Dennis Enviro 400

The Alexander Dennis Enviro400 is a twin-axle low-floor double-decker bus that was built by the British bus manufacturer Alexander Dennis between 2005 and 2018. It replaced the Alexander ALX400, Dennis Trident (from which the Enviro400 was developed) and Plaxton President. In 2014, the Enviro400 was succeeded by the updated Alexander Dennis Enviro400 MMC and production of the classic Enviro400 ceased in 2018.

The Enviro400 is available both as an integral bus and as a standalone bodywork and chassis. The Enviro400 chassis replaced the Dennis Trident 2 (and continued to be badged as the Trident for a time) and was formerly available with East Lancs Myllennium Lolyne and Optare Olympus bodywork; the Enviro400 body replaced the Alexander ALX400 and Plaxton President designs and was sold on Scania N230UD, Volvo B7TL and Volvo B9TL chassis.

First generation (2005–2010)

The Enviro400 was originally launched as an integral product. Soon after launch, the Enviro400 chassis became available with East Lancs Myllennium Lolyne and Optare Olympus bodywork.

As well as an integral bus, the Enviro400 body was available on Scania N-series chassis. The vast majority of N-series Enviro400s built were of the N230UD variant, which sold well with Stagecoach Group. Additionally, two N-series Enviro400s were built on the more powerful N280UD variant of the chassis, both for Express Motors of Porthmadog.

As well as the Scania N-series, a single Enviro400 was constructed on Volvo B7TL chassis before this chassis was succeeded by the Volvo B9TL, on which more examples of the Enviro400 were bodied.

Second generation (2008–2018)

Alexander Dennis released the second generation Enviro400 at Euro Bus Expo in 2008, with the main external visual differences being the incorporation of a line of white LED daytime running lights underneath the headlights in the main front light clusters, redesigned front bumpers and the relocation of the offside emergency exit door. The facelift coincided with the introduction of a Euro 5 compliant drivetrain for the Enviro400. The ''Trident'' moniker on the chassis plates was largely dropped not long afterwards, but the ''Trident 2'' name was retained on Enviro400s built for Hong Kong.

The second generation Enviro400 was superseded by the Enviro400 MMC in 2015 in the UK with no more orders, but in 2016 Alexander Dennis developed a low-height Enviro400 with Enviro400 MMC-style front and rear specifically for Hong Kong market. Production of Enviro400 ceased in 2018.

Powertrain variants

Integral Enviro400

London operator Metroline was the first company to order the Enviro400, ordering 28 for route 24 in June 2005, entering service at the end of the year. One dual door demonstrator, named '' Spirit of London'', was delivered to Stagecoach London to replace the Dennis Trident destroyed during the 7 July 2005 London bombings and a single door demonstrator was delivered to the then Travel West Midlands for evaluation. Both prototypes were exhibited at Coach & Bus Live 2005 in the National Exhibition Centre in Birmingham.

The Enviro400 had sold well in London with a number of operators, such as Travel London and London General (which received the first Euro IV-engined Enviro400 in May 2006), operating these buses. It is also popular with Stagecoach, which placed its first order of 130 low-height models in February 2006, later followed by another 389 buses with Euro IV/V engine. Arriva also received Enviro400s for its UK operations; Arriva Merseyside relaunched its Wirral - Liverpool 'Cross River' services with a batch of 23 in January 2009. A further batch of 12 was allocated to Bootle depot in September 2009 originally for the cross-Liverpool trunk service 60 linking Bootle with Aigburth. However a much larger order of 128 Enviro400s was placed by Arriva for its Merseyside division from the autumn of 2014 onwards with significant numbers in service at Bootle, Green Lane, St Helens, Southport and Speke depots.

The FirstGroup received a large intake of Enviro400s ahead of both the 2012 Summer Olympics and the 2014 Commonwealth Games, which were held in London and Glasgow respectively. These operated under the license of First Games Transport, providing shuttle services throughout the Games before being dispersed to other operators within the FirstGroup following the Games' conclusion. 60 Enviro400s were delivered to Glasgow in 2014. Later in 2014, eighteen Enviro400s were delivered to First West Yorkshire for operation in Leeds.

In 2008, a specially converted Enviro400 was assembled in knock-down kit form for the closing ceremonies of the 2008 Summer Olympics and 2008 Paralympic Games in Beijing. The bus featured as part of the handover ceremony for the 2012 Games, where it was driven into the Beijing National Stadium as a typical London bus before a set of hydraulic pumps opened up the bus, revealing a stage covered in artificial grass which was shaped as various London landmarks.

In 2012, Southern Vectis received 20 for school contracts on the Isle of Wight. These were delivered during late December 2012 and early January 2013 and entered service on a wide variety of school services on the island from 7 January 2013. Southern Vectis then proceeded to order ten more Enviro400s to be used on public routes, mainly route 9, which entered service in January 2014, followed by another order for ten Enviro400s which were delivered in 2016.

Between 2014 and 2015 Arriva North West received a total of 128 integral Enviro400s for a number of services on Merseyside - with 28 arriving in 2014 and the remainder being delivered between January and July 2015. Arriva Buses Wales received a total of 29 high specification Enviro400s between June 2014 and March 2015 for deployment on two new Sapphire services between Rhyl and Llandudno and Chester and Connah's Quay respectively.

Enviro400H

Alexander Dennis launched the hybrid electric Enviro400 Hybrid (often shortened to Enviro400H) at the 2008 Euro Bus Expo, built with a hybrid drivetrain developed in partnership with BAE Systems. The first five production examples entered service with Metroline, followed by larger fleets of Enviro400Hs entering service with operators such as Go-Ahead London, London United, Abellio London and Stagecoach London.

