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user needs and product positioning, create a new and exciting design aesthetic, and verify and validate the result of many years of work.

Reflecting the clean-sheet approach taken for its development, the Crown C-5 is indeed a fresh and clean product that expresses purposefulness, attention to every detail, and an unmatched degree of user-centredness in an IC forklift.

early analysis and research Early field research by the team at dozens of sites identified a set of key ergonomics and design ‘areas of opportunity’ for the new design. First and foremost – and based on the premise that a comfortable operator is a more productive operator – a lift-truck having higher levels of productivity and efficiency

Designing a completely new industrial vehicle from the ground up is an opportunity

that does not come around every day – and that is why I jumped at the invitation to assist Crown’s Design Center with the development of its revolutionary C-5 IC forklift.

The C-5’s roots can be traced back to 2003, and even earlier, with initial research on IC truck markets, users, uses, and competitor product offerings. Like any clean-sheet product development effort should, Crown employed ergonomics and industrial design expertise from the first to the last day of the programme to help identify the functional and performance requirements of the overall machine, define the objectives for the operator’s workspace and interface, flush-out

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left: Attention to detail in the overhead guard maximises upward visibility

Advanced Lift-truck Technology International 2010 41Advanced Lift-truck Technology International 201040

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Advanced Lift-truck Technology International 2010

was among the top objectives. Second, the truck had to have best-in-class drivability and control as well as exceptional levels of comfort and visibility forward as well as to the rear, as lift-trucks are driven in reverse for so much of the time.

Best-in-class ingress and egress was another objective from the outset, with particular attention paid to step height and size, an unobstructed and open entry path, and high and wide overhead guard rails and vertical support posts. Regular maintenance activities were also studied extensively during the research, and maintenance performance objectives from the points of view of the operator and service technician were spelled out. At this stage of development and at the conclusion of the initial research, the ‘clean sheet’ of paper still remained unmarked with no formal design, per se, yet the team had a clear set of objectives and innovative concepts to be explored.

Initial workspace layouts A first step on the ergonomics front was to develop a set of parameters for ‘workspace geometry’ – that is, the basic placement of the seat, floor, pedals, steering wheel, controls, and ranges of adjustability required to accommodate the range of operator sizes. The result was numerous seating test bucks like the

one shown in Figure 1 that illustrate how the C-5 was truly designed ‘from the operator out’.

These seating bucks served as test devices for numerous human factors studies involving large samples of lift-truck operators of all different shapes and sizes. Required ranges of adjustability for the seat and controls, the height of the seat, the location of pedals, and the ease of ingress and egress were studied and restudied using an evolving series of test bucks.

Early research suggested that the general area of IC truck seating warranted considerable attention. A separate research, design, and engineering team was therefore established to develop an in-house seat meeting a stringent set of requirements. It had to establish new standards of comfort and durability, be easy to adjust, and support the operator during forward as well as reverse driving. It was also felt that a seat with a larger, less contoured and restrictive seat pan would provide greater comfort and seating variation for the operator. The many research steps in the program included the recording and analysis of pressure maps of different seats during high-impact driving.

Developmental performance testing and field testsHighly structured operator-centric performance tests were conducted at

key points during the development of the truck. In each, a test course and tasks were created to simulate various warehousing and materials handling scenarios of interest. One or more test truck mules were operated by large samples of experienced drivers. Measures of work performance, including things like the number of loads moved and cycle times, were recorded and analysed.

On the subjective front, operators provided ratings of ride quality and comfort, visibility during different phases of operation, control design and functionality, ingress and egress, and many other factors. The objective performance measures and subjective ratings and comments were used to validate – as well as refine – various aspects of the truck during development.

‘Blind’ tests of mule trucks and competitor IC trucks were also conducted using disguised products without branding, ensuring the validity of results and the conclusions that could be drawn.

In a major undertaking towards the end of the program, and in addition to other field testing tied to machine reliability and other engineering interests, hundreds of pre-production trucks were placed in private, closed facilities throughout the USA and operated as part of each facility’s fleet, sometimes in the most demanding of conditions.

figUre 1 (ABoVe left): One of many early seating bucks used to test workspace geometry and adjustability

figUre 2 (ABoVe rigHt): To evaluate seat types, materials and structures, pressure maps were used – pressure map of the Crown FlexSeat (top) and of a competitor’s seat (above)

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Advanced Lift-truck Technology International 2010

Applications spanned low-duty, to medium-duty, to heavy-duty truck use in which the machines were driven 24 hours a day, seven days a week. Particular emphasis was placed on understanding the success of the machines in heavy-duty applications – a prime target market for the C-5 and an environment for which the truck was designed.

Operators and service technicians provided extensive data and ratings to Crown’s industrial designers to help evaluate all aspects of the operator interface as well as the serviceability of the truck.

Resulting design and ergonomics Although there are dozens of innovations on the Crown C-5 aimed at improving the comfort and performance of the operator, a handful of outcomes of the preceding design and ergonomics work are worthy of special note.

One of the first things operators perceive about the new C-5 are its ‘clean and uncluttered lines’. From the wide and integral first step, to the wide entrance at the floor and beyond to the large, unobstructed foot space, the operator station is an integrated, carefully planned space where a driver can be comfortable as well as productive.

The new Crown FlexSeat represents a new approach to an old problem. It

provides up to 17% more width than competitive seats, a seat pan contoured to accommodate all driving positions, a flexible back rest with side shoulder cutouts to aid driving in reverse, an easily identifiable adjustment control, and a polymer and Dymetrol mesh suspension providing excellent comfort and reduced seat pressure points.

All controls fall conveniently to hand or foot. The wide brake pedal, wider than that of any truck in its class, provides for comfortable braking from alternative foot positions and when driving in reverse, as well as lower brake effort to reduce operator strain.

Steering effort has been reduced too, and the hydraulic levers are easily reached and operated with light efforts. The simple-to-operate push button electric park brake eliminates the obstruction created by a large hand brake lever.

The view from the operating position surpasses that of any competitive machine. The low front cowl and cab-forward seating position places the operator close to the forks to maximise forward visibility. The

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figUre 4 (ABoVe rigHt): The open workspace and accommodating controls of the Crown C-5

figUre 3 (ABoVe): The Crown FlexSeat

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waterfall design of the overhead guard and its strategically placed cross bars provide for clear upward views

of racks, forks, pallets, and loads. Out the back, the lower

counterweight and lower LP bottle position dramatically increase rearward visibility – especially important when driving in reverse.

The counterweight vents have even been designed to deflect heat and exhaust away from the operator compartment, also important for comfortable reverse driving. These and many other features were the direct result of the rigorous design-build-test (DBT) product development process.

The attention to detail is particularly noticeable in the realm of service, from the clever tilt-pivot mechanism for switching the LP tank, to the unprecedented degree of access to the engine compartment, and roomy post-to-post clearance from the side.

The numerous operator-centric features and innovations of the C-5 IC forklift were born out of the dedication of the team to design the best truck they could, but also to their commitment to a methodical process of analysis, design, and testing with the future operator and service technician in mind – which is what ergonomics is all about. ALT

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For further information: Steven Casey, 5290 Overpass Rd, Suite 105, Santa Barbara, CA 93111, USA Tel: +1 805 683 6610 Email: scasey@ergonomicsystemsdesign.com Web: www.ErgonomicSystems Design.com