A gunnery trials program for the ISU-152 SPG was approved #OTD in 1943. Even though it was similar to the SU-152, there were many improvements made to the casemate and fighting compartment, meaning that full trials were needed. #tanks #history #WW2 #WWII

Factory #174 transitioned to producing T-34-85 tanks with improved armour #OTD in 1944. This was the last of Soviet factories to move to building tanks with new turrets with armour up to 90 mm thick. #tanks #history #WW2 #WWII

The 1st Moscow Conference concluded #OTD in 1941. Here, British, American, and Soviet diplomats negotiated the conditions for British and American military aid to the USSR, including payment. The first tanks obtained through "cash and carry" were already on their way. #tanks #history #WWII #WW2

Driving trials of the IS-2 tank began #OTD in 1943. There was a fear that the new heavier main gun would significantly impact the tank's mobility and speed, but this fear proved unfounded. #tanks #history #WW2 #WWII

An order to test mine rollers and night vision equipment for T-34 tanks was given #OTD in 1942. Trials carried out by the 19th Tank Brigade showed that the mine rollers worked well, but the night vision devices had mixed reviews. #tanks #history #WW2 #WWII

#OTD in 1944 the Kubinka proving grounds established a testing program for the captured King Tiger tanks. The 1000 km long test drive turned out to be an optimistic estimate, as even with spare parts the tanks could drive less than 1/8 of that distance. #tanks #history #WW2 #WWII

The British 17-pounder gun was a powerful but unwieldy weapon. Efforts to mechanize it began #OTD in 1942, resulting in the 17-pdr Valentine SP more commonly known as the Archer. #tanks #history #WW2 #WWII

The last shipment of Valentine tanks arrived in the USSR #OTD in 1944. These were Valentine IX tanks armed with 57 mm guns. Tanks like these were used in reconnaissance regiments and as anti-tank screens in regiments armed with Sherman tanks. #tanks #history #WW2 #WWII

The second pilot Covenanter tank was delivered for trials #OTD in 1940. The compact cooling system turned out to be ineffective, causing a lot of problems during usage. There were attempts to correct this, but the Covenanter never became battleworthy. #tanks #history #WW2 #WWII

The trials program for penetration testing of the Ferdinand tank destroyer was completed #OTD in 1943. Tests showed that despite its thick armour, it could be defeated by existing guns including the 122 mm D-25 and 152 mm ML-20. #tanks #history #WW2 #WWII

Several sets of Maus hulls and turrets were constructed, but never used. #OTD in 1944 Hitler proposed using the turrets in fortifications. Blueprints were drawn up, but not a single turret was ever installed. #tanks #history #WW2 #WWII

Operation Typhoon began #OTD in 1941, marking the start of the Battle of Moscow. The plan called for massive pincers to grip the city from the north and south, but only a tiny German force even made it close to Moscow before the tide of war turned. #tanks #history #WW2 #WWII

#OTD in 1942 a proposal was made to use leftover T-60 tank hulls to build armoured sleds that a T-34 or a KV tank could tow into battle as a sort of pseudo-APC. Many experiments were performed, but no such vehicle was ever put into production. #tanks #history #WW2 #WWII

Swamp mobility trials of the Czechoslovakian LT vz. 35 tank were held #OTD in 1938. Thanks to a better suspension than the T-26, it moved much more confidently in difficult terrain. #tanks #history

The Valentine XI was the last type of Valentine tank, featuring a 75 mm gun instead of the 57 mm 6-pounder. #OTD in 1943 Elswick Works delivered their 100th and last Valentine XI tank. #tanks #history #WW2 #WWII

PQ-1, the first regular Arctic convoy, set out for the USSR #OTD in 1941. This tank brought a handful of Matilda III and Valentine II tanks that arrived just in time to take part in the finishing stages of the Battle of Moscow. #tanks #history #WW2 #WWII

Calculations made #OTD in 1943 showed that while the T-43 could be modernized to meet rising requirements, its weight would surpass 35 tons. A decision was made to drop the project and focus on a new tank, which later became the T-44. #tanks #history #WW2 #WWII

