Categories
Cold War Belgian prototypes

M41 LCTS 90

Belgium (1992)
Light Tank – 1 built

At the end of WW2, the US Army was using the 75 mm M6 gun-armed M24 Chaffee light tank, an otherwise satisfactory and reliable light tank. Nonetheless, by 1949, the US Army had decided to replace it, leading to the T41E1 and, which was eventually type classified as the M41. Fitted with the more powerful M32 76 mm main gun, gun stabilization (the British Vickers system), and a rangefinder, the M41 marked a step-change in the firepower of light tanks for US forces. Weighing just 23.5 tonnes (nearly 6 tonnes more than the Chaffee), the M41, powered by a Continental or Lycoming boxer 6 cylinder engine delivering 500 hp, was an agile tank with excellent firepower for its weight. Widely exported, it saw decades of use in dozens of armies around the world, but by the 1990s was seriously obsolete. An inadequate fire control system, no laser range finder, and a gun incapable of tackling even second-line Soviet tanks meant the M41 had had its day. Like other light tanks of WW2 or post-WW2 era, it was simply not able to offer a modern army what was needed in terms of firepower. Whereas particularly Western armies could afford the development of a new era of light, capable, and well-armed platforms offering increased protection, second-rate armies could not. Many armies around the world were still operating or had vehicles like the M41 or AMX-13 in stock or were looking to perhaps add some capability to their armored forces by adding a turret to an APC like the M113

The Belgian firm of Cockerill, with a very long history of development and manufacture, offered exactly this option in the early 1990s in the form of a light turret with a new powerful 90 mm gun, offering performance similar to the well-regarded Royal Ordnance 105 mm gun but without the weight. This option, therefore, potentially allowed more cash-strapped militaries to upgrade otherwise obsolete vehicles to modern firepower standards or to add much-needed firepower to an APC or wheeled platform. For the purpose of tests and to potentially elicit sales, this new turret, known as the LCTS, was mounted on a surplus M41 Walker Bulldog, presumably from surplus Belgian stocks as the Belgian Army had operated 135 of them between 1958 and 1974. Despite the potential benefits on offer, this turret did not find any interest in itself, but its descendants are currently in service with the US Army and other forces around the world.

Design

The Hull

The M41 light tank was of a conventional layout, with the driver in the front, crew space in the central part, and engine in the rear. The turret was mounted roughly centrally on the vehicle and the new LCTS turret was mounted in exactly the same place as the original. The available photograph clearly shows the use of a turret-ring adapter mounted on the hull to match the new turret.

The Crew

Only a single crew member was used in the hull of the M41 light tank and this crew member, the driver, was obviously retained for this demonstrator vehicle too. Sat in the front left of the hull, the driver, his controls, hatches, optics, etcetera would remain unchanged from the M41 or other platform on which the turret could be placed, notwithstanding any additional upgrading done at the same time as adding the turret. The previous crew complement of the M41 consisted of three more men, with the commander, gunner, and loader in the turret but, for this vehicle, that original turret was completely removed and so were these crew positions.

Inside the new turret was space for just two crew, seated roughly side by side. The first, the commander, sat on the left of the turret under a single-piece hatch. He was provided with a single forward-facing sight for the primary weapon and had 5 periscopes around his hatch for observations. Any additional sights, including a thermal sight, were presumably available as aftermarket options for potential buyers.

The second crew member in the turret was the gunner and he sat on the right of the turret, also with a single one-piece hatch. He too had a single primary forward-facing sight for the main gun and an array of 5 periscopes around his hatch for all-round observations. With no loader in the turret, the gunner would have to fulfill this function too, but it allowed for a substantially smaller turret as well, which was a substantial size and weight tradeoff for a reduced rate of fire available.

Automotive

The M41 tank used a 6 cylinder Boxer-type petrol engine from either Continental or Lycoming AOS 895-3 delivering 500 hp at 2,800 rpm. This allowed the 23.5-tonne tank to reach speeds of up to 45 mph (72.4 km/h) on a road. Later versions of the M41, the M41A1, and M41A2 used a fuel-injected version of this engine, the AOSi-895-5.

The suspension was provided by means of 5 double road wheels with rubber tires and 3 rubber-tired return rollers, all running on tracks 21 inches (533 mm) wide. The CD 500-3 cross drive transmission was at the back driving the sprocket to move the tracks and a single idler wheel was located at the front. There is no information in Janes, from Cockerill, or from the photograph of the vehicle available to suggest any changes to the hull used. Any upgrade program from a buyer may obviously have included upgrades to whatever power plant or drive desired. The available photograph of the vehicle from Janes does show some reel on the back deck of the hull, but this does not appear to have any relevance to the design or automotive elements.

90 mm armed LCTS turret on the hull of an M41 light tank. Source: Janes

The Turret

The turret was the whole point of the design. Able to be fitted to a variety of hulls, it was only fitted to the chassis of an M41 light tank for demonstration purposes. Using this hull was a clear sign of the potential market for a turret that could modernize existing light tanks, such as the M41 or AMX-13, which were still in widespread international service but which were otherwise obsolete. Adding this turret would offer potential clients a relatively cost-effective way to make an old platform into a capable modern vehicle without the expenditures needed to develop or purchase a completely new vehicle.

