March 30, 2024: The war in Ukraine began with a Russian attack that included several thousand of the best tanks Russia had. Most of these tanks were quickly destroyed by innovative Ukrainian weapons and tactics. Russia could not build new tanks quickly enough to replace the losses, and after the first year of the war, depended on older tanks from the 1960s or earlier. Russia had about 10,000 of these tanks located in reserve storage sites throughout the country. All of these sites were near a rail line because that’s how Russia moves tanks long distances. Some tanks stored near the Pacific coast were shipped by rail to Ukraine. Before the Soviet Union collapsed in 1991, it was customary to store older tanks rather than recycle them as was done in the United States and Europe.

Russia had a problem because production of new tanks was only a few hundred a year, and once the tanks in reserve were gone, Russia had no more tanks. This caused Russia to be much more conservative and less aggressive in how it used their remaining tanks

Both sides in the Ukraine War have employed 1950s-era T-55 tanks. Russia brought in several hundred T-55s from stockpiles of older T-55 and T-62 tanks that are maintained by Russia because this is what they have always done and having some available for use in Ukraine proved useful.

The T-54 was the first modern Russian tank and entered service in 1947 as the T-44. This was a major upgrade of the World War II era T-34/85. The original T-34 that the Germans encountered in 1941 had a 76mm gun. This was later replaced with a more powerful 85mm weapon.

The T-34 was an unpleasant surprise for the Germans in 1941. It had excellent speed, good armor and was soon upgraded with an 85mm gun. Similarly, there was an upgrade, which included protection from nuclear radiation, to the T-54. The T-55 entered service in 1959. About 100,000 T-54/55 tanks were produced between 1967 and 1979. Thousands, mainly late model T-55s, were still stored in active storage, where tanks were kept ready to use.

In Ukraine the T-55s were used by both sides to support infantry attacks or as defensive pillboxes. This was accomplished by driving the T-55 into an open bunker so that only the turret was visible. These were excellent defensive weapons when facing an attack by enemy armored vehicles, which were fully visible while all the attackers could see was the T-55 turret. The bunkered T-55s were still vulnerable to artillery fire and top-attack anti-tank missiles.

In Ukraine there was a third use for T-55s, but only by the Russians who turned some T-55s into mobile bombs that were sent to enemy positions where they created an enormous explosion. This was because the crew was removed so the interior of the tank could be filled with about five tons of explosives plus a remotely controlled detonator. The driver controls were converted to be operated remotely. These bomb tanks were carried by tank transporters to the front lines and unloaded for use against enemy positions. Several of these bomb tanks were used, with spectacular effect. When the Ukrainians had suitable anti-tank weapons, they were able to hit and destroy or disable the T-55 bomb tank before it was close enough to detonate and cause the Ukrainian casualties.

The Ukrainians also had some of these old T-55s in service. In 2023 NATO member Slovenia sent Ukraine 28 M55S tanks, which appeared quite modern, and they were. The M55S is a heavily modified T-55 tank. In 1999 Slovenia completed the conversion of 30 T-55 tanks into the much superior M55S. The original 100mm cannon has been replaced with a western 105mm rifled gun. A new Israeli fire control system and explosive-reactive armor were added. The suspension was upgraded, and new tracks installed. A modern 600MP diesel engine replaced the original Soviet 580HP diesel. The M55S is similar to the Israeli T55 upgrade that produced the T-67. The original T55 weighed 36 tons and the M55S upgrade created a 38-ton tank.

Ukraine found the M55S useful because it was a modern tank, although not as heavy or well-armed as current Russian T-72B3 or Western M1a1 and Leopard 2 tanks. The M55S did not have an autoloader and was not as vulnerable to destruction as were Russian tanks introduced since the late 1960s. Without the autoloader, the T-55 had a four-man crew, which made the tank easier to maintain and keep operational. The auto-loader vulnerability was not realized until the Ukraine War because Russian tanks had never faced so many top-attack ATGMs (Anti-tank guided missiles) or so many modern tanks with 120 or 125 mm guns. The Russians only realized this when over half the modern, autoloader Russian tanks used during the first few months of the Ukraine War were destroyed or abandoned because of top-attack missiles. These missiles detonated over the turret and that caused the dozen or more shells in the autoloader magazine to explode. This destroyed the turret, often in a spectacular fashion. It turned out that autoloader tanks were eight times more likely to be destroyed in combat than a modern Western tank. This also demonstrated that the M55S was nearly as effective in combat as comparable 1960s era third-generation Western tanks like the German Leopard 1, American M-60, or British Chieftain 1. All of these tanks weighed 50 tons or more and were armed with a 120mm gun. These tanks were faster and more mobile because of much more powerful engines.