Yugoslav Partisans (1945)
Self-Propelled Mortar – Fake
The Second World War is famous for the deployment of large tank formations that saw extensive combat use. It also represents the point when the general development and production of these and other armored combat vehicles took off on a massive scale. However, there are also many examples where, for various reasons, improvised vehicles were built. Germany was well known for implementing a large variety of unique vehicles in this manner, but they were not the only ones. The Yugoslavian communist Partisans, in the hope of salvaging any damaged tank, built some unusual hybrids that consisted of British-supplied US M3 light tanks armed with captured German weapons. While two variants are known to have been built, a third one is often mentioned in various sources, although there is no evidence to prove that it was ever built. This was an M3 light tank, allegedly armed with a mortar.
The M3 Light Tanks in the Balkans
Following the quick conquest of the Kingdom of Yugoslavia during the April War (6th to 18th April 1941), its territories were divided between the victorious Axis forces. Due to the harsh and brutal occupation by the Axis troops stationed in Yugoslavia, by the second half of 1941, two resistance groups started a rebellion against the occupiers. These were the Royalist Chetniks and the Communist Partisans. In the beginning, these two groups worked together in the fight against the occupying Axis forces. The Chetniks were mostly Serbians (former soldiers) who wanted the King to return to power after the war. The Partisans, on the other hand, had members from nearly all nations of the former Kingdom of Yugoslavia (Serbian, Croatian, Bosnian, etc.). They wanted to form a new communist government after the war. While these two shared a common enemy early on, due to the great political differences and different points of view on how to fight the enemy, a conflict between these two forces in late 1941 would break out into open civil war. This lasted until the end of the war and the victory of the Partisans.
By the end of 1943 and the start of 1944, the Communist Partisans were heavily involved in organizing several attacks on the German and their allies’ vital communication and supply lines, military bases and airfields, and other targets, inflicting increasing losses in men and materiel. While, initially, the Western Allies mainly supported the Chetnik movement, due to various reasons (including a lack of major military action against the Germans or even open collaboration with them), this attitude changed drastically from 1943 onwards. The Allies instead focused on supporting the ever-increasing Partisan movement by supplying them with ammunition, equipment, and specialized personnel to help train the Partisan ground forces.
Besides these, Allied High Command agreed with the leader of the Partisans, Josip Broz Tito, to form a tank brigade that was to be equipped with Allied tanks and armored cars. The unit, named the First Tank Brigade, would be formed on 16th July 1944. The British supplied some 56 M3A1/A3 tanks, 24 AEC Mk.II armored cars and two M3A1 scout cars. The Partisan crews were previously sent to Italy to be trained in operating these vehicles. They also managed to salvage a few more damaged tanks from Allied repair facilities.
The first vehicles of this unit arrived in Yugoslavia in September 1944. Both Allied and improvised Partisan-operated transport ships were used to ferry these vehicles across the Adriatic from Italy to the Yugoslavian coastline. The First Tank Brigade would see extensive action against the Germans and their allies until the end of the war in May 1945.
The M3 Light Tank
The M3 Light Tank was designed in 1940 to replace the older and outdated M2 Light Tanks that were in service with the American armored forces. The M3 had many improvements over the M2, including thicker armor, stronger (due to the increase in weight) vertical volute spring suspension (VVSS) with a bigger rear idler wheel, increased speed, and improved firepower consisting of four 7.62 mm machine guns and a 37 mm cannon. The first series was powered by the gasoline-fueled (petrol) Continental seven-cylinder four-cycle radial aircraft engine. After 1942, a new four-stroke diesel radial Guiberson A-1020 engine was used. It had a crew of four (driver, driver assistant, gunner, and commander). From March 1941 to August 1942, some 5,811 Stuarts with petrol engines and 1,285 with diesel engines were built. The much improved M3A1 version was produced from April 1942 onwards. The first batches of M3A1 tanks were built using riveted armor, but later models had welded armor. The changes included an improved turret design (the small commander cupola was removed) with two hatches, reducing the number of machine guns to three on later-built vehicles, and the addition of a turret basket.
