Rooikat Armoured Car

[kaiserbill]

Speaking of the Rooikat armament....


That new version that came to light recently...the one below, looks like it has a 105mm cannon, especially when compared to the vanilla 76mm equipped version, and the 105mm equipped version shown in that middle east arms show years back.
Before that, the only 105mm equipped Rooikat, as mentioned above, looked like the usual Rooikat, but with slight differences, as seen in pic 2.
We also know that a 120mm was designed for the Rooikat.


It would be interesting to know the story behind this recently made public vehicle with the new turret, Grintek LEDS active defence system, and sensors/nozzles....

 

[Matt R.]

Reply to post # 102.

At the time the Rooikat was initially envisaged (late seventies), the lightest production armoured vehicle mounting a 105mm NATO type gun, was the French AMX 30, at about 35 tons. The German TAM (about 30 tons) was at a prototype stage. The low-recoil 105mm guns initially developed by Rheinmetall had not yet seen the light at that time. Afaik, the combat weight initially projected for the Rooikat was around 22 tons. At that time it was inconceivable that a 105mm L7 type gun could be mounted in a vehicle that light. High velocity 76mm (3 inch) guns had been mounted on vehicles in that weight range however, noteably the M41 Walker Bulldog tank (US).


I am convinced that the initial design/planning for the Rooikat bever envisaged a 105mm gun. The guns which might have been considered for the proposed Rooikat include the following, imo.

(snip)

2. The French 105mm F2 MECA gun. This was a new design at that time. It was a medium pressure, smooth bore gun fitted to the AMX 10-RC reconnaisanse vehicle just entering service in the late seventies. That vehicle weighed about 15 tons. The gun relied on a HEAT shell for anti-armour purposes but an APFSDS projectile was later developed. The gun was mounted in a sophisticated 3-man turret with an advanced fire-control system. I think this gun and turret would have been a viable option for 20 ton Rooikat but it would have been very expensive to acquire and, of course, the arms embargo was in place at that time.

(snip)

4. Then we get to the 3 inch guns, with which SA had had a lot of experience. The 77mm High Velocity gun mounted on the Comet was available as was a substantial stock of ammunition. The 17 pounder was available mounted in the Sherman Firefly and as an anti-tank gun, as were large stocks of ammunition. The 76/62 Oto Melara naval gun was in service with SA at that time and the ammunition was being produced in SA. The 77mm gun was used in trials on the Rooikat prototype because it was available. I don't think it would have been seriously considered as the definite weapon for the Rooikat. It is an efficient gun but case capacity is relatively small and it would probably not have been possible to squeeze enough velocity out of the gun, even with a modern gun, using modern propellants and an APFSDS projectile. The 17 pounder would have been an excellent basis for the 76mm gun of the Rooikat. The achieveable performance of the 17 pounder and the Oto 76/62 is probably similar though and the Oto ammo was already in production whereas modernised 17 pounder ammunition would have had to be developed from scratch.

Couple of quick comments :

a) Re. your point #2 above, the French 105mm Mle 57 (aka CN-105-57) gun fitted to the late AMX-13 and Kürassier was available back then, initially with HEAT ('Obus G') and HE, and later on with APFSDS + HESH (still being manufactured by Hirtenberger of Austria).
The 105mm Mle 57 was also used on the Engesa EE-17 Sucuri (FL-12 turret) and the Mowag Shark (FL-12).
Sanctions would have been a problem though.

b) Re. your point #4 above, the French 75mm SA-50 (aka CN-75-50) gun fitted to the early AMX-13 (FL-10 turret) could have been another option in the 75-77mm bracket. My understanding is that the French gun was slightly more powerful than the QF 17-pdr :
- full-caliber AP rounds : 6.4 kg @ 1,000 mps (3.2 MJ) vs 7.7 kg @ 885 mps (3.0 MJ)
- sub-caliber AP rounds : 3.9 kg @ 1,300 mps (3.3 MJ) vs 3.5 kg @ 1,200 mps (2.5 MJ)
I suspect that sanctions would have been much less of a problem with the SA-50 given the number of guns available on the market (e.g from Israel). I'd also think that developing new ammos (APFSDS or HESH) wouldn't be a major issue (especially if Israeli assistance could be available).
On the minus side, the SA-50 had a short barrel life (about 150-200 EFC with AP rounds) and wasn't autofrettaged.

 

[lastdingo]

IIRC the AMX-13's 75 mm was based on the 7,5 cm Kwk 42 (L/70) of the Panther.

 

[Herman]

Reply to post # 123:
You are correct, Matt. After I posted my previous post, I thought about the 75mm gun from the AMX 13. That would have been a good candidate for the Rooikat as well. Singapore developed an effective APFSDS round for this gun, for use in their AMX-13's. These guns were also mounted in the Israeli modified Sherman M50 tanks used during the 1956 war and later during the 6-day war. The performance figures you quote puts this gun firmly into the same league as the 17 pounder. I have 3.7 @ 1204 m/s for APDS from the 17 pounder. I don't have figures for a sub-calibre projectile from the SA-50 gun.The Israeli's reportedly found the performance marginal against the Arab T54 and T55 tanks but that was using full calibre APC shot and a HEAT round (which would gave been particularly poor), I believe. I also forgot about the 105mm gun used in the AMX light tank. That would also theoretically have been a possibility for a 22 ton Rooikat, as you mention.


