Bob Adamson: tachograph technology
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• The purpose of a tachograph is summed up in the preamble to EEC Regulation 3821/85: ". . , the use of recording equipment that may indicate the periods of time referred to in Regulation (EEC) 3820/85 on the harmonsiation of certain social legislation relating to road transport is intended to ensure effective checking on that social legislation."
Regulation 3820/85 itself, limiting drivers' hours, ". . . aims at the harmonisation of conditions of competition, especially with regard to the improvement of working conditions and road safety."
Abuse of these regulations falls into two main areas. Firstly a driver, without the operator's knowledge, will aim to make a financial gain by obtaining an unjustified overnight lodging allowance or using the vehicle for haulage of goods not authorised by the operator.
Secondly, a driver may abuse the regulations with the approval of the operator by driving for above the maximum legal number of hours to reduce overall running costs and give the operator an unfair advantage over his competitors.
Under the new drivers' hours (introduced on September 28, 1986) adherence is more important than ever as a driver could now theoretically have a 95 hour working week with 56 hours behind the wheel of a 38-tonner — and TRRL research (report 1113) indicates that fatigue is a factor in 11% of accidents.
A tachograph records a driver's hours and work periods for checking against the legal maximums but a checker needs to know what to look for on a tachograph chart.
The centre of the chart is reserved for the driver to record his name, start and finish date and location, vehicle number and odometer readings for the start of the first journey and end of the last journey recorded on that chart.
An adjustment knob is provided to alter the time shown on the 24-hour quartz movement built into the tachograph, in case of electrical fault or battery disconnection. In many cases this has been misused by winding the clock forward to show a daily rest period before completing a return journey on a second chart or by winding it back to 'lose' waiting time, for example, and illegally increase a work period.
The distance stylus records the distance covered in the form of 'V's and inverted 'V's; each completed side of a 'V' represents 5km: a total of 101un from peak to peak.
Comparing the 'V' recording and odometer readings reveals any unrecorded distance.
When a tachograph is opened three spring-loaded stylii automatically mark the chart. If it is opened when moving the speed recordings will immediately move to zero. This may be legitimate but should be watched out for. Some drivers have become adept in the electrical manipulation of a tachograph: at its simplest level simply by pulling a fuse. Switches have also been fitted in tachograph power supplies, or electronic interrupter units to 'slow down' the clock — but this leaves a distinctive vertical line on the distance trace which is obvious, at least to the trained eye.
Electronic tachographs allow 'perfect' false charts to be produced but new models incorporate self-diagnostic features to combat manipulation although even these are not foolproof. Bob Adamson says: "It is cost which prevents the manufacture of the 'perfect' tachograph."
Foolproof tachographs may well be on the way; but, according to the Court of Appeal, so are prison sentences for extreme offenders.
It seems, therefore, that the reasons for effective drivers' hours enforcement are not restricted to road safety and unfair competition: it could come down to self-interest.