Soon after the M3A1, a new model, the M3A3, was made to address the poorly designed frontal armor and small fuel capacity of the first versions. The front and side armor of the Stuart M3A3 were angled and the front hatches for the driver and his assistant were replaced by new overhead ones. Due to the extra space that the Stuart M3A3 now had, it was possible to increase the fuel capacity. This version was produced until August 1943, with a total of 3,427 vehicles being built.
Repair Facilities at Šibenik
Following an engagement with the Germans, elements of the First Tank Brigade captured the city of Šibenik (located on the Adriatic coast of modern Croatia) on 3rd November 1944. Before the war, Šibenik had been a large naval shipyard and possessed many repair workshops. The Germans evacuated many machinery and tooling equipment and sabotaged those that could not be removed. Still, there was sufficient working equipment and materials left to meet the needs of the Partisan mechanics, who were in great need of such tools. Months spent fighting the Germans had greatly depleted the unit, which needed major overhauls on its vehicles. The fighting with the Germans had led to heavy tank losses. As there was no way to replenish lost tanks, the Partisans were forced to salvage and repair damaged vehicles whenever possible. Those that were damaged beyond repair were cannibalized for spare parts. The same was done with any captured vehicle or other equipment. Šibenik would remain one of the major Partisan bases for repairs and maintenance until the end of the war. In addition, it also served as a vital training ground for new Partisan tank crews from November 1944 onwards.
Due to a high attrition rate, a great number of M3A1/A3 tanks were either lost or heavily damaged. Given the general lack of replacements, these had to be repaired to keep the whole unit operational. Some damaged vehicles saw their turrets removed completely and replaced with captured weapons. At least one (possibly up to three) vehicle was rearmed with a 7.5 cm PaK 40. It was installed (without the wheels and the trailing legs) on top of the M3 with some improvised armored sides, creating a bizarre vehicle somewhat similar to the German Marder tank hunter series. Two vehicles were armed with a 2 cm Flakvierling anti-aircraft gun. General information about these two vehicles are scarce and difficult to find, mainly as the Partisans kept a poor record of them. It is believed that their construction began either by the end of 1944 or in early 1945. Surprisingly, these three (or more is unclear) survived the war and remained in use for a few more years. Unfortunately, their final fates are unknown.
The M3 Mortar Armed Variant
While there is enough evidence to prove the existence of these two variants, some unconfirmed sources mentioned the existence of at least two more modified vehicles. One of them was a mortar-armed variant. The existence of such a vehicle is often mentioned on various internet websites and even in books. In both cases, besides the basic information that it consisted of an M3 light tank with its turret removed and replaced with a mortar, nothing else is mentioned.
It is often impossible to verify the authenticity or claims of various internet sites with absolute certainty or credibility. Books, on the other hand, are generally more reliable and often give more detailed information and sometimes even a photograph that helps to remove these doubts. Of course, even books may sometimes be confusing, contradictory, or simply wrong.
In any case, the oldest (at least that was available to the author during the writing of this article) possible reference to this potential modification is the book called Od Tenka Do Brigade 1941 – 1945 (Eng. From Tank to Brigade) published in 1955. This book contains various anecdotes, stories, and descriptions of military operations and battles written after the war by witnesses and military personnel. On page 94 is an article entitled Tehnička služba Prve Tenkovske Brigade (Eng. Technical service of the First Tank Brigade). In it, author Major Anton Kurt praised the ingenuity and dedication of the Šibenik maintenance personnel. According to him, they managed to modify two vehicles, with one being armed with a 7.5 cm anti-tank and the second with 2 cm anti-aircraft guns. In addition, in the same book, there is a photograph that the citation claimed to be the modified M3 light tank.
The same vehicle is also mentioned by authors P. Zakonović and U. Janjetović (Tehnička Služba u Narodno Oslobodilačkom Ratu 1941-1945). In this book, published in 1987, it is described that one vehicle was built and equipped with an 82 mm mortar.
Was it Real?
