Procurement of a future icon for London
Engineering icons are often unplanned. It therefore follows that trying to create this status for a product from the outset is a big ask, especially when you are replacing an existing popular and iconic design.
So when Boris Johnson said he wanted a Routemaster-style bus back on the streets of London in 2008, it was understandably hailed as a tough challenge. The 'New Bus for London' would need to be 40% more fuel efficient, produce 40% less NOx, 33% less PM, but critically, it had to be iconic.
David Barnett, development engineering manager at Wrightbus, says: "The brief we were given was that when you walk in to a newsagent in London, you will find postcards of a black taxi, a red phone box, and a Routemaster bus. Fast forward five years and you will see the New Bus for London. This design will define London transport. So no pressure."
The original Routemaster, designed in the early 1950s, has limitations in modern use such as the need for a conductor and limited seats. The new bus would need increased passenger capacity, air-conditioning, a hybrid drive system, and the rear staircase of the original.
"When you look at the original proportions and start to scale those up, you completely ruin the original concept," says Barnett. "The quirkiness of that design is lost altogether."
Wrightbus keeps alive an ethos that is, itself, time served. It says the biggest asset is its skilled manufacturing staff and as a result it's keen to involve them in product development as much as possible. Engineers at the company use Pro Engineer for 3D modelling but get production staff to produce physical mockups to see how things will look in the real world.
"They look at a design in Pro Engineer and mock it up to see how they might build it, what the passenger flow might be like on the staircase, and if is it going to work," says Barnett. "For example, serviceability of the engine, while it fits in Pro Engineer and you can visualise it, how is that going to work when you are in a dirty bus garage at 11pm at night and you have got to get to the air filter? Building mockups in conjunction with 3D models ensures we build a product that not only looks great, but has first-class engineering."
The end design of the New Bus for London uses sweeping glass panels that surround the upper and lower decks, connecting together at the rear staircase. The inside also borrows heavily from the original in its styling. To enable the hybrid drive system and the rear staircase the vehicle length had to be extended. This meant that the entire rear part of the bus is modular, made from composite, and bolted on.
While the use of 3D models has greatly enabled a faster design process, Wrightbus is reticent about buying in to the complete digitisation of the design process. Quite simply, it thinks it doesn't need to, and that it is more about a balance of old and new philosophies.
"Change management and ensuring people are working on the correct version of a design has been a big benefit of using Pro Engineer," says Barnett. "As is the ability to control access, protect out data and share that data out within the company.
"We want to increase the role of it today and move it beyond an engineering tool and drive out all of the non-value added time throughout our process. But, we have got a long way to go and have a lot of hearts and minds to move in the way."