The truck industry has seen an overhaul of its flagship products, thanks to Euro-6 engine emission legislation. Of course the coach and bus industry is no different, but in addition to cleaner emission standards, passenger service vehicles (PSV) also have to consider design, layout and architecture. If they wish to move forward in terms of fuel economy, performance and comfort, the manufacturers of these vehicles cannot afford to stand still.
One such OEM in the UK is Alexander Dennis Limited (ADL), which claims its latest model to be ‘designed by the industry for the industry’. The new third-generation Enviro400 has been designed to be lighter, more fuel-efficient and carries more passengers than its predecessor.
As the replacement to Britain’s biggest-selling double-deck bus, the new Enviro400 has a duty not only to meet the standards met by the outgoing vehicle, but move things forward. With that in mind, ADL says that the new bus does indeed “raise the bar”, and has been ”meticulously thought-out and built as part of a unique partnership involving ADL’s design and engineering teams, customers from across the industry and suppliers with unique, specialist skills”.
ADL claims there are 200 improvements on the new bus that are designed to bring benefits to operators and drivers as well as passengers. In the development of Enviro400, more than 70 operators were consulted as part of a three-year customer engagement programme – while every fault reported on an ADL double-deck from 2006 was investigated as part of a study.
The results of the study have helped the bus achieve a weight saving of 400kg compared with the outgoing model, while the full-length version can accommodate up to seven extra seats. To ensure reliability, a 6.7-litre Euro-6 Cummins engine has been evaluated with those 70 operators giving it their seal of approval.
Inside, the seating capacity has been increased by one more than on a standard London bus, five more on a hybrid variant and seven more on a full-length diesel model. This news is sure to be welcomed by passengers, and also by operators who have the potential to generate more revenue per journey for little extra cost.
Access and ease of maintenance is also improved throughout the new Enviro400. The tailgate to the engine compartment at the rear of the bus opens higher, while the side doors to the power unit open wider and, if necessary, can be removed entirely. Interestingly, body glass can be ‘zipped’ in and out in a matter of minutes due to a new design of window seal.
The body wiring system is housed in one distribution centre located in the upper deck. The system offers shorter, modular sections that can be changed and clipped back into place easily. Specifically, the wires themselves have been carefully chosen to maximise resistance to heat and corrosion, while the entire system is contained inside the body of the vehicle rather than being exposed to dirt, moisture or impact damage.
Likewise, there is improved access to the wiper motor and the fuel tank, which can be removed from inside the bus, and the destination display – now on a pivot mounting – can be reached effortlessly, making cleaning and maintenance far quicker.
Heating and ventilation – a contentious subject within the bus industry – are also revised in the new bus. ADL engineers have made a number of changes, based on a new approach that incorporates a heating unit located in the lower saloon. The deployment of the unit here forces air to all corners of the bus quickly and efficiently, providing a constant temperature throughout. When supplemented by an air chiller, the system can maintain the temperature to around 17-18°C, ensuring that passengers remain warm in the winter and cool in the summer months.
So, happy passengers and operators but what about the drivers? Those piloting the new buses also played a vital role in the design and development of the Enviro400, especially when determining the size, shape and layout of the cab area. The result is a cab with a protection screen at the point of entry that is no longer an adjunct to the design. In the new bus, this screen becomes an integral part of the whole approach being functional but blending impeccably with the surrounding area.
The cab area is spacious and former distracting reflections have been eliminated by the attention to detail, while visibility is further improved with a new wrap-around windscreen, improved sight lines to the front and sides, and well positioned mirrors.
There is all-new switch-gear, adopting the positive feedback buttons that have been favoured by drivers and operators, and the fully-adjustable steering column and seat ensure that everything the driver needs is comfortably within reach.
Increasing technology often means that many bus cabs today are bedecked with screens, some vital and some optional, but often appearing disorganised. Working with operators and drivers, the ADL team believes it has “designed an ingenious layout for screens that is practical, easily reached and unobtrusive”. It is now time to let the public – and operators – decide.