Su-100 v's M36Jackson.

Hi guys,i would like your opinion on the SU-100 and M36,not just which one you prefer or which you think'best'.Obviously the two were completely different to eachother.Yet they seem to have performed at around the same time(late war).How did the Guns compare? for example,and what were the differences in doctrine.?All help would be great,and I think it would make a good thread. Im sorry about any spelling errors,I have at last been allowed to start using sativex,along with my normal painkillers,so please forgive any errors.Cheers,Lee.

 

If you don't mind my twisting the question a bit, the question might not be the guns so much as the merits of better protection vs. all-round traverse. I'm inclined to favor the better armored vehicle like the SU-100 or my favorite tank destroyer, the Jagdpanther. The US tank destroyer doctrine seems to assume that some combination of maneuver, firing from cover, gun range, etc. will enable the TDs to shoot, or 'shoot and scoot', without the enemy getting a chance to shoot back. In an exchange of fire, a heavier gun but lighter armor doesn't really provide an advantage.

 

I have been reading about panzers in Italy and came across a little passage attributed to Albert Speer visiting panzer troops to get some information. This was in relation to Germanys lack of materials to keep producing large amounts of heavy armour plate. So less tanks but heavily armoured ie Tiger, or more tanks lighter armoured but bigger gun.

The panzer crews praised the Sherman for its reliability, climbing and cross country ability compared to their own tanks which, had to largely stay on the roads, could be out climbed and with the Tiger were very prone to breakdown.

The responses he got were that they would prefer lighter vehicles that were more manoeuvrable with a large weapon as their means of influencing the battle (Gun, manoeuvrability, armour).

This response seemed to coincide with what German industry could actually provide and his own thoughts. (yet they still produced the Tiger II).

Whether in attack or defence I think a turreted vehicle would be better than a fixed weapon. Interestingly since WW2 there have been very few fixed weapon type platforms placed in service, even SPG's went with rotating turrets.

 

I'm thinking the last fixed gun platform in major service was the Swedish Stridsvagn-103 (S-Tank).

If I had to choose, I'd prefer fast and a big gun on a turret.

 

IMO It really depends on tactics, for "shoot and scooot" give me speed and visibility, but for supporting an advance over flat terrain where it's possible you may be facing a Panther or Tiger but it's nealy sure some Pak 40 are lurking around you need more armour than on the M-36, and that was a much more common scenario in 1944-45 for the Soviets. Nobody builds TDs any longer, and 360 degrees turrets have become common even on SPGs designed for long range indirect fire.

 

How would they know that? The panzer crews would not know the repair times and availability rates.

 

A few ways, observation first and foremost by the troops builds up an impression. Captured vehicles used by the Germans allows experience. They can then compare to their own vehicles. This was what was reported as I said in a passage attributed to Speers visit to panzer troops in Italy.

The allies had the impression that the Tigers and Panthers were invincible on the battlefield despite the losses of them in battle and the higher losses to breakdowns. The first Tigers I the Brits encountered in Tunisia were knocked out by 6 pdrs (three in about a week, two to AT guns and one to a Churchill). It did not stop the belief that Tigers and Panthers were invincible as opposed to hard to kill.

 

The American style tank destroyer also disappeared after the war, as did the TD battalion and force. Postwar armies mounted their most powerful tank-killing guns on main battle tanks; even the S tank was the "MBT" of its army.

SP direct fire artillery also disappeared. Modern SPGs like the M109 are the successors of the M7, Hummel, etc. rather than the assault gun or tank destroyer. The few postwar exceptions were for special roles like the Soviet ASU-85 for airborne forces.

There have also been vehicles with lighter guns than contemporary MBTs, in the 76-105mm range, often wheeled, in many cases derived from APCs like the Stryker or the South African Ratel. Against tanks, these have to use maneuver tactics much like the thin-skinned M10s and M36s.

