The catastrophic situation faced by the Red Army in the summer and autumn of 1941 gave urgency to this project.
The T-60 had a welded hull. This hull was more rigid, with a low silhouette and well-sloped armor made of rolled homogeneous armor plates. Small dimensions allowed an increase of the front armor thickness to 15-20 mm initially, and later up to 20-35 mm. The side armor was increased to 15 mm (later to 25 mm), and the rear armor was increased up to 13 mm (later to 25 mm). The driver's hatch thickness was 10 mm (later 13 mm). An emergency hatch was placed at the bottom of the tank. The overall capacity of the two internal fuel tanks was 320 litres.
Was designed the new eight-sided conical turret. Protection was provided by 25 mm armor plates welded together. The thickness of the gun mantlet was increased to 35 mm. It is important to note that the KPZ factory manufactured tanks with rounded conical turrets like on the T-40.
On the second T-60 prototype, the DShK machine-gun was replaced with a 20 mm 'ShVAK-tankovaya' gun. This gun was based on the ShAK-20 aircraft gun. Testing of the new gun was conducted at the same time as the first trials of the T-60. This gun was therefore only officially accepted for service on December 1, 1941.
Ammunition consisted of fragmentation tracer rounds, fragmentation incendiary rounds, and armor-piercing rounds with carbide-tungsten cores. Later, sub-calibre armor-piercing incendiary rounds became available, so the armor penetration increased to 35 mm on 60° sloped armor from 500 metres. This allowed the T-60 to successfully combat early German Pz-III's and Pz-IV's as well as German APCs and other lightly-armored targets.
The T-60 was also armed with a coaxial 7.62 mm DT tank machine-gun. The mounting of this machine-gun allowed its use as a light machine-gun outside the tank. It could be quickly dismounted, and was equipped with a shoulder butt and spade grips. Situations where this occurred were quite common. If needed, the TNSh could also be quickly dismounted as its weight was only 68 kg. The closest German counterpart for the T-60 was the Pz-II and "Lynx". The T-60 was slightly better-protected, and had a longer range and better mobility on rough terrain, while its German counterparts enjoyed better reliability and were radio-equipped.
The first T-60s had spiked road wheels, sometimes without rubber tyres. Later, all rubber tyres were removed because of the scarcity of rubber. Road wheels and idlers were made to become interchangeable. The first production tanks did not have radios. Internal communication was performed either by TPU-2 or by signal lamps.
After up-armoring, the weight of the T-60 increased from 5800 to 6400 kg, but due to use of the same engine, the specific power decreased and speed suffered as a result. To increase mobility on swampy and snowy terrain, special removable track extensions for increasing the track width were developed which could be fitted over the standard tracks. The large-scale production of these track extensions was set up from 1942. Compared to other Soviet tanks, the T-60 had the best mobility on snowy and swampy terrain, on water-logged meadows, and in muddy conditions.
In 1942, in spite of the successful development of the T-70, the production of the T-60 continued concurrently up to August 1942. In 1942, the total output of the T-60 was 4164 tanks. In February 1943, the last batch of 55 tanks was sent to the front, after which the T-60 was removed from production.
Large numbers of this tank fought in the Battle for Moscow (1941-42). Those tanks fought in almost tank brigade and battalion strength. On November 7, 1941, 48 T-60's took part in the Red Square military parade. Just after the parade, the tanks were sent to front. The role of the T-60 in the Battle for Moscow was very important because the overall Soviet tank production of that time was extremely low as most Soviet industry was being evacuated.
By the beginning of spring of 1942, 60 T-60 tanks were sent to the Leningrad Front to form the 61st Tank Brigade. It is interesting to note that since Leningrad was encircled by the Germans, it was important to hide delivery of those tanks, and therefore tanks were put on coal barges and well-camouflaged with coal.
Those barges often delivered coal to Leningrad, and the Germans didn't pay them proper attention and allowed them to pass unharmed, and all the tanks were delivered successfully in this manner.
On January 12, 1943 (the first day of the Soviet offensive which broke the Leningrad encirclement), the 61st Tank Brigade together with the 86th and 118th Tank Battalions were engaged in battles as elements of the 67th Army. Tank units of medium and heavy tanks crossed over the ice of the Neva river a day later, after Soviet infantry supported by light tanks and sappers had strengthened the ice for safe tank crossings.
Tanks of the 61st Tank Brigade successfully met with units of Volkhovsky Front, and after that operation, the 61st Brigade received the "Guards" status and renamed the 30th Guards Tank Brigade.
There were several successful attempts to increase the frontal armor of the T-60. Additional 10 mm armor plates were placed on the glacis of the hull and around the turret.
T-60's were used on the Southern Front, especially in the spring of 1942 in the Crimea. These tanks were used in the Kharkov operation as well as during the Stalingrad operation. The Germans called the T-60 the "ineradicable locust."
T-60 tanks were the core of the 1st Tank Corps (commander - Major-General M. E. Katukov). In the summer of 1942, this corps, as an element of the Bryansk Front, was engaged in defensive battles near Voronezh. The 1st Tank Corps and the 16th Tank Corps were combined as a single unit.
In September 1942, during the rugged defense at Stalingrad, the 91st Tank Brigade was engaged in action having T-60 tanks in its service. Many of those little "baby" tanks had impressive nicknames like "Grozniy" (Terrible), "Orel" (Eagle), "Smelij" (Brave), etc.
The Stalingrad battle and the run on the Leningrad blockade became the apogee for T-60 light tank. From the end of 1942, the usage of these tanks decreased. They served well and completed their tasks but they couldn't withstand modern German tanks and the increasing demands placed upon them. The use and production of the T-60 was on the decline.
Soviet tankers didn't love the T-60 because of its weak armament and too light armor. Tankers called them BM-2 which meant "Bratskaya Mogila na dvoikh" (a brother's grave for two).
Breaking the encirclement around Leningrad (January 1944) was the last large operation where the T-60s took part. For example, among the 88 tanks of the 1st Tank Brigade there were 21 T-60's, and 18 T-60's were in the 220th Tank Brigade. At the same time, the 124th Tank Regiment (attached to the Volkhov Front) possessed only ten tanks: a pair of T-34's, a pair of T-70's, five T-60's and one T-40 (still alive! unlikely, but true!).
After that operation, T-60's were used only as convoy vehicles, in signal units, for reconnaissance, and as artillery tractors for ZIS-2 antitank and ZIS-3 field guns. They were also used as commanders' tanks. In that capacity, T-60's were used until the end of the war.
Besides the Red Army, three T-60's served in the Voisko Polskoe (Polish Army) in 1945. Many T-60's were captured by the Germans and Finns. The Germans usually used them as armored tractors, and occasionally they removed their turrets. Some of those tanks were given to Rumania. The Rumanians used them to build a batch of quite successful self-propelled guns "Takam," armed with the ex-Soviet 76.2 mm F-22 installed in a non-rotating compartment open at the top and rear.
The hull and the chassis of T-60 satisfied the Rumanians and were left almost unchanged. Moreover, some sources indicate the Rumanians built two other self-propelled guns armed with a 105 mm howitzer.
After the war, all surviving T-60's were quickly removed from service.