans also had excellent heavy PAK (once the 50mm dropped out as a first line item) and faced only moderately armored allied AFVs, for the most part (a few IS and ISUs, and a handful of Churchills and Jumbos, the only exceptions).

In addition, the Germans got very good at camo and hid their gun ambushes well. I think it is fair to say the allies were comparatively lax about that, especially the western allies (as opposed to the Russians I mean), used to attacking etc.

[coe]

so you are saying that essentially when fighting (if you ignored artillery), US TDs vs. German tanks was essentially a tank versus tank battle?

i don't know the stats on this but as you said TDs did pretty well against the Germans - did they give better than they got and if so why? was it a case of not being on equal ground - i.e. if you were in the open steps of Russia would you rather be in panthers or US TDs. By some accounts it seems that the TDs are better. or perhaps they were better trained by that point.

I assume the U.S. TDs weren't heavly exposed to massed artillery fire as often as the German tanks were which would be a liability to the open top. Otherwise i can imagine the Germans as thinking maybe we should ditch the top of the turret too and have a fast turret also (less weight)

[michael kenny]

Originally posted by JasonC:

[QB] First, US TDs were not lightly armored. The first halftrack mounted French 75s were, and ever since everyone has repeated it like a mantra, but it simply isn't so. The Hellcat was also lightly armored, deliberately (for speed). The M10 and M36 were open topped, but about as armored as any medium tank. It took a full heavy PAK to KO them etc.

Wrong. Why believe me when you can 'hear' what Hunnicutt had to say about the TD experiment.

" The first M36s arrived in Europe in August 1944

and were immediately committed to action in France.

Battle experience brought out the need for additional

changes. Because of its heavy firepower, the M36 was

frequently used as a tank rather than in its original role

as a tank destroyer or self-propelled gun. Under these

conditions, it was vulnerable with its thin armor and

open top turret. Because of the latter, artillery air

bursts and small arms fire often caused casualties to

the crew. In August, the Army Ground Forces directed

the development of an overhead cover kit to provide

protection for the turret crew. These covers were

folding armor tops designed to protect against small

arms fire and shell fragments without completely

sacrificing the all round vision of the open top turret.

Another problem arose from the new waterproof

steel containers being developed for the 90mm rounds.

Since they were too large to fit in the sponsons, new

ammunition racks were designed to permit stowage of

the bare rounds. The new racks were released to

production along with the armored turret tops for all

vehicles produced during 1945.

The continuing demand for 90mm gun motor

carriages resulted in additional production starting in

May 1945. Montreal Locomotive converted 200

MIOAls to M36s during the remainder of the year.

This exhausted the supply of MIOAls requiring the use

of the diesel powered M10. Originally designated as

the T71E1, it was classified as the Substitute Standard

90mm gun motor carriage M36B2 in March 1945.

Starting in May, American Locomotive produced 672

M36B2s by the end of 1945. An additional 52 were

converted at the Montreal Locomotive Works by the

end of the year. This brought the total production of

the M36 series to 2324.

In April of 1945 the development of fording

equipment was completed for the M36 and in June

standardization was approved for the new M83 direct

sight telescope. Battle reports from Europe indicated

that the M36 was being employed more and more in

the role of a tank, a task for which it was not properly

designed. Requests were received for both a coaxial

and a bow machine gun. The latter was already

provided in the M36B1 since it used the standard tank

hull. Complaints about the high ground pressure

resulted in the application of the M4E9 spaced out

suspension and extended end connectors to the late

production vehicles. All of these factors foreshadowed

the demise of the tank destroyer in the postwar army. It

was too much to expect a vehicle originally designed as

a highly mobile self-propelled gun to perform the role

of a tank. All of the modifications such as the auxiliary

armor and folding turret top only served to underline

its deficiencies when compared to a properly designed

tank. Nevertheless, the M36s continued to serve during

the postwar period and were furnished as foreign aid to

a number of Allied nations. They were still in service in

Korea during the mid 1950s.

The passage is from Hunnicutt's legendary work on the Sherman.

Originally posted by JasonC:

[QB] The highest scorers were essentially always the SP TDs, with indirect artillery, tanks, and infantry AT all effective supplements. Mines and towed ATGs and airstrikes got a few more but not in the same league as the previous.