Are these written books enough evidence to support the idea that at least one M3 was armed with a mortar? The first thing that needs to be analyzed is the context of the provided information of these two sources, starting with the first book, which was written to mark the tenth anniversary of the end of the war in Yugoslavia. While it gives several interesting pieces of information about the M3 modifications, they are somewhat too general and lack more specific construction details or production numbers.
The first problem with this book is that the previously mentioned photograph is not what it is described. It is not a tank, but instead, another mysterious vehicle of unclear origin that consisted of a modified German Sd.Kfz.251 half-track armed with two 120 mm mortars. While this vehicle was operated by the Partisans, it was likely built by the Germans at some point in the war. Placing one large 120 mm caliber mortar inside an M3 tank was an impossible task due to the limited space, let alone two of them. It is unknown if the publisher who prepared this book misidentified the vehicle or was wrongly informed. In either case, this is a good indication that this vehicle was not real.
The second point worth considering is that two facts mentioned by Major Anton Kurt in his writings cast doubt on his knowledge in this field. Firstly, he praises the Partisans mechanics who managed to install the larger 7.5 cm gun on top of the M3 without proper expertise and with limited available resources. Interestingly, he particularly praised the fact that, during firing, the vehicle did not move backward due to the powerful recoil. However, author D. Predoević (Oklopna vozila i oklopne postrojbe u drugom svjetskom ratu u Hrvatsko) claims the opposite.
According to him, the whole installation was rather clumsy as, during firing, the whole vehicle would be pushed back several meters due to the extensive recoil of the 7.5 cm gun. He also mentioned that the vehicle was raised slightly up in the air during the firing of the main armament. German Marder anti-tank vehicles, when firing the same gun, did have some recoil issues, but could remain stationary. Of course, these were properly built vehicles (albeit still somewhat of an improvisation) built with better tools and equipment. Either one of these two authors is wrong or some vital information or context is missing.
In addition, Major Anton Kurt also described that the same partisans took a 22-tonne tank that had its 37 mm gun replaced with a much larger 57 mm taken from the AEC II armored car. This was, in fact, not a Stuart but a Somua S35 which weighed a few tonnes less than the Major stated. However, this can be considered only a slight oversight. While these are some curious contradictions, all this does not mean that Major Anton Kurt was completely wrong in his writing. It is important to consider that he wrote in the spirit of the post-war period, where the Partisan struggle had significant political influence, was extensively used as propaganda, and achieved a somewhat mythological status. So while helpful and containing many interesting bits of information, this book should also be taken with a grain of salt.
The second book that mentions the existence of this mortar-armed vehicle only does so briefly. Besides the modification, only the alleged caliber of the mortar is mentioned. This does not help much, as it gives no more context or information about its overall design. In addition, it mentions that, in total, 7 M3s were modified with various weapons. It is known from photographic evidence that at least three vehicles were built. One and up to three were armed with the 7.5 cm gun and two with 2 cm anti-aircraft guns. The number of the former conversions is often confusing in the sources, as they sometimes wrongly include the Howitzer Motor Carriage M8s armed with the 75 mm howitzer developed and built by the Americans in total. Between 7 and 9 such vehicles were supplied to the Partisans during April 1945.
Another vital aspect of this vehicle that needs to be considered is the main armament itself. According to the photograph in the first book, the two mortars shown were obviously larger caliber than the 82 mm suggested in the second book. The Partisans had used many versions of mortars of different calibers. If such a conversion using an 82 mm mortar was really built, then which precise type it was would be almost impossible to know. Yugoslavia was a battlefield where weapons from all warring parties were used.
It is known that these two mortars were actually of 120 mm caliber. These are easily identified, as the use of such larger caliber mortars was limited to the Soviet Union and Germany. In this case, it was the 12 cm Granatwerfer 378(r), which was basically a direct copy of the Soviet PM-38. Using the larger caliber mortar makes more sense due to their stronger firepower, larger ammunition and greater range.
