First QE Class blocks joined at Rosyth
The first of the four CB03 sections, weighing some 850 tons and measuring 40m by 26m by 7m was lifted onto the LB03 block last Friday.
The first centre block section for HMS Queen Elizabeth, the first of two new Queen Elizabeth Class aircraft carriers, was lifted onto the lower mid-block at the Rosyth dockyard in Scotland last Friday.
The process marked a major milestone in the build programme and set the datum point for the rest of the ship.
The Royal Navy’s massive new aircraft carriers are being delivered by the Aircraft Carrier Alliance (ACA), an alliance between Babcock, BAE Systems, Thales and the UK Ministry of Defence. Large individual blocks are being built at six shipyards around the UK and then towed to Rosyth for final assembly and integration.
The huge mid hull section, known as Lower Block 03 (LB03), arrived at Rosyth in August, having been towed from Govan where it was built by BAE Systems. This was followed by the arrival this month of the four sections making up Centre Block 03 (CB03) from Newcastle, where they were built by A&P Tyne. The sponsons for this section (which form part of the ship structure to provide a wider flight deck), constructed by Babcock, are already in Rosyth following delivery of the components from Babcock’s Appledore shipyard in Devon.
The massive 8,000 ton LB03 section is over 20m high, 60m long and 40m wide. On arrival at Rosyth the barge transporting it was sunk to float the block, which was then towed to the main basin and winched into No.1 Dock using a capstan system and alignment aids in the dock, where it was lowered on to the pre-prepared dock blocks. Once in place, the dock gates were closed, the dock drained, and services connected to enable work on the block to commence.
The first of the four CB03 sections, weighing some 850 tons and measuring 40m by 26m by 7m was then lifted onto the LB03 block. This will be followed by the remaining three CB03 sections, each weighing in the region of 600 tons, as well as the sponsons for this centre block.
The lifting of the block sections involves further challenges. Finite element analysis (FEA) has been used to study how the individual blocks will perform when lifted to ensure this is executed safely, and the crane’s lifting attachments have been highly engineered to ensure stability and balance of the load across the hoists.
Assembly of the aircraft carrier will take place in three cycles, A, B and C. The assembly of the sections LB03 and CB03 and associated sponsons to create Block 03 makes up Assembly Cycle A, which has now begun and will continue to summer 2012. Assembly Cycle B will see the joining of Lower Block 02, which will arrive from BAE Systems in Portsmouth next year, and Lower Block 01 (comprising the forward sections from the keel up to the flight deck, including the bulbous bow) which was built by Babcock at its Appledore shipyard in Devon and shipped to Rosyth last year (April 2010). This will take place between summer 2012 and spring 2013. The remaining blocks, including the stern sections and island structures, will be assembled in Cycle C, with the hull fully assembled by 2014. Progressive outfitting will see electrical cabling, mechanical pipe systems, ventilation, and fittings and equipment installed.
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