British Rail Class 333
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The British Rail Class 333 electric multiple units were built by Siemens and are based on the Class 332 trains operated by Heathrow Express.
Sixteen three-car units were introduced in 2000 and are now operated by Northern Rail on the Wharfedale and Airedale lines in West Yorkshire, England (between Leeds, Bradford Forster Square, Ilkley and the North Yorkshire town of Skipton). Occasionally they are used for local services on the line between Leeds and Doncaster. They are based at the Neville Hill depot in Leeds and painted in the livery of West Yorkshire Metro, the local passenger transport executive.
Due to increased passenger numbers, the sets were lengthened to four cars in 2002.