1990s saw more rapid development and changes within the railway. The Kowloon-Canton Railway Corporation (KCRC) signed a contract with Anglo-French manufacturing giant GEC-Alsthom to refurbish the Metro-Cammell EMUs at the East Rail depot at Ho Tung Lau. In 1996, the first refurbished train was put into service, and trains now allow passengers to traverse from one end to another (except for the first class carriage), when trains once ran on four three-car EMUs. All but three of the 351 railcars were refurbished; the only unit exempt from refurbishment was unit E44 (144-244-444), which is currently stored in Ho Tung Lau depot. Each set is still made up of 12 cars (with one first-class car). Prior to the rule proclaimed in 1994 which fixed the number of cars on each set to 12, trains were inconsistent in terms of length, ranging from six cars (two EMUs), nine cars (three EMUs) to 12 cars (four EMUs). In terms of appearance, trains no longer have the monotonous design of having a red stripe running across the middle from the cab to the end; the doors now have a red coating, and the window panes along with the upper part are fashioned with blue paint. The original design of the train front, encapsulating the driver's cab and commonly referred to as the "Yellow-cab", was replaced with a more modern design capped with a silver coating, and a digital display added providing the train's destination. The design of the EMU was modified as well: four more sets of doors being added to each car, adding up to a total of ten sets of doors, each side with five; the introduction of new passenger information plasma display; and more standing space by rearranging seating patterns from the traditional back-to-back seating to a longitudinal design. The yellow-cab train was formally retired with a "Farewell Ride" on 31 October 1999. In 1998, a new signalling system, known as Transmission balise-locomotive (TBL, as used in Belgium), came into operation on the line. This Automatic Train Protection (ATP) system, a replacement for the previous Automatic Warning System (AWS) developed in Britain, ensures a safe distance is maintained between trains. It also allowed an increase in train frequencies from 20 to 24 per hour each way. The control centre was also relocated from Kowloon station to a new facility in the KCRC operations headquarters building at Fo Tan Railway House. Also