155 TMF upgrades.

A multi-staged means of attaining the Holy Grail of Naval Fire Support, the 155 mm gun, is being proposed by RO Defence, now part of BAE Systems Customer Solutions & Support. It involves inserting the 39-calibre gun from the AS 90 Braveheart self-propelled system into the upgraded 4.5-inch (114 mm) Mk 8 Mod 1 mounting as part of a three-phase programme. The company is bidding to upgrade the last of the Mod 0 mountings by replacing the gun shield with a stealthier version and converting the system from hydraulic to electric power while adding built-in test equipment. The 155 TMF (Third-generation Maritime Fire support) would follow this by replacing the 114 mm gun with the 155, modifying the gun shield for higher elevation angles and adapting the loading and supply system. A double-loading cycle and full stroke rammer would be required and the weapon would probably use the single-module L10 charge as well as existing projectiles.

A comprehensive risk reduction study has found the Mk 8 trunions capable of operating with the 39 and 52-calibre barrels, and that some minor changes might be required but the 155 TMF would retain 80 per cent commonality with the Mk 8 Mod 1. Later the 52-calibre gun and an automated magazine could be added.