Alexander ALX500

{{short description|Low-floor double-decker bus body}}

{{more citations needed|date=January 2021}}

{{Use dmy dates|date=July 2017}}

{{Infobox automobile

| name = Alexander ALX500

| image = JF8429.jpg

| caption = New World First Bus Alexander ALX500 bodied Dennis Trident 3

| manufacturer = Alexander
TransBus

| production = 1997–2002

| assembly = Falkirk, Scotland

| class =

| capacity = 61 to 93 seated

| length = 10.6, 11.3 & 12.0 metres

| width = 2.5 metres

| height = 4.4 metres

| floortype = Low floor

| doors = 2

| weight =

| chassis = Dennis Trident 3
Volvo Super Olympian

| related = ALX100, ALX200, ALX300, ALX400

| engine =

| powerout =

| transmission =

| predecessor =

| successor = TransBus Enviro500

}}

The Alexander ALX500 (later known as the TransBus ALX500) was a low-floor double-decker bus body built by Alexander in Falkirk, Scotland between 1997 and 2002.

The Alexander ALX500 was fitted to Dennis Trident 3 and Volvo Super Olympian chassis (they could be distinguished by the design of the engine compartment: with round indicators for Dennis and square indicators for Volvo), and came in lengths of 10.6, 11.3 and 12 metres (35, 37 and 40 foot). The ALX500-bodied buses were sold new to Citybus,{{cite book |editor-last=Chan |editor-first=Danny C. Y. |date=1998 |pages=44–46 |title=Hong Kong Buses Yearbook 1998 |location=Hong Kong |publisher=Northcord International |isbn=9789629200176}} Kowloon Motor Bus, Long Win Bus, New World First Bus{{cite book |editor-last=Chan |editor-first=Danny C. Y. |date=2000 |pages=42–44 |title=Hong Kong Buses Yearbook 2000 |language=zh-hk |location=Hong Kong |publisher=Northcord International |isbn=9789629200275}} and Kowloon-Canton Railway Corporation{{cite book |editor-last=Chan |editor-first=Danny C. Y. |date=2001 |pages=19 |title=Hong Kong Buses Yearbook 2001 |language=zh-hk |location=Hong Kong |publisher=Northcord International |isbn=9789629200329}} in Hong Kong. Due to the climate there, all of them were fitted with air conditioning systems, and as a result lacked a rear window on the lower deck. The extra length of the buses mean the seating capacities were near the 100 mark for the 12.0 metre variant.World News Buses Worldwide issue 214 July 2019 page 44

File:HK TC Tung Chung Long Win Bus S64 Airbus.JPG Alexander ALX500-bodied Dennis Trident 3 rear.]]

Alexander built three prototype ALX500 bodies for prototype Trident 3 chassis in 1997, with the first finished in February 1997. Production of the ALX500 body was started later in the same year, with two examples exhibited in Coach & Bus '97 in Birmingham; but there were some minor changes in appearance, for example the exit door was moved rearward (for 12.0 metre variant only). In 1999, a facelifted version of the ALX500, which more resembled the Alexander ALX400 in appearance was introduced, the first of these bodies were fitted to the first batch of Super Olympians for Kowloon Motor Bus and New World First Bus.

When TransBus International was formed in 2001, the Alexander ALX500 body replaced the standard height, right hand drive version of the Duple Metsec DM5000 body (built for the Dennis Trident 3) which was duplicated with the ALX500 design. In late 2002, the ALX500 body was superseded by the TransBus Enviro500.

All Alexander ALX500 bodied buses are progressively retired by March 2023.{{citation needed|date=October 2023}}