This is a vehicle I designed for a contest, a fictional Romanian light Tank Destroyer.
The contest was to design your own armoured fighting vehicle, and since pretty much everybody would most likely designing their "dream tank" as if they had unlimited resources, I opted instead for something a little more challenging - I tried to come up with the best tank busting vehicle that could be produced by the Romanian industry under wartime conditions and with limited budget.
Considering that, when WW2 started, Romania was not geared up for war, having no weapons industry to speak of, and that by 1944 the country was under heavy Allied air attack, this was not an easy task. In real life all efforts to produce viable fighting vehicles, although based on some good ideas (the "Maresal" tank destroyer, for example, led the Germans to the development of the notorious Panzerjager 38 (t) "Hetzer"), eventually materialised into sub-par vehicles, because of a lack of design practice and manufacturing experience.
Taking all this into account, I am confident my little exercise in design, had it been built, could have gone head to head with a lot of Allied and Axis vehicles (a must, since Romania fought on both sides of the conflict) and still come out on top. It probably wouldn't have altered the outcome of the war significantly, but It would be interesting to see what kind of impact it might have had.
Also, in case you were wondering, all the stamps, stickers and inscriptions on the "historical blueprints" are lifted from scans of period documents.
History of the vehicle:
WARNING, WALL OF TEXT INCOMING!
A tank hunter on a shoestring budget: The Romanian Army "T.A.C.A.B." M-06
By the end of 1943, the Romanian army was facing a critical shortage of armoured fighting vehicles and anti-tank means, a fact which had proved crucial in the disastrous defeats at Stalingrand and the Don Bend. The few remaining vehicles from the pre-war stocks, mostly Czech R2 (CKD Praha Lt35) and French Renault R35 were severely obsolescent in face of the Soviet medium and heavy tanks and deliveries of new PZ III and IV from Germany were few and far between.
As such, several stop-gap measures were implemented - the purchasing of Lt38 tanks from German stock, the up-gunning of the R35 tanks using Soviet captured 45 mm 20K cannons, and, last but not least, the expansion of the tank building programme in the Rogifer (ex Malaxa) factory in Bucharest.
Since 1942 the factory had been engaged in building self-propelled artillery pieces, such as the TACAM T60 and TACAM R2, but those were simply captured 76mm ZIS 3 guns on T60 and Skoda R2 chassis so the factory lacked experience in designing an armoured vehicle from scratch. Thusly, when asked by the ministry to come up with a design for a cheap, easy to produce and effective tank destroyer, they had no option but to use as much existing local, imported or captured material as possible .
The research team was made up primarily of Major Nicolae Anghel, Captain Gheorghe Sambotin and the engineer Constantin Ghiulai, and they started their design work by mounting the 122mm Putilov-Obuhov howitzer md.1904/30 and a coaxial 7.92mm ZB 53 machine-gun on a modified T-60 chassis. The upper structure was made of four sloped armour plates 20-30mm thick giving the vehicle a distinctive turtle shape. The resulting prototype, nicknamed "Maresal" ("Marshal"), received designation M-00 but the preliminary trials that took place on 30 July 1943 at the Suditi test range revealed the tank was underpowered and there were problems with the gun carriage.
Further prototypes, M-01 to M-03 managed to overcome most of the problems, but it was only by the fourth prototype that the design came into it's own, with the incorporation in the design of the exceptional 75mm DT-UDR No.26 anti-tank gun that had been in testing in the same firing range during the spring-summer of 1943.
This artillery piece had just been developed as a collaboration between D.T.UDR-Resita, ASTRA-Brasov and CONCORDIA-Ploiesti and represented a perfect blend between the Soviet ZIS-3 57mm.md 1943, the German Pak 40.75mm.md1940 and the British Vickers 75mm.md.1936 AA gun, produced under licence in Romania before the war. The "Resita model 1943", as it was commonly known, had a tremendously high muzzle velocity of 1030m/s, giving it a maximum effective range of 1200m and could penetrate, with the specially built "Costinescu" 6.6kg armour-piercing ammunition, a plate of armour 100mm thick angled 30° from the vertical at 550 metres, which means that at medium ranges it could take on even heavy tanks like the KV and IS series. It's only real drawback was a severely high rate of wear on the rifling which limited barrel life.
With the development of the fourth prototype in November 1943 the preparation for mass production started. 1000 Hotchkiss H39 engines were ordered from France while other components still not made in Romania were requested from Germany. The new vehicle immediately attracted the German attention and in December 1943 Antonescu presented to Hitler the project and the blueprints of the M-04 prototype. Those inspired the German development of the Hetzer tank-destroyer that mounted a 75mm PAK40 gun on the chassis of the Czech LT vz.38 tank.
