The need for Trishul project

From the point of view of naval tactics, the advent of radar homing heads of liquid fuelled missiles heralded a revolution in the centuries-old-tactics of battle between naval ships by transforming gun battles within visual range to missile encounters much beyond visual range. This development also transformed the nature of the threat because, without any warning, missiles could, by day or by night, regardless of weather, approach their targets at near sonic speed and inflict fatal damage.In all navies, research intensified to cope with the threat posed by sea-skimming missiles. Gradually, concepts of anti missile defence began to crystallise as tiered options. These were:-Throughout the 1970s and 1980s, a spiralling contest took place between new technologies of the homing heads of anti-ship missiles and the countermeasures to cope with every new advance in homing head technology while homing heads showed ever improving circuitry that would overwhelm/defeat the latest countermeasuresGradually, homing heads started combining multiple technologies from radar homing onto the largest echo with infra red homing, along with homing onto the target’s radar/jammer transmissions. The desirability of denying a radar homing missile of a large radar echo led to the incorporation of “Stealth” technology in the design of all future warships.

Technological Challenges for developing Air defence missiles

To start with, it was essential to detect, at as long a range as possible, a slim missile approaching at the speed of sound just a few meters above the sea. Then, it was necessary to have a track and guidance system that could accurately guide the anti-missile missile also flying at least at the speed of sound to hit or arrive within proximity fuze exploding distance of the incoming missile. The combined crossing rate was twice the speed of sound. The slightest error or delay in computation meant that the incoming missile would escape interception and fatally damage its target ship. To cater for this contingency, ships were fitted with small calibre (30 mm) guns having very high rate of fire (thousands of rounds per minute).Initially, ships acquired from the Soviet Union were fitted with AK 230 double barrelled 30mm mountings having autonomous detection and fire control systems.In due course, the double barrelled gun mountings were superseded by AK 630 six-barrelled 30mm mountings to ensure that every ship had this type of terminal point defence. Agreements were negotiated with the Soviet Union for transfer of technology to indigenously produce these mountings under licence.To increase kill probability against incoming missiles by gunfire, it was decided to use 76mm calibre proximity fuzed shells, fired from high rate of fire 76mm guns. Agreements were negotiated with the Italian firm Oto Melara for transfer of technology and indigenous production of these mountings under licence. Hence there is a need to develop AMD s with in the country using its own technology

The Trishul Project

The Navy projected its critical requirement of an anti sea-skimmer missile to the Defence Research and Development Organisation (DRDO). The requirement for an anti-missile was included in the Integrated Guided Missile Development Plan (IGMDP) as Project Trishul, whose objective was the development of an inter-service, short range (9 km), quick reaction (6 sec) Tactical Surface to Air Missile (SAM). The Naval version was required to have anti-skimmer missile capability. The Army version was to be on tracked vehicles and the Air Force version was to be on wheeled vehicles.Trishul missile Guidance consists of three different guiding beams, with the guidance handed over progressively to a narrower beam as the missile approaches the target.According to reports, the range of the missile is 12 km and is fitted with a 15 kg warhead. The weight of the missile is 130 kg. The length of the missile is 3.1 m

The missile can engage targets like aircraft and helicopters, flying between 300 m/s and 500 m/s by using its radar command-to-line-of-sight guidance. It operates in the K-band (20 - 40 GHz), which makes it difficult to jam. In the K-band three-beam system, the missile is initially injected into a wide beam, which then hands it over to a medium beam, which passes over to a narrow beam, guiding it to the target. The Trishul has high manoeuvrability and is powered by a two-stage solid propellant system, with a highly powered HTBP-type propellant similar to the ones used in the Patriot. It is constructed of maraging steel to withstand the stress. Successful flight trials in a tube launched mode using folded fins against balloons and Pilot-less Target Aircraft (PTA) targets were carried out. One flight trial was guided throughout the trajectory using fixed line of sight and infra-red gathering guidance systems as per programmed flight. The army variant, Trishul Combat Vehicle (TCV), is based on a tracked BMP-1 infantry combat vehicle and houses all equipment including radars, command-guidance system and missiles.

Sequence of Events

As part of the IGMDP, the Trishul Project was accorded sanction in 1983, scheduled for completion in 1992 to dovetail with the completion of the Brahmaputra, the first ship of Project 16A. After a timely start, progress became sporadic for a variety of reasons. The sequence of events was:1983: The Government approved the development of these missiles and the structure of the IGMDP.1985: First flight of unguided Trishul from Sriharikota Range (SHAR).1989: Full 9 km guided flight of Trishul. The original concept of gathering the missile into the field of view using TV proved unsuitable for injecting it into the initial narrow 0.6 degree wide gathering beam and later injection into an even sharper 0.43 degree guidance beam.1992: The altimeter-controlled Mach 2 flight of a Trishul missile was successful against a pre-determined trajectory (programmed and stored in the missile) fired at a simulated sea-skimming target mounted 7 meters above the sea. However variation in altimeter control was found to be unacceptable.

