Light Tanks – New saviour of the Indian armoured core
-Subodh Sharma and Alan Jai Kuriako
Amid the on-going border stand-off with China, the army has been more vocal in the possible acquisition of a light tank for Himalayan warfare. The decision received mixed reactions within the defense think-tanks in India. The concept of a main battle tank is a formidable and lethal machine with an absolute balance between;
The concept of light tank is inherently flawed as a compromise must be made in at least one of these three factors governing the performance of the tank. The moment the tank is made lighter it adds another bottle neck, which further complicates the equation. Each of these factors; protection, firepower and mobility can be increased at the cost of the increased weight or vice versa. The inevitable consequences of keeping a tank light is compromise but a lighter tank can be deployed quickly.
Saga of DRDO light tank:
As the need for light tank was sought by the Indian army, many on social media were quick to remind us of the light tank that DRDO developed but eventually ended up receiving a cold shoulder from the Indian army. It was the year 1976 when the Indian army released a GRQR for a light tank, which was approved in 1983. The tanks were to be designed, developed and tested within a span of 3 years. DRDO was not able to achieve such an aggressive timeline despite the platforms being already available. The tank was envisaged on BMP 1 chassis with a Nexter 90mm gun.
The Indian army, which pursued the need with a 1976 GSQR, whispered in July 1985 that a light tank based on the BMP chassis was not needed (the platform was old). However, they did not withdraw their association from the project and even made suggestions that led in 1988 to 105mm turrets being implemented rather than the planned 90mm turrets. In year the 1994, the scientific advisor to Raksha Mantri advised the closure of the project as the project was no longer viable.
Russian tank destroyer – 2S25 Sprut-SD
As the need for the light tank is currently urgent, the obvious option was the 2S25 Sprut-SD from India’s premier weapon supplier (the Russian Federation). The 2S25 Sprut SD is an 18 tonne machine with a 125 mm 2A75 smoothbore gun. The mobility and firepower of this tank is comparable to any modern tank; however, the protection is almost nonexistent (similar to a BMP2/3). Its 2V-06-2S water cooled diesel engine with a power rating of 510 hp helps the tank to cruise through any terrain at a top speed of 71km/hr. The hydropneumatics suspension provides it with excellent stability.
The downside however is the protection of this tank. The hull of the 2S25 is composed of welded aluminium armour with a composite skin to maintain the light weight profile. Through the frontal arc, 40° left and right of the frontal armour provides protection against attack from 23 mm weapons at 500 metres but anything beyond that can pierce it like a hot knife through butter.
Two banks of three smoke-grenade dischargers are mounted towards the rear on each side of the turret as countermeasures to infrared weapons. The tank does not have any active protection system. Other than its ability to be quickly deployed via air drop mechanism, this tank also offers commonality because of its 125mm smoothbore gun. The mainstay of Indian army armor division is T90 and T72 which are also equipped with 125mm smoothbore.
It appears that the immediate short-term requirements for light weight tanks will be filled by 45 units of these tanks. This will also provide the breathing space to DRDO and other private sector companies to design and develop their own tank.
L&T – DRDO Light Tank
In September 2015, Larsen and Toubro emerged as the finalist for a US$800 million contract to supply 100 self-propelled howitzers to the Indian Army. The K9 VAJRA-T, a variant of the K9 Thunder specially designed for operation in the desert areas. By December 2020, L&T will deliver all 100 guns and the production facility will be available for further orders. Once such idea is to leverage the chassis of K9 vajra and build a light tank on that design. As per the reports, a John Cockerill modular turret of 105mm caliber will be mounted on top of this chassis to realize a light tank.
The K9 Thunder can protect its internal crew & on-board equipment against threats such as 155mm shell fragments, 14.5mm armor piercing shells, anti-personnel mines. In case of NBC warfare, mission sustainability is guaranteed by its air purification system and on-board crew gas mask. The protection is not enough to qualify the chassis as a tank hull though, but it certainly offers better protection as compared to the 2S25 Spurt SD.
An additional add on composite armour and ERA panels can enhance the protection which can be further complimented by an active protection system.
The K9 thunder is a 47 tonnes gun and if the chassis of this gun is used to envisage a light tank then tank will be approximately 35 tonnes machine. The add on armour will further increase the weight, thus it is important to consider our priorities so that we do not walk into weight issues similar to the Arjun tank.
Benchmarking Type 15?
The Norinco Type 15 third generation light tank is also known as the ZTQ-15. It is a Chinese third generation light tank operated by the People’s Liberation Army Ground Force. The tank is 33 tonnes without add on armour and 36 tonnes with an armour package. This cannot be India’s benchmark for a light tank as the two countries have different support structures to compliment such a fleet of light tanks. The idea of light tank is rapid deployment and air ferry is synonym of such a deployment.
India operates two strategic air lifters that can be used to ferry these tanks.
- IL 76
- C17 Globemaster III
China on other hand operates
- IL 76
- Xi’an Y-20
While the C17 production line is closed, Xi’an Y-20 has just started the production and it is a Chinese indigenous effort which will make it’s a better option of Chinese to create an integrated infrastructure.
Another option as a replacement to the light tank is a wheeled tank destroyer platform. These are wheeled APCs with a tank turret for heavier fire support. The merits to this idea is that DRDO-Tata already has the wheeled APC (Kestrel/WhAP) platform which has already been tested in the Himalayas. A modular turret can be added on the platform to form a tank destroyer platform that can be used against the Chinese threat.
However, wheeled platforms have an inherent disadvantage. Tracked platforms exhibit a larger surface area onto the ground than wheeled platforms and so tracked platforms can traverse on more difficult ground as compared to wheeled platforms. Therefore, it might be harder to navigate in more diverse Himalayan terrain (it has only been so far tested on relatively level ground).
If the Indian Army chooses this platform (disregarding the terrain limitation issues), it is finally possible for us to kick start the induction of the wheeled APC system into the Indian army (together with the requirement for 200 more APCs with smaller turrets).
Another option for the light tank is something that we are already inducting into the armed forces; the Namica ATGM carrier. This is based of the BMP-2 platform and it contains 8 Nag missiles with 4 more in a ready-to-load format. This can be used against Chinese light tanks as an alternative to a light tank. DRDO has recently unveiled an unmanned NAMICA carrier as well which could launch attacks against Chinese forces without risking the lives of any Indian soldiers.
However, the disadvantage is that there is no sustained fire available. Once the full load (8 units) of missiles in the container is launched, the fire team has to reload the missiles manually which takes up time. The max missile launch possibility is about 12 missiles. After this, the carrier is completely vulnerable to any counter attack. The Chinese also seem to have worked around the issue of very limited armour protection by incorporating an Active Protection System (APS) that launches a defensive projectile against incoming threats. Therefore there is a slight chance of this premise not working out.
The light tank cannot be seen in solo entity, it needs to be part of an integrated war fighting machinery and thus it should be compatible with other components of the integrated command. Although it was acceptable for tanks that could perform in various environments in the past, modern warfare now dictates the need for specialized armour platforms specifically for desert, plain/urban and mountain warfare.