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Military


T-55 Gulmohar

The T-55 Tanks were procured from Russia, Poland and Czechoslovakia in various lots in 1966-67. According to the IISS Military Balance, only 450 T-55s were operational after 2000, and of the 715, modified with night vision equipment and improved fire control, and retained in active service by 2008, 67 were held in reserve. Soviet tanks were factory-overhauled every 7,000 km and often given minor technology updates. Many states have added or modified the tank’s equipment; India, for example, affixed fake fume extractors to its T-54s and T-55s so that its gunners wouldn’t confuse them with Pakistani Type 59s.

To extend the life of the tanks by another 15 to 20 years, it was decided to overhaul the tanks and the 512 Army Base Workshop was tasked to undertake the overhaul. Not in a position to discard these tanks and replace them with new versions due to acute resource crunch, the services overhauled the old ones and increased their life span. The tanks, ~550 in active service and another ~200 in store, were expected to remain in service till 2015 under an upgrade program for the T-55 MBT, called Project Gulmohar. However in 2001, the army decided to phase out the tank over a period of seven years and replace them with upgraded T-72M1 MBTs.

The infrastructure was augmented at the 512 Army Base Workshop, Khadki for the overhaul and the work was successfully undertaken over the years from December 1987. This is the oldest workshop of the Army dating back over 150 years and has completed 100 years after it was shifted to Khadki. Over 1200 machines had been overhauled from here.

The T-55s cost around Rs 4 crore and the overhauling cost comes to around Rs 10 lakh. The cost of overhauling a BMP-1 is around Rs 10 lakh. After overhauling, these tanks will last till the year 2015. The tank was totally stripped, the various assemblies sent to the respective departments for stripping, overhauling, assembling, testing and finally returned for refitment of the tank at the assembly stage. The hull, meanwhile, is repaired and painted before it is sent to the assembly stage.

The 512 Army Base Workshop, Khadki - the country's biggest, oldest, modern workshops and probably the only facility of its kind in Asia responsible for overhauling tanks T-55 and infantry combat vehicles BMP-I, expected in June 1998 to touch the magic figure of refurbishing the 1000th vehicle by the end of the financial year. "We have already exceeded the target of overhauling 800 T-55 tanks having completed 900 tanks from the year 1984 when Project Gulmohar was launched at a cost of around of Rs 232 crore. This would have otherwise cost around Rs 1800 crore,'' Brig R Gossain, commandant and managing director of the workshop told mediapersons. The workshop had bagged the prestigious ISO 9002 award for the overhaul and testing of engines of T-55 Armoured Fighting Vehicles.

The Project Gulmohar upgrade program for the T-55 MBT was almost complete as of late 1999. Some reports claimed that most of India's T-55s had not been upgraded, and that over 90 percent of India's T-54/T-55 inventory is considered non-operational. In October 1999 it was reported by Indian Express that the 512 Army Base Workshop would soon complete overhauling of the Russian made T-55 tanks. The target to complete the 1000th overhaul was to be achieved soon and signal the end of the `Project Gulmohar'. The focus wwould then shift on the overhaul of the BMP-1 infantry combat vehicle.

The 512 Army Base Workshop, the only armoured overhaul workshop in the country, had been engaged in the overhaul of T-55 tanks. The workshop — 100-year-old in Khadki — has completed the overhaul of all the T-55 tanks, the last of which was pulled out on 02 February 2008. “Project Gulmohar has reached fructification as the workshop has completed the overhaul of its last T-55,” said Commandant Brig N K Dutta. “Project Gulmohar was started in 1987 with technical help from Poland. It was inaugurated by the then defence minister K C Pant,” said Dutta.

