"Pseudo S-Tank" on a Scorpion chassis?

[riggerrob]

What if the British decided to max-out the Scorpion light tank chassis by installing a 105 mm L7 gun in a wedged configuration similar to the Swedish S-Tank?
Consider that the L7 barrel was as long (17 feet) as the original hull on the Scorpion (5 road wheels).
We wonder if the extended (0.48 m) Stormer chassis - with 6 road wheels - would have been a better chassis for the 105 mm gun??????
Finally, we wonder how well a dedicated tank-destroyer variant would have sold overseas???????

 

[Fluff]

There was a scorpion 90, I think Malaysia bought some, but that was a low pressure gun.

I think the recoil of a gun from a 50 ton tank, may be a little overpowering for a scorpion at 8 tons, plus the weight of your 105, and ammo.

 

[Nik]

IMHO, snag is that 'S-Tank' suspension was designed to be 'iggled & wiggled' to provide targeting. The Scorpion is a very different, 'Trad' arrangement. I'd reckon such 'active' suspension nigh-impossible to retro-fit. The way around would be limited 'pan/tilt' gun, per the WW2 German tank-killers on repurposed chassis. So, a 'self-propelled field-gun' in all but name. Perhaps have remote-controlled, fast acting 'spade' ??

But, by the time you've added sufficiently lonnng recoil compensator whatsits etc, so the big gun actually stays attached to small chassis after first shot, you're looking at a very un-scorpion sorta vehicle...

Didn't US side-step issues with such over-gunned LAVs via a turret which fired missiles and 105 (??) recoilless rounds from same barrel ??

IIRC, it was not very successful: Much like that RN battle-cruiser design described as 'egg-shells armed with mallets', it was too lightly armoured to go 'in harm's way', carried too little ordnance for more than scouting, and was at weight limit for rapid air mobility...

With hindsight, you could almost class it as a 'Technical'. Unless could now effectively engage drones and helos, TSB, NFC...

 

[BB1984]

I think that, for practical purposes, the Scorpion 90 maxed out that chassis; yes you could get a bigger limited traverse gun but I'm not sure you'd be able to do much the the 90mm couldn't and losing a rotating turret is not a small matter. The Russian 100mm 2A70, as fitted on the BMP-3, might be about the same size/recoil as the 90mm, but even better, with a good sized shell for HE work and the missile option for AT work.

I also think that the S-tank style would be an interesting approach to maxing out the capability of a light AFV capable of lift via helicopter (CH53/CH47 class) and used for airdrop. It allows for a good combination of protection and firepower in a small footprint and the ease of using an automatic loader, along with S Tank style controls, would let you drop the crew to two if you're willing to accept a commander/gunner combination (not desirable, but decreasing the volume under armor is a big deal when trying to protect a lightweight vehicle).

Ref the M1128 Stryker Mobile Gun System, and these kinds of systems in general, they can't be used as tanks but they can do infantry support, following the infantry and then shelling defending strongpoints, and they can do well in the defense (as the US WWII Tank Destroyers, as well as the German Panzerjäger's, e.g., the Marder series, showed). My thoughts on the M1128 are somewhat similar to my thoughts on the Scorpion: there was no reason to try and put a high velocity 105mm on it, maxing out the chassis, when a modern turreted 75mm or 90mm gun, backed up with a couple TOW missiles in a box, could have done all the same tasks with less weight and more available ammuntion.

 

[Fluff]

I think that, for practical purposes, the Scorpion 90 maxed out that chassis; yes you could get a bigger limited traverse gun but I'm not sure you'd be able to do much the the 90mm couldn't and losing a rotating turret is not a small matter. The Russian 100mm 2A70, as fitted on the BMP-3, might be about the same size/recoil as the 90mm, but even better, with a good sized shell for HE work and the missile option for AT work.

I also think that the S-tank style would be an interesting approach to maxing out the capability of a light AFV capable of lift via helicopter (CH53/CH47 class) and used for airdrop. It allows for a good combination of protection and firepower in a small footprint and the ease of using an automatic loader, along with S Tank style controls, would let you drop the crew to two if you're willing to accept a commander/gunner combination (not desirable, but decreasing the volume under armor is a big deal when trying to protect a lightweight vehicle).

