Howitzer gun development

A paupered Artillery Regiment of the Indian Army is now suddenly inundated by a surfeit of weapons systems be they of the original Bofors howitzer vintage reconstructed from drawings that had been gathering dust for nearly three decades or the Indo-South African hybrid that had been languishing because of corruption charges or the Armament Research and Development Establishment product the advanced towed artillery gun system.

The icing on the cake is that all of them are of common calibre-155 mm-making for commonality of ammunition and have modern surveillance and target acquisition systems that have longer ranges and are in keeping with the times. This means that the hitherto standard 105 mm artillery systems (Indian field gun, Abbot mobile howitzer, the 122mm Russian anti-tank weapon, and the 130mm self-propelled Catapult on a Vijayanta tank chassis etc) will be discarded for the more powerful 155mm artillery systems.

It is necessary to go back to the beginning. In the 1980s India felt the need for improved artillery and opted for the Swedish Bofors 155mm howitzer (high trajectory weapon capable of firing over mountain crests). However, allegations of kickbacks to political personalities stalled the project after the first batch of 410 towed guns were delivered. India scrapped the deal and the drawings for the indigenous product were lying in a drawer in an ordnance factory because of the lack of political will to complete the controversial deal. For decades thereafter no artillery was acquired from any source for many years.

Reviving project

In 2012 the government decided to resurrect the Bofors project and the drawings were retrieved. The Ordnance Factories Board began work on an improved version of a 155mm howitzer based on the original Bofors design. It produced the Dhanush. While being based on the original Bofors specifications of 155mm and 45 calibres in length of barrel (that means that while the gun would take a shell that has a base measurement of 155mm, the length of the barrel through which the warhead has to travel is 45 times this figure. This dictates range and accuracy).

Having learned from the experience of using the Bofors gun during the Kargil conflict of 1999 the Ordnance Factories Board produced the Dhanush the capabilities of which have been upgraded by as much as 25 percent over the original Bofors weapon. The Dhanush is better in parameters like range, accuracy, consistency, low and high angle of fire and shoot-and-scoot ability, according to Ordnance Factory Board.

The Dhanush is a towed version which means that it needs a huge truck to drag it around hairpin bends in the Himalayas. The Bofors weapon was taken to Sikkim because the roads allowed it. India needs to improve its road network with mountain roads wide enough with enough clearance at the top to enable it to be taken as close to the likely frontlines to help break up any concentrations of Chinese troops at the forming up area.

The Army which had promised to buy 140 of the indigenous guns once tested placed orders for only 114. For an institution that cried itself hoarse that it was being neglected in its firepower department this was strange. Perhaps it is waiting for the Mark 2 version of the Dhanush which will have a howitzer with a longer barrel (52 calibre to the earlier 45 calibres). This will give it greater range (beyond the current 38 kms) and greater accuracy.  Production began in 2015 and the first of the ‘Indian’ howitzers will be in service this year.

The NDA government’s decision to unblock the blacklisted foreign firms under the cloud of corruption has made it possible to resume the hybrid program of creating a mobile howitzer. The project envisaged the installation of the South African company Denel’s 155 mm howitzer gun turret on an Arjun tank chassis. The combo was tested and approved nearly a dozen years ago but was kept on hold because of the corruption controversy.

The weapon which carries its ammunition on a rack inside the turret fires three rounds in nine seconds in burst-fire mode and eight rounds per minute in sustained bombardment. Of the 400 to be produced half will be on a tracked carrier and half on the Tatra truck. This combination makes for both cross-country and road mobility.

The latter can help boost the inventory wherever dirt tracks exist in the Himalayas.  Named the Bhim, this self-propelled howitzer can fire on a 360 degree plane and deliver a warhead as far away as 52 kms. Army and Border Roads Organisation  engineers will have to ensure bridges in the Himalayas are capable of taking the 52 plus ton weight of the weapon if it is to play an important role in disrupting Chinese concentrations.

The third new 155 mm howitzer is the Advanced Towed Artillery Gun System (ATAGS) being created through a collaborative effort between DRDOs Armament Research and Development Establishment and the private sector Larsen and Toubro and Bharat Forge. It is based on the Bofors design but its innovations are very significant. The first of these is that the total weight of the weapon system has been reduced by two tons which has its resonance on the bridges in the Himalayas. It incorporates the longer barrel of 52 calibre as required by the Indian Army. Reports suggest that the development work will be completed in three years and the testing and calibrations will take another three years. The weapon will be ready for production by 2019.


Just as important as the weapons platform is the munitions that it will deliver. Here the Ordnance Factories Board will have to redeem itself. For many years India has had to buy from foreign sources ammunition for its 155mm howitzers. Now that full scale production is on the horizon, it is time that the OFB also develops a capacity to manufacture within the country the ammunition required to keep the weapon functional.

Many nations have improved the overall range, accuracy and lethality of the 155mm warhead by introducing a base-bleed system in which an internal explosive ignites as soon as the weapon is fired and this “bleeds” an exhaust of hot gases that add to the propulsive power of the original detonation in the barrel and thus adds up to five kms to the range. Another innovation is the rocket assisted propulsion. As the name suggests the inbuilt rocket motor within the shell has a greater thrust than base-bleed. It adds to the range by as much at ten kilometres.

In the arena of accuracy, munitions are now being guided by the global positioning system (GPS). An antenna in the nose-cone (in company with a proximity fuze to disperse the pre-fabricated fragmentation warhead) will mean that an accurately delivered warhead will explode closer to the target than would an un-assisted one. Hence greater accuracy. This technology can be incorporated to all kinds of projectiles including barrel-launched rockets thereby turning an “area weapon” into a precision-guided munition.  In fact this should be the first priority of the Ordnance Factories Board.

Now that India is about to complete its own satellite navigation network (IRNSS) this represents an opportunity to create a “one shot hit” weapon. It would have a salutary cascading effect on whole logistics chain.