A major and visible milestone has been achieved in the Long
Overhaul Period (Refuel) [LOP(R)] on Vanguard class ballistic
missile submarine (SSBN) HMS Vigilant with the successful
completion of flood-up today (16 June) - the first time the
submarine has been afloat in over two and a half years, since dry
docking in November 2008. The LOP(R) is being undertaken by Babcock
at Devonport Royal Dockyard.
The successful achievement of flood-up signals completion of
some 80 per cent of the work programme on HMS Vigilant. Refuelling
- a critical element of the three and a half year LOP(R) which
dictates the overall programme duration - was successfully
completed in November last year. This is supported by a major
revalidation of all reactor systems and replacement of major
equipment such as the main coolant pumps, reactor pressure vessel
head and reactor instrumentation suite, and a significant
commissioning programme. In addition, the LOP(R) has seen a
significant number of upgrades to the tactical and strategic
weapons systems, as well as a vital and substantial overhaul of the
propulsion system including main engines, 700KW motor generators,
refurbishment of the tailshaft, plus major external represervation
work, and upgrades to the accommodation and mess areas.
Since completion of refuelling last autumn, the Vigilant LOP(R)
team has been focused on commissioning submarine systems and
reinstating the submarine structure to provide water-tight
integrity assurance in readiness for flood-up, involving a step
change in vessel condition and a substantial programme of work.
This has included completion of trim, bilge and ballast systems
testing and operational handover of emergency breathing,
communications, flood alarms and fire fighting systems to ship's
staff to support emergency response while afloat. Steam machinery
trials in dry dock have also been successfully completed, providing
an early operational test of the propulsion systems (except turning
the main shaft) and demonstrating the quality of workmanship with
very few defects.
Babcock Project Manager Phil Smith comments: "The significance
of this milestone is huge, not just in terms of the programme, but
in bringing together so many diverse groups of workers in a common
cause. The submarine crew also had a vital part to play in the lead
up, taking operational ownership of a number of systems. To have
successfully achieved flood-up is a major milestone and highly
visible demonstration of the excellent progress being made. Loop
fill (filling the primary reactor circuit) follows closely in July,
and our reactor production teams and reactor test team are driving
hard for this milestone."
He adds: "The partnering agreement1 between Babcock and the MoD
has without doubt contributed to this latest success - the fact
that we strive together as one for the common goal at the coalface
is key. This is a highly complex and challenging programme, and the
joint project team is now firmly committed to meeting the remaining
challenges and achieving the key programme milestones efficiently
and effectively, to ensure successful delivery of the project
within the agreed contract acceptance date next year, representing
optimum value for money for the MoD and Royal Navy."
Flood-up will now be followed by a focus on final completion
through a programme of reactor system testing and commissioning,
and its integration with the propulsion systems through a series of
'Cold and Hot' operations (CHops). This will culminate in Power
Range Testing (PRT) at the end of this year, where the new core
achieves criticality for the first time, generating 'nuclear steam'
to prove the propulsion plant and supporting sub-systems. HMS
Vigilant will then sail from Devonport for sea trials in 2012.
Commenting on this key milestone, MoD Project Contract Manager
Nick Febbrarro said: "An important requirement for the MOD is that
HMS Vigilant is completed to the programme timescale or earlier.
This very important milestone in the drive to meet this requirement
marks the culmination of a comprehensive work package to return
submarine systems and equipment back to service and in accordance
with design intent. Completion of this milestone is testament to
the application of a highly skilled workforce and the significant
investment in time and resources by all stakeholders. During the
commissioning phase we have worked in close co-operation with
Babcock and the Ship's Company and are now in the best possible
shape to take the project forward into the final phase of the
LOP(R) including reactor commissioning."
HMS Vigilant is the third Vanguard class submarine to undergo a
LOP(R) at Devonport. The project represents five years of activity
(including the planning phase) and over £300 million to return the
submarine to the fleet capable of fulfilling her role well into the
21st century. The massive project will involve more than 2.2
million manhours and a total of 2,000 personnel.