Indian artillery acquired 410 guns of 39-calibre 155mm FH-77B howitzers way back in 1987. Since then there was no acquisitions as this deal got mired in corruption and was known as the Bofors scandal. Lack of prolonged acquisitions led to alarming voids in fire power. Finally the stake holders woke up and formulated a fresh blue print of artillery modernisation in 2000 called Field Artillery Rationalization Plan (FARP). FARP was rather ambitious which involved the acquisition of about 3,000 guns of various types to suit every role and terrain in which the Artillery would be employed. FARP also selected 155mm/52 calibre or 45 calibre for majority of the gun systems. Such an approach would accrue great dividends in terms of increased range and intensity of the fire power. The planned period for 3,000 guns was up to 2025. This was indeed a tall order both in terms of technology and budgetary constraints. Until now Ordnance Factory Board (OFB) and its 41 factories were the sole provider of weaponry, ammunition and other military hardware but it was now planned to involve the private industry to broaden the defence industrial base of India and also accelerate the rate of production. It was also hoped that India would be able to take the first baby steps towards export.

Indian Ordnance Factories

The Gun Carriage Factory (GCF) at Jabalpur had been making guns since 1904 which included 105 Indian Field Gun (IFG) and the 40mmL/70 Bofors Air Defence Gun on transfer of technology but these production lines were closed due to lack of demand. The 105mm IFG was designed by the Armament Research and Development Establishment in 1972 and handed over to GCF for its production jointly with a Gun Development team from Artillery headed by Brigadier Gurdayal Singh, an eminent gunner of Second World War vintage. Brigadier Gudayal Singh was a legend within the Gunners who could not read a blue print but could guide the production process at GCF due to his intimate knowledge of guns. The IFG was in service with the Indian Artillery for many decades. The other factory involved in gun/tank manufacture is the Ordnance Factory Kanpur which manufactures ordnances, spare barrels and other spares for all Artillery and Tank guns. It also manufactures ammunition which includes large to medium calibre shells, bombs and stabilisers for Pinaka Rockets. Interestingly the factory was conceived in the year 1942 as Transplantation Project in the wake of impending threat of axis powers emerging from eastern front during World War II. At present OFB has a strong base for the manufacture of higher calibre ordnance and has the only barrel manufacturing capability in India. With such a strong technical base, OFB can greatly leverage joint ventures with private companies who will bring in corporate culture.

Dhanush

While exploring for the solution to modernise Artillery, it was discovered that Bofors of Sweden who supplied 410 guns of 39-calibre 155mm FH-77B howitzers had also provided transfer of technology for the manufacture of FH-77B in India but this fact was lost in the offices of Ministry of Defence.

Development and Trials

It was a challenge to develop the gun from voluminous blue prints and documents running over 12,000 pages which were delivered to India under the first phase of transfer of technology around 1987 but OFB took the challenge head on by developing a gun which was about 20-25 per cent better than the original gun in parameters like range, accuracy, consistency, low and high angle of fire and shoot-and-scoot ability. High angle fire is especially useful in high altitude like Siachen for crest clearance to reach targets located behind a high mountain range. Shoot and scoot is very much required to fire and change (scoot) the gun position quickly to avoid counter battery fire. It was more challenging due to high weight of the gun. It is also very complex to design a weapon system for the Indian environment as it is required to operate from the icy Siachen to the blazing desert of Rajasthan and the plains of Punjab.

It is very complex to design a weapon system for the Indian environment as it is required to operate from the icy Siachen to the blazing desert of Rajasthan and the plains of Punjab

Three Dhanush guns were handed over to the Army for user trials during July 2016. It was hoped that after the successful trials, Dhanush will enter service in phases-with 18 guns in 2017; 36 guns in 2018 and 60 guns in 2019, making a total of 114 guns. But a hurdle turned up in the form of the shell hitting the muzzle brake while exiting the barrel. Muzzle brake is a device connected to the muzzle or barrel of a gun that redirects a part of propellant gases to counter recoil and unwanted muzzle rise. Possible solution was to redesign the muzzle brake but later on it turned out that the culprit was the faulty ammunition. The final trials of Dhanush were completed by June 2018 and in February 2019 it was cleared for series production with its induction formally starting on April 8, 2019.

Indigenisation

The Defence Ministry said in a statement that, “Indigenisation to the extent of about 81 per cent has already been achieved. By the end of 2019, the indigenisation level of the gun will go up to 91 per cent,”

Handing over of first batch of Dhanush Guns

“The OFB has handed over six Dhanush guns to the Army in the first phase. Dhanush is the first indigenously built 155mm x 45 calibre long-range artillery gun with strike range of 38 kilometres,” said the then OFB Chairman Saurabh Kumar, adding that the weapon was a major success story of the ‘Make in India’ initiative. The OFB on April 8, 2019, handed over the first batch of six Dhanush artillery guns to the Army in an ceremony held at GCF. It was reported that the first Dhanush regiment with 18 guns is expected to be ready by the end of 2020. The GCF has received the Bulk Production Clearance (BPC) to manufacture 114 guns from the Army on February 18, 2019. Some salient features of the gun are:

• Automated technology allows three to six guns to be fired simultaneously at a single target, each gun having a capacity to fire 42 rounds in an hour.
• The weight of the gun is under 13 tonnes, making it easy to move and deploy in hilly terrain and remote areas.
• It is a versatile weapon that can operate in all climatic conditions applicable in the Indian environment. The gun is fitted with inertial navigation system with global positioning system (GPS)-based gun recording and autolaying, an enhanced tactical computer for onboard ballistic computations, an onboard muzzle velocity recording, an automated gun sighting system equipped with camera, thermal imaging and laser range finder which enables it to fire by day and night. It can also carry out direct firing on to a target to destroy a target like a tank or a gun.
• The self-propulsion unit allows the gun to negotiate and deploy itself in the field.
• The existing Bofors gun is a 155mm/39 calibre gun with a range of 28 km. The Dhanush developed by OFB is 155mm/45 calibre gun has a range of 38 km. Normally for guns, the length of the barrel is the diameter of the bore multiplied by the calibre thus larger the calibre, longer will be the barrel which will enable a longer range. Thus the range of Dhanush is 38 km. The ammunition of Dhanush is compatible with all North Atlantic Treaty Organisation (NATO) 155mm ammunition system. The range of 38 km gives Dhanush a big advantage over other gun systems.
• Projected cost of one gun is 15.5 crore which is quite cost effective.

Mounted Gun System (MGS)

A vehicle mounted variant of the Dhanush called MGS was showcased by OFB at the Defexpo 2018 show. The gun is mounted on a 8x8 Tatra truck license manufactured by BEML and has a 30 kmph cross country speed and 80 kmph road speed.

Conclusion

The making of Dhanush Gun System is a stupendous achievement by OFB supported by other organisations like the Army, Defence Research and Development Organisation, Directorate General Quality Assurance, PSUs Bharat Electronics Limited, SAIL, and private firms. The OFB is confident of producing 8-10 guns a month within two to three years. Its longer reach of 38 km, automation and state of art sighting system gives a great edge to Artillery over other gun systems. No wonder it was displayed during the 2020 Republic Day Parade.

The Author is former Director General, Army Air Defence and was a member of Integrated Guided Missile Development Programme.