Ref the M1128 Stryker Mobile Gun System, and these kinds of systems in general, they can't be used as tanks but they can do infantry support, following the infantry and then shelling defending strongpoints, and they can do well in the defense (as the US WWII Tank Destroyers, as well as the German Panzerjäger's, e.g., the Marder series, showed). My thoughts on the M1128 are somewhat similar to my thoughts on the Scorpion: there was no reason to try and put a high velocity 105mm on it, maxing out the chassis, when a modern turreted 75mm or 90mm gun, backed up with a couple TOW missiles in a box, could have done all the same tasks with less weight and more available ammuntion.

on the 75 or 90, especially if you networked 2 vehicles, getting hit by constant 75mm is really going to ruin your day.

 

[TomS]

Didn't US side-step issues with such over-gunned LAVs via a turret which fired missiles and 105 (??) recoilless rounds from same barrel ??

Never heard of such a thing. I don't doubt someone suggested it, but 105mm was a really tight fit for a GLATGM until fairly recently.

 

[BB1984]

Didn't US side-step issues with such over-gunned LAVs via a turret which fired missiles and 105 (??) recoilless rounds from same barrel ??

Never heard of such a thing. I don't doubt someone suggested it, but 105mm was a really tight fit for a GLATGM until fairly recently.

The M1128 Stryker Mobile Gun System uses a high pressure 105mm gun (the M68A1E4), which can leverage ammunition stocks from the M60 and early M1 days (though a lot of these were expired and the Army ended up with new purchases too). The original M68 105mm gun was introduced on the original M60; it's the US version of the UK L7. AFAIK, the US has never procured a guided 105mm round and just deployed APFSDS, HEAT, Cannister, and HEP (US designation for HESH) for the M1128.

Deliveries of first pre-production M1128 vehicles commenced in 2002. For date comparison ref the GLATGM option:

• early 80s: USSR had100mm GLATGM for BMP-3, T-55, and 100mm ATG (9K116-1 Bastion variants mostly)
• early 90s: Israeli LAHAT (capable of gun launch from 105mm and 106mmRR)
• 2010 Cockerill, from Belgium, is successfully test firing the Falarick 105 (co-developed with Ukraine, so presumably leveraging the Soviet work)

 

[Nik]

Belatedly remembered it was Shillelagh, the MGM-51, at 150mm,
Which is why I put that (??) against my '105'...

 

[TomS]

Belatedly remembered it was Shillelagh, the MGM-51, at 150mm,
Which is why I put that (??) against my '105'...

The gun round that accompanied Shillelagh was anything but recoilless. It kicked like a mule.

• early 80s: USSR had100mm GLATGM for BMP-3, T-55, and 100mm ATG (9K116-1 Bastion variants mostly)

I'd utterly forgotten that Bastion was that old.

 

[riggerrob]

There was a scorpion 90, I think Malaysia bought some, but that was a low pressure gun.

I think the recoil of a gun from a 50 ton tank, may be a little overpowering for a scorpion at 8 tons, plus the weight of your 105, and ammo.

Considering that S-Tank weighed 43 to 48 tons while Scorpion only weighed 8 tons, which raises the question of whether the Scorpion chassis could even carry a 105 mm gun.
They would definitely need to add recoil spades.
The next question is whether to go for limited traverse and elevation, or just fix the gun solidly to the Scorpion chassis.
If the gun is bolted rigid to the chassis, then they nee to add hydraulic suspension similar to th3e S-tank and add a few side thrusters to nudge the gun the last degree or three in traverse.
Forget about mounting 105 mm gun in the turret of any tank weighing less than 30 tons.
While they were able to sell Mowag Piranha with a turreted 105 mm gun, crews dislike it.

 

[Fluff]

There was a scorpion 90, I think Malaysia bought some, but that was a low pressure gun.

I think the recoil of a gun from a 50 ton tank, may be a little overpowering for a scorpion at 8 tons, plus the weight of your 105, and ammo.

Considering that S-Tank weighed 43 to 48 tons while Scorpion only weighed 8 tons, which raises the question of whether the Scorpion chassis could even carry a 105 mm gun.
They would definitely need to add recoil spades.
The next question is whether to go for limited traverse and elevation, or just fix the gun solidly to the Scorpion chassis.
If the gun is bolted rigid to the chassis, then they nee to add hydraulic suspension similar to th3e S-tank and add a few side thrusters to nudge the gun the last degree or three in traverse.
Forget about mounting 105 mm gun in the turret of any tank weighing less than 30 tons.
While they were able to sell Mowag Piranha with a turreted 105 mm gun, crews dislike it.

