A key component of the highly mechanised weapons handling system
(HMWHS) for the new Queen Elizabeth Class aircraft carriers,
designed and being delivered by Babcock, has successfully completed
factory acceptance testing, marking a significant milestone in the
programme.
The HMWHS provides mechanical handling facilities for moving
palletised munitions around the deep magazine and weapon
preparation areas, and a series of weapons lifts to connect the
magazines, hangar, weapons preparation area, and flight deck.
The components in question are 56 so-called 'moles', which do the
lifting and carrying of the palletised munitions in the magazine.
The HMWHS system consists of a network of two versions of these
prime movers, which traverse forward and aft (longitudinal, version
one) or port and starboard (athwartships, version two), each able
to lift and move a payload to locations within its predefined area
of travel. The moles can transfer payloads between each other, so
the payloads can be located anywhere within the magazine.
The two mole versions are different shapes to enable lifting and
lowering of the palletised munitions in the correct orientation,
onto the set stowage and transfer positions, and are equipped with
electric traverse and lift drives, allowing accurate positional
control within the magazine. A number of lifts provide
interconnection between the magazines and the hangar, weapons
preparation area, and flight deck, and a unique mechanism enables
the mole to access the lift platform without needing to disengage
and re-engage the pinion from the rack. The magazines are unmanned,
with all the moles controlled from a central location, so personnel
are required only where munitions are being prepared for storage or
use.
A significant challenge in manufacturing the moles has been the
achievement of the tight tolerances introduced following completion
of the demonstration phase, to speed up assembly.
Factory acceptance testing took place at Babcock's site at
Whetstone, Leicester, and included dimensional and functional tests
and inspections of the parts and mole drive and lifting
systems.
The moles have now been delivered to the Aircraft Carrier
Alliance's central warehouse, ready for installation once the fixed
rail equipment and lifts have been installed. As the moles are
fully reassembled, installation will involve placing them in the
magazine and electrically connecting them to the rest of the system
via an energy chain system. "The moles are a critical component of
the HMWHS and successfully completing FATs for all moles marks an
important milestone in delivery of the system," Babcock Integrated
Techology director Matt Hatson comments. "The HMWHS is the first
maritime application of shore-based commercial warehousing
processes using automated systems with all-electric control,
adapted for safe transport and stowage of munitions in a warship
environment. Munitions can be delivered, in bulk, to the point of
use at rates that could not be achieved manually, whilst minimising
the manpower requirement in what is traditionally a
labour-intensive process, thus delivering reduced through-life
cost, as well as a saving in onboard living accommodation
requirements." Production of the final software solution for the
HMWHS integrated control system, and manufacture of the various
mechanical, electrical, hydraulic and pneumatic sub-systems making
up the HMWHS are now underway, of which successful completion of
FATs for all moles is part.
The final equipment for the full HMWHS for the first carrier
will be delivered by May 2013, and for both vessels by February
2015.
Babcock has also been active in working with the shipyards to
support the design integration and build strategies. A joint
installation strategy has been developed using Babcock's system
knowledge and ship build experience, to maximise installation and
testing opportunities. Babcock will maintain responsibility for
overall installation and quality of work, as well as performing the
testing required to demonstrate the system meets ACA requirements.
The system in-service support package is being developed with the
MoD and Royal Navy.