Unlike the Maresal, the Hetzer had four instead of two crewman which made the operation of the vehicle a lot easier, so shortly after the designs for the German vehicle were unveiled (after just four months!), the members of the Romanian team found themselves at an impasse wherever to carry on with the production of the M-04 vehicle or design another, enlarged prototype.
Tempers flared and it took a ministry decision to resolve the situation: production of the Maresal would carry on as planned, but a new team, led by Commander Grigore Axinte will asess the work done so far and do all the modifications required to build a larger vehicle.
This was to be called Maresal M-06 (the M-05 designation was reserved for M-04 pre-series models) but almost immediately the project was renamed "TACAB" (Tun Anti Car Autopropulsat Blindat -Armoured Self-propelled Anti Tank Gun) and several fundamental changes were made, transforming the result into a vastly different vehicle from the Maresal.
In a document addressed to the prime minister, Axinte, a naval officer, gave his opinion on the existing prototypes by noting dryly that "the only way to to improve this vehicle would be to remake it from scratch". Indeed, in a recent test of the M-04 prototype the gun retaining ring had given way on recoil and the barrel flew backwards into the firewall with enough force to rupture the gas tank. Luckily the petrol only spilled without catching fire, so the two crewman escaped unhurt.
The first conclusion reached was that the existing suspension and motorisation, while almost fitting the existing 10 ton vehicle, were woefully inadequate for an enlarged version. As such, the team looked into the independent "Christie" suspension of the Soviet BT series fast tanks and the engine and drive train of the PZ III and IV, with aims to creating a hybrid. Ten roadwheels , including complete suspensions, from the middle track of captured Bt 7s were immediately procured, and, along with a 12-cylinder Maybach HL 120 TRM 300HP engine from PZ IV spares, a Zahnradfabrik ZF SSG77 gearbox as well as tracks (early 40cm open horn type), idlers and driving sprockets from a PZ III were all mounted into a specially built hull.
The close relative diameter of the PZ III driving sprocket (83cm), the BT 7 road wheels (82.55cm) and idler (87cm) meant that the track layout came out looking surprisingly close (if a lot smaller) to that of the new PzKpv VI "Tiger" tanks, then passing through Romania on their way to the front. There were no return rollers, and, while the first drive tests showed the need of larger springs to take the weight difference from the BT 7 (13tons) to the new prototype (18 tons with mock weight to simulate gun and ammo on the early tests) on the whole the design proved mechanically robust and relatively easy to maintain.
The Maybach HL 120 TRM engine was gasoline fuelled, produced 300HP at 2600RPM and was set to the back of the vehicle in an enclosed space separated from the fighting compartment by a 15mm thick firewall. Forced air for the engine was provided by a vertically mounted fan set in the roof of the fighting compartment which also supplied overpressure ventilation to the crew via a set of filters fitted with activated charcoal scrubbers to prevent any contamination with noxious fumes or combat gas. The radiators were lifted "as is" from a donor Pz IV and installed, along with their fans, on the upper part of the engine deck near the fighting compartment firewall. The exhaust system consisted of twin trunks set on the rear plate and had a pair of cylindrical mufflers to attenuate engine noise. The smoke itself was vented downwards, as far away as possible from the air intakes.
The superstructure was of welded construction and was composed of four sloped plates and a horizontal one, maintaining the "turtle shell" look also typical of both the Maresal and the Hetzer. Armour thickness was 100mm for the front plate (initially 80mm, but changed mid-way through the building stage) 50mm for the sides and back plate, 20mm for the lower hull and for the top. Six 5mm armoured skirts to protect the drivetrain were also provided, three to a side.
Like the Maresal and unlike the Hetzer, the 75mm gun was mounted in the centre between the driver, located low in the hull to the right, and the gunner, which sat to the left of the gun. The commander was seated high behind the gunner below an all around vision cupola, while the loader/radioman occupied the far left corner of the fighting compartment. The inside space was extremely cramped, especially for the driver, but not overly so.
In addition to that on the cupola, the main entry hatch was located above the loader and there was also a trapdoor in the floor of the fighting compartment on the right side opposite the commander's place to avoid the crew being trapped in the vehicle in case of a rollover.
Because of the central position, gun traverse was a lot better than that of the Hetzer, averaging about 15 degrees on each side while the elevation was -3 degrees and +12 degrees respectively.
Due to it's large recoil mechanism the gun was mounted in an oversized cast circular mantlet 75mm thick with the recoil cylinders themselves protected by an armoured "box", similar to that of the Su 76, made out of 20mm welded steel with a 75mm front plate. Since the gun was located directly above the transmission, a pedestal mount like that of the TACAM or Maresal was out of the question, so instead the whole mantlet was hung from a bracket welded to the front plate.
