Name/Title
East Sussex Constabulary speed measuring device "Solly" 1960Entry/Object ID
723Description
Wooden cased speed measuring device "Solly", with blue plastic instrument panel, 4 switches and electronically operated mechanical stopwatch. The lid of the box has a table to allow timings in seconds to be converted into miles per hour. A paper label is attached indicating that the device was returned to the traffic division store.Use
An early device to measure the speed of a motor vehicle over a set distanceContext
In 1903 a 20 mph speed limit was introduced in England and Wales but this was largely ignored and abolished in 1930. The Road Traffic Act 1936 then introduced a 30 mph in "built up areas" which were defined as a road having street lamps no more than 200 yards apart. Police officers enforced speed limits by using what technology was available, either by timing offending vehicles over a known set distance or by following vehicles at fixed distance and matching their speed.
In 1960 PC D Harriott who was working in the General Transport Office of East Sussex Constabulary, devised a speed measuring device which became known as 'Solly" due to its use of electrical solenoids. A newspaper report in the Sussex Agricultural Express on Friday 6th May 1960 (item 722) contains a report on this device and states that it was constructed by PC Harriott who was an amateur radio enthusiast. The device was attached to two rubber tubes which were placed in a road 110 yards apart. When a motor vehicle ran over the first section of tubing it sent an electrical signal which started the stopwatch, which was stopped when the vehicle ran over the second section of tubing. The operator would then use the table in the lid to convert the time in seconds into a speed in miles per hour. If a vehicle was breaking the speed limit, the operator would alert another officer further along the road by radio so they could stop it and take action against the driver.
It is not known whether this was the only such device in use in East Sussex Constabulary or how much of it was constructed by PC Harriott, though the newspaper report certainly suggests that he made it.
By the mid to late 1960s East Sussex Constabulary was using the Marconi PETA (Portable Electronic Traffic Analyser) system to detect speeding. This was one of the first radar speed detection devices and there are photographs of it being used by the forces female traffic officers.
In the 1980s and 1990s Sussex Police Traffic officers were using a more modern system that automatically measured and calculated speed over two similar road sensors made by the Truvelo company.