Firepower

The LCTS turret was fitted with a pair of 7.62 mm machine guns of a type not specified, as these would be changeable by the client. One of the machine guns was fitted coaxially with the main gun and the other would be mounted on the roof of the turret for anti-aircraft protection. Up to 750 rounds of 7.62 mm ammunition could be carried in the turret.

The main armament, however, was not changeable like the machine guns, as it was inherent to the design. Consisting of the 90 mm Cockerill Mk. 7 gun, this was mounted centrally in the narrow front of the turret. The gun was able to be rotated a full 360 degrees and was capable of -9 to +20 degrees of vertical movement. Turret traverse was powered and the speed of rotation was 30 degrees per second. This meant it would take 12 seconds to make a single full 360-degree revolution.

Two banks of four smoke grenades were carried on each side of the turret. Eight additional grenades were carried inside the turret. Up to 12 rounds of 90 mm ammunition could be carried in the turret, as well as some additional rounds in the hull of the tank, although this would depend on what the donor hull being used would be. For example, mounting the turret on an M113 would allow significantly more potential stowage than on an AMX-13 hull, so the exact stowage could not be determined. It is worth noting that the gun and turret, during various iterations, were trialed for several vehicles, including the British Saladin armored car at one point. Stowage on the M41 for its original 76 mm gun was 57 rounds with 13 in the turret, 11 in a ready rack, and 33 in the hull. For this new smaller turret, just 12 90 mm rounds were able to be carried in the turret and, assuming a substantially smaller or no space for a ready rack, this would still leave hull stowage for around 30 rounds in the hull. In total, therefore, perhaps around 40-45 rounds could be stowed using this turret on a modified M41.

The 90 mm Cockerill gun (also sold as the 90/46 KEnerga by MECAR), launched in around 1982, went through various stages of development. The Mk. 7 was a modification of the Mk. 6 and was itself modified and replaced by the Mk. 8 in 1992. Weighing less than ¾ of a tonne and with a length of 4.365 m (L/48.5), the 90 mm Cockerill operated at a pressure of just 310 MPa and produced a recoil stroke of just 350 to 370 mm.

Ammunition for the Cockerill gun was made by MECAR and included a potent Armor-Piercing Fin-Stabilised Discarding Sabot – Tracer (APFSDS-T) round with a muzzle velocity of 1,500 m/s able to defeat NATO triple heavy targets, High Explosive Plastic (HEP) to defeat bunkers, structures, light armor and also for indirect fire use, smoke, canister, High Explosive Anti-Tank (HEAT), and training rounds.

Armor

The hull armor for the M41, as would be expected from a light tank, was poor, with just 30 mm at 40 deg. on the front, 25 mm on the sides, and 20 mm at 40 deg. on the rear. The new LCTS turret was basic and based on a simple welded steel shell. The basic shell provided protection from small arms fire and could, if required, be supplemented with some additional layers bolted to the exterior to increase protection. This would also increase the weight from 2,400 kg and the ballistic protection improvements would not be sufficient to resist enemy tank fire and would only go as far as providing protection from heavy machine-gun fire. More than that would be somewhat pointless, given that the prospective vehicle on which this would be mounted was relatively lightly armored too.

Conclusion

The LCTS turret was similar in size to the ACEC AK90E turret as fitted to the ACEC Cobra a few years prior. It too mounted a 90 mm gun and seated the two crew side by side. The AK90E turret was larger though, weighing some 200 kg more and able to stow 17 more 90 mm shells than the LCTS. Given that both firms are Belgian, and offered these very similar turrets just a few years apart, it is hard not to see the LCTS as a direct development from the AK90E both on a purely visual comparison but also based on the technical specifications of the two.

The LCTS 90 turret with the Cockerill Mk.7 gun mounted on the hull of a Belgian M41. Illustration by Ardhya “Vesp” Anargha, funded by our Patreon campaign

Comparison between ACEC AK90E and LCTS Turrets

ACEC AK90E LCTS
Crew 2 (Commander & Gunner) 2 (Commander & Gunner)
Main Armament 90 mm Cockerill Mk.7 or Mecar 90 mm KEnerga Cockerill 90 mm
90 mm Ammunition (turret stowage only) 29 12
Secondary Armament Coaxial 7.62 mm MG Coaxial and roof-mounted 7.62 mm MG
7.62 mm ammunition 750 rounds 750 rounds
Traverse Speed 28 deg./sec 30 deg./sec
Elevation Range -10 to +25 -9 to +20
Fire Control OIP LRS 5 incl. Thermal day/night sight and laser range finder unknown
Commander’s Optics 4 M17 observation periscopes 5 periscopes plus gun sight
Gunner’s Optics 4 M17 observation periscopes 5 periscopes plus gun sight

The LCTS, as shown, received no orders. It was undoubtedly a capable platform on which to mount the very capable 90 mm Cockerill gun and combined with some modern fire control and ranging would have provided a serious way to upgrade otherwise obsolete vehicles to a modern standard. Despite the lack of sales, Cockerill continued their development and refining and the descendant design of the LCTS 90 mm is the LCTS 90MP – a highly successful turret with a 90 mm gun in service, amongst others, with the US Army. 

