Mortars on the Eastern Front

The Soviet 120-HM 38 was one of the most successful mortar designs of World War II, and was even copied direct by the Germans for their own use. It combined heavy firepower and mobility and often replaced support artillery with some formations. It was simple and easy to use in action, and fired a heavy HE bomb.

The Soviet 82-PM37 had a calibre of 82 mm (3.228 in) and was a close design relative of the French Brandt mortars. The Soviets introduced a circular baseplate and used recoil springs between the bipod and barrel to reduce recoil forces on the laying and sighting arrangements.

The German 8-cm sGrW34 was greatly respected by the Allies, who came to fear its accuracy and rapid rate of fire, but it was not an outstanding design and much of the praise it earned was mainly due to the careful and thorough training of them mortar crews.

The war was twenty-one months old and still going in Germany’s favour when Hitler ordered Directive 21, or ‘Case Barbarossa’, the code to launch the attack against the Soviet Union. At 3.15am on 22 June 1941, a single gun fired to signal the start of the attack, and from that moment on all other aspects of the war seemed to be of secondary importance. Japan may not have known of Hitler’s intentions, even though they were allied in the Pact of Steel. Italy, on the other hand, knew full well and Mussolini had ordered the deployment of Italian troops to support the attack. Hitler had never attended a military academy but he had a general grasp of strategy. His generals presented him with information and made suggestions, but the final decision was his. If things went according to plan he took the credit, and if they went wrong he laid the blame squarely on the shoulders of others. He believed that the Soviet Union was so corrupt that all ‘we have to do is kick in the front door and the whole rotten structure will come crashing down’. In ordering the invasion of the Soviet Union, Hitler plainly had no idea of the scale of problems which lay before the German Army in this vast country. The distances covered with apparent ease during the early phase of the campaign led the Nazi leader to believe that another victory lay ahead. German intelligence assessments said the Red Army had an armoured force of some 24,000 tanks but believed that most were obsolete and would pose no problem to the modern tank forces and anti-tank guns of the German Army. The Red Air Force would be overwhelmed as their outdated aircraft were shot down by the Luftwaffe’s modern fighters such as the Messerschmitt Bf 109. Within days of the start of the campaign, German troops had advanced deep into the Soviet Union with seemingly nothing to prevent it.

The scale of the attack was unprecedented and included 3 million troops in 146 divisions supported by three air fleets with over 1,800 aircraft. Seven armies and four Panzer groups with 3,580 armoured fighting vehicles, 7,184 pieces of artillery, 600,000 other vehicles for transport and liaison roles and 750,000 horses were committed to the attack. The tank force included 1,440 PzKw III and between 517 and 550 PzKw IV, with the remainder being made up of 410 older PzKw I and 746 PzK II tanks, along with a number of PzKw35(t) and 3(t) tanks. This was blitzkrieg on a grand scale and it looked as though the tactics which had worked so well in Western Europe and against Poland would soon add another victory to Germany’s list of conquests. Some believed that Hitler may have taken on an enemy that was too strong for his armed forces; after all, the Soviet or Red Army was estimated to number around 3 million. Other strategists thought the Soviets were fatally weakened by the army purges of 1937–1938 in which Stalin had ordered the liquidation of around 35,000 officers, robbing the Red Army of 90 per cent of its generals.

