The Goliath crane ordered by Babcock for the final assembly of
the aircraft carriers at Rosyth arrived at the dockyard today from
Shanghai Zhenhua Port Machinery Co Ltd (ZPMC) yard, where it has
been manufactured. The transport vessel (with a beam of 39 metres
and overall length of 244 metres) bringing the crane will enter the
non-tidal basin via the newly widened direct entrance, completed in
December 2010.
The partially-erected crane (with the girder and upper sections
of the legs assembled) has been shipped to the UK mounted on the
deck of a specialist transport vessel from the Chinese crane
manufacturer's fleet, along with all components and erection
equipment including temporary erection towers, which will be used
in Rosyth to complete the crane assembly.
The crane will now be fully erected to its full height on the
ship deck over a six week period, before being transferred from
ship to shore directly onto the crane rails. These were installed
last year (completed in February 2010), involving a total of 380
piles through varying ground conditions into the underlying
bedrock, followed by reinforced concrete foundation beams, and the
rail track. It will take just over four months to erect, test and
commission the crane, for final handover in the summer of 2011,
ensuring that the crane will be ready for its operational
availability target of 1 September 2011.
The Goliath crane will be the largest in Britain, at a height of
68 metres to the underside of the main beams, with a span of 120
metres to cover the construction area of the new carriers at
Rosyth. The crane, which was selected on the basis of its safety,
efficiency and cost, will lift and place the carrier sub-blocks,
and components including the upper blocks and sponsons, bow block,
islands, and aircraft lifts, without disrupting the dockside area
adjacent to the ship.
The crane's 1,000 tonne lifting capacity is provided by three
hooks. The individual capacity of each provides a valuable degree
of flexibility in lifting some awkward loads with difficult centres
of gravity, and allows units or blocks to be turned over, up to a
unit load of 500 tonnes. Two of the hooks are suspended from an
upper trolley (each hook having a 300 tonne capacity) and one from
a central, lower, trolley with a 500 tonne capacity. While the
three hooks have a greater cumulative lifting capacity than 1,000
tonnes, the total capacity is defined by the crane structure.
The arrival of the crane also marks the first use of the newly
widened direct entrance. Rosyth has the largest non-tidal basin for
ship repair in the UK, separated from the Firth of Forth by a
sliding gate entrance to hold the water back. This has been widened
by four metres to over 42 metres (removing eight metres on one
side, and adding four to the other) to allow entry of the blocks
from the various dockyards where they are being built, departure of
the completed vessel, and return for maintenance, in a grand civil
engineering project.
To undertake the direct entrance works, two massive cofferdams
were constructed, one on the main basin side and one on the Forth
estuary side, to create a dry working space. This included sheet
piling to bedrock, and placing large semi-circular steel box
section beams and reinforced concrete beams constructed underwater
and below seabed level. This was followed by a staged excavation to
bedrock at a depth of 20 metres below sea level, on the north side
where a new wall was constructed. Construction of the foundation
for this wall alone involved 5,750 tonnes of mass concrete placed
in one continuous pour. The construction of the direct entrance has
taken around 18 months, and involved around 110 workers. It
followed successful completion of No.1 Dock where final assembly
and integration of the carriers will take place.
Commenting on the latest progress, Babcock project director Sean
Donaldson said: "The arrival of the Goliath crane via the newly
widened direct entrance is a significant visible milestone in the
aircraft carrier programme, and an exciting step forward. The civil
works, crane, electrical package and general shipyard upgrade forms
a £80m programme designed to make the Babcock Rosyth facility
capable of assembling the Queen Elizabeth class aircraft carriers.
All projects within the programme are performing to budget and
schedule, to high safety standards, and when complete the facility
will be unique in the UK."
Aircraft Carrier Alliance Programme Director Geoff Searle said:
"This is yet another important milestone for the Aircraft Carrier
Alliance. The Goliath crane will be the largest structure of its
type in Europe and will dominate the skyline in Fife. The crane is
a vital element in the programme to build both the QE Class
aircraft carriers because the ships are being constructed in such
huge sections, so we needed something capable of lifting up to
1,000 tonnes. It will be great to see the crane in action as blocks
of the ship start to arrive in Rosyth in the months to come and HMS
Queen Elizabeth starts to take shape."