 

I'd disagree with your first statement. If you look at the underlying parameters, fast, highly mobile, powerful gun, lightly armored, the U.S. has and still does utilize this concept. It's just that the anti-tank missle has to a large degree supplanted a large caliber, high velocity gun. You have, shortly post-war the M-50 Ontos, designed as a tank killer it was a lightly armored, fully tracked vehicle, mounting 6 x 106mm recoiless rifles. Armored only against small arms and fragmentation, it was intended to rely on mobility as it's protection against tanks. Today you have CAAT teams, Combined Anti-Armor Teams, TOW anti-tank missles mounted on lightly armored Humvees, part of a battalions weapons company, their purpose is to use high mobility to search out and destroy enemy armored assets. So while the seperate battalion disappeared the asset was retained at a different organizational level.
TOWs mounted on LAV's, Strykers and Bradleys while appearing to be similar (excellent anti-tank weapon on a lightly armored, highly mobile chassis) their purpose is different. They are primarily part of a force of troop-carrying vehicles and are intended to give some anti-tank capability and force protection to the units and troops to which they are attached or in their reconnaissance role to provide some anti-tank capability to support their intended mission (reconnaissance).
The role of the tank has also changed. WWII US tank doctrine saw the tank as primarily an infantry support and exploitation weapon. Modern US tank doctrine sees the MBT as having engaging enemy armor as one of it's main roles. This requires a minimum gun caliber in the 105mm/120mm range (i.e. British L7/US M68 105mm or Rheinmetall/US M256 120mm). Given the comparative performance values it makes more sense to mount the ATM on a light vehicle than the heavy gun and the heavier chassis that would be necessary to support it.
TOW
BGM-71Delta- armor penetration 900mm (35.433in)
BGM-71Echo- (enhanced for use against reactive armor) 900mm (35.433in) in addition to the reactive armor
*in the case of both these weapons range is not a critical factor in armor penetration since kinetic energy is not the primary means of defeating the armor.

105mm L7/M68- maximum penetration is highly dependant on round type, range and velocity. A good average would be 4-500mm at 2000 meters.
120mm Rheinmetall- maximum penetration is dependant on round type, range and velocity but in the case of this gun it's really overkill. The exact penetration figures are classified but the KE M829 APFSDS-T round can impart 9.2 million foot pounds of energy upon it's target at 6000 meters. Basically, it can hit and kill any armored vehicle it can see.

I fully agree.

The Stryker M1128 MGS, mounting the 105mm M68A2, is not intended to engage tanks, it is primarily an infantry support weapons system. The South African Ratel-90, similarly, was intended to provide infantry support, the low velocity 90mm gun had very limited anti-tank capability. Just because they mount a larger caliber gun does not mean they are intended to engage tanks, except as a last resort. If memory serves me correctly the only contemporary tank destroyer using a gun is the Italian B1 Centauro mounting a 120mm gun.

 

One advantage, frequently overlooked, is vulnerability to different type kills. The easiest type of kill to achieve on an AFV is an M-kill (mobility) all you have to do is take out a track or some other component of the running gear. On a vehicle with a 360 degree traverse you still retain it's fighting ability, while on a limited traverse weapon like a SU-100 or Jagdpanther you severely limit it's ability to engage targets. (because you have to traverse the entire weapons system)
That being said, the open tops of the American tank destroyers made the crew very susceptable to fragmentation and to a lesser degree small arms. Kill the crew and the vehicle is out of the fight until re-crewed. The later versions with added overhead cover, to a degree addressed this problem.
That being said, when the US first visualized it's tank destroyers they intended to use them defensively, to counter and kill enemy tanks from ambush, preferably in a hull down position. This is exactly the type of fight the Germans found themselves in, on the defensive and able to hit allied vehicles from ambush at the longest possible ranges.

That's exactly how I understand it.

I don't know if either type held a definative advantage. Had the US tank destroyers been used in the manner of the German Jagdpanzers or Stugs, I think they would have been equally successful. If used offensively in an assault, and I had to choose, I'd have to go with the Jagdpanther like you. Great gun, heavier frontal armor than the SU-100 (75mm vs 80mm). The Jagdtiger is another option, with it's 128mm main gun and 150-250mm frontal armor it appears formidable. Horrible mobility and dependability takes it out of the running, might as well choose an aromored pill box.

 

Thanks guys for the quick response.Were the Two Tank Desttroyers built around the guns they used.?I believe the 100mm gun used in the SU,was developed from an existing Naval gun,and the 90mm gun of the M36,was developed from the existing 90mmA.A.gun.I think I'm correct in assuming the M36 was built on the Sherman Chassis,running gear etc,but the gun itself was mounted in an open topped fully rotating turret.Was this the same turret as the M10"wolverine".?Cheers,Lee.

