CALL OFFICE PLANS

Like ordinary Telephones which had extension plans, Coin Boxes also had their own plans. The plans changed as technology moved on so you may find different types of installation and equipment for a plan.

This is a description of the plans and apparatus that was used. In sub Post-Offices the counter telephone was used to call though telegram messages.

Plan 2B
This consists of two telephones in parallel, one on the counter and one at the call office position. The telephones could be wall type, candlestick or Bakelite.

For CBS No. 1 Systems Diagram N2633 refers.

Plan 2C
This consisted of two telephones and a Key No. 68 to switch between the two. One telephone was for Telegrams and other was used by the attendant and public.

For Magneto Systems Diagram N2411 refers.
For Automatic Systems Diagram N2417 refers.
For CB Systems Diagram N2493 refers.
For CBS No's 2 & 3 Systems Diagram N2685 refers.

Plan 2F
This consisted of two telephones and a Key No. 259, mounted in a Key-Mounting NV, to switch between the two. One telephone was for Telegrams and other was fitted in a cabinet, for public use.

For Magneto Systems Diagram N2755 refers.
For CBS No's 2 & 3 Systems Diagram N2705 refers.

Plan 2G
This consists of two telephones in parallel with a Bellset only fitted at the Attendants telephone position. The Cabinet telephone is not fitted with a dial. Drawing EC1896 (1936) refers.

For Automatic Systems Diagram N2415 refers.

Plan 5A - 1933 to 1960 - PRE-PAYMENT WORKING
This is a standard installation with an exchange line terminating directly onto the coin box, with a Telephone and Generator fitted on the counter..

For Automatic Systems Diagram N2408 refers.

Plan 5A - 1933 to 1936 - POST-PAYMENT WORKING
This is a standard installation with an exchange line terminating directly onto the coin box. Originally using a Telephone No. 190 with a Bellset No. 29, but for CB systems the Telephone No. 238 and Bellset No. 33 was used.

For Magneto Systems Diagram N1108 refers.
For Magneto and Automatic Clear System Diagram N1109 refers.
For CBS No. 1 Diagram N1112 refers.
For Automatic and CB Systems Diagram N2419 refers.

Plan 5C and 5D - Pre 1933 - POST-PAYMENT WORKING
Used in Small Sub Post Offices this plan is for a Counter, Instrument Room (if fitted) and and Coin Box in a cabinet. The Counter telephone is connected to the exchange line and a Switch NT No. 6 is fitted for connecting the Cabinet telephone, which has a Coin Box attached. The Counter and Instrument room can call each other by means of a Bell No. 13A and Press Button G. An Indicator No. 101AP and Buzzer No. 2 are fitted at the Counter. The bells, buzzer and indicator are powered by local batteries.

For Magneto, CBS and CB exchange areas - N1106 refers

Plan 5E - 1933 to 1960 - PRE-PAYMENT WORKING
Used in Small Sub Post Offices this plan is for a Telegram circuit and Coin Box in a kiosk. It is an ordinary telephone and a Coin Box connected to an exchange line via a Relay and Key No. 2. The Relay and Key No. 2 is a mahogany box which has fitted a three position switch (Key No. 283) and an Indicator No. 3800A (was a Relay No. 257A). A Buzzer No. 2 is fitted nearby. The relay, buzzer and indicator are powered by local batteries. The Relay and Key No. 2 provides for the following facilities:-

Key at "Through" - Coin Box and Counter telephone are connected to the exchange line. The indicator operates during the call.
Key at "Kiosk" - Coin Box and Counter telephone are connected to the exchange line. The indicator is disabled.
Key at "Counter" - Counter telephone is connected to the exchange line and if the Coin Box is lifted the indicator operates and a buzzer sounds.

Produced by GEC - see pictures below. GEC diagram KS8054.

For Automatic Systems Diagram N2448 refers.
For CB Systems Diagram N2523 refers.

Relay and Key No. 2
Drawing - 60197
Diagram - N1188 refers.

In 1955 there were about 13,000 Plan 5E installations in the UK. The majority had been provided as the result of the Jubilee Concession which promised a call office outside every Post Office. Under the Plan 5E arrangement, the Sub Postmaster had an ordinary telephone over which they could pass official calls (mainly telegrams). When the Telephone was not in use in the Sub Post Office it was switched through to the call office (which was fitted with a coin box) outside the Office. The Post Office Investigation Department did not like this Plan as they were a continual source of difficulty to them. Sub Postmasters frequently failed to record their private calls and what was more serious was that by engaging the coin box it was possible to prevent a Sub Postmaster from raising an alarm in the event of an attack on his office. In addition, betting frauds could be carried out by handing in a telegram and then holding the call office in use so that the telegram could not be sent forward, until the result of the race was known.

