No_1_1957 — Page 71

The recreation hall and canteen for the cuits, so that the whole of the switching Telephone Company employees occupies apparatus is kept automatically the whole second floor, with the exception constant supervision, and any faults aris- of the area for the small generating station ing, either on subscribers' connections or and the battery charging room. The exchange units, are immediately indicated welfare centre, which includes a doctor's to the exchange maintenance staff. surgery and clinic, will also be located on this floor.

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Power supply at 50 volts D.C. for the exchange apparatus is derived from The seven floors above this are entirely power system of the divided battery float reserved for the Chinese staff, there being principle. Motor generators, normally eight rooms on each floor, each with its running from

346 volt 3 phase public own kitchen. These will provide accom- mains supply, provide the necessary power modation for 54 families and 20 bachelors. under normal conditions whilst, in addi- The bathrooms and lavatories are in banks tion, a battery of 2500 ampere hour on the east side of the building, with a capacity is continuously in circuit, and laundry and clothes drying space separat- automatically takes over the exchange load ing the men's section from the women's. without any interruption to the service

in the event of a power supply failure.

The new automatic telephone exchange was brought into service on 27th July, The various tones, i.e. "Dialling Tone," 1957- This exchange, which is known as "Ringing Tone" etc. and the power re- West Exchange, forms part of the pro- quired for ringing telephone bells are gramme of Hong Kong Telephone Co., provided by two special generator sets Ltd. to expand the telephone facilities known as Ringing Machines. and services in the Colony, and has been designed, manufactured and installed within a total period of two and a half The equipment for the exchange, including switching apparatus and power plant, was supplied by the General Elec- tric Co., Ltd. of England.

years.

With the commissioning of this latest exchange, and on the completion of other installations now in

progress, the Hong Kong Telephone Co., by the end of this will have brought into service year, exchange equipment and associated exter- nal plant to accommodate 40,000 addi- Initially the equipment installed will tional lines since embarking on their cater for 12,000 subscribers' lines, but expansion programme about the beginning provision had been made, when designing of 1950. At present more than 66,000 the building and exchange layout, for stations or subscribers are connected to future extensions to an ultimate of 19,000 the system. lines.

Design and development continue to keep pace with the Colony's progress. INSTALLATION PROBLEMS

The new exchange has several interest ing features. The switching equipment, which operates on the Strowger or "Step

The building of new Exchanges and by Step" System, employs the type SE50 two-motion selector, which is the latest the adding of new lines to the system is in a long line of designs for automatic just one phase of the problem. telephone exchange equipment developed by the G.E.C. The improved performance

These lines have to be connected to subscribers' stations and one can imagine, for instance, the difficulties which are involved in bringing the outside wiring to new build- ings, particularly during a period of such rapid growth and expansion as has been Special equipment racks accommodate taking place in Hong Kong in the past alarm equipment and miscellaneous cir- ten years. It is especially important that

of this new selector mechanism results in a greatly increased standard of service and reliability.

The generating station on the second floor.

Wiring in progress.

Rear view of selector racks, junction equipment racks,

showing space for future extension.

69

General view of automatic exchange equipment.