I think the reason why the Oto 76/62 would have been preferred to the French gun is because the ammunition was already in production in SA. I personally don't think the arms embargo would have been a big issue. I have reliably been told that one whole floor of the South African embassy in Paris was occupied by Armscor during the the eighties, despite the sanctions. The reason that the 105mm gun did not appeal to SA, I believe, is that it had been decided to go for a gun firing sub-calibre kinetic energy rounds. The French gun only fired the non-rotating OBUS-G HEAT shell at that time, as you mentioned. Much work was being done on reactive armour in the USSR as well as in Germany and Israel during the late seventies. Fitting reactive armour to the Angolan T54 and T55 tanks would immediately have rendered the 90mm DEFA guns used on the Eland and Ratels completely ineffective, as well as other, similar HEAT rounds.


Another possible source of armament for the Rooikat, I forgot to mention, were the Belgians. Both Cockerill and MECAR were producing suitable 90mm guns at that time. Cockerill had developed the Mark 4 tank gun as a possible replacement for the 76mm gun of the M41 ligh tank. That gun would also have been eminently suitable for use on the Rooikat. Again though, at that time it was only available with a HEAT anti-tank round. An APFSDS round was later developed.


It is also possible/probable the SA decided to develop a rifled gun rather than a smooth-bore weapon. They had had extensive exprience of the 77mm HV, the 17 pounder, 20 pounder and the 105mm L7, all rifled guns also capable of firing high velocity, sub-calibre projectiles. High velocity smooth bore guns were only then starting to be introduced in the West (Leopard 2).

 

[Matt R.]

IIRC the AMX-13's 75 mm was based on the 7,5 cm Kwk 42 (L/70) of the Panther.

This is a very common misconception :

1) The French firm SAGEM indeed conducted very detailed ballistics studies (IB & EB) of the Panther's 7.5cm KwK-42 with the aim of duplicating the German design as the performances of the 75mm SA-44 gun (intended for the ARL-44 tank) proved disappointing. The KwK clone would have been manufactured by the Chantiers de la Loire. This plan was dropped and the ARL-44 ended up with the 90mm SA-45 gun.

2) The results of the SAGEM results were nevertheless not lost and the KwK became the benchmark in terms of performances for the 75mm SA-50 to be developed for the AMX-13.

3) The 75mm SA-50 was manufactured by the Atelier de Construction de Bourges (ABS later EFAB) rather than the Chantiers de la Loire and the 75mm SA-50 didn't share much features (if any at all) with the KwK. The desired performance was achived through a mix of metallurgical improvements (involving such companies as Imphy and Bedel), chemical improvements,... As a matter of fact, the 75mm x 640R cartridge (rim diameter = 122mm) used by the KwK is quite different from the 75mm x 597R cartridge (rim diameter = 117mm) used by the SA-50.

 

[Matt R.]

Reply to post #125

Herman,

1) The APDS projectile for the 75mm SA-50 gun was extensively tested but remained experimental and was never type-classified. This is due to the French fixation on 'Obus G' at the expense of subcaliber projectiles.

2) The SADF had to develop the APFSDS projectile for the OTO 76mm/62 no matter what and apparently modified the gun itself to accommodate higher working pressures. IOW, starting from scratch could not be avoided, either with the OTO 76mm or with the French 75mm.

3) Quite a few pics of the South African 76mm APFSDS have emerged recently (including high-res cutaways) and the Israeli input in the design of the projectile seems quite obvious. Pictures of the 75mm APFSDS used by Singapore are more difficult to find, but based on whatever I've seen so far, the design looks very similar (at least externally) to the South African 76mm APFSDS. I believe than Israeli involvement in the design of the 75mm APFSDS is common knowledge.

4) As far as the 105mm Mle 57 is concerned, I mentioned it as an option because a) NORICUM of Austria (part of it being Hirtenberger nowadays) proved quite "flexible" when it came to sanctions and b) it's a rifled gun (32 RH @ 7°10') which AIUI is what the SADF had a preference for.

5) While MECAR didn't have much to offer before the introduction of its KENERGA 90mm/46 (1982 IIRC), you may be quite right about the Cockerill MkIV 90mm gun (though I couldn't find the exact date of its introduction). That said, APFSDS only became available with the Cockerill MkVII (introduced in 1983 IIRC) and, - despite similarities -, ammos were AFAIK not interchangeable between the MkIV and the MkVII. Meaning you still would have to develop an APFSDS projectile, which in this specific situation was never developed by anyone (Brazil apparently never really bothered).

This leads to a very last observation : I've never been able to find a brochure showing the range of projectiles available for the 76mm GT4; neither have I been able to locate some detailed spec sheet for the gun itself (with such details as the working pressure, rifling twist & grooves, chamber volume, etc...).

Are these infos classified or did I simply fail to locate the place where they might be found ?

PS : I corrected a typo in my post regarding the APDS used with the QF 17 pdr (wrote 2.5kg instead of 3.5kg for the projectile's mass). The data I have for the APDS 1T is 7.625 lbs for the mass and 3,950 fps for the muzzle velocity.

Edit : Development of the Cockerill MkIV began in 1978. Approximately 32 units produced, of which 22 units for Uruguay's M41 upgrade. The MkIV fired the NR-232 APFSDS projectile.

