towards the end of last year, replaced with standard double decks running more frequently to make up for the loss in total passenger capacity. He also launched a competition for a design for the New Bus for London. With the announcement of the winner, Johnson invited manufacturers to bid for building a prototype fleet of vehicles to the new design. The one catch was that Transport for London would have the rights to the design, as it would pay the full development costs. Some might think this was a reasonable proposition, but it was unacceptable to major international manufacturers contributing many years of their highly valued and closely guarded technical expertise. In the end it came down to a straight contest between two British manufacturers; Alexander Dennis and the successful bidder, Wrightbus, based in Ballymena in Northern Ireland. Transport for London introduced London-based Heatherwick Studio to work hand-in-hand with Wrightbus on the design. At the time Thomas Heatherwick was an unknown name in the automotive world. It may have been tense for the free ranging mind of Thomas Heatherwick and his design colleagues to come up against the rigidity of the strict regulations of the European Union for driver and passenger safety. However, Mayor Johnson was determined to create a new icon for London, as well known as the previous red double deck buses and black taxicabs. Wrightbus garnered a contract worth around $18 million to develop eight pre-production NB4L prototypes. The company and Heatherwick were up against the clock from the beginning, as the next Mayoral election in London is this May. Johnson wanted to have the prototype fleet in service and seen by millions of Londoners before the critical date. NB 4L also had to meet the latest hybrid specification. Working closely with Siemens the company had its own patented light and strong aluminium construction system. Only the low-floor underframe is steel. NB4L features three doors and two staircases. A double-width door is located at the front alongside the driver and ahead of the front axle. The second double-width door opens behind the front axle. One interesting feature is the traditional-styled open rear
platform leading to a second staircase at the rear of the bus and into the lower deck. This door can close off so one driver can operate the vehicle during off-peak periods without a conductor to tend to the passengers and ticketing, which is effectively the same two-door layout as all other double deck buses running in London. To accommodate the door and staircase arrangements the overall length came out to 36-ft 9-in, quite a bit longer than most other double deck buses running in the capital. The cleverly packaged hybrid drivetrain at the rear of the vehicle uses a compact 4.5 litre Cummins ISBe diesel engine that drives a generator to power the Siemens hybrid drive system. The rear axle drives with regenerative braking to recuperate energy stored in compact lithium-ion batteries. I saw the first nearly complete prototype at Wrights factory in the spring of last year. It was certainly different and broke away from the rather square shape of most double deck buses. There is an abundance of glass, particularly around the staircases, and a deep lower front windshield. Its asymmetric styling and prominent round headlights look nearly retro in style. The rear dome is most distinctive, almost totally panelled except for a curved glazing feature over the rear staircase. Unlike any other bus, it must surely meet the mayorâ€™s wishes for an iconic design. Wrightbus has its own well-established reputation for design and styling. Several British prepared to invest in up-market features have demonstrated that by making the passenger area
The interior is of a high standard. A wheelchair passenger parks facing rearwards against the padded board on the right.
Published on Apr 3, 2012