TMA-79

Socialist Republic of Romania (1979-1984)
Medium Artillery Tractor – At Least 1 Prototype Built

The TMA-79 (Tractor Mijlociu de Artilerie Eng: Medium Artillery Tractor) was an attempt by Romania to replace older Soviet artillery tractors and offer a domestically-produced alternative to the newly acquired ATS-59 and ATS-59G Soviet tractors. On paper, the vehicle would prove to be more powerful and have a higher payload, but due to mechanical issues, it never entered mass production. Instead, its cabin was shortened and the engine was replaced, creating the TMA-83, which saw service until 2005.

Development

After 1947, the newly formed Romanian People’s Republic’s (RPR) military capabilities relied nearly entirely on what wartime equipment they could get their hands on, hence why Romania operated German Panther tanks for a short period. Only in the 1950s did gradual restructuring of the military begin. To modernize the artillery segment, Soviet wartime 122 mm A-19 and 152 mm ML-20 howitzers were purchased. For towing these heavy pieces, the Soviet AT-S 712 heavy tractor was purchased, while lighter ordnance was towed by ZiS-150 trucks and AT-L tractors.

By the 1970s, Romania also purchased the more capable Soviet ATS-59 and ATS-59G tractors. Simultaneously, the political situation in Romania would change, and a gradual separation from Soviet reliance and influence began, especially in terms of military industry. By the late 1970s, several Soviet and Chinese licenses of anti-tank and howitzers were procured and mass-production began in the 1980s, some examples being the 100 mm Md.1977 anti-tank gun, and 130 mm Ob.Md.1982, 152 mm Ob.Md.1981 howitzer and 152 mm Ob.Md.1985 howitzers. During the same period, development of indigenous tracked prime movers began as well at the Institutul de Cercetare și Inginerie Tehnologică al Armatei din București (Eng: the Army Development and Technological Engineering Institute in Bucharest), or ICITA. The first tractor to be developed, the TAR-76, was based on the Soviet AT-L and could tow lighter weapons, up to 122 mm howitzers.

For towing heavier howitzers and a higher payload, work began at ICITA for a medium tracked tractor, under the name TMA-79. Much like the TAR-76, it would use components from Soviet tractors, namely the ATS-59 and ATS-59G. The first prototype was built at the 102nd Truck and Tank Maintenance Base (today this is the 102nd Maintenance Battalion) in Bucov, in 1979 and tested during the following years. It is unclear how many TMA-79s were built.

Despite the similarity to its Soviet counterparts, several fundamental changes were made, including lengthening the size of the cabin and the engine being moved to the front, while the sprocket and final drive were moved to the rear. These changes were, however, unsuccessful. Despite the increased payload and towing capacity, the vehicle was significantly heavier and reliability was likely poor, hence why it never entered service.

Design

To allow for more efficient use of the space on the vehicle, the engine was moved to the front of the cabin, as opposed to being in a separate compartment, like on the ATS-59G. The cabin itself was longer, with a total of four doors (two per side). Despite these changes, the flatbed volume remained largely the same, and thanks to the larger 360 hp engine, its towing and carry capacity was increased, at the cost of weighing nearly 16 tonnes.

The vehicle had a pulling weight of 15,000 kg, and could transport up to 4,000 kg on the flatbed. Thanks to the redesign of the flatbed, it now had a greater transport volume by 25% to 75%, depending on the type of material transported, compared to its Soviet counterparts. It was also equipped with a winch, with a pulling force of 12,000 kg.

Chassis

Based on the hull of the ATS-59, the chassis of the TMA-79 would see minor changes. With the engine moved to the front, the sprocket was moved to the rear to make space for the final drive and gear box, running across the center of the hull. All of the individual components were taken directly from the Soviet tractors, including the road wheels, sprocket and idler. There were five road wheels per side, sprung by torsion bars.

Cabin

The cabin resembled the smaller TAR-76 more than the ones on Soviet tractors. Each side had two doors, for a total of four, as well as observation hatches in the roof, for the front-left passenger and rear-right passenger(s). The driver’s position was on the left side of the cab and he could control the vehicle with two tillers. To his right was the engine and, along the dashboard, were the radio and climate controls. The cabin could seat eight personnel, and at least another two could sit in the rear flatbed. The windshield consisted of three individual windows, with two windscreen wipers. The lights consisted of two main blackout headlights and indicators. A spotlight was mounted right above the side mirror on the driver side of the cabin. The cabin was thermally insulated using polystyrene and melamine fiberboard panels.

