Aeronautical Instruments & Tools
Price = n/a
Royal Observer Corps Portable Telephone for Observer Posts RAF Ref Nos 10G/125
The Royal Observer Corps was a Civil Defence organization, formed in 1925 and which operated until disbanded in 1995. Its main objective was to detect, identify, track and report sightings of allied and axis aircraft flying over the UK. To meet this aim Observer Posts were set up in areas liable to attack and each post was connected by a direct telephone line to a Central Control and provided warning of raids, giving numbers, heights and types of enemy aircraft. Used in conjunction with information provided by the early-warning radar sites, this was a vital input to help develop an overall picture of incoming attacks and all this information had to be put together to ensure Fighter Command were in the right place at the right time. Each Post had two observers on duty with one responsible for the working of the Post, watching and listening for aircraft and estimating height, direction and numbers. His no 2 Observer operated the Post Field telephone and reported in up to date information and also listened to reports from other posts.
Our Field Post Telephone is of the early pre-war pattern AD 163 B; this was later superseded during WWII by an economy version of simplified construction model nos AD1542. It is therefore an extremely rare survivor that almost certainly served in the early years of the war and during the Battle of Britain. This model carried a hand cranked "magneto" and was linked directly through to the Observer Centre via the telephone line network. The phone operated by turning an handle which generated an electrical charge in order to ring the bells of other telephones on the same line and to alert the operator. These telephones were used with a head and breast set that was worn by the observer; when not in use the mouth trumpet was turned away. Interestingly our headset only carries one receiver which appears to be a trait of these early sets. Another detail often missing is the 'Alphabetical Speaking Codes' chart cemented on the front fold down flap. This would now be known as 'the Phonetic Alphabet' but this one in early from is quite different to that in current use and appears to have been superseded in 1942.
The oak case is in sounds condition with just a few chips indicative of a unit that has served. The leather carry handle to the top is still solid as are all the brass fittings, hinges and catches. The inner section, which carries the magneto handle, slides out to reveal the interior and the location for two dry cell batteries is accessed. These are now missing and whilst all the electronic parts seem to be in place we have no idea if it could be restored to working condition so is on offer, like all out stock, as an historic collectable. Inside is chalked '10' and on the back wall of the case another original touch is a printed wiring diagram. The back of the case carries a brass plaque reading 'Telephone Observer' and 'DIAG AD 163B'. Above is a brass plate that when rotated allows the headset jack plug to be connected. The case measures 12.75" x 8.75"x 9 1/2" (31.5 cm x 22 cm x 24.5 cm). This is a museum quality piece and of significant historical interest to both Royal Observer Corps and RAF collectors alike that could well have played an important part in the most significant air battle of WWII. This is the first example of one of these early units we have seen in many years and believe it will be a long wait before we find another.