The strength of the Soviet Red Army in June 1941 stood at 5.5 million troops in all branches, and it was equipped with 91,400 pieces of artillery and mortars, but only 2,780,000 troops and 43,872 pieces of artillery and mortars were deployed in the west to oppose the German attack. The German Army also had the combined support of a further 1 million troops from their allies of Hungary, Italy and Bulgaria, who between them had almost 12,700 pieces of artillery and mortars. A typical Soviet tank division at the time had eighteen mortars to provide fire support and forty guns for anti-tank and anti-aircraft defence. A German panzer division at the time had thirty mortars and seventy-two guns for anti-tank and anti-aircraft roles. A Soviet artillery division had more than 100 HM38 heavy mortars of 120mm calibre organised into a special mortar brigade to provide fire support, something to which the Germans did not have any equivalent. The fighting was fierce from the very beginning and just three weeks after the start of the German attack the Soviet Army had lost 8,000 tanks, along with 9,427 pieces of artillery and mortars. Soviet losses continued to mount over the following weeks. For example, in the fighting around the Smolensk Pocket between July and September 1941, the Red Army lost 486,000 men killed, wounded or taken prisoner along with more than 1,300 tanks destroyed and 9,920 artillery pieces and mortars destroyed or captured. Six months later, having lost much ground by withdrawing before the Germans, the Soviet Army had lost hundreds of thousands more men killed and captured, while vast stocks of weapons and ammunition were either destroyed or captured in the fighting. Tank and aircraft losses were huge and available artillery and mortars were reduced to fewer than 22,000. The number of 120mm calibre mortars captured by the Germans and the stocks of ammunition was so great that they were pressed into action against their former owners without any need to convert them for service. Indeed, the Germans were so impressed with this weapon they even developed their own version, known as the 12cm calibre GrW42.

Soviet armaments production fell, and resupplying all the lost weapons and re-equipping new divisions would take time. The Soviet Red Army realised that it needed time to regroup, rearm and reorganize if it were to stop the advance of the German Army. Once that had been achieved it would then be in a position to push the invader back. One strategy used was the age-old tactic of giving up ground, called ‘scorched earth’. This meant that the Red Army left nothing behind in its wake that would be of any use to the Germans. This placed a heavier burden on the already over-stretched supply lines of the German Army, which had to bring everything forward as it pressed ever-deeper into the country. In turn this tactic bought the Soviets time to gather sufficient forces and weapons to mount a counter-offensive. The number of troops killed, wounded and taken prisoner continued to rise, and the levels of weapons, tanks, vehicles and aircraft lost was a testimony to the ferocity of the fighting. After six months of seemingly unstoppable advance, the German Army finally ground to a halt in the temperatures of —30 degrees in the outer suburbs of Moscow. The Red Army seized the opportunity to mount a counter-attack on 5 December, and with 720,000 men supported by 670 tanks, 5,900 pieces of artillery and mortars and over 400 rocket launchers they pushed the Germans back almost 150 miles to recapture the city of Smolensk. Moscow was safe for the time being but far from completely secure.

The weight of the German attack made the Soviets recognise that their industrial centres were at risk of being captured or destroyed, and a massive effort was put into moving hundreds of factories, especially those producing weapons for the army, thousands of miles to the east beyond the Ural Mountains. This placed them beyond the range of German bombers and armaments production could begin to replace losses. Britain and America sent military aid in the shape of tanks, aircraft and trucks. Britain even produced versions of the HM38 120mm calibre mortars to replace the losses incurred by the Soviet Red Army. This was a special production because the British Army had never at any time used such a weapon. Once the relocated Soviet factories were firmly established, weapon production began to increase and the losses of the early months were made good. The factories also produced heavier calibre mortars such as the M43 160mm, which weighed 1.15 tons in action and could fire a HE bomb weighing 90lbs out to ranges of over 5,600 yards. These heavier mortars were breech-loading weapons and regiments equipped with them were formed to serve with the Artillery Armies. Armed with this combination of weapons, such artillery units would unleash massive bombardments to smash the German forces with weight of firepower.

The Soviet Army was not entirely without combat experience, having sent advisers to support the Republican forces during the Spanish Civil War. They also sent weapons including tanks, aircraft and artillery which were operated by small numbers of Soviet troops. The Red Army had also been engaged in frequent border clashes with Japan, such as the incident near the Soviet port of Vladivostok in 1938. On another occasion, between March and September 1939, Soviet and Japanese troops fought a series of engagements in the area of Khalkin Gol which saw Soviet troops defeating the Japanese. At the time, Japanese troops were engaged in fighting in China and these border clashes with the Soviet Union had caused thousands of casualties to both sides. The short but bloody Russo-Finnish War between November 1939 and March 1940 had also added to the combat experience of the Red Army. In all of these engagements, troops and weapons had been tried and tested in combat, which would later be used during the opening engagements against the German Army in 1941. After the early German successes, which led to the capture of vast stocks of Soviet equipment, some of these weapons would end up being used against them.