More modern authors, for example, B. B. Dimitrijević and D. Savić (Oklopne jedinice na Jugoslovenskom ratištu 1941-1945) and D. Predoević (Oklopna vozila i oklopne postrojbe u drugom svjetskom ratu u Hrvatsko) do not mention that the M3 were ever modified in this manner. Furthermore, B. B. Dimitrijević explains that the alleged M3 mortar vehicle never existed and that it was simply mistaken with the half-track contraption armed with the two mortars.
What Would It Have Looked Like?
Given that there is no reference or mention of its alleged design, it is only possible to speculate at this point. In general, during the Second World War, none of the warring nations even bothered producing self-propelled vehicles based on a tank chassis that were armed with mortars for indirect fire support. Germany and the US Army employed half-tracks for this role, as they were cheaper and more easily available than proper tanks.
However, the Germans did make some field modifications on at least one tank for this role. The occupying forces stationed in France had plenty of captured tanks that were lying around. While pressed into service for various auxiliary tasks, by 1944, these were obsolete as frontline combat tanks. At least one AMR 35 light tank was modified by removing its turret and placing an 82 mm mortar on top of it. For crew protection, an extended superstructure was added. How many were rebuilt is unknown, but at least one vehicle survived and it could serve as a reference point for the M3 mortar conversion. However, it is important to note that these two conversions are completely unrelated and serve only as speculative comparisons.
The 8 cm Schwerer Granatwerfer 34 auf Panzerspähwagen AMR 35(f), as it is now known, had its mortar base bolted down to the AMR superstructure. This was done to provide a stable firing platform. The Partisans would have likely done the same, either using welding or more probably bolts. Other modifications such as changing the shape of the mortar stabilizing legs may also have been done. It is unlikely that they would have tried to squeeze the mortar inside the M3’s cramped interior due to the limited size of the turret ring. Instead, it would have been partially placed on top of the tank superstructure. Some armor would have been added to provide some rudimentary protection for the crew. Lastly, an ammunition storage bin had to be added, either stored inside or on top of the vehicle.
The other overall characteristics, such as ammunition load and number of crew members could only be speculated. The 82 mm mortar ammunition was rather small in size and it should not have been a problem to store a lot of it inside or on top of the tank. The crew would have hypothetically consisted of a commander, gunner, loader, and driver.
Conclusion
Based on the presented information, the whole M3 armed with a mortar variant appears to be nothing more than a wrongly identified photograph that led to confusion during the early years after the war. As there is no reliable information or a photograph that would confirm the existence of this vehicle, it is probable it never existed.
The Partisans in the Šibenik workshop certainly had the technical knowledge and equipment to make this modification. The question is if they would actually have done that and whether it would have been worth the effort and time spent. Given the M3’s weak firepower, it would have benefited them greatly to construct another vehicle armed with an anti-tank or other kind of direct-fire gun. Placing an 82 mm mortar on the M3 tanks would simply have been a waste of limited resources.
Light Tank M3A3 with Mortar Technical Specifications |
|
|---|---|
| Engine | Continental 7-cylinder petrol 250 hp air-cooled |
| Armament | One 82 mm or larger mortar |
| Armor | 13 to 51 mm |
Sources
B. B. Dimitrijević, (2011) Borna kola Jugoslovenske vojske 1918-1941, Institut za savremenu istoriju.
P. Zakonović and U. Janjetović (1987) Tehnička Služba u Narodno Oslobodilačkom Ratu (1941-1945)
Od Tenka Do Brigade 1941 – 1945, Uredništvo Vojnog Glasnika
B. B. Dimitrijević and D. Savić (2011) Oklopne jedinice na Jugoslovenskom ratištu 1941-1945, Institut za savremenu istoriju, Beograd.
D. Predoević (2008) Oklopna vozila i oklopne postrojbe u drugom svjetskom ratu u Hrvatskoj, Digital Point Tiskara
B. Perrett (1980) The Stuart light tank series, Osprey Publishing
M. Babić (1986) Oklopne Jedinice u NOR-u 1941-1945, Vojnoizdavački i Novinarski Centar
I. V.Hogg (1997) German Artillery of World War Two
D. Predoević (2002) Armored units and vehicles in Croatia during WW II, part I, Allied armored vehicles, Digital Point Rijeka