 

[Herman]

Matt, thank you for these posts; lots of interesting info here.
Do you know what the base diameter is of the 17 pounder case (7.52 x 583R) and the 77mm HV (77 x 420R). I've being trying to figure out how the case volumes of the 17 pounder and the 76/62 Oto compare. The Oto case is longer (76 x 636) but the 17 pounder seems to be fatter. I expect case volumes will be more or less similar? I assume the Rooikat case is identical to that of the Oto gun except for the priming (before Denel switched to caseless ammunition for the Rooikat).


As far as the French fixation with the the Obus G type ammunition is concerned: the CN-105-F1 gun used in AMX-30 was also designed around the Obus G. It could fire ammunition designed for the L7 gun but as far as I know, the rifling pitch was slower than the L7, rendering the French gun unable to stabilise APDS. An effective APFSDS was however later developed for it.


I also read that the SA APFSDS projectile for the Rooikat's gun is of Israeli/German design. I suppose the projectile of the SA gun and that of the Singaporean AMX-13 gun may be very similar or even identical.


Janes'states that the Cockerill Mk 4 gun was rifled piece with progressive right hand rifling, from 2° to 7°10', i.e. identical to that of the French CN-105-F1, its Israeli D1504 derivative and the 105/57 of the AMX-13 and the Kurassier. The ammunition for this gun is not the same as the that for the later Cockerill Mk VII. The Mk 4 fired a comparitively large HE shell, weighing 10.6Kg at 730m/s, a 5.9Kg HEAT shell at 1000m/s and a 7kg HESH shell at 790m/s. Looking at the rifling stated for the gun, I suppose these were conventional spin-stablized projectiles, except for the HEAT which would have had a slip-ring.


The Cockerill Mk 4 would have been a good gun for the Rooikat, I think. It has adequate performance to allow a decent APFSDS round to be developed and the HE shell is much more useful than 6.2kg job available to the 76mm gun.

 

[Herman]

P.S.: Jane's states that the Cockerill Mk IAA1 (Mk 4) fires fin-stabilized ammunition, despite the rifling. The purpose of rifling was therefore the same as the low-angled rifling used in many of the other smooth bore guns, despite it being apparently the same angle as that found in French conventionally rifled guns.

 

[Herman]

Reply to post #122.


The new turret is fitted with the 105. I measured it while visiting family in Bloemfontein, in 2013.

 

[Matt R.]

Matt, thank you for these posts; lots of interesting info here.

1) Do you know what the base diameter is of the 17 pounder case (7.52 x 583R) and the 77mm HV (77 x 420R). I've being trying to figure out how the case volumes of the 17 pounder and the 76/62 Oto compare. The Oto case is longer (76 x 636) but the 17 pounder seems to be fatter. I expect case volumes will be more or less similar? I assume the Rooikat case is identical to that of the Oto gun except for the priming (before Denel switched to caseless ammunition for the Rooikat).

2) As far as the French fixation with the the Obus G type ammunition is concerned: the CN-105-F1 gun used in AMX-30 was also designed around the Obus G. It could fire ammunition designed for the L7 gun but as far as I know, the rifling pitch was slower than the L7, rendering the French gun unable to stabilise APDS. An effective APFSDS was however later developed for it.

Herman :

1) Unfortunately, I don't have the diagrams that would provide the dimensions you're looking for (all I have is the rim diameter of each cartridge).

That said, you may be able to approximate the respective cartridge case volumes based on the propellant mass :
* for the 76.2mm x 583R : 8.25 lbs, i.e. 3.74 kg (17-lb projectile @ 2,900 fps)
* for the 76.2mm x 636R : 7.85 lbs, i.e. 3.56 kg (14-lb projectile @ 3,000+ fps)

Then working your way backwards assuming a propellant density of 1.65 g/cc in both cases (which seems to be a reasonable assumption based on the quick checks I did), you end up with the following respective volumes :
* for the 76.2mm x 583R : about 2,268 cc
* for the 76.2mm x 636R : about 2,158 cc

This is a very rough approximation given that some parameters (e.g. propellant packing density) are not taken into account, but this doesn't look completely unreasonable at first glance.

That said, this may only be part of the story since it's not clear to me what the differences between the GT-4 and the OTO 76mm/62 might be in terms of chamber volume, working pressure, etc... Neither do I know the type of propellant used by the South African for their APFSDS (e.g. impetus,...).

2) AIUI, the 105mm Mle 57 (AMX-13) and the 105mm Mle 62 (AMX-30) used the exact same Obus G (OCC F1), the former with a Vo = 800 m/s, the latter with a Vo = 1,000 m/s.

The French actually worked on a 105mm APDS projectile for their 105mm Mle 57 until 1961, then somehow decided that the Obus G was the way to go and only resumed their studies of subcaliber projectiles (APFSDS) in 1970, with a first prototype (APFSDS) being ready for testing in 1972.

 

[Abraham Gubler]

Matt, thank you for these posts; lots of interesting info here.
Do you know what the base diameter is of the 17 pounder case (7.52 x 583R) and the 77mm HV (77 x 420R). I've being trying to figure out how the case volumes of the 17 pounder and the 76/62 Oto compare. The Oto case is longer (76 x 636) but the 17 pounder seems to be fatter. I expect case volumes will be more or less similar? I assume the Rooikat case is identical to that of the Oto gun except for the priming (before Denel switched to caseless ammunition for the Rooikat).

This is what the shells look like. The 76mm L62 cartridge is 900.4mm long complete with shell, 635.5mm long case.