To support the German attack against the Soviet Union, the Hungarians and Romanians deployed 44,000 and 358,000 troops respectively. Hungary had been Germany’s ally in the First World War as part of the Austro-Hungarian Empire. Romania had been Germany’s enemy in the First World War, but in the war against the Soviet Union, Romanian troops fought alongside German troops as allies and together with Hungary they deployed between them a combined force of 3,445 artillery pieces and mortars. Now, as Germany’s allies once more, they deployed between them a combined force of 3,455 pieces of artillery and mortars. Only a year earlier, in June 1940, Romania had been militarily undecided and as the main oil-producing country in the region it was seen as strategically vital to both Germany and the Soviet Union. Germany had pre-empted any move which may have been made by the Soviet Union by infiltrating troops into the country on the pretext of training the Romanian Army. In reality they were deployed to safeguard supplies of oil to the German Army, along with those of Hungary and Bulgaria. By September there were some 18,000 so-called German instructors in Romania, whose presence was still being explained as necessary to help modernise the army. By November all pretence was dropped when the country’s Prime Minister, Ion Antonescu, signed the Axis Pact which allied Romania with Germany.

The Romanian Army incurred heavy losses throughout the Soviet campaign, especially during the fighting in the region of the Ukraine and Crimea. In June 1941, Romanian troops were serving as part of the German Eleventh Army to capture Sevastopol, where a force of over 720 mortars was engaged in the action. By August 1942, the Romanian Third and Fourth armies were engaged in the fighting at Stalingrad. Germany supplied the Romanian Army with a large proportion of weaponry, including anti-tank guns and mortars. Some of these weapons were from captured stocks of French mortars such as the Brandt 60mm Model 1935. They also received 81mm Brandt Model 1927/31 and Model 1939 weapons. Romania had an armaments industry capable of producing machine guns, small arms and mortars, including a 120mm calibre weapon called the Model 1942, built by Resita. This weapon was towed on a two-wheeled carriage and had a barrel length of 6.1ft and weighed over 617lbs in action. It could fire HE bombs weighing 35.25lbs out to ranges of 6,780 yards. The Romanians also had pre-war permission to build the French 50mm Brandt Model 1937 mortar under licence, which the Romanian Army later used during fighting against the Red Army. This weapon weighed 7.27lbs in action and could fire HE bombs weighing 1lb pound out to ranges of 550 yards. It also used other mortars, including a version of the German heavy calibre 12cm GrW42 produced by Rosita.

The Hungarian Army made its first military incursions of the war when it independently invaded neighbouring Slovakia in October 1939. The country was pro-German but it did not commit itself to joining the Axis Pact until November 1940. The Hungarian Army had a peacetime strength of just 80,000 troops and like Bulgaria and Romania its weaponry was outdated and it was largely reliant on horses to move artillery. With German support the country very quickly expanded its strength and, in June 1941, put troops in the line alongside German and Romanian forces during Operation Barbarossa. Within a month of the campaign starting, a unit called the Hungarian Rapid Force (also known as the Hungarian Rapid Corps), comprising about 40,000 men, and composed of troops from VIII Corps and 1 Mountain Brigade, advanced deep into the Donets Basin alongside the German Seventeenth Army, where it took part in the Battle of Uman which garnered thousands of Red Army prisoners. The Second Hungarian Army was composed of nine light infantry divisions, each of which had two infantry regiments with their structure supported by obsolete tanks such as Panzer Mk I which only had machine guns. The Second Army was deployed to Stalingrad, where it was given the task of holding a front line some ninety miles long. When the Red Army offensive of January 1943 was launched it very quickly penetrated the positions held by the Hungarian troops, who fell back leaving some 148,000 killed, wounded and captured, losing much weaponry in the process, including more than 400 mortars of 81mm calibre.