Also on the front glacis, to the left of the gun was a 7.92mm ZB 53 vehicle machinegun set in the same spherical mount found on the Lt35 , that was also fired by the gunner but could be trailed independently from the main gun, which in practice was of questionable use.
Ammunition supply was 51 rounds for the main gun situated in three ammo racks (right back side of the hull, left of the the commander's chair and behind it, against the back firewall) and around 1500 rounds of ammunition for the machineguns.
All optics except the X1.8 telescopic gunsight for the hull machinegun (Czech made original) were built in Bucharest by IOR using German "Schott" glass and consisted of a X2.5 telescopic gunsight set to the left of the main gun, a X4 magnification 12 degrees FOV panoramic periscope for the gunner and a 10x45 scissor type M38 binocular periscope for the commander. Also present were a few vision blocks - the commander had a cupola reused from a Stug III, the driver was provided with two armoured vision ports and two other were present on the hull sides. This was a direct response to one of the noted weaknesses of the Maresal, which was lvery poor visibility. Also, to improve close combat capabilities two pistol ports with armoured covers were cut under each of the side vision blocks.
A further 7.92mm ZB 53 machinegun with full tripod would have been carried inside and could be deployed (the tripod legs slotted into special brackets that held them firm) on the roof of the vehicle in front of the loader's hatch for defense against infanty or aviation. Also, the series vehicles would have had three smoke candle launchers placed on the hull sides, even though the prototype never had them.
The radio equipment was operated by the loader and consisted of a German Telefunken Fug 5 10 W.S. emitter and Ukw Ea receiver situated in the right front part of the hull, with a whip antenna protruding through the side armour. Platoon and company commanders were to be fitted with an additional Lorenz 20 W.S.d and Telefunken 80 W.S.a transmitter sets and additional "star" type antennas to the expense of ammo storage.
The vehicle carried 450 litres of gasoline in three internal fuel tanks which provided a range of around 200km. Although the prototype never had anything but the basic equipment, the series vehicles would cave carried stowage racks for four jerry cans. To prevent catastrophic fires (or a repeat of the Maresal M-04 incident mentioned earlier), the engine compartment was fitted with an automatic fire suppression system based on pressurized carbonic acid gas of the same type used in the IAR 80 fighter. Further manual foam fire extinguishers were located inside the fighting compartment and one strapped to the outside of the hull opposite the gasoline filler cap for the left side fuel tank.
The maximum road speed was 45Km/h and cross-country 28km/h.
Although a bit higher than the Maresal at 2.08 m in height, the TACAB M-06 had a very low silhouette, about 10 cm lower than that of the Stug III/IV or the Hetzer. Other dimensions were: Hull Lenght- 6.58m, Hull Width- 3.18m, Total Lenght- 8.21m and fully loaded weight- 21.5 tons.
On 10 May 1944 the High Command of Mechanisation ordered the production of 1000 Maresal and TACAB tank-destroyers that would have formed thirty-two anti-tank battalions. A training battalion (designated M Battalion) was formed in the 2nd Tank Regiment. The first series of 10 vehicles was planned for June and it was estimated a steady production of 100 pieces per month would be in place by September.
Due to the disruption caused by heavy allied bombings, the delivery of the first series was postponed for 1 November 1944. It had been decided that the first 200 tank-destroyers would be M-05 Maresal and the rest of 800 M-06 TACAB, who, despite the fact it had proven itself the better of the two vehicles still needed a few adjustments before being sent into series production. On 8 June 1944 a convention was signed by the Romanian Ministry of Defence and the OKH, which foresaw the co-operation for the mass production of Maresal and TACAB as well as a German order for several dozens of both vehicles in the early months of 1945. The Germans also offered the license of the Praha engine used by the Hetzer for the Maresal as well as the desperately needed PZ III/IV engines and parts for the TACAB.
Unfortunately the events following the 23 August 1944 Insurrection and subsequent defection to the Allied side led to the cancellation of production on 29 August, with a single soft-steel TACAB prototype complete and ten fully armoured M-05 in various stages of assembly.
On Stalin's direct order and invoking the terms of armistice which forbade Romania any more independent military research, on 26 October the Soviet Army confiscated all the prototypes and the first series of the M-05 Maresal as well as all the documentation for both tank destroyers.
It is unknown what happened to them and we can only hope at least one vehicle survives in a forgotten corner of the Kubinka Tank Museum...
By a sheer stroke of good fortune, two drawings from TACAB's original documentation turned up in 2009 in Uryupinsk, Volgograd Oblast, in a folder detailing horse feed requisition in the area during 1942-43. Nobody is quite sure how they got there.
To sum up, the M-06 TACAB was a medium tank destroyer with heavy armour, low silhouette, very good firepower and mobility and probably the closest match to it would be the German Panzerkampfwagen E25 developed in early January 1945.