Volvo is unusual in having a factory just to build cabs for its machines.Dan Gilkes went to Sweden to see how it produces more than 11,000 a year
THERE ARE plenty of details to concentrate on when designing a new machine or revising an existing model.More power from the engine is usually pretty high on the list, alongside improved fuel consumption, lower noise and increased productivity.
Somewhere in that list comes the operator's cab. Redesigning a whole cab is no small job and most companies will simply improve the specification of an existing cab structure for a machine facelift.
But what about when the time comes for a complete cab overhaul, or when the company enters a new market sector and has to come up with an operator station from scratch? At Volvo Construction Equipment, operator ergonomics and cab design rank pretty high. So high, in fact, that the firm has a stand-alone cab company, based in Hallsberg in Sweden, that provides cabs and cab design assistance to all its manufacturing plants globally.
The Hallsberg site builds around 11,500 cabs a year, mainly for wheeled loaders and ADTs.That figure includes a number of wheeled loader cabs that Volvo builds for Komatsu's plant in Germany and a small number of cabs for Atlas Copco drilling machines and Kalmar lift trucks.
The cab division's people work closely with the manufacturing plants, assisting with excavator cab design in Korea and specifying the design for cab suppliers to the compact plant in France.
So how do you come up with a cab design? Is it just a box on top of the chassis, or an integral component of the machine? Research and development director Jonny Lindblom says cab designers have to get involved with the operators on site to understand their needs.
'It's not enough to understand about ergonomics.You have to get your boots on and get out there, ' he says.
When you get cab design right, the benefits are obvious, both for operators and for the manufacturing plant.Volvo's wheeled loader Comfort Care Cab for instance was so right that the basic structure has remained the same for nearly 15 years, yet still offers a competitive cab environment today.
'You have to look at the operator's interaction with the machine, ' says Mr Lindblom.
'How does the interface work? We want to be world leaders, so we have to focus on the application.'
The cab division sends out teams of engineers, designers and ergonomics specialists, both from within Volvo and from external sources, to sites around the world to carry out studies of the needs of the operator in as many applications as possible.
'We are out there gathering information and videoing operators at work. It costs us a lot, but it's worth it, ' says Mr Lindblom.
They look at the full spectrum of requirements, from ergonomics and comfort to productivity and safety. Ergonomic methodology has increased rapidly over the past five to 10 years, assisted of course by developments in technology that allow for greater use of computer modelling. But there is still no replacement for actually getting out on site.
'That's our strength, ' says Mr Lindblom.'Rather than just buying in a cab from an external company we are a Volvo company.
'Ergonomics is not just common sense.And it's not just using yourself as a model, you need a broad scope of operators to understand what's needed.A skilled operator is worth taking care of, but a comfortable machine is also worth taking care of.'
Having taken video footage of operators at work, examined the applications and talked to the people in the cabs, the team then sits down and puts together a wish list - more space, greater glass area, lower noise, better seating, and so on.The job then, in conjunction with the machine designers and product teams, is to prioritise the points on that list.
Once the wish list has been set and the design criteria established, Volvo Cabs moves on to prototyping and building mockups of the cab structures.Again computer-aided design helps, making it possible to go through much of the prototype stage without having to construct actual cabs.
'We are building more of our cabs with a modular approach, ' says Mr Lindblom.'In the future the customer will have more choice of specifications.'All of which bodes well for the operator and, through increased productivity, for the customer.
Global economies of scale for a multi-million operation
VOLVO has occupied the Hallsberg site since 1868.The present cab plant was built there in 1975.
Volvo Cabs became a separate division in 1997, originally to look at synergies between the various production plants around the world but now having responsibility for all Volvo cabs worldwide.There are five basic wheeled loader cab structures, which then become 10 cabs for the various loaders in the Volvo lineup.A single cab is used for all three models in the latest range of ADTs.
In addition to the cabs, it fabricates around 20,000 fuel and hydraulic oil tanks for articulated haulers and wheeled loaders.A second facility next door to the cab plant builds high-capacity hydraulic cylinders for Volvo, fabricating around 51,000 cylinders in 2004.The site employs 740 staff and last year turned over e135 million (£85 million).