The Volvo Ailsa B55 was a front-engined double-decker bus chassis manufactured in Scotland by Ailsa, Volvo's British subsidiary in which it owned 75%, from 1974 until 1985. It is only for BNDEP 65 during the trial (SBS4741U) from 1981 to 1992, and between January 1992 and 1 December 1993 is on AMDEP 74, after which it was scrapped when Leyland Olympian 3-Axle began production.
In addition, Timothy North had also purchased the bus in 1980, and the bus was de-registered in 1985 after 5 years of service.
As part of its Alternative Vehicle Evaluation programme, Singapore Transport took delivery of three Mark III vehicles in 1984. The programme was intended to evaluate alternative vehicle types for future fleet replacement in Singapore, which, at that time, was purchasing Leyland Titans and MCW Metrobuses.
The most interesting of the three vehicles was fleet number V3. This vehicle maintained the usual front entrance door, but had an additional exit behind the rear axle and a second staircase adjacent. This had the advantage of improving passenger flow during loading and off-loading at peak times. But the second staircase created a blind spot for the driver and the vehicle was restricted to crew operation. The vehicle remained unique, although London Buses rebuilt the rear, removing the doors, but leaving the staircase in place. After a fatal crash on a stormy night in which V3 crashed into a Mini and turned over on its side, the bus was sold for scrap. V3 was rescued from a scrap dealer by Black Prince Buses and extensively rebuilt, retaining both staircases. In March 2006, it was purchased by Roger Wright's Singapore Bus Company and can now be seen restored to Singapore condition at rallies and running days across Southern England.
No further orders for new B55s were placed by Singapore Transport, but numerous second-hand examples were purchased from the South Yorkshire and West Midlands PTEs in the late 1980s.
A solitary Ailsa chassis was bodied as a single-deck bus by Marshall for Strathclyde PTE. Later, the same operator created a second single-decker, by converting an Alexander-bodied double-decker, the upper deck of which had been damaged.
A number of 2-axle Ailsa B55 were sold overseas. Indonesia received 320 buses between 1981 and 1985. China Motor Bus in Hong Kong received eight between 1975 and 1978 (six out of these eight buses were destroyed by fire). Citybus had purchased Volvo B55 in 1979, which was there until the formal retirement in 1988.
In all, just over 1,000 B55s were built, 890 of them being bodied by Alexander. Of the remainder, 64 Ailsas received unusual Van Hool McArdle bodies built in Dublin - 62 buses for the South Yorkshire PTE and two for A1 Service, Ayrshire. Northern Counties bodied some for Derby Corporation. and Cardiff Bus, a total of 35 were also bodied by East Lancs Coachbuilders for Tayside and a small number were also bodied by Marshall for Strathclyde and Derby Corporation.
The last significant number of Ailsas in service in the UK were operated by Cardiff Bus, who had 18 in regular service in 2007. They were withdrawn at the end of 2007. However, as at February 2014, ten Ailsas remain in service for school work, school contracts and rail replacement with Edwards Coaches of South Wales.
There are now around 30 Volvo Ailsas in preservation, with the Glasgow Vintage Vehicle Trust having five. The Sheffield based 388 Group have 2 Van Hool bodied examples, one of which being A1 Services - PSJ 824R. With Tayside being the most prolific buyer of the Ailsa, there are also a significant number in various stages of restoration with Tayside Vintage Vehicle Society, and two preserved examples regularly visit rallies and events throughout the country, WTS 273T and the open top WTS 272T. A number of Cardiff Bus Volvo Ailsas have been preserved, one such example being NDW412X, owned by the 302 Group.