 

[kaiserbill]

Reply to post #122.


The new turret is fitted with the 105. I measured it while visiting family in Bloemfontein, in 2013.

Thanks Herman.


I was going purely on eyeball, having pored over quite a few pics of the original 76mm equipped Rooikat, and that original Rooikat 105mm equipped one displayed in the Middle East.
The fume extractor and some other details indicated it was a 105mm, but thanks for the hard confirmation.


Be interesting to know what the story behind the design was.
I think the LEDS active defence system was started about a decade back, but this may, of course, have been retroactivally fitted to the vehicle, and not been part of the original design. Or it may well have been part of an overall programme.

 

[Matt R.]

Matt, thank you for these posts; lots of interesting info here.
Do you know what the base diameter is of the 17 pounder case (7.52 x 583R) and the 77mm HV (77 x 420R). I've being trying to figure out how the case volumes of the 17 pounder and the 76/62 Oto compare. The Oto case is longer (76 x 636) but the 17 pounder seems to be fatter. I expect case volumes will be more or less similar? I assume the Rooikat case is identical to that of the Oto gun except for the priming (before Denel switched to caseless ammunition for the Rooikat).

This is what the shells look like. The 76mm L62 cartridge is 900.4mm long complete with shell, 635.5mm long case.

Below are some reasonably accurate dimensional data for the 76.2mm x 636R (Italian brass cartridge) :
* rim diameter = 114 mm
* base diameter = 103.5 mm
* diametric taper = 0.04 mm / mm

Could find anything equivalent for the 76.2mm x 583R and 76.2mm x 420R. Best I can offer is the img attached ; from left to right: 6 pdr 7 cwt APDS (57 x 441R); 75mm US/UK tank (75 x 350R); 17 pdr APDS (76.2 x 583R) and 77mm APCBC (76.2 x 420R)

Rim diameter :
* 76.2mm x 583R : 135 mm
* 76.2mm x 420R : 116 mm

Hope this helps.

 

[Herman]

Reply to post #133:
Be interesting to know what the story behind the design was.[/size]I think the LEDS active defence system was started about a decade back, but this may, of course, have been retroactivally fitted to the vehicle, and not been part of the original design. Or it may well have been part of an overall programme.
[/size]
[/size]I expect the new version of the Rooikat turret was developed not for S.A. itself but for export. The turret could be interesting for mounting on any of the tracked ICV's in the weight range 20-40 tons now being produced, to create a light tank, or for an armoured car based on one of the "tour bus" 8 x 8 wheeled APC/ICV's now being produced by a number of manufacturers.
[/size]
[/size]Do you have any info on the LEDS active defence system?

 

[Herman]

Reply to post # 133:


Sorry, that didn't go well.
I expect the new turret for the Rooikat was primarily developed for export. It could be fitted to any tracked ICV > 25 tons to create a light tank. It would also be suitable for an armoured car based on any of the large 8 x 8 "tour bus" wheeled APC/ICV's now being produced by a number of manufacturers.


Do you have any info LEDS active defence system?

 

[Herman]

Reply to post # 131>


Matt

Lots of interesting info, once again. Your numbers support the notion that the 17 pounder and 76/62 Oto are in the same ball park as far as power is concerned. I have always thought that the cartridge - barrel combination of the 17 pounder was a bit overbore: the barrel was too short for the case capacity. This is supported by reports of enormous muzzle blast and flash when firing the thing. The 17 pounder would probably have been a significantly better gun if it had had a 60-65 calibre barrel, like the Oto, or even a 70 calibre barrel like the Kw.K.42 L/70 of the Panther. The German gun's cartridge case was 57mm longer than that of the 17 pounder but the shell was slightly slimmer.

[/size]As you mention, the Obus G ball-bearing mounted HEAT shell was used in the CN-105-F1 (AMX 30) at 1000 m/s, the shorter derivative D1504 (Israeli Sherman M51) at 905 m/s and in the Mle 57 of the A at 800 m/s. I did not realize that the French had been busy with APFSDS that early. [size=78%]

 

[Herman]

The problem with the Rooikat is that it was, as with the Rooivalk helicopter, a case of too much, too late. By the time the Rooikat arrived, it was a highly sophisticated, expensive and relatively complex vehicle sporting hunter-killer fire control features, night-fighting capability and lots of bells, whistles and things that open and close. It arrived too late for the war however and was therefore useless. A simpler armoured car introduced around 1982/3 would have been preferable. Something like the French VAB 90, possibly with another axle added and fitted with the Rooikat gun or with the a 17 pounder piece, would have been perfectly suitable.

 

[Matt R.]

1) Janes' states that the Cockerill Mk 4 gun was rifled piece with progressive right hand rifling, from 2° to 7°10', i.e. identical to that of the French CN-105-F1, its Israeli D1504 derivative and the 105/57 of the AMX-13 and the Kurassier. The ammunition for this gun is not the same as the that for the later Cockerill Mk VII. The Mk 4 fired a comparitively large HE shell, weighing 10.6Kg at 730m/s, a 5.9Kg HEAT shell at 1000m/s and a 7kg HESH shell at 790m/s. Looking at the rifling stated for the gun, I suppose these were conventional spin-stablized projectiles, except for the HEAT which would have had a slip-ring.

2) The Cockerill Mk 4 would have been a good gun for the Rooikat, I think. It has adequate performance to allow a decent APFSDS round to be developed and the HE shell is much more useful than 6.2kg job available to the 76mm gun.