ACEC AK90E turret. Source: Janes

M41 LCTS 90 specifications

Total weight M41 or other vehicle hull weight plus 2,400 kg (turret) as mounted on the M41 estimates ~23 tonnes
Crew 3 (commander, gunner, and driver)(assuming donor vehicle uses a single hull crewmember – commander and gunner in turret)
Engine 6 cylinder Boxer-type Continental or Lycoming AOS-895-3 petrol engine delivering 500 hp at 2,800 rpm or the AOSi-895-5 fuel injected version
Armor bulletproof – capable of being improved
Armament 90 mm Cockerill Mk.7 gun plus two 7.62 mm machine guns
Ammunition 12 x 90 mm rounds (turret) plus hull stowage, 750 7.62 mm rounds

Sources

MECAR. KEnerga 90/46 lightweight gun system advertisement.

MECAR 90 mm Mk.3/ Mk.8 ammunition at mecar.be

Foss, C. (1994). Janes Armour and Artillery. Janes Information Group

Cockerill (John cokerill Ltd.). Performance Tables for 90 mm Mk. 3 gun.

Icks, R. (1972). M103 Heavy tank and M41 Light Tank (Walker Bulldog). AFV Profile Weapons 41. Profile Publications, UK

Categories
Cold War Belgian prototypes UAE Armor

Sabiex HIFV, The ‘Golden Unit’

Nation Belgium/United Arab Emirates (2005)
Infantry Fighting Vehicle – 1 built

The United Arab Emirates (UAE) was the only nation that bought the Italian OF 40 (OTO-Melara/Fiat 40 tonne) tank in the 1980s. They first bought the Mk.1 and were not pleased with the vehicle leading to a further delivery of Mk.2 vehicles and upgrading of the Mk.1 to Mk.2 standard very soon afterwards. Even so, these tanks were not considered mobile enough nor sufficiently well armed by the UAE for their envisaged role in the Middle Eastern battlespace. Ultimately, the UAE was left with an undesired stock of tanks and OF 40 based armored recovery vehicles (ARV’s). The UAE, already operating the much more advanced, better protected, and better armed Leclerc MBT, did not need these older vehicles. Despite rumors of these vehicles being sold to Bosnia-Herzegovina as surplus in the late 1990’s they instead appear to have simply been put into long-term storage in the Gulf nation.
The UAE did, however, operate a number of BMP-3’s which, despite being well armed, were not well armored which led to the search for a suitable replacement for them.

OF 40 Mk.2

OF 40 based Sabiex HIFV showing the substantially altered profile of the vehicle. Source: Al Badie Group

Hull development at Sabiex’s Belgian plant. The hull has been totally stripped off and a new improved mine resistant floor is being added. Old features like the driver’s floor hatch from the OF 40 are eliminated. Source: Al Badie Group

New internal side armor being fitted at the Sabiex plant. Source: Al Badie Group

Sabiex OF 40 based HIFV leaving the Sabiex plant in Belgium – Source: Sabiex.com

Sabiex HIFV undergoing trials in Belgium in 2007. Source: Al Badie Group

Sabiex HIFV during trials in Belgium in 2007. The position of the driver gives a good idea of the problems of driving a vehicle with such a large frontal blind spot.

Sabiex HIFV during testing in Belgium in 2007. Source: Al Badie Group

Development

By 2005, a possible new role for the OF 40 tanks was found. The Belgian firm of Sabiex International, based in Tournai, received a €12 million (euro) (US$15.8 million) contract from the UAE to reuse components of the OF 40 during the development and evaluation phase of their own IFV/APC program. Also involved in this joint-venture were the South Technology Company (STC) along with the Al Badie Group (ABG). STC specialise in engineering, upgrading, addition armoring (including landmine protection) and optronics.
The purpose of this new vehicle was to replace the existing UAE BMP-3’s fleet. The result of the STC/Sabiex/ABG venture was something rather unusual. The goal was the construction of a prototype Heavy Infantry Fighting Vehicle (HIFV) which saw one OF 40 shipped to Sabiex in Belgium, dismantled and refurbished. The new prototype vehicle was partially completed in 2007, sufficiently for trails in Belgium to take place. The development work was done by 2010 and the completed vehicle shipped back to the UAE for desert trials. In the UAE, this vehicle is officially known as ‘the Golden Unit’ as a test prototype and, having passed its desert trials, was to then to proceed to 2nd stage development by STC. This further conversion work based on the Sabiex development was planned to take place at the production facilities of ABG in UAE, but had not started by mid-2010.

