Apparatus and Equipment

A small electronic switching system, even with the installation of 100 to 200 offices per year, would require production of a modest number of frames. Similarly, a new small electronic switching system cannot by itself support a large number of new apparatus codes that arc normally incorporated in new system developments. Therefore, the No. 2 ESS has been designed to utilize much of the No. 1 ESS apparatus and thereby take advantage of the high volume, low-cost items associated with that system.1-2 No. 1 ESS type peripheral equipment is also utilized: ferreed networks, ferrocl scanners, and similar trunk and service circuits. Except for the smaller number of frames, a No. 2 ESS office appears strikingly similar to a No. 1 ESS office. Utilizing existing standard apparatus provides a further dividend within the Western Electric Company. Start-up costs and development of machinery to fabricate new apparatus items are minimized, and existing standards and frame assembly techniques can be used. For these reasons, the first No. 2 ESS model at Bell Telephone Laboratories, Indian Hill, Naperville, Illinois, more nearly represents a production system than other early models for previous developments. This contributed significantly to minimizing development intervals. Economies are realized in the system by controlling the size of 2817