I would love to see the data used to reach that conclusion

[Kingfish]

Originally posted by michael kenny:

</font><blockquote>quote:</font><hr />Originally posted by JasonC:

[QB] First, US TDs were not lightly armored. The first halftrack mounted French 75s were, and ever since everyone has repeated it like a mantra, but it simply isn't so. The Hellcat was also lightly armored, deliberately (for speed). The M10 and M36 were open topped, but about as armored as any medium tank. It took a full heavy PAK to KO them etc.

Wrong. Why believe me when you can 'hear' what Hunnicutt had to say about the TD experiment.

" The first M36s arrived in Europe in August 1944

and were immediately committed to action in France.

Battle experience brought out the need for additional

changes. Because of its heavy firepower, the M36 was

frequently used as a tank rather than in its original role

as a tank destroyer or self-propelled gun. Under these

conditions, it was vulnerable with its thin armor and

open top turret. Because of the latter, artillery air

bursts and small arms fire often caused casualties to

the crew. In August, the Army Ground Forces directed

the development of an overhead cover kit to provide

protection for the turret crew. These covers were

folding armor tops designed to protect against small

arms fire and shell fragments without completely

sacrificing the all round vision of the open top turret.

Another problem arose from the new waterproof

steel containers being developed for the 90mm rounds.

Since they were too large to fit in the sponsons, new

ammunition racks were designed to permit stowage of

the bare rounds. The new racks were released to

production along with the armored turret tops for all

vehicles produced during 1945.

The continuing demand for 90mm gun motor

carriages resulted in additional production starting in

May 1945. Montreal Locomotive converted 200

MIOAls to M36s during the remainder of the year.

This exhausted the supply of MIOAls requiring the use

of the diesel powered M10. Originally designated as

the T71E1, it was classified as the Substitute Standard

90mm gun motor carriage M36B2 in March 1945.

Starting in May, American Locomotive produced 672

M36B2s by the end of 1945. An additional 52 were

converted at the Montreal Locomotive Works by the

end of the year. This brought the total production of

the M36 series to 2324.

In April of 1945 the development of fording

equipment was completed for the M36 and in June

standardization was approved for the new M83 direct

sight telescope. Battle reports from Europe indicated

that the M36 was being employed more and more in

the role of a tank, a task for which it was not properly

designed. Requests were received for both a coaxial

and a bow machine gun. The latter was already

provided in the M36B1 since it used the standard tank

hull. Complaints about the high ground pressure

resulted in the application of the M4E9 spaced out

suspension and extended end connectors to the late

production vehicles. All of these factors foreshadowed

the demise of the tank destroyer in the postwar army. It

was too much to expect a vehicle originally designed as

a highly mobile self-propelled gun to perform the role

of a tank. All of the modifications such as the auxiliary

armor and folding turret top only served to underline

its deficiencies when compared to a properly designed

tank. Nevertheless, the M36s continued to serve during

the postwar period and were furnished as foreign aid to

a number of Allied nations. They were still in service in

Korea during the mid 1950s.

The passage is from Hunnicutt's legendary work on the Sherman.

</font>

[michael kenny]

This bit:

"Under these

conditions, it was vulnerable with its thin armor and

open top turret"

The tables in Hinnicutt show that the TD's had lighter armour on every aspect except the lower front hull. An inch less on the upper sides and about half on the sides. Half an inch on the turret front and 1.25 inches on the turret sides.

[ December 21, 2006, 05:17 PM: Message edited by: michael kenny ]

[Kingfish]

Jason did acknowledge that the US TDs were open topped, so I don't see a contradiction there. As for thin armor, which TD is Hunnicutt referring to? As I pointed out, both the M10 and M36 had comparable armor protection as the most common Sherman variant of the time.

[michael kenny]

Originally posted by Kingfish:

Jason did acknowledge that the US TDs were open topped, so I don't see a contradiction there. As for thin armor, which TD is Hunnicutt referring to? As I pointed out, both the M10 and M36 had comparable armor protection as the most common Sherman variant of the time.

No Jason said:

"US TDs were not lightly armored. ..............The M10 and M36 were open topped, but about as armored as any medium tank."

