A maneuver war requires a large fleet of motorized vehicles, including artillery tractors. This lesson was learned back during the First World War. It is no wonder that the Red Army cared about mechanization so much. Soviet industry carried out their orders. A whole series of specialized tractors were designed in the 1930s. Many of them were built in great numbers and some were even the most numerous in their class.
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| Voroshilovets, the best Soviet artillery tractor. The Voroshilovets could tow heavy guns even faster than the rating of their chassis. |
It so happened that production of artillery tractors ceased after the start of the Great Patriotic War. Some claim that the USSR should have built more tractors instead of tanks. This article will tell the story of why this was a bad idea and compare the results of Soviet mechanization with that of the Germans.
Was it really that bad?
Before the Revolution, automotive production in Russia was miserly. Russian factories could barely handle assembly of foreign designs. There were some tractors, but very few. Fully fledged production of tracked tractors only came by the end of the 1920s. Agriculture was the priority, but the military did not lose hope of getting a purpose made artillery tractor. Their wishes were granted by the mid-1930s.
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| The path to tracked tractors began with these vehicles produced at the Obukhov factory. |
At this point, let us define some terms that may not be so obvious. An artillery tractor and an agricultural tractor are not the same thing. Agricultural tractors were used to tow guns in some cases, but they were modified accordingly. Even the S-65 built for the military had a fully enclosed cabin. A proper artillery tractor is something else entirely. It is based on a special chassis. A tank chassis as it usually won't do. It is also not a race car. Its main task is to tow artillery, and the speed of a heavy gun is limited. For instance the top speed at which the 152 mm ML-20 gun-howitzer could be towed was just 25 kph. An artillery tractor also tows ammunition and crewmen, not just the gun,
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| Obukhov factory 2.5 ton tractor. |
The Kommunar 9-30 was already an artillery tractor when it came to top speed (15 kph), but not in other ways, as it had no way of moving the crew. The Comintern tractor that replaced it was already an artillery tractor. It could tow corps and high power guns at 15-25 kph, depending on the load. A B-4 203 mm howitzer can't be towed at more than 16 kph. The average speed of a motorized column rarely exceeds 15 kph anyway, especially if heavy artillery is involved. Lighter guns could be towed at 25-35 kph, but heavy guns could rarely exceed 25 kph.
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| The final variant of the Kommunar was capable of medium speeds that heavy guns could achieve. |
The comparison with German halftracks is commonly made, but rarely in a realistic setting. German halftracks were indeed faster, but only without a load. In Soviet trials, an Sd.Kfz.9 halftrack reached 55 kph when empty but with a cargo of 20 tons its average speed on a highway fell to 21 kph. With a 211 mm Morser 18 in tow (12 tons) the maximum speed was 24 kph. This is comparable with the speed of a Voroshilovets. The Sd.Kfz.9 did not perform well in trials as its fuel consumption was high and it had poor tractor. This is the devil in the details, as many comparisons usually only mention the top speed of an unladen tractor.
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| Comintern, the Red Army's first true artillery tractor. At the moment of its creation, there was nothing like it in the whole world. |
Of course, not everything was perfect. Nevertheless, four classes of artillery tractors were available by the start of the Great Patriotic War. These were the Komsomolets tractor for light anti-tank guns, STZ-5 for divisional guns, Comintern and S-2 for corps and heavy AA guns, and Voroshilovets for heavy high power guns. Corps and high power gun tractors could also be used for evacuating tanks. Out of the three classes of tractors, three were built on an original chassis that met requirements and were available en masse. The numbers look less favourable when only the whole production run is considered, but when numbers are split by year then one can see that most German halftracks were built after 1941.
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| The STZ-5 was the Red Army's most numerous specially built tractor. |
There is another nuance with numbers. The Red Army had 39,622 tracked tractors as of January 1st, 1941. About 13,000 were high speed artillery tractors, the rest were regular tractors. The GAU did not consider this satisfactory, as there was a shortage of special purpose tractors for corps guns. Nevertheless, mechanization of corps artillery reached 100%. While the Germans had more artillery tractors, they had nothing that could be mobilized during the war. As a result, corps level artillery in German infantry divisions was horse drawn.