Outside of London, the Enviro400H was popular with the Stagecoach Group, who starting in 2010, ordered examples delivered in a green variant of the standard Stagecoach livery for their Stagecoach Oxfordshire, Stagecoach Yorkshire, Stagecoach Manchester, and Stagecoach North East subsidiaries.

Other operators who purchased Enviro400Hs included National Express West Midlands and National Express Dundee, ordering a total of nineteen for service in Birmingham and Dundee in 2013; East Yorkshire Motor Services, who purchased ten for cross-city services in Kingston upon Hull in 2011; Reading Buses, who had 31 Enviro400Hs delivered between 2010 and 2011; Lothian Buses, who took on 15 of the type in 2011; the Oxford Bus Company, who took on examples to upgrade its park & ride fleet, and First Glasgow. However, reliability issues and maintenance costs have seen many operators convert their Enviro400Hs to use diesel powertrains, with East Yorkshire providing most of these conversions, while Reading Buses converted one of their Enviro400Hs to a plug-in electric vehicle.

Scania Enviro400

Stagecoach announced on 28 February 2007 that it had ordered 25 Enviro400s with Scania N230UD chassis, which were subsequently delivered in early 2008. These were followed by another 56 for delivery in 2009, 100 for 2009/10, 100 for 2010/11, 91 for 2011/12 and 57 for 2012/13. Five were delivered to Stagecoach in Lincolnshire in 2012 for Lincolnshire InterConnect service 6, serving Skegness, Horncastle and Lincoln.

Another significant operator of Scania Enviro400s is Nottingham City Transport, who ordered a total of 62 Scania N230UD Enviro400s, with first deliveries beginning in 2014. Further examples were delivered throughout 2014 and 2015, with most receiving colour-coded route branding for services across the city. These Scania Enviro400s were delivered with audio-visual next stop announcements, mood lighting and leather seating.

The Oxford Bus Company received eleven high-specification Scania Enviro400s in 2009 for service on the Brookesbus network. Wilts & Dorset also received some examples. Two were delivered to independent operator Stephensons of Essex in 2013.

Volvo Enviro400

On 13 October 2006, Solent Blue Line received a Volvo B7TL/Enviro400 meeting the Euro III emission standard, with the interior in Wilts & Dorset livery. This remains a one-off as all subsequent Enviro400s on Volvo chassis were built on the B9TL chassis. An Arriva demonstrator was shown at Euro Bus Expo in 2006 to the latter standard.

Irish municipal operator Dublin Bus was the first operator to order the Volvo B9TL-based Enviro400, taking delivery of 100 on the updated Volvo chassis in two batches between 2007 and 2008. East Yorkshire Motor Services later took delivery of five Enviro400-bodied Volvo B9TL in December 2007, which entered service in January 2008. London General also received three Enviro400-bodied Volvo B9TLs in October 2008, which were evaluated against integral Enviro400s and Wright Eclipse Gemini-bodied Volvo B7TL and B9TLs extensively featured in Go-Ahead's London Central and General fleets. No further orders resulted in the United Kingdom, although London General's Enviro400s were briefly loaned to Arriva London North for evaluation ahead of delivery of their Volvo B5LHs.

Exports

Globally, more than 6,000 integral Enviro400s have been sold as of January 2016.

Hong Kong

Citybus received two air-conditioned Enviro400 demonstrator (7000-7001) for evaluation in 2009. They are equipped with 8.9L Cummins ISLe engine and ZF Ecolife 6AP1403B gearbox. In November 2010, an extra order of 38 Enviro400s (7002-7039) were placed, these buses had a denser seat configuration and entered service in 2011. A further order of 20 Enviro400s (7040-7059) had been placed and these buses started to enter service in 2013.

MTR Corporation also ordered nine Enviro400s (140-148) for MTR Bus service, these buses entered service in 2012. Two more Enviro400s (149-150) entered service in 2018. All of them are equipped with ZF Ecolife gearbox

Kowloon Motor Bus received a Enviro 400 demonstrator (ATSE1) in 2009, it entered service in February 2010 and equipped with a 8.9L Cummins ISLe engine and ZF Ecolife 6AP1403B gearbox. A further 50 Enviro400s (ATSE2-51) were ordered in 2012 and registered between 2012 and 2013. They are designed with a denser seats configuration and equipped with a Voith DIWA 864.5 gearbox.

New World First Bus ordered 60 low-height Enviro400s, these entered service in 2016 and 2017. They had a Cummins ISLe engine and Voith DIWA 864.5 gearbox.

New Lantao Bus ordered 14 low-height Enviro400s, which are similar to New World First Bus' batch. They entered service from October 2018 and have served route 3M since January 2019.

North America

The Enviro400 was introduced to North America exclusively as an open-top bus for sightseeing purposes. It is not available as a public transport vehicle, unlike the similar Alexander Dennis Enviro500.

On 11 November 2010, Alexander Dennis announced it had received an order for 10 Enviro400s from Coach USA subsidiary Twin America, in New York.

Specifications

Internal layout

The Enviro400 features an innovative seating layout that maximises use of seating space on the lower deck by placing two forward-facing moulded seats onto the front nearside wheelarch box with a small luggage shelf on the rear half, and also (on full-height models) a single forward-facing moulded seat on the front off-side wheelarch hub between the driver's partition and the staircase.

Powertrain

The engine is a six-cylinder Cummins driving through a Voith or ZF automatic transmission. The maximum speed, like all British buses, is electronically limited to . A hybrid-electric version of the powertrain was also available.

See also

* List of buses
*'' Spirit of London'', an Enviro400 built to replace the bus destroyed in the 7 July 2005 London bombings.

References

{{Alexander Dennis

Enviro400
Double-decker buses
Hybrid electric buses
Low-floor buses
Open-top buses
Vehicles introduced in 2005