This is not correct. The TD's had less armour than the tanks

90mm GUN MOTOR Carraige M36

Weight, Combat Loaded: ................ 63,000 pounds

Weight, Unstowed:...........................58,000 pounds

Power to Weight Ratio: Net.............14.3 hp/ton

Gross...............................................15.9 hp/ton

Ground Pressure: Zero penetration............12.9 psi

ARMOR

Type: Turret, rolled and cast homogeneous steel. Hull, rolled and cast homogeneous steel; Welded assembly

Hull Thickness:................Actual........................Angle w/Vertical

Front, Upper ....................1.5 inches.....................55 degrees-Lower........................4.25 to 2.0 inches.........0 to 56 degrees

Sides, Upper.................... 0.75 inches...................38 degrees

-----------Lower...................1.0 inches.......................0 degrees

Rear.................................0.75 inches ...................0 to 38 degrees

Top, Front........................0.75 inches....................90 degrees

--------Rear.........................0.375 inches..................90 degrees

Floor................................0.5 incheS......................90 degrees

Turret Thickness:

---Front (gun shield).........3.0 inches......................0 degrees

---Sides.............................1.25 inches....................5 degrees

---Rear...............................1.75 to 5.0 inches.........0 degrees

---ToP................................0.375 to 1.0 inches.......90 degrees

------------------------------------------------

MEDIUM TANK M4A3(75)W

Weight, Combat Loaded.............69,600 pounds-

Weight, Unstowed......................63,100 pounds*

Power to Weight Ratio: Net ...........12.9 hp/ton

Gross..............................................14.4 hp/ton

Ground Pressure: Zero penetration 14.3 psi

*A11 weights based on T48 or T51 tracks

ARMOR

Type: Turret, cast homogeneous steel.

Hull, rolled and cast homogeneous steel; Welded assembly

Hull Thickness.................... Actual............................Angle w/Vertical

Front, Upper..........................2.5 inches........................47 degrees

----------Lower.........................4.25 to 2.0 inches.............0 to 56 degrees

----------Sides...........................I.-5 inches........................0 degrees

----------Rear...........................1.5 inches.........................10 to 22 degrees

Top.......................................0.75 inches.......................83 to 90 degrees

Floor, Front..........................1.0 inches.........................90 degrees

----------Rear............................0.5 inches........................90 degrees

Turret Thickness:

--Gun Shield..........................3.5 inches...........................0 degrees

---Rotor Shield.......................2.0 inches..........................0 degrees

---Front..................................3.0 inches..........................30 degrees

---Sides..................................2.0 inches..........................5 degrees

---Rear...................................2.0 inches...........................0 degrees

---Top.....................................1.0 inches..........................90 degrees

------------------------------------------------

The subject is tricky because you have to be careful which model of M4 Sherman you compare to the M10/M36/M36B1/M36B2

An M4/M4A1/M4A3(mid) is not the same as an M4A1(76)W/M4A2/M4A2(76)W/M4A3(75)W.

Also the early M36 models were converted from the M10A1 and thus had the earlier spec for that chassis.

However the fact is the TD was created as a lighter answer to the tank. If not then why build them?

[Kingfish]

Originally posted by michael kenny:

No Jason said:

"US TDs were not lightly armored. ..............The M10 and M36 were open topped, but about as armored as any medium tank."

This is not correct. The TD's had less armour than the tanks

Which I don't think he's is actually arguing this point. Note the bolded word. He's not saying they have the same armor protection.

However the fact is the TD was created as a lighter answer to the tank. If not then why build them?

My understanding is that they were designed and fielded as a result of the established doctrine at the time, that of TDs will fight enemy armor and med tanks to be used as infantry support and breakthrough vehicles. Having said that, I don't believe that the US TD design was governed strictly on the basis of speed and agility over armor protection. Consider that the M18, a good example of the "speed" design philosophy, came after the M10, and the M36 came after the M18. So if anything it appears that the trend was more for a hard hitting gun and decent armor, and accept the compromise of slower speed, than the other way around.

[JasonC]

I've simply studied every instance in which the Germans actually attacked with armor in the west, against the US and how they were stopped. There aren't that many.

Salerno counterattack - highest scoring US assets were the SP TDs.

Lehr counterattack - highest scoring US assets were the SP TDs.

