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Six Daring Class Type 45 anti-air warfare destroyers are being assembled, launched and outfitted for the UK Royal Navy at BAE Systems Surface Fleet Solutions’ Govan & Scotstoun shipyards in Glasgow. The bow sections, masts and funnels for all six ships are being built in Portsmouth. These destroyers will have an overall length of 152.4 m, space for a crew of 235, a displacement of 7350 tons, a top speed greater than 27 knots and its range greater than 7000 nautical miles. The first one is HMS Daring and is to enter service in May 2009.
The ship’s hull is manufactured in sections or “blocks” in a fabrication shop adjacent to the berth and slipway. Five blocks are moved in total to build one ship of which the heaviest block weighs over 1400 tons.
Hydraulic lifting and load transfer
Each block is transported to the slipway and aligned longitudinally to the slipway on multi-wheeled transportation vehicles. During this procedure the slide-tracks on the slipway are removed so that the vehicles can drive the blocks into position.
The Enerpac Synchronous Lifting System is now used to lift the block free from the transport so that they can be driven away. During the lifting procedure the 16 points PLC-controlled synchronous lifting system operates within strict load and stroke constraints to ensure that the desired load paths into the ship's hull structure are maintained. With the transport removed and the hull segments supported by the hydraulic system, the blocks are weighed with the synchronous lifting system to confirm the design calculations.
Slide-track installation, lowering and block manipulation
The next step is the slide-track installation. The slide-tracks on the berth’s slipway can then be re-installed. The block is lowered synchronously and the load is transferred on to the slide-tracks. The hydraulic lifting system permits the manipulation of the blocks prior to welding to the adjoining section. This manipulation – lifting, lowering and rotation, is a PLC-controlled hydraulic movement.