In 2015 India signed a contract with Russian and Indian shipyards to refurbish and upgrade six of the nine Indian Kilo class submarines. This will cost about $129 million each for each of these subs and are essential in order to have these boats available until the late 2020s. India recently sent the first of their Kilos to Russia for the work to be done there. Another three will follow and the remaining two will be refurbished in an Indian shipyard with Russian technical assistance.
India bought ten Kilo class boats from Russia in the early 1980s and received then between 1986 and 2000. One was lost due to an accident in 2013, leaving nine in service and no replacements likely to arrive before the early 2020s, if then. Thus the urgent need for an expensive refurb.
The Kilos weigh 2,300 tons (surface displacement), have six torpedo tubes, and a crew of 57. They are quiet and can travel about 700 kilometers under water at a quiet speed of about five kilometers an hour. Kilos carry 18 torpedoes or Klub anti-ship missiles (with a range of 300 kilometers and launched underwater from the torpedo tubes). The combination of quietness and cruise missiles makes the Kilo very dangerous to large enemy warships. Russians use their Kilos are mostly for home defense. Nuclear subs are used for the long distance work. India, however, uses the Kilos as their primary combat subs.
The Kilo class boats entered service in the early 1980s. Russia only bought 24 of them but exported over 30. It was considered a successful design, especially with export customers. Russia has 17 Kilos in service (and six in reserve) and six Improved Kilos on order. More than that is on order from foreign customers.
The 2015 Kilo refurb contract came after Indian accident investigators concluded that the loss of one of the Indian Kilos in August 2013 was due to human error by one of the crew. This incident began when the INS Sindhurakshak caught fire and exploded while docked near Mumbai. The 16 year old submarine had recently returned from Russia after an $80 million refurbishment. Eighteen sailors were killed as the sub sank at dockside. The cause appeared to have been an accident but the initial investigation revealed that there were two explosions involved. The first explosion was small and appeared to be the result of human error or equipment failure. The second, larger explosion was one of the torpedoes. These torpedoes were designed to not explode in circumstances like this, unless someone had tampered with it. That cannot be determined until the Sindhurakshak is brought to the surface and a detailed examination of the torpedo fragments is conducted. That won’t happen until August. At that point the forensic experts can go inside and reconstruct exactly what happened. Most of the evidence is trapped inside the pressure hull of the sub and what exploded, when and why can easily be determined by reassembling the pieces and running chemical analysis on fragments.
What was particularly alarming to the investigators were the common problems found with an earlier (March 2013) accident with another Kilo class sub (INS Sindhuratna). In this case it was a fire caused by flammable gas from the subs batteries. The problem here was that Sindhuratna has also gone through a recent refurbishment and that should have included replacing the 240 batteries. That was standard procedure because as these batteries get older they are more prone to these types of fires. But the Sindhuratna batteries were not replaced because procurement bureaucrats never got around to authorizing it. That is a common failing of the Indian procurement bureaucracy, in this case triggered by fears that anti-corruption investigators might uncover bribes being paid for the new batteries and bringing suspicion on all the procurement officials involved with the Sindhuratna refurbishment, whether they were guilty or not. In cases like that the procurement bureaucrats tend to do what is safe for them and that often means doing nothing.
Indian investigators initially feared that key problems with the fires in both subs was poor Russian quality control. That proved not to be the case. The key causes in both accidents were poor Indian management of procurement and work done in India. While there have long been quality control problems with Russian built equipment, especially ships, armored vehicles, and aircraft, the Russians have made progress in dealing with these failings. The Kilo that was completely destroyed had returned from the Russian refurbishment eight months earlier and had successfully completed a three month shakedown cruise. All indications were that everything was in good order and there were no known problems with the crew or the boat.
While India is trying to reduce the incidence of corruption in military procurement, it has proved even more difficult to reform the military procurement bureaucracy, whose failings have prevented new subs, to replace the elderly Kilos, from being obtained in time. That is not an isolated incident because the army and air force have similar complaints.