Fleet Support Limited (FSL) has fitted the first new Mark 8 MoD 1 4.5 inch gun to a Royal Navy Type 42 destroyer as part of a docking period on HMS York in Portsmouth.

The new gun replaces the previous 4.5 inch unit and involves a package of design, installation and commissioning work as part of the overall maintenance programme on HMS York, which is due to be completed later this year. FSL has already gained experience of the new gun after fitting a similar unit to a Type 23 frigate but the task on a Type 42 destroyer involved a considerable number of design and installation modifications.

Having removed the old gun, along with its associated controls and hydraulic pack, FSL gutted the control room and rebuilt it to accommodate new electrical cabinets, also installing new controls and fitting a replacement ring fire system, before the new gun, weighing some 15 tonnes, was positioned.

FSL Project Manager Roy Ashton explained: “Although the work was spread over three decks in similar fashion to the Type 23, the installation on HMS York presented several new challenges. “We have gained valuable experience in the required design and mechanical package and the next stage will be setting to work before firing trials commence.” The new gun’s main role is naval gunfire support and its secondary role is surface and tactical illumination. Its distinctive shape is designed to reduce radar cross sectional area. Advantages over the older gun include weight reduction, easier maintenance, lower running costs and increased reliability. The Mod 1 uses modern digital technology with only the final stage of ammunition loading being hydraulic.

HMS York Weapon Engineer Officer Lieutenant Commander Brad Wright, explained: “The York team are delighted to be the first destroyer to be fitted with the Mod 1 gun and look forward to putting it through its paces when we undergo Operational Sea Training next year. The improved availability, reliability and maintainability of the Mod 1 gun will significantly improve our ability to deliver naval fires in support of operations ashore."