Sabiex HIFV prototype hull on display. Source: Sabiex

OF 40 MTU power pack reconditioned for use in the Sabiex HIFV. Source: Al Badie Group

Design

The OF 40 was a conventionally laid out tank with the Fiat-built (licensed) Motoren und Turbinen Union MB 838 CA M500 supercharged, liquid cooled, ten-cylinder multi-fuel diesel engine producing 830hp. The engine, transmission and drive were at the rear. The basic dimensions of the original OF 40 hull were retained as was 7 roadwheel layout with each pair of double wheels mounted onto a swing arm and torsion bar with hydraulic shock absorbers at the front and rear wheel stations.
The Sabiex design saw the reversal of the vehicle layout. The original OF 40 MTU type power pack was retained but now sat at the front of the vehicle allowing the rear to be converted for infantry use. Additionally, the placement of the engine in the front of the vehicle allows for additional protection over the frontal arc. This concept has been tried elsewhere with other tanks such as the Centurion in Jordan being reversed and turned into the Temsah. The only modification done in UAE other than adding the BMP-3 turrets appears to be some work on the exhaust louvers which are reduced from 5 to 3.

Sabiex HIFV fitted with BMP-3 turret in the UAE. The modified exhaust louvres can be seen.


Illustration of the Sabiex HIFV, or ‘The Golden Unit’. Produced by Yuvnashva Sharma, funded by our Patreon Campaign.

Close up of the drive sprocket from the Sabiex HIFV also shows the thickness of the front lower plate of the vehicle’s armor.

Protection

The vehicle is still made from all-welded steel armor for the hull and Sabiex claim protection is provided to STANAG 4569 level 5 with additional protection against the Russian TM-57 anti-tank mine. Significant additional protection has been added internally with a new inner armored bulkhead providing the whole of the sides with spaced armor. Significant additional protection on the floor of the vehicle is also provided with the elimination of the old driver’s escape hatch in the floor and a new floor put in place. The front lower part of the vehicle appears to be made from an outer layer of ~40 mm thick armor plate, and the nose is assumed to consist of a large section of spaced armor.

Detail of new nose armor which has had the OF 40 headlamps (M60 style) fitted to it. The driver’s digital video camera driving aid can be seen behind it (the small whitish rectangle). Source: Al Badie Group

Front view of the Sabiex HIFV hull in its two-tone desert camouflage pattern. This was later changed to an all- sand-yellow scheme in the UAE

Armament

The only information relating to armament is that the prototype was shown fitted with a surplus turret from one of the large number of BMP-3’s operated by the UAE. That BMP-3 turret is fitted with a 100mm 2A70 main gun, a 30mm 2A72 coaxial autocannon, and 7.62mm PKTM coaxial machine gun.
Had the program gone ahead, the Golden Unit would have been one of the most heavily armed and armored HIFV’s in the world.

Drivers station seen from inside, looking towards what used to be the bulkhead between the fighting compartment and the engine bay. A turret is not fitted and the new flooring over the improved mine protected floor can be seen. Source: Al Badie Group

View of the right-hand side of the driver’s position during construction. The front of the vehicle is to the right and not the direction in which the fitter is facing or seated. Source: Al Badie Group

Crew

The Sabiex design called for a crew of just two, a driver who sat in the front left of the fighting compartment and a commander/gunner. Without the turret fitted, there is a large central space between the back of the driver and the four infantry seats, which could be used for a variety of purposes but, even with the turret fitted, the four rear seats remain. This would allow for up to 5 additional crew members with one assisting in the crewing of the BMP-3 turret. This would bring the maximum complement up to 2+5 with a turret. Access to the vehicle for the driver is via his own hatch but the infantry accesses the vehicle via the large power-operated rear ramp or the rightwards opening single door within the ramp. A rectangular hatch in the side of the right-hand side of the vehicle and other features include small video cameras at the front and back to assist the driver.

View inside the Sabiex HIFV through the rear boor shows the thickness of the substantially improved floor to be mine resistant. Source: Al Badie Group

Weight

Operating without a turret the Sabiex HIFV has a mass of 35,000 kg, and 45,000 kg (45 tonnes) with the BMP-3 turret making it heavier than the OF 40 MBT on which it was based.

Sabiex IFV with BMP-3 turret fitted – Source: Defence Blog

Elevated rear view of the Sabiex HIFV showing the considerable bulk of it. Two of the four infantry seats can be seen folded on the left. Source: Al Badie Group

Conclusion

The program began in 2005 and trials were conducted in Belgium in 2007. Further trials were conducted in 2010 in the UAE with work on converting the remaining OF 40 vehicles scheduled to commence at the ABG production facilities but never did. Following delivery of 436 Leclerc MBT and variants to the UAE from the French firm of Nexter Systems, all remaining OF 40 vehicles are officially withdrawn from service. Only one OF 40 is known to have been modified and the status of the program appears to be canceled. The status of the test vehicle is not known but is assumed to be in storage in the UAE. The Golden Unit as a prototype was successful and if the remaining stock had been converted, the UAE would have had a very well armed HIFV.