Tankograd was created not just by relocating existing factories, but by reallocating new ones to tank production. #OTD in 1942 the first T-34 tanks were completed at UZTM in Sverdlovsk, which previously built heavy construction machinery and tools. #tanks #history #WW2 #WWII

#OTD in 1943 factory #627 proposed a 50 ton heavy tank with an electric transmission. The proposal was declined, but a very similar tank was eventually built: the IS-6 (Object 253). This tank was only a prototype and was not accepted into service. #tanks #history #WW2 #WWII

Trials of a SU-31 SPAAG based on T-60 components began #OTD in 1942. The trials showed that the SPAAG had identical mobility to the light tank and that the parallel engine layout showed a lot of promise. This solution migrated to the SU-12 (SU-76). #tanks #history #WW2 #WWII

The first wartime contract for Char B1 tanks was signed #OTD in 1939. The army wanted 400 more heavy tanks but only 34 from this contract were finished before France surrendered. #tanks #history #WW2 #WWII

Ceremony held at the Birmingham Railway Carriage & Wagon Company #OTD in 1941 to commemorate the first shipment of Valentine tanks to the USSR. A small quantity of these tanks arrived in time to fight in the Battle of Moscow in November-December 1941. #tanks #history #WW2 #WWII

Information in the Red Army was shared horizontally as well as vertically. #OTD in 1944 the 1st Ukrainian Front shared data on the field trials of their King Tigers with the 2nd Ukrainian Front while official trials at Kubinka were only beginning. #tanks #history #WW2 #WWII

The first M4A2(76)W tanks were issued to Red Army units #OTD in 1944. These tanks only reached the front line in the winter and were used in battle starting in January of 1945. #tanks #history #WW2 #WWII

Delivery of tanks to the 33rd Tank Brigade #OTD in 1942. A mix of KV-1 and KV-1S tanks can be seen in this shipment. These would be some of the first KV-1S tanks to be issued. KV-1 tanks were issued alongside them until existing stocks were depleted. #tanks #history #WW2

#OTD in 1926 Harry Knox's light tank design was chosen as a potential replacement the for ageing M1917. It was a step forward, but the exceptional performance of Christie's tanks and looming Great Depression ensured that the project never saw mass production. #tanks #History

The Maus V1 hull (Typ 205/I) arrived in Spandau for assembly #OTD in 1943. The hull was fully equipped, but a turret was never installed. Only a dummy weight was used in trials. #tanks #history #WW2 #WWII

The T-10M tank was accepted into service #OTD in 1957. Its main distinguishing feature over the T-10B was the use of an improved 122 mm M-62 gun that replaced the D-25T, variants of which were used on Soviet heavy tanks since 1943. #tanks #history #ColdWar

Mikhail Koshkin, the leader of the design team at factory #183 that created the legendary T-34 tank, died #OTD in 1940 after contracting pneumonia during a trial of his tanks. #tanks #history #WW2

By 1944, Germany was in desperate need of a cheap and light armoured vehicle that could be produced in great numbers within Germany. #OTD in 1944 a variant of the Jagdpanzer 38 called Jagdpanzer 38D was chosen for this purpose. #tanks #history #WW2 #WWII

Two King Tiger tanks arrived at the Kubinka Proving Grounds #OTD in 1944. The journey took a month and a half since the captured tanks had to drive to the train station for shipping, but kept breaking down despite being almost brand new. #tanks #history #WW2 #WWII

#OTD in 1945 the SU-101 returned for a second round of trials. Despite many improvements, the limitations of the T-44 chassis made themselves known. Since the war was over, it was preferable to wait for a tank destroyer based on the T-54. #tanks #history

The Mozdok-Malgobek Operation concluded #OTD in 1942. The German offensive towards the Caucasus oil fields was successfully defeated, depriving the Nazis of fuel necessary for a prolonged war. #tanks #history #WW2 #WWII

