Special fire telephone used in exchange buildings This is the later model called the Mark 4

Fire emergency phone for use in CB and Automatic telephone exchanges.  These were used to call the Fire Brigade and went via the area operator suite.

The Mark 1 was probably used by the National Telephone Co.

The Mark 4 version consisted of a Telephone No. 232 mounted on a Bellset which in turn is mounted on a wooden box that houses batteries and a hand generator.  The hand generator is locked by means of a releasable metal bar.

The Mark 4 was introduced in 1938.

Telephone included (1928):-
1 x Bell, Magneto 1000w.
1 x Coil, Induction No. 3 or No. 14 .
3 x Condensers, M.C. No. 1.
2 x Cords, Instrument No. 116.
1 x Cord, Instrument No. 222.
1 x Frame, Notice No. 1.
1 x Generator N.T. No. 1001.
1 x Key, No. 72, red.
1 x Key-mounting V.
1 x Receiver, Bell No. 1A.
1 x Transmitter N.T. No. 13.
1 x Transmitter No. 1 and Adapter, transmitter, if used for maintenance.

Telephone included (1946 and 1956):-
1 x Bell-set No. 26.
1 x Glass No. 3.
1 x Cap, Lamp No. 2-1C.
1 x Jack, Lamp No. 10.
1 x Clip No. 31.
1 x Key No. 72, Red.
2 x Condenser, M.C. No. 102.
1 x Key-mounting, V.
1 x Cordage, Instrument No. 2/B, Brown, 18".
1 x Relay No. 503A.
1 x Relay-cover, AK.
1 x Frame, Notice No. 1.
1 x Telephone No. 164, Black, with Cord No. 3/63KB, 33".
1 x Generator No. 26A with  adapter, generator, D 63018 and Handle, Generator No. 15 (earlier supplies fitted with Generator No. 8A).
1 x Telephone No. 1/232CB, Incomplete (minus Base, Telephone No. 1/162).

To be requisitioned separately as required:-
3 x Cells, Leclanché DS 5
1 x Lamp No. 2- ... V.

Circuit diagram - N181 (GPO).
Circuit diagram - N181 (NTC)
Circuit diagram - C.B. 1185.

Drawings - 63018/1 and 63018/2 (Mark 4).

Specification - D1299.

Adjustment of Magneto bells

Telephone No 81 (Mark 4)

Looking down into the unit with the lid open

External view


Pictured above is the Telephone No. 103
It has an big generator which needed an enlarged cover

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Last revised: December 18, 2022