1) AIUI, the French 105mm guns (Mle 57 & Mle 67) had a uniform RH rifling (32 grooves @ 7°10'). The French 105mm G2 gun (LRF) is (was?) offered with a uniform RH rifling (either 28 grooves @ 9°54' or 32 grooves @ 7°10'). While not as good for gyro-stabilization as the L7/M68 (uniform RH 1 in 18 with 28 grooves), this seems more appropriate than the progressive rifling giving by Jane's for the Cockerill MkIV 90mm gun.

As you've stated in another post, I believe that all 90mm projectiles intended for the Cockerill MkIV were both fin- & spin-stabilized. This was also the case for the Cockerill MkVII and my understanding is that it remains the case for the Cockerill Mk8 (progressive RH rifling from 6° to 9° ?).

2) Some time ago, I did some quick & dirty estimates of the performance of the APFSDS fired by the 76mm GT-4 and found it to be quite close to what's being advertized for the Cockerill Mk8 with M690A2 APFSDS, so probably close enough to the performances of the previous Cockerill MkVII.

OTOH, ammunition stowage would have remained more or less the same (GT-4 cartridge is 76.2mm x 636R with rim diameter of 114 mm vs Mk8 cartridge is 90mm x 580R with rim diameter of 111 mm).

So, sanctions aside, I tend to agree with you that the Cockerill MkIV 90mm gun could have been a decent solution for the Rooikat.

 

[Matt R.]

The problem with the Rooikat is that it was, as with the Rooivalk helicopter, a case of too much, too late. By the time the Rooikat arrived, it was a highly sophisticated, expensive and relatively complex vehicle sporting hunter-killer fire control features, night-fighting capability and lots of bells, whistles and things that open and close. It arrived too late for the war however and was therefore useless. A simpler armoured car introduced around 1982/3 would have been preferable. Something like the French VAB 90, possibly with another axle added and fitted with the Rooikat gun or with the a 17 pounder piece, would have been perfectly suitable.

In the early 1970s, Panhard developed a family of armored wheeled vehicles based on their M2 VCAI 8x8 demonstrator (presented at Satory 1971) :

* M4 : 4x4 APC variant which competed for the VAB program (vs Renault & Berliet)
* M8 : 8x8 variant which competed against the AMX-10RC
* M6 : 6x6 APC variant developed for South Africa and apparently featuring a turreted 90mm gun (project Bourboel ?)

I suppose that the M6 failed to materialize because of the sanctions implemented later on in the decade.

 

[Matt R.]

Reply to post # 131>

Matt

Lots of interesting info, once again. Your numbers support the notion that the 17 pounder and 76/62 Oto are in the same ball park as far as power is concerned. I have always thought that the cartridge - barrel combination of the 17 pounder was a bit overbore: the barrel was too short for the case capacity. This is supported by reports of enormous muzzle blast and flash when firing the thing. The 17 pounder would probably have been a significantly better gun if it had had a 60-65 calibre barrel, like the Oto, or even a 70 calibre barrel like the Kw.K.42 L/70 of the Panther. The German gun's cartridge case was 57mm longer than that of the 17 pounder but the shell was slightly slimmer.

1) Muzzle blast and flash might be due to the specific design of the muzzle brake, which would probably have been re-designed to accommodate APFSDS projectiles anyway, had the SADF opted for the QF 17-pdr.

2) In addition to the French 75mm SA-50 gun, it might be interesting comparing the QF 17-pdr with the US M32 76mm used on the M41 Walker Bulldog :

* full-caliber AP rounds :
- SA-50 : 6.4 kg @ 1,000 mps (3.2 MJ)
- QF 17-pdr : 7.7 kg @ 885 mps (3.0 MJ)
- M32 : 6.6 kg @ 975 mps (3.1 MJ)

* sub-caliber AP rounds :
- SA-50 : 3.9 kg @ 1,300 mps (3.3 MJ)
- QF 17-pdr : 3.5 kg @ 1,200 mps (2.5 MJ)
- M32 : 3.7 kg @ 1,257 mps (2.9 MJ)

An APFSDS projectile (designated M464) was developed for the M32. Using a propellant that's not particularly energetic (M30), the 2.5kg projectile (1.68kg tungsten penetrator) offered a MV of 1,433 mps. This may not be as good as the GT-4 in terms of performances, but not so far away.

Incidentally, the OFL-105-G1 APFSDS fired by the 105mm Mle57 gun was similar in terms of performances (1.6 kg penetrator with a MV of 1,475 mps).

I suspect that the QF 17-pdr was obsolete at the time (as far as metallurgical properties are concerned for instance) and may not have been regarded as a desirable option when weighted against the OTO 76mm/62 which was of more recent design (autofrettaged, etc...).

 

[kaiserbill]

In the early 1970s, Panhard developed a family of armored wheeled vehicles based on their M2 VCAI 8x8 demonstrator (presented at Satory 1971) :

* M4 : 4x4 APC variant which competed for the VAB program (vs Renault & Berliet)
* M8 : 8x8 variant which competed against the AMX-10RC
* M6 : 6x6 APC variant developed for South Africa and apparently featuring a turreted 90mm gun (project Bourboel ?)

I suppose that the M6 failed to materialize because of the sanctions implemented later on in the decade.

