HMS Astute In-Service Maintenance Period Completes On-Schedule

HMS Astute, the first in class of the most technologically advanced nuclear powered attack submarines to serve with the UK Royal Navy, has successfully undergone a substantial in-service maintenance programme, completed on-schedule. It was led by Babcock, the Royal Navy’s strategic support partner for the submarine flotilla, working closely with BAE Systems and the Ministry of Defence as a joint project, for optimum efficiency during the transfer from build and commission into full operational use.


The programme, undertaken at Faslane, has seen close working and industry alliancing put into practice to achieve the demanding and extensive workscope within the challenging six month timescale required. The move sought to capitalise on the collective knowledge and experience within the submarine enterprise and address any issues on this first-of-class submarine, to schedule, quality and cost.


As the first of class, HMS Astute is effectively the prototype and, as is the nature of prototypes, design amendments are required. For this Base Maintenance Period (BMP), the more significant work packages undertaken included modifications to the hydraulic systems to increase capacity, operability and capability, and the full inspection and re-tubing of the port combined cooler (a first-of-class requirement and a significant engineering challenge, involving disassembly within very tight available space). Babcock also took advantage of the docking period to undertake a full internal and external hull inspection package (which would usually be carried out in a longer maintenance period), and BAE Systems undertook a number of design changes to fitted equipment and defect rectifications, with assistance from Babcock as required. This cost-effective approach has the potential benefit to reduce maintenance times in future operating cycles.


Collaborative working has been key to the successful, on-schedule delivery of this maintenance period. Babcock’s usual in-service support practices and processes have been applied, with project and change management being essential elements to control workscope growth throughout the period and maintain the timeline. Joint planning has continued and grown during the BMP, with a single master plan to control resources, systems and nuclear logic sequencing.

“We have worked collectively and proactively with BAE Systems and the MOD both in planning and throughout delivery of the BMP to return HMS Astute to the fleet in the best possible material state,” Babcock Submarines Managing Director Mike Homer said. “This maintenance period has also demonstrated how this collaboration can be successfully implemented, and the experience will be applied to Ambush’s first BMP next year, with joint working practices applied from the outset. Additionally, in a separate project, we have also been working with BAE Systems to review Astute class transition from build to becoming operational, and ways to improve efficiency and value for money. This work is still underway.”


Elsewhere, Babcock has also undertaken work to look at development of a Modified Operating Cycle (MOC) for Astute class submarines, taking a fresh approach to the traditional cycle of at-sea periods to maintenance periods, as part of the Submarine Enterprise Performance Programme (SEPP) collaboration between the MOD, Babcock, BAE Systems and Rolls-Royce. Work undertaken by Babcock on submarine maintenance activity schedules and a modified cycle has involved reviewing the type of basic maintenance undertaken (preventative vs necessary) and the need for and regularity of through-life inspections, requiring consideration of several hundreds of tasks ranging in regularity from daily to once in a submarine life. Early findings indicate that an improvement in submarine availability in the order of 20% could be achieved, as well as more efficient use of resources.


Following this successful BMP HMS Astute will now leave the Clyde for further sea trials before her full operational handover.