Could be more useful, to copy Ontos, and stick say 4 x wombats onto a scorpion.

 

[A Tentative Fleet Plan]

If we're discussing air-portable vehicles with the 105mm L7, what about the various proposals for GST.1006?

View: https://youtu.be/tE7MPTDlYYU

 

[Arjen]

Forget about mounting 105 mm gun in the turret of any tank weighing less than 30 tons.

One CV90 was fitted with a RUAG 120 mm Compact Tank Gun. CV90 weighs ~24 tons.

 

[TomS]

Forget about mounting 105 mm gun in the turret of any tank weighing less than 30 tons.

One CV90 was fitted with a RUAG 120 mm Compact Tank Gun. CV90 weighs ~24 tons.

Also the Thunderbolt M8 demonstrator.

M8 Thunderbolt Armored Gun System - TankNutDave.com

The M8 Thunderbolt Armored Gun System was a demonstrator to show that a 20 tonne vehicle could use a 120mm smoothbore main gun. Its now called AGS 120 by BAE.

tanknutdave.com

 

[BB1984]

There was a scorpion 90, I think Malaysia bought some, but that was a low pressure gun.

I think the recoil of a gun from a 50 ton tank, may be a little overpowering for a scorpion at 8 tons, plus the weight of your 105, and ammo.

Considering that S-Tank weighed 43 to 48 tons while Scorpion only weighed 8 tons, which raises the question of whether the Scorpion chassis could even carry a 105 mm gun.
They would definitely need to add recoil spades.
The next question is whether to go for limited traverse and elevation, or just fix the gun solidly to the Scorpion chassis.
If the gun is bolted rigid to the chassis, then they nee to add hydraulic suspension similar to th3e S-tank and add a few side thrusters to nudge the gun the last degree or three in traverse.
Forget about mounting 105 mm gun in the turret of any tank weighing less than 30 tons.
While they were able to sell Mowag Piranha with a turreted 105 mm gun, crews dislike it.

Could be more useful, to copy Ontos, and stick say 4 x wombats onto a scorpion.

Rheinmettal's Rh 105-11 SLR (SLR * Super Low Recoil) was only advertised as suitable down to 14 ton platforms, so yes: 8 tonnes is a stretch. The M56 used a conventional 90mm on a 7 tonne chassis, so a very long recoil 105mm might be doable with a similar approach, but why you would want to do that in the ATGM era is a good question.

For the Scorpion, it's worth noting that the US trialed an autoloading 106mm RR on the even smaller M114 and that the LAHAT can be fired from a 106mm RR.

 

[riggerrob]

There was a scorpion 90, I think Malaysia bought some, but that was a low pressure gun.

I think the recoil of a gun from a 50 ton tank, may be a little overpowering for a scorpion at 8 tons, plus the weight of your 105, and ammo.

Considering that S-Tank weighed 43 to 48 tons while Scorpion only weighed 8 tons, which raises the question of whether the Scorpion chassis could even carry a 105 mm gun.
They would definitely need to add recoil spades.
The next question is whether to go for limited traverse and elevation, or just fix the gun solidly to the Scorpion chassis.
If the gun is bolted rigid to the chassis, then they nee to add hydraulic suspension similar to th3e S-tank and add a few side thrusters to nudge the gun the last degree or three in traverse.
Forget about mounting 105 mm gun in the turret of any tank weighing less than 30 tons.
While they were able to sell Mowag Piranha with a turreted 105 mm gun, crews dislike it.

Could be more useful, to copy Ontos, and stick say 4 x wombats onto a scorpion.

Rheinmettal's Rh 105-11 SLR (SLR * Super Low Recoil) was only advertised as suitable down to 14 ton platforms, so yes: 8 tonnes is a stretch. The M56 used a conventional 90mm on a 7 tonne chassis, so a very long recoil 105mm might be doable with a similar approach, but why you would want to do that in the ATGM era is a good question.

For the Scorpion, it's worth noting that the US trialed an autoloading 106mm RR on the even smaller M114 and that the LAHAT can be fired from a 106mm RR.

The US Army also test-flew an auto-reloaded recoil-less rifle hung under a helicopter (Bell Huey-Cobra?), but soon concluded that it was impractical.