When ergonomics equals economics
August 1st 2006

Does good ergonomic design really improve productivity? In the design of its new VeracitorTM VX series of lift trucks, Yale Europe set out to find the answer

When Yale Europe launched its new VeracitorTM VX Series of 1.6 to 3.5t lift trucks it had set out to deliver a new counterbalance truck for launch throughout the global market in the shortest possible time and at a competitive price. In itself a tough design challenge.

But in the design of the IC Veracitor, which derives its name from the word veracity meaning adherence to truth, Yale had also set out to establish a truth – does good ergonomic design improve productivity?

Over its 85 year history of manufacturing operator ergonomics has featured strongly in the design concept at Yale as it has always maintained a belief that good ergonomic design improves productivity.

Recognising the need to design-in market leading operator ergonomics, the development team of the Veracitor VX Series sought assistance from external consultants in the specialist areas of bio-mechanics and human factors. They started the design process with a comprehensive review of operator ergonomics, which involved wiring up operators with electrodes to measure muscle strain under all operating conditions.

This established the base-line data for the development programme and allowed them to evaluate all the human factors in lift truck operation, or usability, in a logical manner.

Once the optimum operator ergonomics design was established, it was tested using different jury groups of operators.

As a consequence, the step height onto the truck was lowered from the industry average 40cm to35 cm, improving access onto the truck, reducing muscle strain and, together with the new design of overhead guard, increasing shoulder clearance for the operator.

Operator comfort

Next the design team turned its attention to operator comfort. They increased the floor space by 20% for the operator and designed operator seat options including full suspension and swivel seats, specified by application type. They also minimised noise, heat and vibration, to produce one of the quietest and smoothest trucks to drive and included a 3-point isolated drive-train, designed to reduce the noise and rolling vibration associated with truck operations, which when coupled with Yale's Continuous Stability Enhancement system (CSE), limits steer axle articulation and is reported to offer smoother travel over rough surfaces.

Ease of Operation

For ease of operation, Yale reduced the diameter of the steering wheel to 30cm so that using the standard spinner knob, the steering can be changed from lock-to-lock in just four turns. The steering column is infinitely adjustable for tilt to help achieve the best steering wheel height and reach for every driver. Hydrostatic power steering was fitted as standard.

New E-hydraulic controls offered on the Veracitor VX Series include the choice of; conventional cowl mounted hydraulic levers, Accutouch electro-hydraulic minilevers or the latest Palmtech joystick, two of which include a fully adjustable armrest.

The addition of a rear drive handle, fitted with an optional horn button, to assist driving in reverse and the option of a swivel seat, rotating 11 degrees to the right and 5 to the left were two further ergonomic enhancements developed as a result of the jury panels.

Yale also introduced the EZ-Tank Drop- Down Bracket, which simply rotates the gas cylinder into a lower vertical position to simplify replacement and reduce the chance of back strain.

ADS reduces braking effort by 50%

As frequent braking is a major source of muscle strain, careful attention to brake pedal positioning, an extra wide pedal and braking effort reduced by 50% all contribute to ease of operation. At the heart of this ergonomic breakthrough is the Auto Deceleration System (ADS) available with the Techtronix transmission. ADS automatically slows the truck when the driver releases the throttle pedal by engaging the opposite direction selected clutch pack to reduce the travel speed of the truck, which can be programmed to suit application and operator requirements.

Remembering that part of Yale's aim was to launch the Veracitor across the global market, the designers had to consider that different lift truck cultures dictate preferred working practices and the need to meet the operator height and weight differences is seen across different markets. By taking a common ergonomics model based on a 5 percentile small Asian woman at the lower end of the scale to the 95 percentile tall Scandinavian male at the upper end, Yale believes it has designed the optimal ergonomics package, adjustable for the majority of lift truck users.

So the answer to "does good ergonomic design improve productivity?", is yes. Yale has the data from thousands of hours testing in all markets to prove conclusively that attention to ergonomic design is a major contributor to enhanced productivity and the result is the new Veracitor VX Series.

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