Turretless Sabiex IFV during desert testing circa 2010 – Source: Sabiex

Sources

Sabiex.com
IHS Janes
Defence.blog
Albadiegroup.com
Roe.ru
Additional material from Ed Francis

Sabiex HIFV specifications

Dimensions 7 x 3.35 x 2.1 m (hull only)
Total weight Approx. 35 tonnes (hull), 45 tonnes with BMP-3 turret
Crew 2 crew plus 5 infantrymen
Propulsion Fiat built (licensed) Motoren und Turbinen Union MB 838 CA M500 supercharged, liquid cooled, ten cylinder multi fuel diesel engine producing 830hp
Suspension Torsion bar suspension with hydraulic adjustment
Armament BMP-3 turret available, 100mm 2A70 main gun, 30mm 2A72 autocannon and 7.62mm PKTM machine gun
For information about abbreviations check the Lexical Index
Categories
Cold War Belgian prototypes

ACEC Cobra Tank – Cobra 25 and 90

Belgium Kingdom of Belgium (1977-1990)
Light Tank – 1 built

From AFV to tank

Despite the lack of successful orders for the APC/AFV version of the Cobra, the ACEC Cobra’s powertrain was successful and compact enough to warrant a further attempt to enter the armoured vehicle market, this time in the light tank category.
In order to make a tank which was still as small as possible but capable of packing a big punch ACEC redesigned the Cobra hull. This was the final version of the hull produced and involved a complete rearrangement inside although the wheels, track and suspension arrangement remained the same. The single driver was now located centrally where the engine used to be and the engine and motors were moved to the back of the vehicle in a conventional arrangement for an unconventional tank. It still retained the electrical transmission meaning it was still very light and had excellent acceleration but now came in a light tank, and a reconnaissance version.
The reconnaissance version was known as the Cobra 25, with a crew of 3 men, 2 of whom were in the turret. The weight was still under 10 tons and mounted the 25mm Oerlikon KBB cannon (25 x 181) and a secondary 7.62mm machine gun in the turret along with an OIP/SCS-5 x 8 periscope each for the commander and gunner, a x8 night sight for the gunner and a x6 night sight for the commander. The cannon was able to be elevated to 60 degrees allowing this vehicle to double up in the air defence role as well. This very adaptable design too sadly received no orders.

tACEC Cobra 25 fitted with the Cockerill C25 turret
A final turret, the 2 man (gunner on the right and commander on the left) AK90E was designed by ACEC in around 1984 and was fitted with a 90mm MECAR/KENERGA main gun, capable of firing a full range of 90mm ammunition including APFSDS type rounds, and a secondary 7.62mm machine gun. It was also capable of fitting the Cockerill Mk.7 90mm gun.
The turret was intended to be available for other vehicles as it weighed just 2,600kg but never received any orders. Made from armour steel welded all around, the front could withstand armour piercing 7.62mm ammunition at 500 metres but the sides and rear were rated only for 7.62mm ball. The main armament could be elevated from -10 to +25 and the turret could complete a full rotation in about 28 seconds.
Marketed correctly as a ‘deadly threat to battle tanks’ ACEC had produced a very light, innovative and simple package ideally suited to the export market especially as it was under 10 tons in weight.

View of the ACEC Cobra 90 with rearranged hull and mounting 90mm Cockerill gun

ACEC AK90E electrical turret (smoke dischargers not fitted)
There were only a couple of other modifications to the ACEC Cobra 90 hull. The original driver’s hatch featured a single large front view port  on the hatch which opened in a manner similar to the Soviet T-34 of WW2. This was modified later with additional side view ports on the hatch as can be seen on the surviving vehicle. This hull also had optional side skirts which could be removed too. The turret is sometimes seen with a large spot lamp which could be mounted on either side of the gun.

ACEC Cobra 90 showing early single viewport drivers hatch, the optional side skirts raised and no spot lamp on the turret.


ACEC Cobra 90, illustration by David Bocquelet

Photo credit: armyrecognition.com
Surviving ACEC Cobra 90, serial number 9601135 at the Depot of the Royal Museum of the Armed Forces, Kapellen, Belgium with gun removed.

Conclusion

The ACEC Cobra was a highly innovative vehicle, it just came at the wrong time. By the time it was ready for production there were already plenty of competitor designs for an AFV/APC and even light tank. The electrical drive system was probably off-putting for many mainly traditional buyers of arms unwilling to consider that it might be better than what they may have been used to. The Cold War ended not long afterwards too meaning a huge reduction in conventional forces in Western Europe and a glut of surplus equipment on the open market killed off what was a very promising line of development as the parent firm was sold off. With it died the prospect of a full range of variants based on this design such as the Cobra Command Post, Ambulance, Cobra Engineering vehicle, and Cobra Mortar Carrier fitted with a 120mm heavy mortar.
It is perhaps ironic that many of the features of the Cobra are once more being investigated to solve the same problems of reducing size and weight from rubber tracks to electric drive. Even the choice of the RCDU was ahead of its time with remote weapons stations common now.
The Cobra 90 tank is reported to have been shown at an international arms fair in Kuala Lumpur in about 1985 giving an indication as to the potential markets being sought but despite the advantages this design offered over its contemporaries it too failed to secure any orders. The Cobra tank prototype thankfully survives at the Belgian Tank Museum, Kapellen along with the APC versions, although the 90mm gun has been removed from the tank. The ACEC Cobra, be it the APC or the tank variant, might not originate from the most well known European tank making nation but the designs were well planned, well executed and well reviewed. Sometimes it doesn’t matter if you are better and cheaper than your competitors and the Cobra today is almost forgotten.

