Halle 902 is a Tatra T-4 tram preserved at the National Tramway Museum, Crich, Derbyshire. It represents the largest series of tramcar ever built worldwide. About 17.000 of these cars were built with minor variations as types T3 and T4 by CKD Tatra in Prague, Czech Republic. They were sold to tramway operators all over the former Eastern bloc, namely in Czechoslovakia, East Germany, Yugoslavia, Romania, Bulgaria and the Sovjet Union. 902 is now unique as it was converted to double-ended configuration by the operator and for preservation regauged from metre gauge to standard gauge using modified bogies from Leipzig in Germany. It was bought to be equipped with a wheelchair lift to complement the car 3006 from Berlin. As yet, Halle 902 has not been converted, and it is currently (March 2008) a static exhibit.