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| The Komsomolets was also successful and numerous. |
It should come as no surprise that the Germans eagerly grabbed any Soviet tractor they could find. There were plenty STZ-5 and S-65s in the Wehrmacht. Recall the aforementioned Sd.Kfz.9. With a 20 ton trailer its speed in mud dropped to 8.6-10 kph. With a 21 cm Morser 18 it could achieve 11 kph. Meanwhile, the S-65 put out 5-7 kph, regardless of whether it was in the mud or on a highway. The STZ-5 also put out about 10 kph on average in these conditions. It is not surprising that the Steyr RSO/01 followed a similar ideology. It was not fast, but it could still move well in mud. This ended up being Germany's most common artillery tractor.
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| The Stalinets S-2 only major failure among pre-war tractors. It could not fully replace the Komintern. |
One must remain a realist. The Soviet artillery tractor program had many shortfalls. At the same time, the grass on the other side of the fence was not as green as it can seem. The Germans had a constant shortage of tractors and even a rapid increase in production did not cover the shortfall. By 1944 there was an average deficit of 50%. The Red Army could compensate by mobilizing agricultural tractors plus a small amount of vehicles through Lend Lease. The Germans had no other source of tractors. Some of their halftacks also ended up without a mission, like the Sd.Kfz.1 designed to tow the 3.7 cm Pak. It could pull the 7.5 cm Pak 40 only with great difficulty. As a result, the Germans had to make do with ersatz gun tractors like the Sd.Kfz.3 Maultier and Steyr RSO.
How much could a tractor cost?
Let us now talk about why the tractors disappeared from the Soviet production schedules and what was done to bring them back. The Komsomolets anti-tank gun tractor disappeared first. On one hand, the reason seems simple: to free up resources for the T-40 amphibious tank and its land-based replacement, the T-30. Some say that the tank should not have been built at all. However, it is not that simple. The Komsomolets turned out to be incapable of properly towing the new 57 mm ZIS-2 gun back in the spring of 1941. A replacement was quickly found in the GAZ-61-416. However, the real killer of the Komsomolets tractor was not the ZIS-2, but the T-50. It was supposed to be built at factory #37 in Moscow, and so production of the Komsomolets was stopped as of August 1st, 1941. The tractor would have died in either case.
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| Attempts were made to build tractors on a tank chassis. The T-26-T was mass produced but caused little joy. |
The Voroshilovets died next when factory #183 was evacuated to Nizhniy Tagil. Many attempts were made to revive the Voroshilovets on the T-34 chassis. However, putting such a tractor into production would mean reducing T-34 output. The tractor, renamed to AT-45, was pitched to factory #75. It did not prosper here. The need to produce the T-44 meant that only a pilot series was completed. And yet, there are few who claim that the T-44 was useless and that tractors should have been built instead.
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| Evidence against building tanks as artillery tractors. The GAZ-22 built on the T-40 chassis was rejected because of the engines. Even dual ZIS-5 engines did not help. |
The S-2 and S-65 were the third to be cut. This time, the KV-1 was to blame. Production had to be increased urgently in the fall of 1941, and there was no way to do it except at the cost of tractor production. The tractors were not forgotten. Steps to revive production were made in 1942. A hybrid of the S-2 and S-65 called S-10 was supposed to be put into production, but ChKZ received new orders in the summer of 1942: build T-34s. Tractor building in Chelyabinsk only resumed after the war.
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| Production of the GAZ-61-416 to replace the Komsomolets began only in October of 1941. Even if it was built instead of the T-60, it would have taken half a year to bring production up to acceptable numbers. |
The STZ-5 lasted the longest. An attempt to bury the divisional artillery tractor that also served as a chassis for M-13 Katyusha launchers was met with hostility. Production only ended in 1942 when things at Stalingrad got quite dire. The ZIS-42 was planned to replace it. The NATI-D was supposed to be the real divisional artillery tractor, but it was "promoted" to corps artillery where the need was greater.
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| ZIS-42, the most common Soviet artillery tractor produced in 1943-45. A wartime substitute, but better than nothing. |
The topic of Soviet wartime tractors is a fascinating one, with many designs that remained on paper. The archives also still hold many good arguments for why tractor production unfolded the way it did, and no other way.