Here is the Boerboel (Panhard M6), in these threads.
A Boerboel is a massive South African breed mastiff type dog, by the way.


http://www.secretprojects.co.uk/forum/index.php/topic,9088.msg223767.html#msg223767


and some further info:


http://www.secretprojects.co.uk/forum/index.php/topic,1937.msg223794.html#msg223794


It seems it was part of the trials and tests that led to the Ratel...not too successfully.


The Ratel 90 then would be the analogue or counterpart that fulfilled that requirement, and was indeed used as an armoured car in places the Eland (AML90) was deemed unsuitable due to terrain.

 

[Herman]

Reply to post #134
When South African forces encountered enemy armour in Angola, all that was initially avaible to counter the threat was the Eland. This was unsatisfacty because of 2 reasons: the mobility of the little car could not match that of the Ratel. Mobility was further bedevilled because of a petrol engine. The second reason that the 90mm gun of the Eland was marginal. It was relatively low velocity, making engagement at long range difficult, and the efficacy of the HEAT shell was iffy, usually requiring several hits on a T54 to effect a kill. The mobility problem was solved by fitting the Eland turret on the Ratel. This was seen as an interim solution until the arrival of the Rooikat. Development of the Rooikat took too long however because a too sophisticated vehicle was developed. A case of better being the enemy of good.

 

[Abraham Gubler]

Development of the Rooikat took too long however because a too sophisticated vehicle was developed. A case of better being the enemy of good.

I disagree with this. Anything that the RSA could have developed that was less sophisticated than the Rooikat would not be much more capable than the Ratel 90. They would have had to use off the shelf weaponry so fire power and fire control would be the same as the Ratel 90. The hull and running gear could have been optimised for the armoured car mission but would this have provided much of an improvement over the Ratel? The only other off the shelf gun alternative to the 90mm F1 was recycled 17 Pounders (from Fireflies) or 77mm guns (from Comets). There were only a handful of 77mm guns (20-30) on hand and the 17 Pounders would need a new development recoil system to be manageable in an armoured car (and the recoil system in the Ratel 90 was the significant failure point in combat for that system). Also the stock of 17 Pounders would require a lot of work to bring to operational standard because they had been in unmaintained storage for so long.

The Rooikat on the other hand was only made redundant by the change in strategic requirements brought about by unforeseeable political changes. Back in the 1970s, early 1980s, it was unreasonable to expect a prediction at the arms development level that both the Soviet Union and Apartheid would collapse by the 1990s. It was however reasonable to expect that if the SADF defeated the Owambo insurgency in the 1980s (which they did) they could face new Soviet and Cuban reinforcement of the Owambo and even ANC in the 1990s. Which could include the next generation of Soviet weapons, like T-72 tanks, on the ground.

Since "N boer maak 'n plan" the SADF/ARMSCOR had the next generation of weapons in development to face these threats. Including the Rooikat armoured car and the RSA version of the Leopard 2 tank called the TTD (so a Leopard can change its spots). The Rooikat, Rooivalk and ZT3 were available for service (with the Luiperd hot on their tails) at the time when the SADF could have faced a more potent tank threat in southern Africa. And if they had been required they would have made a real mess of any attacking tank force using T-72s.

 

[Hot Breath]

TTD is noted to utilise some Leopard 2 technology and so isn't a true member of the Leopard 2 family. It appears narrower and taller than the Leopard 2 and seems to carry less protection and a lower calibre gun (at least on the TTD prototype).

 

[kaiserbill]

That TTD was the prototype.


It was intended to equip it with the local 120mm that was developed (see the SA prototypes thread for a pic of the gun being tested).
Indeed, that was the entire point behind the new tank...to fight more modern Soviet tanks deployed in the future.
It is also why the design kept in mind a possible upgrade to a 140mm main gun from the beginning.


Also, we aren't sure what the final armour array of the TTD in operational form would have been.
As it was, the basic vehicle weighed over 58 tons, which was over 3 tons heavier than the vanilla early Leopard 2.

 

[kaiserbill]

Speaking of the armament of the Rooikat...I think was posted by Graugrun in another thread.


Also, the second pic is of that new turret from the rear.

 

[Matt R.]

Here is the Boerboel (Panhard M6), in these threads.

A Boerboel is a massive South African breed mastiff type dog, by the way.


http://www.secretprojects.co.uk/forum/index.php/topic,9088.msg223767.html#msg223767


and some further info:


http://www.secretprojects.co.uk/forum/index.php/topic,1937.msg223794.html#msg223794


It seems it was part of the trials and tests that led to the Ratel...not too successfully.


The Ratel 90 then would be the analogue or counterpart that fulfilled that requirement, and was indeed used as an armoured car in places the Eland (AML90) was deemed unsuitable due to terrain.

Thanks for the pics of the Boerboel / Panhard M6 (which I had not seen before).

The French STAT (Section Technique de l'Armee de Terre) found the 8x8 suspension arrangement of the M2/M8 excessively complex when weighed against the expected benefits.

I thought that Panhard had opted for more simplicity with the M6 (e.g. something along the lines of the ERC/VCR family), but the information posted in the other threads suggest it wasn't apparently the case.

 

[Matt R.]

Development of the Rooikat took too long however because a too sophisticated vehicle was developed. A case of better being the enemy of good.

