Yugoslav Stuart-Pak Self-Propelled Gun

Yugoslav Stuart-Pak Self-Propelled Gun


In mid-1944., Yugoslav Partisans received a number American light tanks M3A3 Stuart from the British. These were used to equip the First Tank Brigade of NOVJ (“People’s Liberation Army of Yugoslavia”), which was raised in Bari in summer of 1944. by the British. Unit was given 56 Stuart Vs, and landed on Croatian coast in autumn of 1944. As several tanks had damaged turrets, these were removed in a workshop in Šibenik (captured in November 1944.) and replaced by German antitank gun 7,5 cm PaK40. New assault guns / tank destroyers were simply called Stuart-Pak.

US Stuart tank (M3A3) was a hybrid model between older M3 and newer M5. It has some of the improvements in the armor and turret that would be more extensively present on the M5. Several thousand M3A3 Stuarts were produced. None entered service with the US Army, but were rather sent to allies: British, French, Poles, Chinese and others. British later sent their tanks to the partisans, as the tank itself was already outdated by 1943. due to weak armament and thin armor. Partisans themselves left no documentation regarding the Stuart-Pak tank – they never in fact made any.

M3 Light Tank in Balkans

After the Axis conquest of Yugoslavia, two groups began “resistance” against the occupation. Specifically, these were the Communist Partisans and Chetniks. Now, neither of them really cared about resisting the Axis. Communists only began their fight after the Axis invasion of USSR, while Chetniks only cared about destroying the Croatian state, regardless of whether it was headed by the Ustashi, Communists or anybody else. Partisans and Chetniks were sometimes allies, sometimes enemies, and just like with everybody else in the war in Yugoslavia, political-diplomatic relationships were extremely fluid and confused.

By the late 1943. and early 1944., Partisan movement has spread widely, and was involved in a number of attacks on Axis supply lines, outposts etc., even while also receiving shelter with Italian Fascists. From 1943. onwards, Western Allies began supporting the Partisans instead of the Chetniks, sending them ammunition, equipment and military advisors.

Allied High Command made an agreement with Partisan leader, Josip Broz Tito, to form a tank brigade to be equipped with Allied tanks and armored cars. First Tank Brigade was formed on 16th July 1944. The British supplied some 56 M3A1/A3 tanks, 24 AEC Mk.II armored cars and two M3A1 scout cars, and Partisans salvaged some damaged tanks from Allied repair facilities. Crews were sent by Partisans to be trained in Italy.

The Brigade would see extensive action against the Germans and their allies until the end of the war in May 1945. Large number of M3 tanks were lost or heavily damaged in combat. Some of the damaged tanks had their turrets removed and replaced by captured weapons. Several different modifications existed, one of them being a Stuart-Pak that is the topic of this article. In case of Stuart-Pak, modification was done by installing a captured 7.5 cm PaK 40 on top of M3A3 tank, creating a vehicle in many ways similar to German Marder series.

Modified Stuart tanks

While the Partisans were grateful for Stuart tanks – bad tank is better than no tank, after all – they were quite disappointed with their firepower. The Stuart was armed with 37 mm anti-tank gun which had been insufficient for antitank duties even in 1942., let alone 1944./5. While it could handle obsolete French and Italian tanks that were majority of tanks in Yugoslavia, a number of them were more modern tanks such as Panzer III, Panzer IV, StuG III and captured T-34s. These were well protected against the 37 mm gun. Stuart’s 37 mm gun was also ineffective against enemy fortified positions. This forced the Partisans to utilize AEC Mk.II armored car as anti-tank vehicles, as it had 6 pounder (57 mm) gun. This in turn forced them to use infantry for reconnaissance, which led to increased losses.

Some attempts were made to rearm tanks with more powerful guns, such as modifying Somua S-35 to carry Ordnance QF 6-pounder. This design however was ineffective, and the vehicle was lost on its first combat mission.

