Digital tachographs dominate the fleet now, but analogue units - the stylus cutting traces into a wax-coated chart - are still legal and still in daily use in older vehicles. Fleets running heritage units, specialist older vehicles or the odd veteran tractor need to know the analogue rules, because they differ in ways that surprise drivers trained only on digital.
Analogue tachograph recordings are made by a stylus cutting traces into a wax-coated chart. Three separate styluses mark the recordings: one traces the activity modes (driving, other work, and so on, selected by the driver with the mode switch), one traces speed, and one traces distance. The whole record of a day’s driving sits on that single paper disc, read by eye or under magnification when anyone - operator, examiner, court - needs to reconstruct the day.
That physicality defines the analogue regime. There is no memory chip to download: the chart is the record, and keeping, handling and analysing charts is the compliance workload.
The replacement rules are permissive for older vehicles: if the vehicle is operating only within the UK, then the original analogue or digital tachograph that was fitted can still be used, and a faulty analogue or digital tachograph can be replaced like for like or better. So a UK-only older vehicle may keep its analogue unit, and if it fails, another analogue unit - or a digital upgrade - can go in.
The international position is stricter and has tightened with smart tachograph 2 requirements for vehicles in international traffic, so an operator whose older vehicle suddenly takes EU work needs to check what the vehicle must carry before accepting the job.
The daily routine that keeps analogue legal: the driver inserts a clean chart at the start of duty, enters the required centrefield details by hand - name, date, vehicle registration, odometer readings, place of start and finish - sets the mode switch accurately through the day, and removes, signs and files the chart at the end. Charts are the driver’s records and must be carried for the current day and the legally required previous days, produced to an examiner on request, and then handed in for the operator to keep and analyse.
Because the record is a single fragile disc, the failure modes are physical: charts torn on insertion, styluses fouled by wax build-up, charts swapped between vehicles, and the classic - a chart that ran past 24 hours because nobody changed it overnight. Each one produces either a missing record or an unreadable one, and both are offences in practice.
Analogue units carry one notorious gotcha that the government’s guidance calls out directly: the 12-hour clock face. Make sure the time is correct for am or pm - both times are displayed identically on an analogue tachograph’s 12-hour clock face. A unit set twelve hours out records a plausible-looking day that is entirely wrong, and the error is invisible on the face. Analogue tachographs must also continue to display the correct time - which for the UK includes adjustments for British Summer Time, so the clocks going forward and back are analogue events, not automatic ones.
Chart analysis is a skilled read: the traces are measured against the chart’s printed scales, activity periods are summed, and the day’s driving, work and rest are reconstructed by hand or with a chart scanner. Operators must analyse charts for hours compliance just as they analyse digital downloads - the duty to check follows the rules, not the technology. Completed charts go into the driver’s file and are retained for the required period, available to DVSA on request.
Analogue is legal, workable and unforgiving. It demands more of the driver - every mode selection manual, every chart a fresh physical record - and more of the office, because analysis is slower and error-prone. Fleets that keep analogue vehicles compliant do it with tight chart discipline, time checks at every shift change (that am/pm trap), and someone in the office who can actually read a trace.
Mixed fleets create a specific risk: drivers moving between digital and analogue vehicles and applying the wrong habits in each. The digital driver in an analogue cab forgets the mode switch and the chart centrefield; the analogue veteran in a digital cab wonders why there is no chart to sign. The control is a short vehicle-specific brief whenever a driver takes a different unit - the tachograph type, the mode discipline it needs, and the record it produces - plus an office that knows which vehicles generate charts and which generate downloads, so every driver’s records are complete whichever cab they sat in. A missing chart day and a missing download day look identical to an examiner: both are gaps in the record, and gaps are what the whole system exists to prevent.