Sources

https://www.historyofwar.org/articles/weapons_acecCobra.html
https://cyberneticzoo.com/tag/belgian/
Janes Armour and Artillery 1985
Forges de Zeebrugge https://fz.be/
Cobra: der erste Schutzenpanzer der Welt mit elektrischer Kraftubertragungsanlage, P. Crevecoeur, 1980
Belgian Historical AFV Register V2.0, Michael van Loon, Neil Baumgardner, October 2012
Belgian Tank Museum https://www.belgian-tankmuseum.be
KBA/KBB 25 mm Cannon, Ordnance & Munitions Forecast, July 2002
International Defence Revue 4/88, 2/90

 Cobra 25 specifications

Dimensions 4.77(hull), 5.30m(over gun) x 2.75m x 1.38m(hull), 1.95m(turret)
Total weight, battle ready 9,500kg
Crew 3 (driver, gunner, commander)
Propulsion Cummins VT-190 V6 diesel 190hp
Suspension Helical springs with hydraulic shock absorbers on wheel 1 and 5
Speed (road) 75-80 km/h (46.6 – 49.7 mph) / 5km/h (water)
Range 600 km (372.8 mi)
Armament 25mm Oerlikon KBB cannon with 250 rounds
Armor All welded steel hull and turret providing protection 105mm HE shell bursts, small arms fire from NATO 7.62mm ball (at any angle or range) frontally proof against 7.62mm AP ammunition.
Total production 1
For information about abbreviations check the Lexical Index

 Cobra 90 specifications

Dimensions 4.77(hull), 6.89m(over gun) x 2.75m x 1.38m(hull), 2.0m(turret)
Total weight, battle ready 9,500kg
Crew 3 (driver, gunner, commander)
Propulsion Cummins VT-190 V6 diesel 190hp
Suspension Helical springs with hydraulic shock absorbers on wheel 1 and 5
Speed (road) 75-80 km/h (46.6 – 49.7 mph) / 5km/h (water)
Range 600 km (372.8 mi)
Armament 90mm MECAR, 90mm Cockerill Mk.7 with 30 rounds
Armor All welded steel hull and turret providing protection 105mm HE shell bursts, small arms fire from NATO 7.62mm ball (at any angle or range) frontally proof against 7.62mm AP ammunition.
Total production 1
For information about abbreviations check the Lexical Index
Categories
Cold War Belgian prototypes

ACEC Cobra IFV

Kingdom of Belgium (1977-1990)

Infantry Fighting Vehicle – 4 built

Belgium is not the first country to leap to mind for most people when they think of tanks or armored fighting vehicles, yet it has produced a few particularly interesting designs over the years. One of the these, which is virtually unknown, is the ACEC Cobra.
The Cobra is not a single vehicle but a platform, adaptable, lightweight and cost effective using diesel-electric drive to ensure the lowest possible weight and maximum space. The ACEC electric drive was one of the biggest selling points of the design allowing the Cobra into an exclusive club of diesel electric military vehicles.
The small and highly innovative Cobra was produced by the now defunct firm (acquired piece by piece by other companies until 1989) of Ateliers de Constructions Electriques de Charleroi ‘ACEC’. ACEC specialised in the manufacture of electrical motors including those for electric locomotives, and in 1970 ACEC did some work as part of the French Crotale surface to air missile program. As far back as 1967, ACEC had started work on electrical transmissions for tracked vehicles and, by 1970, had produced a version of the M24 Chaffee Light Tank fitted with an electrical transmission and an AMX 10P with one by 1978 too.

Direct Current motor reduction gear and brake assembly for the ACEC Cobra

The original Cummins diesel used on the ACEC Cobra producing 112 kW at 3300 rpm. Later versions increased output to 140 kW at 3300 rpm

