there were various seating capacities for on a small minority used and rail/airport services. Summerhill based AV 116-130 were built with dual door bodies for use on the Airlink services. Outside London, Arriva ordered ALX400s on both the Dennis Trident and Volvo B7TL chassis in comparatively smaller numbers compared to Stagecoach and the FirstGroup. On the Volvo B7TL chassis, 20 ALX400s were delivered to Arriva Yorkshire in 2000, 49 were delivered to Arriva Medway Towns in 2004 as part of Operation Overdrive, and 30 ALX400s were delivered to Arriva Merseyside in 2006, while on the Dennis Trident chassis, 30 ALX400s were delivered to Arriva Shires & Essex in 2000. In late 2005 Alexander Dennis launched the Enviro400 model, intended as a replacement for the ALX400. Despite the bulk of the 2006 Stagecoach double-decker bus order favouring the Enviro400 model, also chosen by London operator Metroline, in July 2006 Dublin Bus placed a repeat order for 100 of the type on Volvo B7TL chassis. Production of the ALX400 bodywork ceased after the delivery of these 100 ALX400-bodied Volvo B7TL in late 2006. Gallery References External links Alexander Dennis buses Double-decker buses Low-floor buses Vehicles introduced in 1997