These clocks with a distressed / aged dial and genuine glass are much better quality than other replica sector clocks. If you want something different to the average boring wall clock this could be it, these clocks make a great talking point in an office, workshop, garage, reception area etc. You can see two original clocks in the images of the RAF sector rooms and there is also an image of an original clock from the second world war on which we based this model.
These clocks were originally known as "colour change clocks", they were introduced in 1917 during the First World War by the RFC (Royal Flying Corps) which was the predecessor to the RAF, they were used to monitor the movements of German planes and airships and further developed in World War 2. These clocks became famous in the Battle of Britain and many were still in use during the Cold War on some airforce bases. These original clocks are now highly sought after and originals can sell in UK auctions for an average of between £5,000-£8,000 ($6,500-10,500)!
There were several versions of the clock during the war and the face details varied somewhat from one design to another but the clocks all had a similar appearance with the red, blue and yellow triangles and were either electrical or mechanical, this clock made by MWC has a sweep second hand just like the original electric version.
People often ask us how the clock was used and basically the Sector Clock was a fundamental part of Ground-controlled interception (GCI) before modern computerized systems were put in place for airspace control. The clock face is marked with five-minute red, yellow and blue triangular segments. It has an outer 12-hour ring and an inner 24-hour dial.
Aircraft position was recorded along with the colour of the triangle beneath the minute hand at the time of sighting. This was reported to sector headquarters, where counters of the relayed colour were used to represent each air raid on a large table with a map of the UK overlaid with a British Modified Grid. As the plots of the raiding aircraft moved, the counters were pushed across the map by magnetic "rakes". This system enabled "Fighter Controllers" to see very quickly where each formation was heading and allowed an estimate to be made of possible targets. The age of the information was readily apparent from the colour of the counter. Because of the simplicity of the system, decisions could be made quickly and easily.
This actual clock measures 30.5cm (approx 12") and is housed in a strong and robust casing.
The clocks have a high accuracy silent quartz movement so that you avoid the annoying ticking sound every second with cheap quartz clocks which can become seriously annoying to many people. The clock is supplied ready to go and complete with a battery.
NOTE: You can see the original second world war clock in the RAF sector room images.