Arracourt counterattack - highest scoring US assets were the SP TDs.

Elsenborn sector of the Bulge fight - highest scoring US assets were the SP TDs. Also scored elsewhere, but the TD to tank comparison is particularly clear there.

Etc. Every time the Germans actually attacked, the SP TDs gave better than they got and outscored the US tanks by large margins.

As for why, better intel, spotting advantages (including notice from friendlies), buttoned Germans in the US defensive zone, undoubtedly leading to a high portion of first shots. All the tankers on both sides stress that the first shooter usually won.

Also, visibility was often quite limited (night or fog or just tight terrain), making initial LOS short. US TDs had no trouble KOing Panthers under such conditions. Broad daylight in perfect weather was not avoided if they could help it, because of allied air power.

[Michael Dorosh]

JasonC was saying that in order to KO a US TD, you needed to employ the same weapons you would use against a tank - a PaK, LATW, tank gun, etc. Matters of millimetres of armour seem like minutia compared to the broad points he's making. Quotes of armour thickness from Hunnicut are beside the point.

[michael kenny]

Originally posted by Michael Dorosh:

JasonC was saying that in order to KO a US TD, you needed to employ the same weapons you would use against a tank - a PaK, LATW, tank gun, etc.

Yes but as the armour on a TD was from .5 inch (turret front, hull was an inch less) to 1 inch less you could do it with less powerful weapons, and with mortars and small arms as Hunnicutt noted.

Matters of millimetres of armour seem like minutia compared to the broad points he's making. Quotes of armour thickness from Hunnicut are beside the point.

Far from being 'beside the point' they show that the claim of matching armour is simply not correct. TD's had, by design, less armour than contemporary Shermans. That is why kits were made to uparmour them and a turret roof was added.

The point is that the TD concept was considered a failure. A failure as to the concept and not in how they performed. Jason's 'broad point' is based on erroneous information.

I was aware that contradicting Jason would upset some and thus made sure I put the information I used in the post.

Originally posted by JasonC:

[QB] I've simply studied every instance in which the Germans actually attacked with armor in the west, against the US and how they were stopped. There aren't that many...................Every time the Germans actually attacked, the SP TDs gave better than they got and outscored the US tanks by large margins

However there is no information in the above that allows you to check if the claims are correct. At present we are asked to simply take it as given.I would like the information used to calculate the losses and the method used to verify the claims. Is that asking too much?

[The_Enigma]

Id like to clear up something, what do we all mean by towed AT guns.

A gun which is being pulled by a, truck or whatever, which then has to unlimbered etc?

[dieseltaylor]

GD

JasonC was saying that in order to KO a US TD, you needed to employ the same weapons you would use against a tank - a PaK, LATW, tank gun, etc. Matters of millimetres of armour seem like minutia compared to the broad points he's making. Quotes of armour thickness from Hunnicut are beside the point.

Manifestly untrue as 37mm AA could penetrate most thinner parts of a TD at 1000 metres. I suspect a 50mm could do it from even further. A 20 mm would have to wait till sub 500 metres.

As for giving glorious stories of TD's effectiveness I am reminded of Gullivers Travels where Gulliver is swarmed by the Lilliputians. I suspect noticing some one 100-500 metres away pointing a rifle at him would not necessarily rated top in Gullivers mind if he viewed the Lilliputians as potentially lethal.

Not to say that they did not do sterling work but I like context to go with statements. After all

I've simply studied every instance in which the Germans actually attacked with armor in the west, against the US and how they were stopped. There aren't that many.

Salerno counterattack - highest scoring US assets were the SP TDs.

Lehr counterattack - highest scoring US assets were the SP TDs.

Arracourt counterattack - highest scoring US assets were the SP TDs.

Highest scoring by total or per vehicle? If two were present and acored 2 kills each that would be very high, if there were 60 and they scored 4 out of total bag of ten they could still be highest scoring weapon system.

I am sure JC would want us to know how it is without us repeating his research : )

[coe]

howabout this, any stories or studies about TDs on the attack?

or TDs when they had to deal with German tanks in open terrain?

[realest]

You know, the more i think about the reverse slope bug..... i don't consider it much of a bug.

