A very enthusiastic IAF officer, Gp. Capt V.S Narayanan, a Technical Signals Officer, single handedly produced a project report for possibility of developing guided weapons in India. He had indicated that all guided weapon systems in different classes and types then available were logically composed of various sub systems of a limited number of technological variants. In principle, by developing only a limited number of variants of each type of sub-system, the country would be able to evolve a great number of missiles systems by employing appropriate permutations.
As a fall out of this study, he had already examined the possibility of “indigenising” SA-75, a surface-to air (SAM) system, which was a recent acquisition by IAF. Gp. Capt V.S Narayanan, was involved in the acquisition and deployment of the system.
He had examined the possibility of different sub-systems being manufactured by different industries in the country, so that eventually the whole system could be indigenised.
While, Defence Research and Development Laboratory (DRDL), Hyderabad, was excited about the new project, it had reservations on “one to one” copy (those days’s “reverse engineering” phrase was not in existence). They argued that the information and system available with IAF can be used as reference and not “one to one” copy. However, IAF argued that they wanted “one to one” copy for cost savings in training and deployments and they were satisfied by the system itself. Also, the sub-system can be uprated if IAF wanted.
The IAF had projected, 432 missiles would be needed from 1981 – 1986. A sum of Rs 16 crores (Cr) was earmarked that included 4 cr in foreign exchange and the build up of labs.
The Devil Program
Newly promoted, Air Commodore VS Narayanan arrived at DRDL as the new director, in 1971. Two scientists Mr. AV Rangarao and Mr. S Krishnan, who were from the Anti-Tank-Missile project earlier, already knew him earlier. In September, 1971, the final CCPA paper on the “Devil Program” was published.
The SA-75 was of cruciform configuration with wing, tail control surfaces. It was capable of maximum acceleration of 16 G. There were small stabilizers near the nose. The booster has cruciform fins for stability of missile during the booster stage. The missile had 2 stages. The first stage of the missile used solid propellant and had a thrust of 50 tons for a period of 4 seconds. During this stage the missile control was locked and Roll – Stabilized. The second stage was liquid with gasoline as fuel and nitric acid as stabilizer.
First suggestion from DRDL scientist that the RCRS was old and the vacuum tubes could be replaced by solid state design, which occupied less space, had less weight and more reliability. Mr Surya Kanth Rao redesigned RCRS in flat 4 weeks and then onwards a host of sub-systems were redesigned. Mr. Rangarao produced a 5 volume opus for roll on plan. All laboratories had contributed their own plans to this master plan. Hosts of young blood were recruited from prestigious universities. These recruits include Pahlada, Saraswat, Avinash Chander … etc.
The first INS
Shri SD Burman, who looked after the telemetry and instrumentation, formed a young team to develop an Inertial Navigation System (INS), from the sensors available then “Ferranti Accelerometers and Gyros.” A 12 Bit hardwired computer was developed to implementing leveling, gyro compassing and navigational algorithms. The system was powered by a huge Aplab power supply weighing 4 times more that of the actual system. The system was tried out in AVRO HS-748 aircraft with reasonable success.
Airframe, motor and propellants
The Devil missile frame was primarily made of Magnesium Alloy. Very little was known about harnessing the alloy. Devils propulsion system consists of booster sustainer combination where solid propellant booster constituted the first stage, propelled by liquid engine. The solid motor was design of several grains totaling about ½ ton. The liquid engine was a sophisticated piece of engineering during its time as it was regeneratively cooled by the propellant. The propellant was fed into combustion chamber by power driven turbine pumps. This turbo pump itself was driven by a separate monopropellant gas generator. The construction of the engine was entirely by stainless steel corresponding to AISI 304. The Devil SAM was powered by 26 volts, 60 Ampere battery.
The first Devil missile was launched on 25 September, 1978. The test flights were done in air force station Suryalanka, which is a sea station in the Bay of Bengal, overnight drive from Hyderabad. They still test SAM’s regularly at Suryalanka. The Devil was tough missile, capable of withstanding tropical climatic conditions, all weather servicing and operation with surface head wind of nearly 30 knots and prevailing ambient temperature. The missile itself could be held on launchers for up to many months (with periodical “load up” checks) before it had to be returned for complete check up.
The warhead was of controlled fragmentation type yielding thousands of fragments. The fragments were heavier than optimum weight in anti aircraft role. The weight of the explosive was 100 Kgs, ensuring sure kill of aircraft. The Single Shot Kill Probability (SSKP) was in excess of 0.9. The entire system had a SSKP varied with number of missiles and distance, but, on an average the knock out average was 7 out 10 targets that it engages at the rate of one missile per target.
The Devil missile met its all targets; however, the project was closed as the IAF no longer wanted this missile type.
The Devil missile project laid foundation for the future Integrated Guided missile Development Program (IGDMP).