The only other off the shelf gun alternative to the 90mm F1 was recycled 17 Pounders (from Fireflies) or 77mm guns (from Comets). There were only a handful of 77mm guns (20-30) on hand and the 17 Pounders would need a new development recoil system to be manageable in an armoured car (and the recoil system in the Ratel 90 was the significant failure point in combat for that system). Also the stock of 17 Pounders would require a lot of work to bring to operational standard because they had been in unmaintained storage for so long.

I believe this assessment that recycled 77mm or the QF 17-pdr not being the right tools for the job is spot on, for the reasons outlined in the post.

In my opinion, the most "reasonable" alternative to the GT-4 was the French 105mm Mle57 (CN-105-57), which had been available off-the-shelf for some time and could have be available much earlier.

Since the 105mm Mle57 used the same ammunitions as the 105mm Mle62 and its 44-cal Israeli derivative (e.g. OCC-105-F1 HEAT, OE-105-F1 HE), I believe that the Israelis could have helped with the ammunitions, and could likewise assist with the development of a suitable APFSDS projectile.

As for the gun itself, one might imagine South Africa managing to obtain a production license right before the start of the arms embargo of November 1977. After that date, getting technical documentations and/or assistance (or even blanks) from alternative sources (e.g. NORICUM of Austria, SITECSA of Spain) shouldn't have been much of a problem.

The 105mm Mle 57 gun would that way be available sooner and offer quite reasonable performances (though not quite as powerful as the 76mm GT-4 when it comes to anti-armor).

Then you'd have to design the turret, the hull / chassis, the FCS, etc...

With the benefit of hindsight, it could be argued that a chassis along the lines of the French VBC / Brazilian Sucuri / Irish Timoney 6x6 (specs here, pic below) fitted with the FL-12/FL-15 turret would have done the job reasonably well.

At the same time, as suggested in post #144, none of these options would have been as "future-proofed" as the Rooikat.

 

[Matt R.]

The 105mm Mle 57 gun would that way be available sooner and offer quite reasonable performances (though not quite as powerful as the 76mm GT-4 when it comes to anti-armor).

As a sidenote to the previous post, the OFL-105-G1 APFSDS fired by the 105mm Mle57 gun was an early design, and wasn't nearly as optimized as, - for instance -, the OFL-105-F3 APFSDS which entered service in 1987 for the 105mm MECA F2 gun used by the AMX-10RC.

Using a design based on the OFL-105-F3 APFSDS, one might obtain anti-armor performances very much in line which those offered by the 76mm GT-4 gun.

In addition to a more up-to-date APFSDS projectile, the range of projectiles available for the 105mm Mle 57 gun would include HEAT (OCC-105-F1 : 10.95 kg @ 800 m/s), HE (OE-105-F1 : 12.1 kg @ 700 m/s, HE payload of 2kg Hexolite 50:50) and HESH (by Hirtenberger of Austria).

On the minus side, projectile stowage capacity might have suffered, but not necessarily as much as one might imagine : the 105mm HE projectile is about 910mm long (105mm x 528R cartridge, rim diameter of 120mm) whereas the 76mm HE projectile (naval design by Diehl) is about 910mm long (76mm x 636R cartridge, rim diameter of 114mm).

 

[Herman]

Reply to post #144

[/size]You are probably correct in saying that the statement that the Rooikat was “too much, too late” is only true with the “retrospectroscope” and that at the time of the development of the Rooikat, the spectre of having to possibly fight more sophisticated Russian/Cuban armour, justified the extended development period and sophistication of the Rooikat. The only real criticism that can be levelled at the Rooikat, when it was introduced at the end of the eighties, was that it was badly undergunned. At the time of its introduction, there were 5 armoured cars available armed with a NATO type 105mm gun, all lighter and smaller than the Rooikat.
The Iveco Centauro 8x8 (24 tons).
The Engesa Sucuri 6x6 (18.5 tons).
The Cadillac Gage V600 6x6 (18.2 tons)
The AMX 10RC 6x6 (16 tons)
The LAV 105 8x8 (14 tons)
The most successful of these vehicles is the Centauro which is operated in large numbers by Italy and Spain. The LAV 105 was produced for the US Marines but cannot be labelled a resounding success. None of the others were produced in significant numbers. Afaik the Sucuri , V600 and AMX were only produced as prototypes.[size=78%]

Despite the qualities of the 76mm gun of the Rooikat, it is simply not in the same class as the 105 L7 gun.

 

[TomS]

The LAV-105 was not manufactured in "significant numbers" either -- just three prototypes for the Marines, who never adopted the type for service.
The AMX-10RC didn't have an L7 gun, it had the French MECA F2 gun that Matt R. mentioned in passing a few posts ago.

 

[Herman]

Reply to post #141
Matt, was the M32 based on the 76mm M1 gun used in the Sherman, in WW2? Same chamber size?

 

[kaiserbill]

The LAV-105 was not manufactured in "significant numbers" either -- just three prototypes for the Marines, who never adopted the type for service.
The AMX-10RC didn't have an L7 gun, it had the French MECA F2 gun that Matt R. mentioned in passing a few posts ago.

Indeed.


Additionally, the Rooikat was produced and in service before the Centauro too.


Also, it is worth remembering that the Rooikat is an uncompromised design, unlike some of the others that were originally troop carriers/lighter vehicles, with either thinner armour/higher volumes and/or less power/manoeuvreability.

 

[Matt R.]

