Engine Room Telephone (Shutter Pattern)
This Apparatus has been specially designed for use in Engine Rooms, and is generally used in connection with a
Double-shutter Type of Instrument fitted in the Wheel House on Navigating Bridge. The Ear-pieces,
with which this Apparatus is provided, completely
shut out exterior noises, so that orders may be heard clearly and answered promptly.
The provision of, a circuit of these Telephones between the Bridge and Engine Room will be found of considerable advantage, as the range of orders which can be transmitted by means of the usual Telegraph is necessarily limited, while with this Telephone detailed instructions may be given.
Taken from the GEC Telephone Catalogue, K Section, 10th Edition, 1908