The ordinary infantry platoon had runner and pyrotechnics and particularly isolated posts had lamp or field telephone as well.
The company and higher formations usually had all the above means with the exception of Pigeon which was not normally provided below Brigade HQ level.
Eastern Command established a Signal Centre at Hertford.
Not surprisingly, virtually all formations and units made use of civil telephone. Instructions were given for the use of civil telephone during active operations that calls should be kept as short as possible and only held when absolutely necessary in order to reduce congestion. For security, to guard against false orders or messages given by enemy agents, the normal procedure was to ring off then after a pause of three minutes ring back the officer alleged to have given the order to confirm the authority of the order.
Field telephone was only suitable for communication over relatively short distances due to the high resistance of field cable. It was mainly used for Observation Posts, and communication between Company HQ to Battle HQ’s. Field cable used in the Army was normally D3 (either single or twisted strands of 1 tinned copper and 7 hard tinned steel). Heavier cable, such as D8, was normally used for artillery positions.
Lines to unit and formation HQ’s were poled cable, either P.O. poles or W.D poles. In some cases, e.g. from artillery observation posts to battery positions, the cable was buried at a depth of 6”, deeper if possible in the vicinity of the observation post and gun positions. All lines, whether G.P.O. or W.D., were tested daily. If “Stand To” was ordered all lines were to be tested hourly.
Teleprinter was used for communications at Division and higher HQ’s level.
Wireless equipment varied from simple sets which could be carried on one man’s back in the forward areas to large semi-fixed stations capable of high speed working over long distances. Other sets were fitted in trucks, armoured cars and tanks to maintain communications while on the move. Wireless could either transmit a series of dots and dashes, i.e. Morse code, referred to as wireless telegraphy (W/T) or voice (radio telephony – R/T). Wireless worked best away from trees, buildings, cliffs, and power and telephone wires. During normal conditions, if considered necessary cipher was to be used for W/T. During active operations, W/T used a simple procedure, known as VE message procedure, to ensure messages were sent as simply and fast as possible; if intercepted by the enemy, he would not have time to act on it.
In normal circumstances, wireless call signs and frequencies were changed weekly. Wireless would exchange calls one hour before sunrise then be on listening watch until sunrise. At all other times wireless silence was to be maintained unless “Action Stations” was issued, enemy landings were taking place or if line communications failed.
In case of a breakdown in normal communications, a mobile R/T station was located at 11 Corps HQ which would broadcast orders and information to lower formations and units (Division HQ, Brigade HQ, Battalion HQ and Artillery Regts) included within a Wireless Network Intelligence Plan. These had been issued with receiving sets. The network was known by its code word, “BEETLE”. On “Action Stations”, BEETLE receivers were to listen for five minutes for the first five minutes of every clock hour.
Emergency wireless communication (code named “PANDA”) was provided to ensure direct contact between the RAF and Army. This included any Field Forces with a role in providing airfield relief columns.
Left - Field Telephone
Middle - Field Telephone, Observation Post
Right - Portable Wireless
Daylight Signalling Lamp: There were two types of daylight signalling lamp – short range lamp and long range lamp. The daylight signalling lamp, short range, was readable under average conditions at a distance of two miles with the naked eye or three to four miles with a telescope. At night the distances were six miles with the naked eye and nearly twice that with a telescope. The lamp was mounted either on a stand or spike. The daylight signalling lamp, long range, was readable with the naked eye at a distance of eight miles.
Examples of instances were lamps were to be used included:
- Call to Naval ships for support.
- Battery Observation Posts normally also had lamps for visual signalling with the gun positions.
- One of the means of communication between RAF aerodromes and relief columns
Morse Flag: Generally impractical for field use due to the problem of concealment. It was mainly used as an alternative to the lamp if for some reason that was unavailable.
Morse Flag - first positions of dot and dash
Daylight signalling lamp and stand
Pyrotechnics: The following were the standard light signals:
- Golden Rain – call for defensive fire. To be fired by Company HQ’s.
- Light and sound, 3 star red – Enemy actions on land (i.e. alarm signal for enemy landings or attack of any nature). To be fired by Royal Navy, Coastal Defence Batteries, Company Commands, Observation Posts and isolated platoon and section posts. The signal was not to be repeated by a post that had not heard or seen any attack.
- Light, 5 star green – Enemy surface vessels sighted. To be fired by Royal Navy, Coastal Defence Batteries, Company Commands and Observation Posts.
Army Co-Operation Aircraft also used light signals – see below.
Despatch Rider: Despatch rider was the only way to carry certain orders and reports which did not lend them to telegraphic form. They could also help avoid congestion on other communication means by carrying routine orders and other administrative material which was too urgent for the post. Despatch riders in normal conditions ran up to three times daily to Company HQ’s. Despatch riders would be the only means of communication if all other methods failed.
Aircraft: Army Co-operation Aircraft could drop messages at designated dropping stations (near Division and Brigade HQ’S). For other Report Centres, the aircraft would fire two green lights calling for the Report Centre sign; Report Centres would respond by waving a yellow flag in a full circle horizontally.
Most Co-operation aircraft were also equipped with wireless (both W/T and R/T).
Aircraft could also request identification by firing a series of white light signals. Troops were to respond by waving a yellow signal flag horizontally in a half circle in front of the body when facing the enemy or in the direction of movement for three minutes. Also as many troops as possible in forward areas should have a yellow identification symbol, usually sown onto the respirator, which they should hold out at arms length if the aircraft fired the recognition signal.
Pigeon: Carrier pigeons operated in situations where it was possible to establish lofts and birds could be taken out to fixed posts from which to carry back messages to their lofts. They were essentially an emergency service, useful if the other means of communication were impractical or not possible. They had a number of advantages: