90mm GMC M36 ‘Jackson’ in Yugoslav Service

Socialist Federal Republic of Yugoslavia and Successor States (1953-2003)
Tank Destroyer – 399 Supplied

After the so-called Tito-Stalin split that took place in 1948, the new Yugoslav People’s Army (JNA- Jugoslovenska Narodna Armija) found itself in a critical situation. It was impossible to acquire new modern military equipment. The JNA had been heavily dependent on Soviet military delivery and aid in armament and weapons, especially armored vehicles. On the other side, the Western countries were initially in a dilemma whether to help the new communist Yugoslavia or not. But, by the end of 1950, the side arguing in favor of providing military assistance to Yugoslavia had prevailed.
In the middle of 1951, a Yugoslav military delegation (led by General Koča Popović) visited the USA in order to achieve military cooperation between these two countries. These negotiations were successful and, on the 14th November 1951, an agreement for military aid was concluded (Military Assistance Pact). It was signed by Josip Broz Tito (Leader of Yugoslavia) and George Allen (American ambassador in Belgrade). With this contract, Yugoslavia was included in MDAP (Mutual Defence Aid Program).
Thanks to MDAP, the JNA received, during 1951-1958, plenty of military equipment, and armored vehicles, like the M36 Jackson, were amongst them.

During military exercises, somewhere in Yugoslavia. Having captured a large amount of German military equipment, one should not be surprised by the fact that the JNA soldiers were equipped with German WW2 weapons and other equipment. Photo: SOURCE

The M36

As the M10 3in GMC American tank hunter had insufficient penetration power (3in/76 mm main gun) to stop the new German Tiger and Panther tanks, the US Army needed a more powerful vehicle with a stronger gun and better armor. A new 90 mm M3 gun (modified AA gun) was developed relatively quickly. It had enough penetration power to destroy most German tanks at long ranges.
The vehicle itself was built by using a modified M10A1 hull (Ford GAA V-8 engine), with a larger turret (this was necessary due to the larger dimensions of the new main weapon). Despite the fact that the first prototype was completed in March 1943, production of the M36 started in mid-1944 and the first delivery to units on the front was in August/September 1944. The M36 was one of the most effective Allied tank destroyers on the Western front in 1944/45.
Along with the main version, two more were built, the M36B1 and the M36B2. The M36B1 was built by using a combination of M4A3 hull and chassis and the M36 turret with the 90 mm gun. This was considered necessary due to an increase in demand for these vehicles, but it was also cheap and easy to carry out. The M36B2 was based on the M4A2 chassis (the same hull as for the M10) with the General Motors 6046 diesel engine. Both of these versions were built in some numbers.

The rare M36B1 in JNA service. Photo: SOURCE
The M36 had a crew of five: commander, loader, and gunner in the turret, and driver and assistant driver in the hull. The main armament was, as already mentioned, the 90 mm M3 gun (elevation of -10° to +20°) with a secondary heavy 12.7 mm machine-gun located at the top of the open turret, designed to be used as a light AA weapon. The M36B1, as it was based on a tank chassis, had a secondary ball-mounted Browning M1919 7.62 mm machine-gun in the hull. After the war, some M36 tank hunters had a secondary machine-gun installed (similar to the M36B1), received an improved main gun and the open top turret, which was an issue during combat operations, was modified with a folding armored roof for extra crew protection.
Unlike other tank-hunter vehicles of the same type used by other nations, the M36 had a 360° rotating turret which allowed a great level of flexibility during combat.

In Yugoslavia

Thanks to the MDAP military program, the JNA was reinforced with a large number of American armored vehicles, including the M36. During the period of 1953 to 1957, a total of 399 M36 (some 347 M36 and 42/52 M36B1, the exact numbers are unknown) were supplied to the JNA (according to some sources the M36B1 and M36B2 versions were supplied). The M36 was to be used as a replacement for the obsolete and outdated Soviet SU-76 self-propelled guns in the anti-tank and long-range fire-support roles.

The M36 was used during military parades often held in Yugoslavia. They often had political slogans written on them. This one reads ‘Long-live the November elections’. Photo: SOURCE
A number of infantry regiment batteries equipped with six M36 vehicles were formed. Infantry divisions were equipped with one anti-tank unit (Divizioni/Дивизиони) which, besides the main command battery, had three anti-tank battery units with 18 M36s. Armored brigades of armored divisions were equipped with one battery of 4 M36s. Also, some independent self-propelled anti-tank regiments (with M36 or M18 Hellcats) were formed.
Due to bad international relations with the Soviet Union, the first combat units that were equipped with M36s were those who guarded the eastern border of Yugoslavia against a potential Soviet attack. Fortunately, this attack never came.
Yugoslav military analysis of the M36 had shown that the 90 mm main gun had enough penetration firepower to efficiently fight the mass-produced T-34/85. Modern tanks (like the T-54/55) were problematic. By 1957, their anti-tank capacities were considered inadequate to deal with modern tanks of that time, although they were designed as tank hunters. According to JNA military plans from 1957 onwards, the M36s were to be used as fire support vehicles from long distance and to fight on the sides of any possible enemy breakthrough. During its career in Yugoslavia, the M36 was used more as mobile artillery then as an anti-tank weapon.
According to the ’Drvar’ military plan (late 1959), the M36 was ejected from use in infantry regiments but remained in use in mixed anti-tank units (four M36 and four towed anti-tank guns) of many infantry brigades. Mountain and armored brigades had four M36. First line infantry and armored divisions (marked with a capital letter A) had 18 M36.
The M36 was often used on military parades during the sixties. By the late sixties, the M36 was removed from the first line units (most were sent to be used as training vehicles) and moved to support units equipped with missile weapons (the 2P26). In the seventies, the M36 was used with units equipped with 9M14 Malyutka ATGM weapons.
Although the process of modernizing military technology was initiated in the 1980s, there was no adequate replacement for the M36, so they remained in use. The Soviet towed smoothbore 100 mm T-12 (2A19) artillery was considered better than the M36, but the problem with the T-12 was its lack of mobility, so the M36 remained in use.
By the decision of JNA military officials in 1966, it was decided that the M4 Sherman tank would be withdrawn from operational use (but for various reasons, they remained in use for some time afterward). Part of these tanks would be sent to units equipped with the M36 to be used as training vehicles.

Development of New Shells and Ammunition Supply Problems

The 90 mm main gun did not have enough penetrating power for the military standards of the fifties and sixties. There were some attempts to improve the quality of the ammunition used or even design new types and thus improve the characteristics of this weapon.
During 1955-1959, experiments were carried out with new types of domestically developed and manufactured ammunition for the 90 mm gun (also used by the M47 Patton II tank which was supplied through the MDAP program). Two types of ammunition were developed and tested by the Military Technical Institute. The first was the HE M67 round and late during the seventies a new slowly-rotating HEAT M74 round was developed and tested. These tests showed that the M74 round had good penetration power. The pre-production of this type of ammunition began in 1974. Order for the full production was given to the ‘Pretis’ factory. This round was supplied to all units equipped with M36 and M47 tanks.
In the late fifties and early sixties, despite great help from the West, there was a great problem with maintenance and ammunition supply. Many tanks were not operational due to insufficient spare parts, lack of ammunition, an insufficient number of repair workshops, equipment defects, and an insufficient number of adequate vehicles for delivering supplies. Perhaps the biggest problem was the lack of ammunition. The problem with 90 mm ammunition was such that some units ran out of shells (during peacetime!). Available ammunition for the M36 was at only 40% of the necessary.
With the Soviet technique, the problem was solved by adopting domestic production of the ammunition. For the Western vehicles, the problem with ammunition was solved by purchasing additional ammunition, as well as by attempting to produce domestic ammunition.

Croatian M36 077 “Topovnjaca”, War of Independence, Dubrovnik brigade, 1993. Illustrated by David Bocquelet.

GMC M36, fitted with the armored roof, used by one of the Yugoslav successor states, the Republika Srpska. This one has an unusual and a bit ridiculous markings ‘Angry Aunt’ (Бјесна Стрина) and ‘Run away, Uncle’ (Бјежи Ујо) inscriptions. Illustrated by Jaroslaw ‘Jarja’ Janas and paid for with funds from our Patreon campaign.

Modifications

During the long service life of the M36 in the JNA, some modifications and improvements were carried out or were tested:
– On some M36s, a domestic-built infrared night vision device (Уређај за вожњу борбених возила М-63) was tested. It was a direct copy of the one used on the M47 tank. It was tested in 1962 and produced in some numbers from 1963 on. At the beginning of the seventies, a number of M36 vehicles were equipped with a similar system.
– Besides the original 90 mm M3 gun, some models were rearmed with the improved M3A1 (with a muzzle brake) gun. Sometimes, a heavy 12.7 mm M2 Browning machine-gun was used, located on the turret top. The M36B1 version had a hull ball-mounted 7.62 mm Browning machine-gun.
– By the seventies, due to significant wear out in some vehicles, the original Ford engine was replaced with the stronger and more modern engine taken from the T-55 tank (according to some sources, the T-34/85 tank’s V-2 500 hp engine was used). Because of the larger dimensions of the new Soviet engine, it was necessary to redesign and reconstruct the rear engine compartment. A new opening door measuring 40×40 cm was used. Brand new air and oil filters were installed and the exhaust pipe was moved to the left side of the vehicle.

This M36, in the process of being scrapped, was equipped with the T-55 engine. Photo: SOURCE
– An unusual fact was that, despite experimenting with various types of camouflage for its armored vehicles in addition to its primary grey-olive (sometimes in combination with green) color, the JNA never adopted any use of camouflage paint for its vehicles.
– The first radio used was the SCR 610 or SCR 619. Due to obsolescence and reorientation towards Soviet military technology, these were replaced with the Soviet R-123 model.
– Headlights and infrared night vision devices with an armored box were added on the front armor.