By the end of 1944., at “La Dalmatien” workshop in Šibenik there was present a number of Stuarts with turrets that were likely damaged beyond repair. In order to salvage the vehicles, a decision was made by Partisan authorities in Šibenik to try and install a number of captured German weapons, hoping to increase their effectiveness. It is unclear how many different modifications had been planned or carried out, but only two can be confirmed: at least one vehicle armed with German 7.5 cm PaK 40 anti-tank gun and a second armed with 2 cm Flak 38 Flakvierling anti-aircraft gun. B.B. Dimitrijević, D. Savić and D. Predoević state that three tanks had been modified into Stuart-Pak. D. Predoević explains that Partisan documents regarding the 4th Army mention use of four Stuart self-propelled guns, but these were in fact the American Howitzer Motor Carriage M8s armed with the 75 mm howitzer, developed and built by the Americans. Between 7 and 9 such vehicles were supplied to the Partisans during April 1945., and were likely the cause of confusion as to the number of Stuart PaK vehicles built (as some Internet sources state up to five Stuart PaKs). Alleged diary of a member of a staff of 1st Tank Brigade mentions four M3A3 conversions, of which one with Flak 38 20/4, two with PaK 40 7.5 cm and one with PaK 38 5 cm. Conversion with PaK 38 was lost in a fight near Bihać due to a direct hit of a 100 mm howitzer manned by Croatian troops.

The Modifications

Damaged M3A3 Stuarts were used for this modification as they were present in greater numbers. The original tank turret was replaced by a three-sided shield and a 7.5 cm PaK 40 anti-tank gun.

The Gun

PaK 40 was the best anti-tank gun available in Yugoslavia, more than sufficient to engage any tank in Yugoslavian theatre even until the end of the war. How exactly they were mounted on the tank body is unknown. A likely solution is usage of reinforced base – likely using metal bars – on which the gun would be mounted along with its cradle mount. Wheels and trailing legs would have been removed, with gun being either welded or bolted in place. This means that the gun will have retained its original elevation (-5 to +22 degrees) and traverse (65 degrees). There was no front gun travel lock. It is also unknown how the modifications affected vehicle’s weight, balance and driving performance.

Using PaK 40 in this manner however presented a number of challenges. Major question is how and where the relatively large PaK 40 ammunition was being stored. Internal storage would have severely limited number of available rounds. Storing rounds within the fighting compartment would have caused similar problems. Secondary armament consisted of the original hull-mounted Browning 7.62 mm machine gun.

Armored Protection

Armored protection of the vehicle is unknown, but can be guessed at. The hull kept its original Stuart armor – 38 mm on upper front, 44 mm lower front, 25 mm sides and rear. The gun kept original twin layer gun shield – each plate 4 mm thick with 25 mm of space between them. Sides of the new fighting comparment were protected by plates of unknown thickness, made from salvaged German vehicles too damaged to repair. These appear to have been somewhat thicker than either of the plates in gun shield but thinner than shield overall – so thickness may be guessed at maybe 10 – 15 mm. Armored plate was also added to fill the space between the gun and the hull. While gun shield and side armor protected the crew from shrapnel and small arms fire, the top and the back of the fighting compartment were completely open.


Crew itself likely consisted of four: driver and assistant in the gun, and loader and gunner on top in the fighting compartment. Assistant was also machine gun operator, while loader was likely also commander of the vehicle.

In Combat

Stuart Paks were ready in early 1945., but spent time training crews. Vehicles were dispatched to the frontline in late March 1945., and saw combat against the Germans. Stuart Pak vehicle(s) were used in battles near Mostar, Bihać and Drenovača during Feburary and March 1945.

At the end of April, Stuart Paks were engaged in heavy fighting near Ilirska Bistrica. On 28th April 1945., Germans, supported by captured T-34s and “Panthers” managed to push back the Partisans. No real Panther had ever been used in Yugoslavia during the war, so these could have been StuG IIIs or perhaps Panzer IVs. The Partisans counterattacked and pushed the Germans back. During this battle, a Stuart Pak managed to destroy a German T-34 tank. It was noticed that the gun recoil during firing would push the whole vehicle back several meters. Modified Stuarts (both PaK and Flak versions) also participated in capture of Trieste in May 1945.

Vehicles were likely sold for scrap following the end of the war.


Stuart Pak was an attempt to quickly build a vehicle capable of destroying any enemy target. While this succeeded, lack of balance in the vehicle likely resulted in overall disappointing performance. Gun’s recoil caused heavy wear and tear on the vehicle, and was also a tactical issue. Small and poorly protected fighting compartment and small ammunition load would also significantly limit its effectiveness. It did manage to destroy several tanks.


Crew4 (Gunner/ commander, loader, driver and driver assistance)
PropulsionContinental 7 cylinder petrol
250 hp – air cooled
Speed58 km/h (36 mph) road
29 km/h (18 mph) off-road
Range120 km at medium speed (74.5 mi)
Armament7.5 cm PaK 40 Anti-Tank Gun
ArmorFrom 13 to 51 mm (0.52-2 in)

Further Reading




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