Plan 5E - 1960 to 1980 - PAY-ON-ANSWER WORKING

1. General
A Call Office Plan No. 5E comprises a normal call office installation sharing the use of an exchange line with another telephone in a P.O. Sub-Office; the primary use of the latter telephone is for the dictation of telegrams. Post payment has been designed for use in S.T.D. areas with pay-on-answer working to allow local calls to be made from the Sub-Office without either inserting money in a coin-collecting box or the assistance of the operator, by sending simulated coin pulses when a call is made.

2. Brief description
A Box, Coin-collecting, No. 705 is fitted in the kiosk. In the Sub-Office a Telephone No. 710L, Metering-unit No. 2A and a battery of six Cells, Dry, DS1 are required. The circuit of the Metering-unit No. 2A is shown on Diagram N604 and the connexion and operation of the complete installation is shown on Diagram N2455.

Telephone No. 710L
Four buttons are fitted, and reading from left to right these are marked EXCH, KIOSK, PAY and Buzz CO. The first two are locking and the others are non-locking. Switch-hook restoration is provided. A red LINE ENGAGED lamp is fitted on the left-hand side of the telephone.

Metering-unit No. 2A
This is approximately 9in. x 5in. x 5.25in. high and is suitable for mounting on a wallboard or for standing on a counter. A key protrudes through the front of the metal cover and a number wheel meter is visible through a window in the cover. The magneto-generator handle is packed inside the cover for travelling but protrudes through the right-hand side of the cover when fitted for use.

To provide access to the relay connexions when the unit is wall-mounted, the relay mounting strip can be removed and attached to the adjacent bracket, which also acts as a cover guide.

3. Operation
Except when the telephone in the Sub-Office is in use the kiosk telephone is connected to the exchange line and calls may be made and received normally. When the kiosk telephone is in use the red LINE ENGAGED lamp on the Sub-Office telephone glows. A caller attempting to use the kiosk telephone when the line is in use by the Sub Postmaster will hear a continuous buzz in the receiver.

If the line engaged lamp is not glowing, calls may be made from the Sub-Office by lifting the handset, pressing the EXCH button and dialling on receipt of dialling tone. If pay tone is received the PAY button should be pressed once so that it can be ascertained whether the call has been correctly established. One unit will be recorded on the exchange meter and the local office meter. Further operations of the PAY button may be made as required if the length of the call warrants it. If the handset in the kiosk is lifted while a call is in progress a buzzer will sound in the Sub-Office. If the KIOSK button is pressed the exchange call is held and the Sub-Office telephone is connected to the kiosk telephone. It is thus possible to inform the caller in the kiosk that the line is temporarily engaged and that he will be informed as soon as it is free. The original call can be re-established by pressing the EXCH button again. If the person in the kiosk refuses to replace the handset the buzzer can be silenced by pressing the BUZZ CO button. This button is non-locking to prevent the caller in the kiosk being forgotten. When the line is free the kiosk can be called by pressing the KIOSK button and turning the generator handle.

Incoming calls normally ring the bells in both the Sub-Office and the kiosk. Before vacating the office the staff should operate the key on the metering unit; this disconnects the bell and also reduces the drain on the battery by disconnecting the LINE ENGAGED lamp in the telephone. The key should be restored to the normal (horizontal) position before the handset is lifted to avoid the risk of interrupting a call from the kiosk. If the key is not restored the buzzer will sound and pressing the Buzz CO button will not silence it.

4. Battery
The installation is designed to operate if the battery potential is above the reject value of 5.1V. If the voltage falls below this value coin pulses will not be sent and the meter will not be stepped.

5. Provision of Metering-Units
It is intended that these should be used in situations where the provision of an additional line solely for the use of the Sub-Office would be unduly costly.

Telephone No. 710 with a Metering Unit No.2A.
For Automatic lines Diagram N2455 refers.

Metering-Unit No.2A
Circuit Diagram - N604
Drawing - 91725

Plan 5F - 1933 to 1960 - PRE-PAYMENT WORKING
This plan is for a Telegram circuit and a Coin Box in a cabinet, when used in small sub Post Offices. It is an ordinary telephone in parallel with the coin box. A Key No. 253, enclosed in a Key, Mounting NV, is fitted near the telephone on the counter and this provides the follow facilities:-

Key normal - Both bells ring and telephones are connected in parallel.
Key operated - The coin box is disconnected from the line affording secrecy for the counter telephone user.

For Automatic lines Diagram N2412 refers.
For CBS 2 & 3 Systems Diagram N2705 refers.
For Magneto Systems Diagram N2755 refers.

Pictures