The most successful of these vehicles is the Centauro which is operated in large numbers by Italy and Spain. The LAV 105 was produced for the US Marines but cannot be labelled a resounding success. None of the others were produced in significant numbers. Afaik the Sucuri , V600 and AMX were only produced as prototypes.

1) As Tom S. mentioned earlier, the LAV-105 wasn't produced adopted for service by the USMC, despite the two-man LW 105mm turret (designed by Cadillac Gage Textron) apparently proving quite satisfactory during firing tests (according to R.P. Hunnicutt in Armored Car).

2) The AMX-10RC is concerned was actually produced in significant numbers (457 vehicles in total, of which 337 for the France, 108 for Morocco and 12 for Qatar). As mentioned by Tom S., the AMX-10RC didn't use a NATO-standard 105mm gun, but the lightweight / low pressure 105mm MECA F2 gun.

 

[Matt R.]

The AMX-10RC didn't have an L7 gun, it had the French MECA F2 gun that Matt R. mentioned in passing a few posts ago.

As you most likely know already, the French developed a three-man turret (TGG-105 initially, gradually refined into a more modular design renamed TML-105) as part of an upgrade package for the AMX-10RC. This turret featured a NATO-standard 105mm gun (Model G2).

The new turret was successfully qualified on the AMX-10RC chassis (test campaign began in January of 1993), but was eventually dropped from the upgrade package a few years later because of budget constraints.

The TML-105 was installed and/or tested on a variety of other chassis, both wheeled (Piranha 10x10, Vextra,...) and tracked (Mars 15, CV-90, Puma) but failed to gain customers. GIAT abandoned its marketing efforts some time in the early 2000s (2003 ?), but continued to promote the 105mm G2 gun for some time thereafter.

 

[Matt R.]

Reply to post #141
Matt, was the M32 based on the 76mm M1 gun used in the Sherman, in WW2? Same chamber size?

R.P. Hunnicutt (in Sheridan) doesn't mention any connection between the M1 and the M32, and their respective main specs look very different :

76mm M1A2 gun :
* diameter of bore : 3.0 inches / 76.2 mm
* length of bore : 52 cals
* overall length of gun : 167.75 inches / 4,261 mm
* total weight of gun : 1,204 lbs / 546 kg
* chamber capacity : 142.6 cubic inches / 2.4 litres
* rated maximum powder pressure : 43,000 psi (copper)
* cartridge : 76.2 x 539R

76mm M32 gun (with late muzzle brake) :
* diameter of bore : 3.0 inches / 76.2 mm
* length of bore : 60 cals
* overall length of gun : 192.40 inches / 4,887 mm
* total weight of gun : 1,709 lbs / 775 kg
* chamber capacity : 197.0 cubic inches / 3.2 litres
* rated maximum powder pressure : 46,000 psi (copper)
* cartridge : 76.2 x 580R

 

[Matt R.]

Also, it is worth remembering that the Rooikat is an uncompromised design, unlike some of the others that were originally troop carriers/lighter vehicles, with either thinner armour/higher volumes and/or less power/manoeuvreability.

Looking at the vehicles listed by Herman :

* the AMX-10 RC was designed as a wheeled 105mm AFV, with the IFV variant (AMX-10 RTT) being designed afterwards (and maybe coming too late to gain market acceptance).

* the Centauro 8x8 was likewise designed as a wheeled 105mm AFV, with the IFV variant (Freccia) being designed afterwards (and ending up being more successful than the RTT from a commercial standpoint).

* the Sucuri 8x8 was, as far as I am aware, also designed as a wheeled 105mm AFV, with no IFV/APC variant that I'm aware of (maybe due to the demise of Engesa).

* the Commando V600 was based on the Cadillac Gage V300 with some substantial modifications.

* the LAV-105 was indeed based on the USMC LAV family of vehicles (with relatively minor modifications).

To take just this single example, the AMX-10 RC is as much as "uncompromized" a design as the Rooikat might be, its "inferior" performances (thinner armor, lower speed, lesser range,...) largely reflecting different requirements (with substantially different mass / volume envelopes) and different design / in-service timeframes.

 

[Herman]

Reply to post #152.
A prototype of the AMX 10-RC was built with the Rheinmetall Rh-105-11 SLR (Super Low Recoil) gun, fitted into a modified version of the original turret, in the late eighties. This gun fires all ammunition suitable for the standard 105mm L7 gun. The gun weighs 1380kg, is fitted with a recoil brake with an efficiency of 35% and it has a normal recoil length of 925mm and a recoil force of 110kN. It was suggested by Rheinmetall that the French replace the 105mm F2 MECA guns on the armoured cars with this, much more powerful gun, but the latter decided to keep the original gun. The SLR gun was also mounted in Mowag Shark 8x8 prototype and the Swedish Ikv light tank.

 

[Herman]

Reply to post #154.
Additionally, the Rooikat was produced and in service[/size] before[/size] the Centauro too.
[/size]
[/size]Strictly speaking correct, but the vehicles entered service within one year of one another.
[/size]
[/size]Rooikat: The first Rooikat vehicles were produced in 1989 and the vehicle became operational with the SADF in 1990.
[/size]
[/size]Centauro: Preproduction batch of 10 vehicles were produced in 1989, production started in 1990 and introduction into service in 1991.

 

[Herman]

Reply to post #155.


Correct Matt, but as I noted in a previous post, the AMX-RC armed with the NATO compatible 105mm SLR gun was not produced in significant numbers.