19 transporter bridges were built to completion worldwide. Of those, four were in the UK: Newport, Middlesbrough, and two over the Mersey (one at Widnes, and one at Warrington). Three of the UK transporter bridges remain, at Warrington, Middlesbrough and Newport, of which the last two are still operational.
Connecting Middlesbrough, south of the River Tees, to Port Clarence, to the north, the Tees Transporter Bridge boasts an overall length of 851 feet and a span (between the towers) of 590 feet. Longer overall than its Newport cousin, although with a span of 56 feet less, the bridge is the longest remaining transporter in the world. (The longest ever built was that between Widnes and Runcorn: it had a span of 997 feet and was 1,150 feet long overall. It was demolished 1961-62.)
Commonly called the Middlesbrough Transporter Bridge, and known locally as The Tranny, the bridge was designed by the Cleveland Bridge and Engineering Co. Ltd, of Darlington. It was built between 1909 and 1911 by Sir William Arrol & Co., of Glasgow, famous for construction of the Forth Bridge.
The bridge is of cantilever form. The structure employs 2,600 tons of steel, plus another 600 tons in the caissons. This compares with 1,326 tons for the more elegant, wider-span, Newport bridge, which relies on its suspension cables for much of the necessary tensioning.
Still operating six days a week, the bridge was Grade II* listed in 1985, with the winch house, piers, railings and gates separately listed Grade II. The third gondola was installed in 2011. Suspended from the truss, which is 160 feet above high water, this can carry nine cars and 200 people, and crosses the river in just 90 seconds.
No comments:
Post a Comment