Modern city telephone exchanges operate on the central-energy system. With it there are no dry cells or magnetos at the subscriber’s stations. Electrical energy for both signaling and talking is supplied by a storage battery located in the central office. For this reason an arrangement of this type is called a “central energy” or “common-battery” system. Instead of the switchboard having a drop for each subscriber’s line, it has a small incandescent lamp which is associated with the line. This lights when the subscriber removes his telephone receiver from its hook. For city telephone lines it would be infeasible to use open wires on insulators because there could not be placed on the poles a sufficient number of cross arms to support even a small proportion of the telephone lines which radiate from an exchange. Furthermore, open-line construction for city conditions would be very expensive and difficult to maintain. Hence, in the city exchanges, lead-covered cables, each containing from 20 to 1,200 pairs of conductors, are employed. Where a number of these cables are routed parallel to one another, they are carried in ducts in underground subways. In the residence sections they are supported on poles. It follows that the circuits and connections in a large city telephone exchange are exceedingly complicated. There are thousands of small wires, each of which serves a different purpose. Considered as a whole telephony involves careful work and attention to detail. Much of it is of the same order as fine instrument making.
Departments of telephone companies include: Engineering department, commercial department, auditing department, plant department, traffic department.
PLAN No. 1219. ENGINEERING DEPARTMENT
This department plans and supervises the development and construction of the property as a whole. In it plans and specifications are prepared for buildings, exchange layouts, subways, and other components. To obtain a position of responsibility in the engineering department one must have had theoretical training and a number of years of telephone experience, but there are usually engineering-department positions in which men of little experience but with some theoretical training can start as draftsmen or clerks, advancing as they acquire experience. In this respect, the engineering department of a telephone company offers somewhat the same possibilities for disabled men as do similar departments in street railways or electric-power companies. Hours of work and compensation will be about the same. However, for a man who has had telephone experience, it is desirable usually to continue in that line. Telephony is probably more exacting and involves greater detail than does power work and may on that account be preferred by some.
PLAN No. 1220. COMMERCIAL DEPARTMENT
Contracts for telephone service are obtained by the commercial department. It is the sales organization of a telephone company selling telephone service to the public. In this work there should be opportunities for soldiers with minor disablements who have had prior telephone experience, and who possess the “selling instinct.” The salary will probably range from $60 to $160 per month.
PLAN No. 1221. AUDITING DEPARTMENT
The qualifications for men in this department are about the same as those required of men in any accounting organization. These are treated in detail in one of the other Federal Board monographs.
PLAN No. 1222. PLANT DEPARTMENT
Much of the telephone plant is built and all of it is maintained by this department. It is often segregated into two general divisions, (1) construction division and (2) maintenance division. To administer these there are a construction superintendent and a maintenance superintendent. Then each division may be further subdivided in sections as follows: (a) Aerial-line section, (b) cable section, (c) repair section, (d) wire chief’s section, (e) installation section, (f) cable-report section, and (g) clerical section.