A list of desired features for the next generation of T-34 tank was composed #OTD in 1940. These features were supposed to be put into production with the T-34M in 1941, but the invasion by Nazi Germany prevented this upgrade. #tanks #history #WW2 #WWII

#OTD in 1942 the Red Army began experiments to see how T-34 tanks could be protected from HEAT and APCR ammunition. The result of these experiments was the installation of 16 mm thick spaced armour on two brigades worth of T-34 tanks, but the idea as not developed further #tanks #History #WW2 #WWII

Convoy of STZ-built T-34 tanks, 1942. A mix of welded and cast turret tanks can be seen here. These tanks still lack the wartime simplifications that were characteristic of later T-34 tanks built in Stalingrad. #tanks #history #WW2 #WWII

Tanks and SPGs of the 2nd Ukrainian Front driving along Wiener Straße in Schwechat, a suburb of Vienna, spring 1945. #tanks #history #WW2 #WWII

Soviet mobility trials of the GMC M10 tank destroyer began #OTD in 1943. The vehicle's mobility was on par with the M4A2 tank that Soviet testers were already familiar with. Adding spurs to the rubber tracks made climbing slopes a lot easier. #tanks #history #WW2 #WWII

Work on 122 mm guns with muzzle velocities of 1000 m/s began #OTD in 1943. These guns were designed to fight future German superheavy tanks, although since those tank never showed up there wasn't much pressure to put the guns into mass production. #tanks #history #WW2 #WWII

Kirov factory developed a replacement for the ISU-152 on the new IS-3 chassis in 1945. The army took its time in giving permission to start trials, and even trials of the gun only began #OTD in 1945. By the time the vehicle was ready, the army lost interest. #tanks #history

A set of instructions on fighting Ferdinand tank destroyers was distributed #OTD in 1943. One of the biggest weaknesses of the vehicle was a large rear hatch which could be targeted with Molotov cocktails. #tanks #history #WW2 #WWII

Production of LTP tanks for Peru began #OTD in 1938. Threatened by German annexation, the Czechoslovakian army nearly bought these tanks themselves, but the Munich Agreement made armed resistance pointless and the tanks went to their intended owners. #tanks #history

Trials of the 122 mm D-25 gun ended #OTD in 1943. The gun passed trials, but the muzzle brake was deformed during firing. It was replaced with a design copied from the Ferdinand. #tanks #history #WW2 #WWII

Major deliveries of KV-85 tanks began #OTD in 1943. This was a stopgap vehicle, allowing a heavy tank with an 85 mm gun to go into production quickly and letting ChKZ master production of a new turret before switching to a new hull for the IS-1. #tanks #history #WW2 #WWII

Adna Chaffee was born #OTD in 1884. He fought to establish a tank force in the interbellum period and laid the foundation for the US armored forces. He died in 1941, but was immortalized in the nickname of the Light Tank M24. #tanks #history #ww2 #WWII

A detailed report on the Tiger tank was published in the Tactical & Technical Trends magazine #OTD in 1943. It was theorized that this tank had deep water fording capability for an amphibious landing in the UK, so it was drawn with a snorkel attachment. #tanks #history #WW2 #WWII

A decision was made to put the T-44 tank into production at factory #75 #OTD in 1944. This decision effectively meant that it would not see combat in WW2, as factory #75 lay in ruins and delivery of any T-44 tanks at all was a small miracle. #tanks #History #WW2 #WWII

Obsolete LT vz.34 tanks returned to action in 1944. A number of tanks were used by the Slovakian resistance during the Slovakian National Uprising. The Germans captured ten of these tanks #OTD in 1944, which were then used by the Tatra Tank Division. #tanks #history #WW2 #WWII

The DS-39 machine gun was accepted into service #OTD in 1939. It could have replaced both the bulky Maxim gun for infantry and DT machine gun for tanks, but sufficient production was not reached before the German invasion and so it replaced neither. #guns #history #WWII #WW2

#OTD in 1941 HTZ-16 ersatz tanks first saw battle not too far from the factory they were made in. For obvious reasons most were lost fairly quickly, but some survived at least until mid-1942. #tanks #history #ww2 #WWII