 

According to my book the M36 chassis was based on the M10A1 which in turn was based on the M4A3. Grandchild I guess you would say. The turret was designed from scratch as the gun wouldn't fit the existing turrets. The M36B1 variant used a standard M4A3 hull (187 built). Another variant M36B2 used the standard M10 chassis some with turret covers (237 built).

 

AFAIK the only Centauro to mount a 120mm gun are the few built for Oman, standard Italian production models carry a low recoil 105mm gun capable of firing the same ammo as the L7 gun, I believe the 15 wehicles the US bought for testing were also 105mm variants.
The Centauro and 105mm Stryker look very similar, Italy is currently deploying the Centauro derived Freccia 8 weeled APCs so the "mecanized" (weeled) units will end up with a mix of 105mm and 25mm 8 weelers (looks familiar?).
There is obviously a need to give heavier firepower than the 25mm can provide to the weeled units involved in counter insurgency, but the L7/M68 is overkill unless at least a secondary A/T role is envisaged in case the units get involved in a more conventional scenario. Post war ATGMs, after a brief flirt with recoiless guns, have replaced A/T guns for protection of non tank units against armour, but this is very different from the WW2 TD concept that envisioned batallion sized units to neutralize enemy armour, IMO a failed doctrine as "shoot and scoot" is really good only for mobile defense, if attacking or tied down to protecting a critical position you need more armour, the "pill box like" Jadgtigers and Elephants could be very hard to dislodge if well sited, though barely more mobile than a Pantherturm. The Germans had a lot of experience with the "light and big gunned" concept, though they believed 360 traverse was not that necessary for "shooot and scoot" (Marders, Emil, Nashorn, and the like) but went for "heavy" whenever they could afford to.

 

The post war AT missiles have really replaced the infantrys organic AT guns as opposed to any form of vehicle mounted gun, with the hand held rockets etc being the replacements for the bazooka type weapon.

The L7 105mm has a very useful HESH round (I don't know if anyone except the Brits used it), it is pretty potent at most targets and particularly useful against buildings (it was still used by the RE's until the 90's on their AVRE's as a demolition round although not as good as the 165mm HESH round it served with).

Limited traverse weapons are of greater use at distances where there limited traverse can still cover a relatively large area, when you start getting close though you have to start moving the vehicle to relay that limited traverse, you also can only cover a smaller amount of the battlefield. turreted can cover large areas from a static position no matter how close the enemy get. They also have the advantage that when moving they can still lay their weapons in a different direction to travel (although the driver has to be more mindful of the turret position).

 

I don't believe so. It is still utilized, as I mentioned before they used CAAT teams, offensively, in basically the same role during the 2003 invasion of Iraq.

IMO this is also incorrect, heavily armored units have become more and more an offensively utilized weapon. Mobility and maneuver warfare are the current doctrines. The Anti-tank missle has almost totally supplanted the need for heavily armored, big gun vehicles in the defense. If you need to hold a critical area, dug in infantry with AT-4's, Javelins, and TOW's, backed up by a mobile force of lightly armored, 360 degree arc of fire, AT missle mounting platforms like Humvee's, LAV's, Strykers or Bradleys, would be more effective. Another modern, anti-armor platform we failed to mention is the helicopter and in actuality it is used in a manner similar to the US WWII tank destroyer. Many such as the Apache and Kiowa Warrior have mast mounted sensors to allow them to stay under cover while tracking/acquiring targets. Then they "pop up" and fire TOWs, Hellfires, 20 or 30mm guns, etc. at the enemy armor and drop back down to cover. The heavy AP rounds from their Gatling gun are very effective against the lightly armored upper surfaces of armored vehicles.


A Kiowa Warrior showing mast sensor.

I think you'll find that the Germans went with the limited traverse option because it was cheaper, faster and easier to build this type of vehicle, not because it was the optimal choice.

leccy1 wrote:

Very good point and one I failed to address in my earlier post. The limited traverse of these weapons was a greater or lesser liability depending on terrain and the expected engagement distance. On the steppes of Russia where they had a clear field of fire out to their maximum range their limited arc of fire was of lesser import. In situations where engagement ranges were reduced the limited arc of fire became an exponentially greater limiting factor as range decreased. Offensively it was a greater liability than defensively, and in closer terrain a greater liability than in open terrain.

