History of Sector Clocks

They were originally known as 'colour change clocks' when introduced by the RFC in 1917 to monitor the movements of German aircraft. They played a significant role in the B of B and continued to be used by the RAF & ROC.

Function

The Clock had a 12 hour dial and an inner ring for the 24 hour time, widely used by the military and was marked with red, blue and yellow triangular segments. The position of the sighted aircraft was recorded, together with the colour of the triangle beneath the minute hand at the time of sighting. This data was then reported to sector headquarters such as Bentley Priory, where counters representing each air raid were placed on a large table, which had a map of the GB overlaid and squared off with a British Modified Grid. The colour of counter to use for a new sighting was determined by the time of the sighting, the proper colour being indicated by the minute hand of the clock. 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 allowing 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

Full scale 13inch diameter ,high quality recreation of a wartime RAF Sector clock, as used in fighter sector control rooms during the darkest hours of the Battle of Britain. The  clock face has been produced from a painstaking digital copy of an original sector clock. The face is mounted in a lovely dark wood case with a hinged brass bezel. The clock is powered by a quartz movement and a battery is included.

 The face hinges forward to give access to the wooden back box containing the movement

220 Volt oil heater. It has a nice A/M crown. I can only assume this is for preheating oil in big aero engines. Looks serviceable.

£25

Arrestor Hook (pg2 misc)

Rudder lock (pg2 misc)

3 Unique manuals (pg2 misc) B

This piece from a Sunderland flying boat, it is some kind of air circulation control valve, it has a rotating bezel to open and shut it. The Sunderland was developed from the Imperial Airways Empire civilian flying boat. It represented a dramatic increase in fighting capability over earlier, biplane boats. From the outbreak of war in 1939 the Sunderland was ceaselessly at work hunting and destroying U-boats, rescuing seamen and engaging so effectively with enemy aircraft that the Luftwaffe nicknamed it 'the flying porcupine'. On many occasions a single Sunderland fought off five or more hostile aircraft. One was attacked by 
six Ju-88's, shooting down three of the German aircraft and driving off the others. The Mark III introduced an improved hull form and - from 1940 onwards - Sunderland's of all marks carried ASV radar, Leigh lights for illuminating surfaced submarines, and increasingly advanced avionics.

N/A

Warning horn (pg2 misc)

Click on the picture to enlarge

A framed montage of four Luftwaffe WWII aces  with four signatures  and details of their victories.

Click on the picture to enlarge

A framed montage of four Luftwaffe WWII aces  with four signatures  and details of their victories.

camera mount seen under

This is a camera control box fitted to Spitfires of the PRU (photo recognisance unit ) This un harmed fast and high flying aircraft took photos of targets before and after raids and carried out essential information gathering operations. PRU Spitfires did not carry the usual camouflage patterns and were painted pale blue of sometimes even pink. The camera was mounted in the radio compartment behind the cockpit and the aircraft had to fly on its side to take pictures.

Seen under a MK XIV Spitfire of the PRU

 On the next page is a complete camera set up.