Alexander Dennis Enviro500 (3 Door)

For the Concept Bus unveiled in 2016, see Alexander Dennis Enviro500 Concept Bus.

Alexander Dennis Enviro500 (3 Door)
Artist's Impression for ADL 3-Door Double Decker Bus (Photo: LTA)
Concept rendering of the ADL 3-Door Double Decker Bus (Photo: ADL)
Manufacturer Alexander Dennis Limited (ADL)
Bodywork Enviro500 MMC Facelift
Years in operation 2020 onward
Technical Data
Length 12.5 metre
Engine TBC
Transmission TBC
Accessibility Low Floor & Wheelchair-accessible
Emission Standard Euro VI (SCR)

Following the public showcase in 2016 and the revenue service trial of a 3-Door concept bus in 2017, the Land Transport Authority (LTA) initiated purchases of 100 3-Door Euro 6 Diesel Double Decker Buses in May 2018.

Under Contract PT342 РProcurement of 3-Door Euro 6 Double Deck Diesel Buses awarded on 25 April 2019, Alexander Dennis would deliver fifty units of these buses, with deliveries expected in 2020. The remaining fifty buses would be fulfilled by ST Engineering Land Systems.

The Alexander Dennis Enviro500 (3 Door) Bus is based on the Alexander Dennis Enviro500 Concept Bus, which was one of two concept buses displayed to the public during the LTA’s Our Bus Journey carnivals held in 2016. The concept bus was purchased by LTA in 2015 (under Contract PT236).

These 50 new Alexander Dennis Enviro500 (3 Door) Buses would join the existing operational fleet of 216 Alexander Dennis Enviro500 public buses in Singapore, procured in 2 batches. They will also be the first Euro 6 Enviro500 buses in Singapore.

Technical Information:

History of the Enviro500 (Click to expand)

The Enviro500 is part of the Enviro series of Dennis low-floor buses which was launched in 2002. The original Enviro500 was produced by Dennis (then known as TransBus International) modified from a Dennis Trident 3 (hence the original name Trident E500).

In late 2003, a face-lifted version was offered; the second-generation Enviro500 (or Enviro500 MkII), featuring both modified chassis and bodywork. The Enviro bodywork was also compatible with the Volvo B9TL chassis, and Kowloon Motor Bus of Hong Kong acquired over 80 such vehicles. From May 2004, when Transbus International was reorganized into Alexander Dennis Limited, or ADL (while absorbing Walter Alexander Coachbuilders and Dennis Specialist Vehicles), future Enviro500s would be marketed under ADL.

Originally offered with the Euro III Cummins ISMe335 (also from the Trident 3), the more environmentally-friendly Cummins ISLe340 option was available in Euro IV and Euro V ratings, relying on Selective Catalytic Reduction (SCR) technology to reduce emissions. Voith or ZF transmissions with SensoTop or TopoDyn fuel-saving features are offered for the Euro V rating. A hybrid electric version (Enviro500H) is also offered, using GM-Allison’s parallel hybrid drive system. Cummins also offers Euro VI-rated engines for newer Enviro500 buses.

In 2012,¬†Alexander Dennis revealed the¬†third-generation Enviro500¬†aimed at the Hong Kong market. Named the¬†Enviro500 MMC (for Major Model Change), it boasts a new exterior styling adapted from the Enviro400, along with an all-new interior. The new chassis features improved maintainability, reliability and reduced operating costs. New design features included offsetting the longitudinally-mounted engine and gearbox, along with a safer straight staircase and fuel tank underneath the stairs, a design feature adapted from the Enviro400. The chassis was offered in lengths between 11.3m and 13.0m lengths. A rear-axle steering system is also made available, supplied by ZF (Servocom¬ģ RAS).

The Enviro500 MMC is also known as the Enviro500NG (for New Generation), Trident E500 Turbo, or simply E50D (with ‚ÄėD‚Äô indicating diesel) or E50H (with ‚ÄėH‚Äô for hybrid). The¬†Hybrid¬†variant was made available in 2013, incorporating a series hybrid drive-train by BAE Systems (HybriDrive series-E), achieving the Euro VI emission standard.

According to Alexander Dennis Limited (ADL), the bus will feature a full-flat floor design along with three passenger doors and two staircases, one at the front and one at the rear of the vehicle, allowing commuters to move through the vehicle quickly and safely. It will also use the latest aluminium composite body technology and a host of new safety and energy-saving features.

Initial concept renderings reveal that the rearmost axle is used as the drive axle, which differs from the standard Enviro500 offering where the middle axle is the drive axle.  Significant redesigning work would also have been involved to relocate engine bay components to accommodate the right-hand-drive, third door and fully flat floor design.


Several concept renders were released by LTA and ADL shortly after the announcement of the tender result.

See Also:
External Links & References:

6 thoughts on “Alexander Dennis Enviro500 (3 Door)

    • 16 July 2020 at 2:43 AM

      The Last Unit were Delayed Registration Date till 2021 due to Covid-19 in 2020

  • 7 October 2019 at 11:45 PM

    I want 3-Door Buses Deployment on Service 88, 143, 179 & 190

  • 29 April 2019 at 4:15 AM

    Hopefully using the Euro6 Cummins L9 with 370hp 1600nm..As for ST bus can opt for the new Euro6 MAN 9000cc 360hp/1600nm

    • 16 December 2019 at 6:40 PM

      It’s actually supplied with a Daimler OM936LA.6


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