Sweden is going ahead with a plan to replace its current signal intelligence (Sigint) vessel, the 1,400-ton HMS Orion (A 201) built in the 1980s, with the much larger, 3,600-ton HMS Carlskrona (M 04) that is to be converted from its current role as a training ship to a Sigint platform.

Although the Carlskrona is just as old as the Orion (in fact it was commissioned in 1982, two years before Orion), it has almost three times the displacement and is significantly longer (350 ft. as opposed to 200 ft.) than the current Sigint ship.

While Orion is well suited for Sigint operations in the Baltic waters that are off Sweden's eastern and southern coasts, it is less suitable for worldwide deployment.

Carslkrona will have a better ability to perform electronic intelligence gathering missions at longer distances from Sweden's shores, while its size also means it can carry more equipment and analysts if necessary.

According to a statement from Sweden's defense materiel administration FMV, the conversion of the Carlskrona is to be completed by the end of 2009.

The work will involve the removal of weapons systems (the ship currently carries two 57-mm. and two 40-mm. gun mounts and the associated fire control systems), the installation of Sigint equipment and the installation of a propulsion plant that is optimized for lengthy low-speed loitering operations.

The bulk of the conversion work package will be competitively procured, FMV says, but the work connected to the Sigint equipment installation requires special security clearances meaning that this will most likely be done at a government-owned site.

The Sigint ship is used alongside two air force-operated Gulfstream Sigint aircraft based at Malmen Air Base near Linkoping. The Sigint operation is in the hands of a special government agency known as the FRA.