As Germany’s ally, the Hungarian Army continued to fight and at the beginning of February 1945 still had 214,000 men deployed. Some elements had surrendered in late 1944 but other units staunchly held out by the side of Germany until the end of the war in May 1945. The fighting would eventually cost 300,000 casualties and many taken prisoner. The weapons used by the infantry units included mortars such as the 50mm calibre 39M produced by FÈG and a Hungarian-built version of the GrW36, known as the 36M. Hungarian factories such as Dimàveg, EMAG and Bàmert produced 81mm calibre mortars such as the 36/39M and 100mm calibre 41M. The 36/39M was a Brandt design weighing 187lbs in action and capable of firing a HE bomb weighing 9lbs out to ranges between 55 and 4,700 yards. Also produced by the factory of Diòsgyor, these weapons were in service at the rate of four per battalion. Factories also produced the 120mm calibre 43M, a Hungarian version of the German GrW42, and Dimàveg also produced the 90mm calibre 17M, a version of the Czechoslovakian Lehky Minomet vz/17 produced by Skoda. Hungarian troops also used captured Red Army weapons such as the 42M 82mm calibre mortar.

Finland also joined the war against the Soviet Union, referring to their renewed fighting as the Continuation War; to some this was seen as an ideal opportunity to complete unfinished business from two years earlier. The Finnish Army deployed more than 300,000 troops with over 2,000 pieces of artillery and mortars. Although Finnish troops did fight in other areas of the Soviet Union as volunteers serving with the Nordost Battalion of the SS Wiking Division, the main effort was concentrated in the northern area of the Karelian Isthmus. Here they took up positions and maintained the blockade whilst the Germans occupied positions to the south to besiege the city of Leningrad in an operation which would last almost 890 days or twenty-nine months between September 1941 and January 1944. Volunteers from occupied countries such as France and Belgium came forward to fight in SS units known as the Charlemagne and Wallonien divisions respectively, and even some Dutch nationals volunteered to serve in the Nederland division, all of which had to be equipped with standard service weaponry. Germany’s European allies, Romania, Hungary and Finland, also had to be supplied with weapons, which placed a strain on support services to keep them equipped and production output was also under pressure.

Germany’s other European ally was the state of Bulgaria, which had also been allied to Germany in the First World War. The Bulgarian Army consigned itself to conducting anti-partisan campaigns in Greece and Yugoslavia and by mid-1944 comprised twenty-one infantry divisions and two cavalry divisions, along with other units such as two frontier brigades. It was an outdated force, despite its armoured brigade being equipped with over 120 tanks of French and German design, and lacking in modern anti-tank guns. It made extensive use of horses for transport of supplies, which actually turned out to be ideal for use in the mountainous regions in sweeps against partisans. Bulgaria joined the Tripartite Pact on 1 March 1941 but did not participate in the fighting in the Soviet Union. The army was equipped mainly with German weapons, including mortars of 8cm and 5cm calibre, along with a range of captured enemy weapons which were considered sufficient for the role in which the troops were engaged.

The Germans had been halted and forced back when some units were within 15 miles of Moscow. Weather conditions had played a significant part, with sub-zero temperatures preventing ammunition and fuel from being brought forward. The Red Army pressed forward and by February 1942, under the command of General Georgi Zhukov, had pushed the Germans back between 90 and 180 miles in some places. The Soviets kept up the pressure, hoping to surround the Germans as they consolidated at Kharkov. Sensing the threat, the Germans moved first and attacked. By 23 May they had surrounded their attackers and captured 200,000 men and killed a further 70,000. Hoping to seize the initiative again, Hitler ordered the 6th Army to change the axis of its advance and head south against the great industrial city of Stalingrad on the western bank of the Volga River. This was demanding too much of his armies, but despite warnings from his generals that their forces would be overstretched, Hitler insisted his orders be carried out.