1997: RAWS 03 (the search radar for detecting the incoming sea-skimmer) systems was installed in Dronacharya and became fully operational.May 98: The missile tracking/guidance system was installed at Dronacharya, set to work, tested and tuned, integrated with the launcher and rendered ready for firing the first missile, which was also by then completed by BDL, Hyderabad.Jun 98: The first missile was fired from Dronacharya against a simulated target. Thereafter, 14 telemetry version naval missiles were fired on a variety of simulated targets, Chukar Pilotless Target Aircraft (PTAs) for a higher flying missile and a static model on a pontoon for the sea skimmer version.By end 1998, crucial sub-systems of the overall project completed development and became available from different locations for integration as a total system at the proving range in Cochin. These were the search radar for initially detecting the incoming missile, the guidance system for the outgoing missile, the missile launcher, and its barbette for reloading the launcher.By the early 1990s, NHQ concluded that the Trishul project was not likely to be completed by the time that INS Brahmaputra would become ready for delivery. In view of the vital requirement of anti-missile defense, NHQ started looking for an alternative.

Budget for the projectA sum of Rs 282.68 crore had been incurred on the development of the system.

Applications

The missiles developed under are short range surface to air missiles. A surface to air missile is designed for launch from the ground to destroy aerial targets like aircrafts, helicopters and even ballistic missiles. These missiles are generally called air defense systems as they defend any aerial attacks by the enemy. Even though many of the missiles failed under this trishul project some of them have effectively helped in the defense services of the country. Most of the technology developed under this project has not helped to produce effective missiles. But this has given an ample amount of experience to the team working on it and some of the technology been used in other projects like maitri to develop good air defense missiles. It was mainly developed to protect Indian naval assets.

Results

Naval version of trishul was successfully flight tested in guidance mode as an anti sea skimmer against low altitude sea target. Trishul is employed by Indian Army and Air Force against low flying aircraft. The Indian Navy will also use this weapon system in anti-missile role against Exocet and Harpoon possessed by Pakistan.

Among 40 test flights, Trishul underwent seven successful test firings over the years at INS Dronacharya,the Indian Navy’s offshore establishment at Kochi.Eventhough some tests were successful,there were several technical problems involved.Trishul missile development program has been delayed due to technological problem.Trishul missiles are used as technology demonstrator.The defence ministry decided to dump the short-range quick-reaction missile because "its command guidance never worked properly."

Drawbacks

The Trishul project relied on equipment already in service with the Indian services, to drive down logistics costs, and reduce program development costs and development time. The Army variant, relied on a locally modified variant of the Signal (now Thales) Flycatcher radar, integrated into a single launcher with a four missile pack, along with separate electronics for missile guidance. The Air Force variant separated the missile launchers on Kolos Tatra trucks, locally manufactured by India's BEML. The Naval variant was the most ambitious, with a flight control system with an integrated radar altimeter to intercept sea skimming missiles. The Trishul's guidance was Command Line of Sight with a three beam guidance system, which proved to be the bane of the project and caused repeated failures during trials.

Due to the Trishul's persistent development problems the Indian Air Force, the Indian Army and the Indian Navy began upgrading their existing short range SAM systems or purchasing replacements. The Indian Air Force has since procured batteries of the SPYDER SAM system and the Indian Army is upgrading its OSA-AKM/ SA-8 systems with Polish assistance. The Indian Navy has also moved on to the Barak SAM system.

A radar-guided SAM goes through three stages before intercepting a target-it is directed onto the target by a wide radar beam which locks on to the target; this beam reduces to a medium beam and finally to a narrow beam on which the missile rides on to intercept the target. Trishul failed to seamlessly integrate the beams and guide itself to the target.

The missile could not achieve its high-arching trajectory and developed problems in the second-stage. The second stage of the two-stage, solid-fuelled missile apparently failed to separate. The test failed to achieve most of the operational parameters set for it, The defense experts contend that the test cannot be termed a complete failure as it takes eight to 10 test firings for a missile to evolve completely.

The missiles, surveillance and fire control radars were to be co-mounted on a suitable platform which should be mobile enough to match the mechanised forces. The major problem during trials was that the missile could not lock-on and engage a fast moving target. Active seeker technology was not available to DRDO. The project was foreclosed around 2002 but DRDO continued to

improve upon it (the DRDO jargon is ‘competence building’). It was finally closed in February 2008

This short-range surface-air missile (SAM) that has been described as similar to the Russian SA-8 Gecko with more modern electronics

Reviews

Development of Trishul missile system has been completed as technology demonstrator," Defence Minister A K Antony said in a written reply in Rajya Sabha before closing this project.

Missile experts say Trishul's basic design was fatally flawed. Prolonged delays ensured it would not only be a generation behind contemporary anti-missile systems but inadequate against modern threats like smart bombs. "The only way to change it would be to go back to the drawing board and redesign the whole missile," says an official who worked on both Barak and Trishul.

It will be a lesson for the DRDO to cut its losses in long delayed programmes and go in for joint-ventures like the Indo-Russian BrahMos cruise missile.Air Commodore Jasjit Singh(retired),Director, Centre for Air Power Studies, says even in failure ,Trishul can provide valuable lessons. “It gives our scientists enormous data and experience and opens avenues for a Trishul-2 or a successful joint –venture a few years down the line.

It has been reported that the experience gained from the Trishul program will be utilized for a brand new SAM known as the Maitri, which will be codeveloped with the European MBDA missile agency.