After several years of study, ACEC determined that, rather than try and modify an existing vehicle to take an electrical transmission, it would be better to start from scratch with a whole new vehicle. As a result, in 1977, as a private venture, ACEC started working with the Belgian Army to create an APC with an electrical transmission, which would have allowed the new vehicle to be much lighter and more spacious than its contemporaries.
By the end of 1981, three prototypes had been completed by ACEC and finished their evaluation trials with the Belgian Army. A fourth vehicle with an improved engine was allegedly delivered for testing by 1985, but may simply be confused with the Cobra 90. Other trials were conducted in the USA by TACOM and the Department for Organization and Armament in Abu Dhabi, both of which found the handling and mobility to be very good.
The power from the engine in a conventional vehicle goes through a clutch and gearbox, through various reduction gearing and to the drive sprocket. For the Cobra, by using the power to drive just a generator, power could go directly to the gear reduction drives for each wheel instead, thus avoiding a lot of complex machinery, bulk, and more importantly, weight. Other advantages an electrical system offers over the traditional mechanical system are that it makes driving much simpler (no gear changes needed for example), steering is light and easy, thus reducing driver fatigue, and the maintenance of complex gear trains is eliminated.
Being lighter and using a generator system for power, the Cobra had a 600km range of action. Finally, the Cobra’s electrical transmission allowed it to accelerate faster than a mechanical transmission. The transmission also allowed the Cobra to accelerate and drive just as fast backwards as it did forwards.This is very useful for a reconnaissance vehicle, as it allows it to get out of trouble fast.

Early ACEC Cobra prototype hull, either P1 or P2, during fabrication. The spartan but rather spacious interior has two simple metal benches running lengthwise along each side. The driver’s stations can be seen at the front and are not closed off from the troop space. From inside, both front hull machine gun mounts can be seen and the arrangement of the drivers either side of the engine is clear. Two hatches (one circular and one rectangular) can be seen for the turret and additional crew egress respectively. Two smaller rectangular hatches are above the driver’s stations.

Dimensions

Weight was very important to the Cobra’s design. At only 7.5 tons (nominal), it was light enough to appeal as an export to many third world countries which lacked heavy infrastructure, as well as to Western forces, as a C-130 Hercules could carry three complete vehicles, making it easy to deploy. By the time of the fourth prototype, the combat weight was given as 8.5 tons, which still provided it with a power to weight ratio of over 20 hp per ton.

ACEC Cobra prototype number 3 during evaluation, note the full length track skirt and simple single machine gun mount on the central hatch. The tools are also stowed on a different location to later versions where they are on the sides.

Construction

The Cobra was manufactured as a welded all steel hull providing protection against all small arms fire including armor piercing ammunition.
Propulsion from the diesel engine was distributed by electrical motors to the rubber tracks driven by sprockets at the rear. The rubber belt track had steel links and rubber pads and the wheels were rubber tired meaning that the rolling noise of the Cobra was very low, due to the low engine noise, lack of transmission whine and lack of ‘squeaky’ track noise. The suspension consisted of helical springs with a hydraulic shock absorber on the first and last of the five wheel stations and four track return rollers.
The vehicle had a very large hatch in the back for the soldiers to enter/dismount with water-propulsion propellers either side of it. When entering water and engaging the propellers the front mounted trim vane automatically rose up on the front of the hull.

View of the rear of the Cobra showing rear door and the steerable propulsion propellers. Note the steering vanes not present on the earlier vehicles.
The APC version could seat up to 10 soldiers (5 each side). The crew (driver and co-driver) sat either side of the front mounted engine.

ACEC Cobra prototype number 4 with roof mounted heavy machine gun showing its trim vane in the raised position at the front and the large door and water propulsion propellers at the rear.

Engines

The first three prototypes (P1 to P3) were powered by a Cummins V-6 diesel engine producing 143 hp at 3300 rpm but P4 was fitted with a more powerful Cummins VT-190 supercharged diesel producing 190 hp at 3300 rpm. Another source states an 155 hp engine was used at one point. Water propulsion was supplied by means of two 3-blade propellers mounted at the back either side of the large rear door.

Various views of ACEC Cobra early prototype P1 or P2 lacking side skirts completely, no equipment on the sides, the folding trim vane and mounting twin anti-tank rockets. Note the 2nd visible machine gun port isn’t blanked off and that the mudflaps at the front appear to be simple rubber flaps rather than the hinged metal ones later.


ACEC Cobra prototype number 3 with a single machine-gun mounted on the cupola and initial set of sideskirts. Illustration by Tank Encyclopedia’s own David Bocquelet
Three surviving ACEC Cobra APC’s at the Depot of the Royal Museum of the Armed Forces, Kapellen, Belgium. Confusingly, the plain green painted vehicle appears to have another modification to the rear of the side, possibly connected to the hydrojet propulsion and removal of the propellers. The camouflage painted vehicle lacks this modification despite having a later registration number. 9601136 (plain green), 9601137 (sand), and 9601138 (camo) respectively. All vehicles display the later exhaust and muffler on the right hand side and the flat front ‘nose.’ This museum also holds serial number 9601135 which is the tank version. Photo credits:(left) armyrecognition.com, (center) Belgian Tank Museum, (right) army recognition.com.

Close up view of the ACEC lightweight (300kg) electric turret as fitted to the ACEC Cobra APC and mounting an FN 12.7mm M2HB heavy machine gun. Elevation range is -10 to +50. The searchlight moves with the gun as does the M20 x6 periscope. The turret is rated completely immune to 7.62mm ammunition at any angle or range as is the 10cm thick viewport. Space is provided in the back for a radio to be fitted.