The advance forces arrived at the outskirts of Stalingrad in August and more troops and weapons followed. At first it seemed like a relatively easy campaign. With the Germans receiving plenty of supplies and the Luftwaffe maintaining air superiority, the army was guaranteed support. But first appearances crumbled as Soviet resistance strengthened. As the fighting intensified, so the expenditure in ammunition increased dramatically. By the end of September, after the first full month of fighting, the 6th Army had fired 23 million rounds of small arms ammunition. In addition the artillery and tanks had fired 685,000 shells and the troops had thrown 178,000 hand grenades and fired 750,000 mortar bombs. It was a level of expenditure in ammunition that would increase as the battle spread to encompass the whole of a city which, by the end of December, lay in ruins. As another winter set in, the demand for ammunition and fuel became unsustainable, with German supply lines overburdened and overstretched.

The supply routes were broken completely when the Soviet Army encircled the city in a massive manoeuvre designed to isolate the Sixth Army from the rest of the German forces. There was nothing coming in by road or rail, and in an effort to support the army the Luftwaffe tried to fly in supplies. Despite promises of 600 tons of supplies per day, the air force could not meet even the most basic needs of the besieged army. Mortar bombs were lighter than artillery shells and these were transported in preference, but eventually the supply of this ammunition also failed. The Soviet Army on the other hand had no problems with resupply, though production had to be increased to meet demand. Manpower levels were not a problem to the Soviet Army either, whereas the German losses could not be made good. The end came on 30 January when the German commander, Field Marshal Friedrich von Paulus, surrendered. The battle had cost the Germans 300,000 men killed and wounded, with more than 100,000 taken prisoner. Germany’s allies had sustained 450,000 casualties. It was the turning point of the war in the east.

At the time of Stalingrad a Soviet infantry division had 9,500 men organized into the standard triple formation with regiments and battalions. The military planners reorganized this structure to distribute weapons to provide a division with an increase in artillery support and a company with six 120mm mortars, which gave each regiment more field guns and 160 mortars. Further changes were made in the structure which, by 1944, saw a Soviet tank corps equipped with a specialist mortar regiment within its organization equipped with twenty-four mortars of 120mm calibre, and each of the three battalions of the mechanized infantry brigade had six 82mm mortars. In April 1945, when the Red Army was fighting in the suburbs of Berlin, even cavalry divisions with a troop strength of 5,040 men, with 5,128 horses and 130 vehicles to tow antitank guns, would be equipped with eight heavy mortars and supplied with trucks to transport the division’s eighteen medium mortars and forty-eight light mortars, along with the ammunition required for the weapons.

By 1944, a German infantry division fighting on the Eastern Front had 12,352 troops still divided into three regiments, though manpower shortages had reduced the number of battalions down to only two for each of these. By now the light 5cm mortar had been taken out of service, but some units continued to use the weapon as long as they had supplies of ammunition. The situation with manpower levels for the German Army continued to worsen, and by 1945 an average infantry division had barely 7,000 men and was desperately short of weapons, ammunition and other essential supplies such as food, fuel and medical support. By comparison, the Soviet Army infantry division had 9,200 men with three infantry regiments, each with three infantry battalions. Part of the artillery support for the divisional firepower was provided by a specialist mortar company with six 120mm calibre heavy mortars. In contrast, a German panzer division had 13,725 men with an armoured regiment and a motorised regiment of panzer grenadiers, each divided into two battalions and each equipped with four 120mm and six 81mm calibre mortars. A Soviet tank corps had 10,500 men, with an integral regiment of mortars equipped with twenty-four weapons of 120mm calibre, and three battalions of infantry, each with 600 men and their own 81mm mortar units. On paper the German divisional strength was greater but in reality the manpower levels were very rarely operational. Whilst Soviet manpower levels were lower than the German equivalent, they had more divisions deployed overall to give greater troop concentrations. The problems the Germans faced were further compounded by lack of resupply with ammunition and replacement weapons. The Soviets’ logistical routes, on the other hand, were secure and supplies of ammunition, weapons and reinforcements could be moved without fear of being attacked.