The Kilo Class (Project 877) submarine was designed for anti-submarine and anti-ship warfare in the protection of naval bases, coastal installations and sea lanes, and also for general reconnaissance and patrol missions. The Kilo is considered to be to be one of the quietest diesel submarines in the world. The submarine consists of six watertight compartments separated by transverse bulkheads in a pressurised double-hull. This design and the submarine's good reserve buoyancy lead to increased survivability if the submarine is holed, even with one compartment and two adjacent ballast tanks flooded. The foreplanes are positioned on the upper hull in front of the fin or sail. The command and control systems and fire control systems are located in the main control room which is sealed off from the other compartments.
Diesel-Electric Submarine - Project 877
The Project 636 design is a generally improved
development of the Project 877EKM Kilo class
that represents an interim design between the
standard 'Kilo' and the new Lada project. The
Project 636 is actively promoted for the world
market by the Rosvoorouzhenie state-owned company.
This submarine has improved range, firepower,
acoustic characteristics and reliability. Visually
distinguished by a step on the aft casing, the
length of the hull is extended by two frame
spacings (2 x 600 mm). The additional length
permitted increasing the power of diesel-generators
and mounting them on improved shock-absorbing
support, and reducing twofold the main propulsion
shaft speed. Owing to these improvements, the
submarine speed and sea endurance were increased,
while the noise level was radically decreased.
The low noise level of the submarine has been
achieved with the selection of quiet machinery,
vibration and noise isolation and a special
anti-acoustic rubber coating applied on the
outer hull surface.