In combat

Even though the M36 was completely outdated as a military vehicle in the early nineties, it was still used during the Civil War in Yugoslavia. This was mostly due to the simple reason that it was available in large quantities and, since no stronger tank forces were available in sufficient numbers (many improvised armored vehicles, tractors and even armored trains were used), something was certainly better than nothing. Nearly all 399 were still operational by the beginning of the war.

During the Yugoslav wars of the nineties, almost all military vehicles had different inscriptions painted on them. This one has an unusual and a bit ridiculous marking ‘Angry Aunt’ (Бјесна Стрина) and ‘Run away, Uncle’ (Бјежи Ујо) inscriptions. ‘Uncle’ was a Serbian ironic name for the Croatian Ustashe. In the upper right corner of the turret, it is written ’Mица’, which is a woman’s name. Photo: SOURCE
Note: This event is still politically controversial in the countries of former Yugoslavia. The name of the war, the reasons for the beginning, who and when started it and other questions are still being debated between politicians and historians of the former Yugoslav nations. The author of this article sought to be neutral and to write only about the participation of this vehicle during the war.
During the confusion of the beginning of the Civil War in Yugoslavia, and the gradual withdrawal of the JNA from the former Yugoslav countries (Bosnia, Slovenia and Croatia), many M36s were left behind. All participants of this war managed to capture and use certain numbers of this vehicle under various circumstances and conditions.
As most tanks, armored personnel carriers and other vehicles were mainly used in the infantry fire support role, the older vehicles could still be used without fear of engaging modern vehicles. Thanks to the M36’s good gun elevation and strong explosive shell, it was considered useful, especially in the mountainous parts of Yugoslavia. They were mostly used individually or in small numbers (larger groups were rare) for the support of infantry battalions or company advances.
During the war, the crews added a rubber ‘boards’ on some M36 vehicles, partially or on the whole vehicle, in the hope that this modification would defend them from high-explosive anti-tank warhead (this practice was carried out on other armored vehicles as well). Such modified vehicles could often be seen on television or images published during the war. Whether these modifications were effective is hard to say, although almost assuredly they were of little value. There were several cases when these modifications were claimed to have helped protect the vehicles which had them. But again, it’s difficult to determine whether these occurrences were due to this ‘rubber armor’ or some other factor. One such vehicle can be seen today at the Duxford military museum in Great Britain. It was bought after the war with the original Republic of Srpska markings.

M36 with improvised ‘rubber armor’. Photo: SOURCE
After the end of the war, most M36 tank hunters were withdrawn from military use due to the lack of spare parts and obsolescence and were scrapped. The Republika Srpska (a part of Bosnia and Herzegovina) used the M36 for a short period of time, after which most were sold or scrapped. Only the new Federal Republic of Yugoslavia (consisting of Serbia and Montenegro) still continued to use them operationally.
According to the armament regulations instituted by the Dayton Agreement (late 1995), the former Yugoslav countries had to reduce their numbers of military armored vehicles. The Federal Republic of Yugoslavia retained the right to have around 1,875 armored vehicles. By this regulation, a large number of older vehicles (mostly T-34/85 tanks) and 19 M36s were removed from service.
Some units which were equipped with the M36 were based in Kosovo and Metohija (Serbia) during 1998/1999. In that period, the M36s were engaged in fighting the so-called Kosovo Liberation Army (KLA). During the NATO attack on Yugoslavia in 1999, a number of M36 were used in the fighting in Kosovo and Metohija. During this war, only a few were lost due to NATO air strikes, apparently mostly thanks to the camouflage skills of the Yugoslav ground forces.

The old M36 and the new M1A1 Abrams meet during the withdrawal of the Yugoslav Army from Kosovo in 1999. Photo: SOURCE
The last operational combat use of the M36 was in 2001. They were defending the southern parts of Yugoslavia against Albanian separatists. This conflict ended with the surrender of the Albanian separatists.
Changing the name of the country from the ‘Federal Republic of Yugoslavia’ to ‘Serbia and Montenegro’ in 2003, the M36 had, ironically, outlived yet another Yugoslavia. By the order of the High Command of the Armed Forces of Serbia and Montenegro (in June 2004) all usage and training on the M36 was to be terminated. The crews who were on training on this vehicle were transferred to units equipped with the 2S1 Gvozdika. In 2004/2005, the M36 was definitively removed from military service and sent to be scrapped, ending the story of the M36 after nearly 60 long years of service.
Several M36s were placed in various military museums and barracks in the former countries of Yugoslavia and some were sold off to foreign countries and private collections.

Links & Resources

The illustrated guide to Tanks of the world, George Forty, Anness publishing 2005, 2007.
Naoružanje drugog svetsko rata-USA, Duško Nešić, Beograd 2008.
Modernizacija i intervencija, Jugoslovenske oklopne jedinice 1945-2006, Institut za savremenu istoriju, Beograd 2010.
Military Magazine ‘Arsenal’, Number 1-10, 2007.
Waffentechnik im Zeiten Weltrieg, Alexander Ludeke, Parragon books.
www.srpskioklop.paluba.info