Tractor driver hours cut work under scutiny

22 February 2002




Tractor driver hours cut work under scutiny

By Andy Collings

LEGISLATION under development within the EU Physical Agents (Vibrations) Directive will potentially limit the whole body vibration (WBV) exposure levels of tractor drivers and, as a result, the number of hours they are allowed to drive.

But this development should now be delayed until further investigations have been completed, says the Silsoe Research Institute (SRI) which has undertaken a pilot research study to quantify WBV emissions levels produced by a range of modern tractors.

Using test conditions, the SRI revealed that the exposure limit values recorded were considerably in excess of those proposed by the directive.

However, the SRI is keen to point out that it is not yet known if tractors exhibiting these vibration emission levels will expose their drivers to the daily averaged vibration exposure levels which would exceed the directives limit.

As a result, it says further investigation is required to determine the link between WBV emissions in test conditions and the WBV exposure encountered during typical agricultural operations.

The tests performed by the SRI called for a John Deere 5300, MF 4255, New Holland TS115, Renault Ares 620 RZ and a New Holland TM165 to be driven at set speeds over two track types – one smooth and the other rough. Measurements of vibration in the transverse, longitudinal and vertical plains were recorded.

The two lightest tractors – the JD 5300 and MF 4255 which did not have cab or axle suspension – exhibited the highest vibration. Those tractors with forms of suspension – the Renault and the larger New Holland – were also the heaviest and, as such, less likely to produce high levels of vibration.

Even so, the SRI says that while this suspension was responsible for reducing vibration levels, it says had there been no suspension it is likely the results would have been in line with unsuspended tractors. &#42


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