I guess when it gets down to it, while we debate which vehicles or types were better. Each participant ended up with the best (though not perfect) type for their needs. Germany fighting defensively on both fronts and with limited production capabilities, went with a big gun, heavy frontal armor, limited traverse, easier and cheaper to produce types utilizing existing chassis. The US with robust production capabilities, fighting an offensive and maneuver type of war went with the more more mobile, lightly armored, turreted type. The Soviets faced with having to assault defensive positions across more open terrain went with the type that was heavily armored on the frontal arc, with a big gun and limited arc of fire.

 

A WW2 defensive line, mostly made up of foot infantry, really only had the option of holding or getting destroyed by a mechanized enemy, in that scenario "shoot and scoot" will leave the PBI in the lurch. Modern forces usually have enough mobility to pull back before getting overun unless the attacker has a huge fire superiority.

The soviet assault guns's role in the attack was usually long range overwatch but to perform that effectively they needed to be able to position themselves in sight of the German MLR and withstand what firepower the defenders could divert from the advancing force.

The Germans could have continued to build Marder III and Nashorns instead of going to Hetzers and panzerjaeger IVs, they were cheaper than their successors, IMO that they stopped the production of the former in favour of the latter is significant.

IIRC ATGM and "scoot and shoot" teams were considered by NATO as a counter to the Soviet "tank hordes", (there was even talk of using masses of WV "buggies" equipped with HOT launchers for the role) , but the tradeoff of "space for losses" was found to be unacceptable as there was not enough "space" to trade with. There were also a lot of doubts that the light unarmoured vehicles could operate as succesfully in a high firepower density environment as they did in the various "Toyota wars".

 

So the main difference was doctrine,when discussing these two T.D's.Would that be accurate.?I mean,during the latter stages of ww2,the eastern front became less steppe(seemingly endless horizon,no decent roads etc),and more like western Europe,although I'm not aware of the exact area the red army reached during late 1944.?Cheers,Lee. Sorry if I'm not making much sense here,I'm on new medication,thanks.

 

Many are forgetting city fighting. Block to block stuff. In that case, I would sure want a turret. A fixed gun chassis will have to completely expose itself, such as at an intersection, to train it's gun. While an M36 would have to stick it's nose out a way for the gun to clear a corner, less of it is exposed, and can scoot backwards out of sight faster than an SU-100 could. By that time, almost all US TD's had some sort of over the top armor, hinged plates, etc, to protect the crews against shrapnel or snipers.

 

IMO in an urban environment all round traverse is less important than having a closed top and a BIG gun, AFVs will operate behind an infantry screen so getting anbushed by a moving enemy tank is unlikely. Ot the oteher hand you can expect lots of incomming bad stuff from above (mortars an grenades from upper floors), a "standard" M4 would perform a lot better than an M36 as at the likely engagement ranges even the M3 gun is likely to penetrate an enemy AFV on the first shot.
Against buildings you may need something more than a 75mm, the Soviets and Germans both used limited traverse assault guns for infantry support in built up areas, but wanted a lot of HE firepower to tackle stone buildings, also due to Soviet infantry retaining the ATR anything with less than 40mm all round was a bad idea for the Germans so they ended up with the Brumbar and the Soviet JSU 152 looks very similar. There are some instances of allied troops bringing in M7 Priests of even M12 155s for direct fire against particularly resistant strongpoints.

 

This has become a good, wide-ranging discussion; but if we could venture back to topic for a moment, neither the M-36, SU-100, not any WWII tank destroyer was well-suited for urban warfare - not that that excluded them from being so used on occasion! Their raison d'etre, a high-velocity tank-killing gun, was largely wasted. The vehicles we're discussing, and I might even toss in my pet Jagdpanther, were among their respective armies' best tank-killing weapons and relatively few in number, so it would have been particularly inappropriate to use them in other than their intended role.

We first touched on post-war developments when it was pointed out that they included few successors to the SU-100. However it's equally true that, while armies indeed continued developing antitank platforms, there were few M-36 types either. As noted, most light, fast gun carriers were not primarily AT weapons. Dedicated antitank units almost always use missiles rather than guns. Vehicles like ASU-85 or Ontos were developed for specific roles, usually air-mobility. There's not much in the post-war world than helps us with 4th wilts' original question.

Of course anything can happen. Ontos was one 'tank destroyer' which proved useful in urban combat, through the outside-the-box technique of firing all six 106s simultaneously to knock down whole buildings.