Northrop Grumman will upgrade the inertial navigation systems for Swedish Navy submarines under a new contract awarded by Kockums AB.

Under the contract, Northrop’s Sperry Marine will supply five mk39 mod 3C ring laser gyro systems for installation on two Gotland Class and two Södermanland Class submarines, one of which will be used for spares and training.

The mk39 mod 3C is a high-performance, low-cost inertial navigation system that provides accurate positioning and precise attitude data to the vessels’ SESUB combat management systems.

Northrop Grumman International Naval Systems vice-president Nolasco DaCunha said the mk39 mod 3C offered a combination of advanced performance, superior shock and vibration resistance and traditional Sperry Marine reliability.

The installation work of the navigation systems will be carried out by Kockums AB, and is scheduled to be complete by 2011.