If you take into context that it could be used to simulate "well dug in" positions where the AT gun is supposed to sit somewhere with a limited kill arc with lots of dirt work around it.... then it makes the "bug" add some realism. As intense trenchwork would offer the gun team protection they otherwise would not have.

I understand the game has trenches.... but just a different view.

[Corvidae]

And again, a thread has wandered into the land of grog.

......__

...../...\===

.o""""""""""o\

.\oooooooo/

[Kingfish]

Originally posted by coe:

howabout this, any stories or studies about TDs on the attack?

During the campaign in Brittany the Americans employed several TD battalions, which due to the lack of German AFVs were used mostly as bunker busters.

[coe]

I know the thread has wandered...sorry about that -

As for the bug...I suppose if you had the gun showing it would be interesting if an AP round on a flattish like trajectory just took the AT gun's top off...

Has any one used TDs on an attack against German tanks defending (i.e. would we expect the same results as the reverse? or worse or better)

[birdstrike]

A few days away and the thread goes from bad to worse?

Originally posted by coe:

Has any one used TDs on an attack against German tanks defending (i.e. would we expect the same results as the reverse? or worse or better)

Seeing that most middle-late war German tanks are at least armed with a 75-mm gun which can KO basically any allied tank (except for Churchills) at ranges common in CMAK, I'd say TDs do not have a disadvantage to a 'real' tank in terms of armor. On the other hand they are cheaper and have a more powerful gun that gives them at least a chance to KO almost all German tanks. This means more bang for the buck. So yes, I'd say Allied TDs 'should' do better than German tanks in a pure armor duel, and certainly better than Allied tanks versus German armor.

[michael kenny]

Originally posted by birdstrike:

I'd say Allied TDs 'should' do better than German tanks in a pure armor duel, and certainly better than Allied tanks versus German armor.

Providing nobody happens to be firing at the TD!

Nothing happens in a vacuum and there are many other weapons that can kill a TD other than a tank. In a game though I suppose anything goes.

In real life the tanks won out and the TD was a dead end.

[dieseltaylor]

birdstrike.

In game you will find that if the Germans are unsporting they will make your TD's uncomfortable with mortars and light ATG. Nothing more embarrassing than having your TD's reverse out of cover during a mortar barrage to be nailed by waiting German tanks

The slow rate of fire of the M10 versus a Panther means in an even fight the Panther normally seems to win the majority of time.

An ambush weapon fine but they need additional distractions to give them a good chance against Axis armour.

I do find that trying to isolate them from other weapon systems on the battlefield so you get 1 to 1's irritating because the whole point of the game is to make sure that if you are fighting then the individual battles are rigged to be unfair to your advantage.

I like to see people fielding TD's as they have the extra vulnerability that gives a slight edge : ).

[birdstrike]

I think the question was about TDs fighting armor exclusively - I didn't assume other weapons to be around.

But I agree, the Panther is possibly the biggest threat to TDs when it comes to tanks.

(I should add "ingame")

[dieseltaylor]

On the other hand they are cheaper and have a more powerful gun that gives them at least a chance to KO almost all German tanks. This means more bang for the buck. So yes, I'd say Allied TDs 'should' do better than German tanks in a pure armor duel, and certainly better than Allied tanks versus German armor.

Cheaper? I assume we are talking in game then. I have fought 15 a side M10's and MkIV's. About three kills either side and the rest of the time we skulked waiting for the other to advance : )

I have had several battles were M10's lose to Panthers but over all I do not suppose in over 100 CMAK battles I have fought more than 3 armour only battles. I can hardly claim to be an expert on armour only battles.

[The_Enigma]

Has any one used TDs on an attack against German tanks defending (i.e. would we expect the same results as the reverse? or worse or better)

A recent opponent had 4 M10s. I had 2 platoons of Mk IVs. As i advanced his TDs opened fire and destroyed several of mine.

I halted my tanks, repositioned a few and within a few turns they were butchered, the M10s that is.

[coe]

hmmm howabout at range? e.g. 1000-2000m - how are the allied guns there?

If TDs were on the assault over open ground I can imagin it might be like T-34's advancing over an open steppe against a Panther and PzIV mix...actaully how does the 75mm Pak L43 stack up against the 76mm and 90mm. This presumes the allies have their ammo availability and the Germans don't have tungsten anymore.