ACEC Cobra APC during trials fitted with 12.7mm FN M2HB machine gun. It was at some point painted orange in perhaps a nod to the Dutch. Note the second machine gun hull mount is covered with spare track parts and that the ‘nose’ is the same profile as the rest of the glacis.

Armament

Standard fitting on the APC version was a single 12.7mm M2HB machine gun on the roof in a small turret fitted with vision blocks and two 3-barrel smoke dischargers (operated by one of the mounted soldiers) and a 7.62mm machine gun for the right hand side crew position fixed in a ball mount in the hull front. P4 was fitted with this weapon setup. A second hull machine gun mount in front of the other drivers station was also provided and is visible in some photos.
The RCDU ‘Remote Control Defence Unit’ was developed by Fabrique Nationale Herstal SA (FN) firm of Belgium and tested on one of the Cobra prototypes. It consisted of twin FN MAG 58 7.62mm machine guns (1500 rounds) weighing 258 kg or a single 12.7mm FN M2HB machine gun (600 rounds) weighing 300 kg in a remote station mounted on the roof capable of being operated by the crew who controlled it from below by means of a TV monitor. The RCDU could also be fitted with infra-red cameras and an additional compartment for more ammunition if required.

ACEC Cobra showing the twin 7.62mm RCDU in place and the second machine gun hull mounting position blanked off.
Other options for arming the Cobra APC was the use of the Oerlikon-Contraves GAD-AOA turret with model 204GK 20mm cannon, as well as the option for the Euromissile MILAN compact turret.

ACEC Cobra prototype hull with GAD-AOA turret and model 204GK 20mm cannon. Worthwhile noting here is the visible 2nd machine gun mounted in the hull front, the folding trim vane (as opposed to the automatic trim vane) and the raised ‘nose’ between the two drivers’ positions. For these reasons it is believed that this is one of the first prototype vehicles used as a demonstrator and these features are repeated on the vehicle used for the experimental RCDU and LAU-97.
A fire support version of the Cobra called LAU97 was tested in 1985 and was fitted with the FZ70 70mm rocket launcher with 40 rockets on a fully traversable mount on the roof of the vehicle. The FZ70 rocket was a product of Forges de Zeebrugge (FZ) now part of the Thales group and was an unguided rocket weighing approximately 4.3 kg and carrying 1 kg on high explosive intended for use against unarmored targets. The launcher however could also take a full range of 70mm rockets including anti-personnel, anti-tank, smoke, incendiary, illuminating, and flechette. It was able to fire them out to 8 km and designed for saturation of an area 200 x 300m.

Cobra LAU97 fitted with FZ 70 mm multiple rocket launcher, 1985. Note the precarious decision to have the rear hull top rectangular hatch open which, while ideal for reloading the launcher, would be suicidal to have open during launch.

Conclusion

The ACEC Cobra APC/IFV was small, maneuverable, and well designed. Cheap and simple to operate and train crews on it offered a capable platform for a wide variety of roles. For a relative newcomer to the military vehicle industry ACEC produced a remarkable vehicle which sadly did not receive any orders. With the end of the Cold War there was no market for a new vehicle, especially one challenges some of the preconceptions of the diesel-electric drive used and this the remaining vehicles. It wasn’t the end of the Cobra story, there was one final version of the vehicle, a light tank based on a redesigned hull.

Sources

https://www.historyofwar.org/articles/weapons_acecCobra.html
https://cyberneticzoo.com/tag/belgian/
Janes Armour and Artillery 1985
Forges de Zeebrugge https://fz.be/
Cobra: der erste Schutzenpanzer der Welt mit elektrischer Kraftubertragungsanlage, P. Crevecoeur, 1980
Belgian Historical AFV Register V2.0, Michael van Loon, Neil Baumgardner, October 2012
Belgian Tank Museum https://www.belgian-tankmuseum.be
KBA/KBB 25 mm Cannon, Ordnance & Munitions Forecast, July 2002
International Defence Revue 4/88, 2/90

 Cobra AFV / APC specifications

Dimensions 4.52 x 2.75 x 1.76 m
Total weight, battle ready 8,600kg
Crew 2 + 10 (driver, co-driver, + up to 10 soldiers)
Propulsion Cummins VT diesel 143hp (P1 to P3) / Cummins VT-190 V6 diesel 190hp
Suspension Helical springs with hydraulic shock absorbers on wheel 1 and 5
Speed (road) 75-80 km/h (46.6 – 49.7 mph) / 5km/h (water)
Range 600 km (372.8 mi)
Armament Single or double front hull 7.62mm FN MAG with;
7.62mm FN MAG on hatch ring / twin 7.62mm RCDU / single 12.7mm RCDU / 12.7mm ACEC turret / 20mm GAD-AOA turret / Euromissile MILAN compact turret (MCT) / FZ70 rocket launcher / 12.7mm with twin AT rocket launcher
Armor All welded steel hull and turret providing protection 105mm HE shell bursts, small arms fire from NATO 7.62mm ball (at any angle or range) frontally proof against 7.62mm AP ammunition.
Total production 4
For information about abbreviations check the Lexical Index