Powerplant

The engine was the D 199-12 V, a direct-injection V-12 diesel with a maximum power of 360 hp at 2,300 rpm. Its maximum torque was 1,280 Nm at 1,600 rpm. This engine was produced at the Timpuri Noi factory, on the outskirts of Bucharest. The gearbox had 5 forward gears and 1 reverse. The planetary braking system allowed for a turning radius of at least 3.5 m. Transmission between the engine and gearbox consisted of 2 axles, one of which was connected to a hydrostatic pump which transferred power to the cable winch, and the other axle was connected to the final drive. A preheating system was installed for easier starting of the engine during low temperatures.

TMA-83

The TMA-79 would never enter mass-production. Why this happened is unclear, however, the heavy weight of the vehicle (which was nearly 16 tonnes, compared to 13 and 14 tonnes on the Soviet ATS-59) was probably a problem. Another issue, and most likely the fatal one, was mechanical issues caused by the engine, transmission and repositioning of the final drive. The transmission/gearbox was likely borrowed from the AT-S 712, which was already known to be troublesome.

Nonetheless, the vehicle was revised at ICITA. The engine, now replaced with a V-2-350T, was moved back to its original position, in the center of the hull, and the cab was shortened. Thus, the sprocket and final drive were kept in the front of the hull. Curiously, the capacity of the cabin did not decrease despite the smaller cabin. The pulling and carrying weight also remained unchanged, although the top speed dropped significantly. The new tractor would enter production at the Mizil Mechanical Plant under the name TMA-83 and would see service until 2005 when, due to its poor reliability, slow speed and high operation costs, was removed from service alongside most other track tractors.

Conclusion

The TMA-79 was the first attempt at making a medium sized artillery tractor using components from existing vehicles and without relying on imported parts. Despite its impressive capabilities on paper, it likely suffered from mechanical problems, which led to the redesign to a more conventional layout, nearly identical to that of the ATS-59G. Nonetheless, the vehicle and its successor remain an example of the hardheaded will of Romanian military and industrial independence from the Soviets, often leading to less-than-ideal projects.

TMA-79 Specifications
Dimensions (L-W-H)	6.88- 2.7- 2.68 m
Total weight, battle-ready	15,800 kg
Crew	12 (8 in cabin, 4 in flatbed) (TMA-79)
Propulsion	360 hp (V-12) D 199-12 V
Speed	52 km/h (empty) 42 km/h (fully loaded, with towing load) 25 km/h on dirt (fully loaded, with towing load)
Suspension	Torsion bar, 5 wheels per side
Armament	N/A
Armor	N/A
No. Built	At least 1 prototype built

Sources

Manual TMA-84, 1988

Artileria Romana in date si Imagini – Col. conf. Univ. Dr. Adrian Stroea, Lt. Col. Gheorghe Băjenaru

Asigurarea Tehnica de Blindate si Autotractoare – Gen. Lt. Eng. Tiberiu Urdareanu

Bultinul Tehnica Militara 1/1982 (Tractorul Mijlociu de Artilerie Românesc) – Major Eng. Eugen Petre

Sasiu Multifunctional de Geniu – Lt. Col. Eng. Pompiliu Bolan, Eng. Ilie Nicolae

(PDF) Contribuții la istoria dotării cu armament a armatei române între 1944 și 1959 | Sămușan Alin Bogdan – Academia.edu

(DOC) Evoluția dotării cu automobile a armatei române între 1948 și 1957 | Sămușan Alin Bogdan – Academia.edu

(PDF) Motorizarea tracțiunii în armata română între 1948 și 1957 | Sămușan Alin Bogdan – Academia.edu

Tun-obuzier cal. 152 mm (arsenal.ro)

Tractor ATS-59 | Encyclopedia of Military Equipment (war-book.ru)

SAGETILE DACIEI (2) – Romania Military (rumaniamilitary.ro)

Tractor AT-S | Encyclopedia of Military Equipment (war-book.ru)