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| The STZ lasted the longest of all pre-war tractors. About 8000 units were made in 1941-42. 3052 of its German equivalent, the Sd.Kfz.11, were completed in this time. It's no wonder that the Germans put the Steyr RSO/01 into production. |
It is also amusing to see claims that the T-60 was a waste and a tractor with the same engine should have been built instead. Let us play the game of alternative history. First of all, we must stop the People's Commissariat of Aircraft Production, who took away the engine plant from GAZ in 1940. This makes it more likely that the GAZ-61 could go into production sooner. The engine alone is not enough. One must also fight off the start of ammunition production at GAZ, which ate into the resources of the automotive branch, and then shoot down all the German aircraft that pounded the factory in 1941, harming the automotive plant in particular. Even so, the production of the GAZ-61-416 would not be great for 1942, maybe just a few thousand vehicles. The limiting factor was the constant velocity joint that was only put into production in the fall of 1941. Even so, this part was problematic and responsible for failures of the front axle on the GAZ-61.
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| Stalinets S-10, an ersatz tractor designed in 1942. The army didn't like it since there was no truck bed. |
An attempt to build a tracked tractor instead of the GAZ-61-416 runs into the issue of the engine. You can forget about the GAZ-11 and its derivatives in this case. The GAZ-22 project clearly showed that the GAZ-11 is entirely insufficient for a tracked tractor. The GAZ-22 drove around on its own very well, but turned into a tea kettle the moment a gun was hooked up.
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| NATI-D tractor. Unlike the GAZ-22, this tractor had two ZIS-5 engines and did not overheat when towing even corps artillery. |
Few people understand what a tractor engine is. Not every engine can go into a tractor. For this reason, the GAZ-11 and its derivatives were used in tanks, APCs, trucks, but were not even considered as tractor engines. It was simply not made for the task. Even putting a ZIS-5 engine into the GAZ-22 was not enough. It needed the ZIS-16, a bus engine that had a lot of potential in tractors, but it could not be built in large enough amounts.
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| Ya-12 corps artillery tractor. The only thing it retained from the tank was the running gear, and even that was modified. |
Even if the engine could be sourced, how do you convince ZIS to switch to producing engines for someone else? How do you convince GAZ to accept a "foreign" engine? "Not invented here" syndrome would make this an uphill battle. There is a reason why the GAZ-22 was abandoned the moment GAZ lost its engine plant. No engine, no tractor. The only place where such a trick would work was the Yaroslavl Automotive Factory. It had no engine plant at all, so they were used to "foreign" components. That is where the Ya-11 with a pair of GAZ-MM engines was born, followed by the Ya-12 and Ya-13.
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| The issue of tractor shortages was considered back in the fall of 1941. The growth spurt of Soviet SPGs in the spring of 1942 was a direct consequence. |
Some may point at the Ya-11 and say "just build that", even drawing conversion diagrams. It is much harder to build a tractor than to draw one. The Ya-11 has little to do with the tank. Even the running gear elements were lightened. It does not use a hull "tub", but a frame. As a result the Ya-11 was longer than the T-70 but weighed more than a third lighter. The tank could not be converted into a tractor quickly. ARV conversions are not evidence otherwise, as they are very different vehicles. There was no bandaid solution.
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| 1646 A-19 corps guns were built in 1941-45, but 1735 ISU-122 in 1944-45. Production of A-19 guns dropped after 1944. |
The GAU was not blind and foresaw the drop in artillery tractors. A review of the situation was called in the fall of 1941. The result was a new SPG program, because of which production of towed ML-20S howitzers in 1944-45 gave way to the ISU-152 SPG and the A-19 gun gave way to the ISU-122. 14,500 ZIS-3 divisional guns, or a quarter of the total production run, were also put into SU-76 SPGs. The very same GAZ that many view as an ideal producer of tractors built most of these SU-76es (7500 from 1943 to 1945 inclusive).
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| The Red Army still had 9631 tractors of this type by the end of the war, 8220 of which were still functional. It was not perfect, but mechanization of corps level artillery reached 100%. |
History took the only possible route. Putting a tank into production was the correct decision. An artillery tractor is not as simple of a thing as many expect, nor is it just a converted tank. One can dream, but it should avoid making those dreams into a fantasy.