Babcock achieves key milestone in submarine maintenance

Babcock has marked a major milestone in the substantial Revalidation and Assisted Maintenance Period (RAMP) on Trafalgar class submarine HMS Trenchant – the largest RAMP undertaken to date in Devonport – with the achievement of flood-up, marking the conclusion of some 16 months in dry dock.

This significant RAMP involves a challenging programme of maintenance, system revalidation and capability upgrades, with the successful achievement of flood-up signifying approximately 70 per cent completion of the work-package. 

Activities to date have included the installation of a new composite rudder, overhaul of both port and starboard circulating water systems, the largest RAMP survey package ever undertaken, torpedo tube revalidation, and pressure hull revalidation.  It has also involved a significant package to survey and overhaul the Sonar 2076 flank arrays, installation of the Defence Information Infrastructure, a large galley upgrade, a major tank maintenance programme, and application of the recently developed internal non-destructive testing (NDT) inspection method for tail shafts.  Moreover, Trenchant will undock with an exceptional finish; the product of extensive tile refurbishment and ‘fairness of form’ work, as well as the application of a new signature-reducing paint system. 

Additionally, the RAMP has seen the trial of an eddy current non-destructive testing (NDT) technique that allows weld lines to be inspected without paint removal.  This has proved successful, and will now be introduced for use in future RAMPs. 

Over the next 12 months the team will focus on completing the remaining work, which needs to be undertaken while the vessel is afloat.  This includes the completion of maintenance and upgrade to the nuclear steam raising plant (NRSP), which involves the submarine being heeled, restricting the wider activities that can be undertaken onboard.

Commenting on the achievement of flood-up, Babcock Boat Manager John Pitt said: “We have worked closely with the MoD and Royal Navy, combining our respective areas of specialist knowledge and experience as a joint team to undertake this challenging programme of work successfully and we are delighted to have achieved flood-up, being a significant and highly visible milestone in the project.  We have applied and developed key project management tools to optimise schedule adherence and cost control, and will continue to work closely with the MoD and Royal Navy to deliver the RAMP successfully.”