T-55 Tank, excluding its armaments, being the best fighting vehicle of its class and OQF 105/531A (105mm Tank Gun L7) having indisputable excellent fire power, upgunning of T-55 Tank with 105mm armament, makes the best combination of vehicle and gun. For the Armoured Corps, DRDO's ARDE made a significant contribution by the successful development of Up-Gunning kit for the T-55 MBT. The original 100 mm gun of this tank was retrofitted with 105 mm of the Vijayanta which greatly enhanced the fire power of the tank. Standardization of the gun and ammunition for both the tanks has brought about a major reduction in the logistic burden. With the combination of a rugged chassis and turret with a high performance gun and ammunition system, the upgunned T-55 compared well with the T-72s and Vijayantas.

Even after the advent of the highly sophisticated anti-tank guided missiles that can defeat main battle tanks (MBTs), it is now generally accepted that the most cost effective weapon to fight and defeat heavily armoured MBTs is the high-velocity K.E. Ammn fired from gun mounted on tanks. This is accomplished in the current generation tank guns by firing Fin Stabilized Armour Piercing Discarding Sabot (FSAPDS) ammunition. In principle, it depends upon the high kinetic energy, super-dense, arrow-shaped, penetrator launched at hypersonic velocities to defeat the multilayer armour with which the modern MBTs are protected. The deceptively simple looking design, however involves some of the most demanding design and production technologies. ARDE has successfully developed the 105 mm Fin Stabilised Armour Piercing Discarding Sabot (FSAPDS) ammunition for the Vijayanta and Up-Gunned T-55 MBTs. ARDE can justifiably feel proud that with successful productionisation of this advanced ammunition, India has joined the ranks of a few select nations who have the capability of the design, development and production of FSAPDS ammunition and has effected a major saving in the foreign exchange by eliminating the import of technology.

T-55 UpgradationIndia retained several hundred T-55 tanks with infantry divisions. Since the T55 were still in useful condition they had been given to the infantry divisions to boost their firepower because the 100mm gun on the T 55 packs quite a punch. And India invested a lot of money on T55 upgradation. The T-55 Upgradation utilizes the Arjun MBT's 120mm rifled gun firing unitary APFSDS and HESH semi combustible cartridge case ammunition. The Arjun's armament system is the most powerful one available to Indian developers today. The Tank retains the Arjun's third generation director type integrated FCS (Fire Control System) including a sophisticated digital ballistic computer.

It may be noted that the Arjun FCS is an updated one(with digital components replacing the original analogue ones) as compared to the original, which faced numerous technical problems. Firepower trials validated the efficacy of the updated Arjun FCS and led to its acceptance by the Army. Capable of firing on the move, the Tank Ex also is fully "night ready" with the gunner having a thermal imager integrated with his main sight. A standby articulated sight is provided as backup for the main sight. The tank commander (as in the Arjun MBT) has his own fully stabilized sight with relevant controls for surveillance, target acquisition and engagement, giving excellent hunter-killer ability. The tank also incorporates an Auxiliary Power Unit (APU) to operate the weapons systems in silent watch mode.

The usage of the Arjun turret design indicates that the Tank may also have its "ready" ammunition stored in the bustle (as in the Arjun),separated from the crew and provided with blow off panels. This would be a significant protective feature in line with "western" design practices. Kanchan is an extensively tested and successful armor, which is available for retrofit to other IFV programs. The Tank also had fully integrated Nuclear Biological and Chemical (NBC) protection.

This upgrade did not proceed into metal.

  Original T-55 Upgunned T-55
Gun 100 mm D 10TG or 105/531A modified OQF
100 mm D 10T2C barrel, fitted into modified T-55 breech mechanism.
Length of barrel 5350 mm 5347 mm
Weight of barrel 937 kg 753 kg
Rate of fire 5 to 6 round/min 7 to 8 rounds/min.
  AP HEAT APDS HESH
Muzzle velocity 895 m/s 900m/s 1470m/s 732 m/s
Max range 4000 m - 3500 m 8000 m
Armor penetration at 1000 m 130 mm 300 mm 350mm 350 mm
Accuracy 90% Probability Zones
1000 m ±1.2x1.2 ±1.6x1.6 0.6x0.6 0.7 x 0.6
2000 m ±2.4x2.4 ±3.7x3.7 1.2x1.2 2.1 x 2.0



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