Falkirk Wheel
Planners decided early to create a dramatic 21st-century landmark structure to reconnect the canals, instead of simply recreating the historic lock flight.
[4][5] In 1976, the BWB decided after a meeting with local councils that the Forth and Clyde Canal, fragmented by various developments, was to have its remaining navigability preserved by building new bridges with sufficient headroom for boats and continuing to maintain the existing locks.
[6] A 1979 survey report documented 69 obstructions to navigation, and sought the opinions of twenty interested parties to present the Forth and Clyde Local (Subject) Plan in 1980.
[7] In 1996, when sufficient funds had been accumulated, the Commission invited applications to "do anything they thought desirable ... to support worthwhile causes which would mark the year 2000 and the start of the new millennium.
[7] The BWB had made an earlier plan for the reopening of the canal link, which comprehensively covered the necessary work.
[8] The plans called for the canals to be opened to their original operating dimensions, with 3 metres (9.8 ft) of headroom above the water.
[12] The Morrison–Bachy Soletanche Joint Venture Team submitted their original design, which resembled a Ferris wheel with four gondolas, in 1999.
[20] Kettle described the Wheel as "a beautiful, organic flowing thing, like the spine of a fish,"[17] and the Royal Fine Art Commission for Scotland described it as "a form of contemporary sculpture.
"[12] Models and renderings of the Falkirk Wheel were displayed in a 2012 exhibition at the Victoria and Albert Museum in London.
[22] In March 1999 Donald Dewar, the Secretary of State for Scotland, cut the first sod of turf to begin work at lock 31 on the Forth and Clyde Canal.
The structure was then dismantled in the summer of 2001, and transported on 35 lorry loads to Falkirk, before being reassembled into five sections on the ground and lifted into place.
[3] The 180 m (590 ft) Rough Castle Tunnel was driven in three stages, with the two upper quarters being drilled with a standard excavator before the lower half was dug using a modified road planer in 100 mm (4 in) layers.
[15][26] Twenty metres (66 ft) of loosely packed backfill from the mining operations containing large sandstone boulders was not considered adequately solid foundation for the size of the structure, so deep foundations with thirty 22 m (72 ft) concrete piles socketed onto the bedrock were used.
[15] Due to the changing load as the wheel rotates in alternating directions, some sections experience total stress reversals.
[14] On 24 May 2002, Queen Elizabeth II opened the Falkirk Wheel as part of her Golden Jubilee celebrations.
[15][13] It takes 22.5 kilowatts (30.2 hp) to power ten hydraulic motors, which consume 1.5 kilowatt-hours (5,100 BTU) per half-turn, roughly the same as boiling eight kettles of water.
[37] The area housing the machinery to drive the wheel is located in the final pillar of the aqueduct, and contains seven chambers connected by ladders.
[38] Access is by a door located at ground level or an entrance halfway up the tower, with a gantry crane to facilitate the installation of equipment.
[39] The large central gear is fitted loosely over the axle at its machine-room end and fixed in place to prevent it from rotating.
[39] The docking pit is a drydock-like port isolated from the lower canal basin by watertight gates and kept dry by water pumps.
[20] When the wheel stops with its arms in the vertical position it is possible for boats to enter and exit the lower caisson when the gates are open without flooding the docking pit.
