The initial indigenous development of artillery guns in India started in the 1970s with the Artillery Gun Development Team under Brigadier Gurdyal Singh at Gun Carriage Factory, Jabalpur.[10] This resulted in the introduction of 105 mm Indian Field Gun and its variant, the Light Field Gun into the Indian Army.
The purchase of Haubits FH77 guns manufactured by Bofors in the 1980s included technology transfer to OFB. After many years being unable to acquire or import foreign artillery guns due to the corruption charges, OFB developed the Dhanush gun based on the technical data package that was included in the purchase of the FH77. Improvements and modernisation of the original construction included lengthening the gun barrel from 39 calibres to 45, inertial navigation-based sighting system, auto-laying facility, onboard ballistic computation and an advanced day and night direct firing system.[11]
An order, worth ₹1,260 crore (equivalent to ₹21 billion or US$250 million in 2023), was placed with OFB around 2013 for 114 guns and 300 more planned. The guns were to be manufactured by Gun Carriage Factory Jabalpur. The gun cost was at ₹14 crore (equivalent to ₹22 crore or US$2.6 million in 2023) apiece with 80% indigenous content. Very few components like APU, electronic dial sights and a few other small items are imported.[11][12]
From 6 to 30 June 2014, the gun underwent its final summer trials at Pokhran Field Firing Range. This was after the successful winter trials in Sikkim at an altitude of 3,500 metres (11,500 ft) at sub-zero temperatures. Dhanush outperformed the Bofors gun by 20 to 25 percent in parameters like range, accuracy, consistency, low and high angle of fire, and shoot-and-scoot ability. There had been a pause in trials due to a barrel burst incident in August 2013 but was later investigation reported an issue with "old ammunition with air bubbles" and no problem was found in barrel design or metallurgy.[11]
Three Dhanush guns were handed over to the Indian Army for user trials in July 2016.[13] Battery trials were expected to be completed by July 2017 with 18 guns entering service in 2017, 36 guns in 2018, and 60 guns in 2019, for an Indian Army order of 114 guns.[14] Each regiment has 18 guns and two are reserved.
The Dhanush experienced a few problem during trials, failing on three occasions in a row in 2017.[15] It was reported in July 2017 that the howitzer failed the last phase of testing, due to the shell hitting the muzzle brake. A redesign of the barrel by widening it was being considered to solve the issue.[16] Later an investigation revealed the incident happened due to a defective shell. Further trials were conducted by firing about 5000 shells in the desert regions and icy glaciers of the Himalayas without any incident.[17] In June 2018, Dhanush completed final development trials.[18] In February 2019, it was approved for series production.[19]
Manufacturing
The first batch of 6 guns were officially inducted by the Army on 8 April 2019. 93 Field Regiment becoming one of the first units to be armed with this gun and had the honour to participate in the 71st Republic Day Parade and Army Day parade in 2020 with its new equipment.[20]
A recent manufacturing disruption occurred due to the untimely procurement of a spare part needed for a sub-assembly. The production of Dhanush has restarted following a pause due to a shortage of spare parts. In FY2023–2024, Advance Weapons and Equipment India Limited (AWEIL) intends to deliver the Indian Army with 26 brand-new howitzers. With this, the Army will have 50 Dhanush weapons overall. The Army received the first set of 6 guns in April 2019. Accidents such as barrel bursts and muzzle brake strikes marred the early years of manufacturing. At that point, the Ordnance Factory Board (OFB) was in charge of the Gun Carriage Factory in Jabalpur. New terms and conditions were signed with the new entity AWEIL following the corporatization. According to the revised terms, the delivery is proceeding as planned.[12] The guns are to be delivered by 2026.[21]
As of March 2024, the guns for second regiment are in induction phase.[22]
As of February 2020, IIT Madras, in partnership with IIT Kanpur, Armament Research and Development Establishment (ARDE) and Research Centre Imarat (RCI), is working on redesigning an existing 155 mm shell using ramjet propulsion that can cover 60 km+ range. It will be made compatible with Haubits FH77, Dhanush, K9 Vajra-T and DRDO ATAGS. The shell will incorporate a Precision Guidance Kit for trajectory correction. IIT Madras will ensure that Munitions India can manufacture the shells. Prototype is expected to be developed within three to fove years as the design was ready. As pf then, many technologies were proven already and further facilities for lab and prototype testing woulld be required like advanced wind tunnel.[23]
Reports emerged in February 2024, that Munitions India Limited along with Indian Institute of Technology Madras is developing the first 155 mm Smart Ammunition for the Indian Army Regiment of Artillery. The developmental time is about 2 years. The goal of this partnership is to improve artillery shell accuracy and lethality at the time of terminal impact. The munitions can be launched from 155 mm 39- and 45-calibre guns including Dhanush, DRDO ATAGS and K9 Vajra. The shells will can achieve a Circular Error Probability (CEP) of 10 m (33 ft) against the current conventional ammunitions 500 m (1,600 ft) CEP, a 50 times improvement. This will require housing of cutting-edge technologies such as miniature electronics and sensors with guidance, navigation, and control systems. The 155 mm Smart Ammunition shells will primarily utilize NavICsatellite guidance to increase accuracy and have a GPS-back up option. In order to meet different tactical needs, the 155 mm Smart Ammunition is made to work with current artillery guns and has sophisticated characteristics including fin stabilization, canard control, and a three-mode fuse operation.[24] A minimum range of 8 km and a maximum range of 38 km are anticipated. In addition, this Smart shell has three different explosion modes: delayed, height of burst, and point detonation.[25][26][27][28]
Variants
Towed variant (Original 45-calibre)
Towed 52-calibre: AWEIL upgraded the gun system into 155mm 52-calibre which can now fire up to 42 kilometres (26 mi). Dhanush weighs less than 14,000 kilograms (31,000 lb). The newly upgraded gun has double baffle muzzle brake and retractable barrel and has a unified sighting system for day and night warfare againat static and moving targets. The gun barrel has a length of 8,060 mm (317 in) and a weight of 2,790 kg (6,150 lb) and an elevation range of -3°/+70°. It has three modes of rate of fire: burst rate (three rounds in 30 seconds), intense rate (12 rounds in three minutes) and sustained rate (42 rounds for one hour). The upgraded Dhanush successfully completed the internal testing phase.[29][12] The gun system is likely to participate in the Towed Gun System tender for induction into the Indian Army.[30]
A vehicle mounted variant of the gun called Mounted Gun System was showcased by OFB at the Defexpo 2018 show. The gun is mounted on a 8x8 Tatra truck manufactured under license by Bharat Earth Movers Limited (BEML) and has a 30 kilometres per hour (19 mph) cross country speed and 80 kilometres per hour (50 mph) road speed.[32]
