APPLYING CARRIER TELEPHONE SYSTEMS 583 



tions. Separate testboard lines have been established in several offices 

 opening off, or convenient to, the main operating aisle in front of the 

 toll testboards. The voice frequency patching jack bays at carrier 

 terminals have been located, where practicable, near the secondary toll 

 testboard equipment. These arrangements have been made in order 

 to facilitate operating and maintenance, particularly during light load 

 periods when a small force is on duty. 



The amplifiers and group modems have been closely associated with 

 the high-frequency patching bays and sealed test terminals in order to 

 limit cabling lengths. Channel modems and carrier supply have been 

 located convenient to the other equipment but within wiring limitations 

 to the voice frequency patching bays. 



The adequacy of all floor plan layouts, in providing for ultimate re- 

 quirements, particularly at large terminal offices, was studied. This 

 problem was given special consideration where it is expected that 

 routes in addition to the initial one may be developed later for carrier 

 operation. For example; at New York it was necessary to plan for the 

 development of K carrier and other broad band facilities on four 

 separate routes requiring a considerable amount of space for the 

 necessary terminal equipment. The installation of carrier equipment 

 at this office, therefore, has been made in space separate from the exist- 

 ing voice equipment. A floor plan arrangement of the equipment lay- 

 out at New York is shown in Fig. 19. 



Order Wires and Alarm Circuits 



One or more auxiliary stations have been associated with an ad- 

 jacent main or terminal office for maintenance control. Interoffice 

 trunk and alarm equipment provide talking and signaling facilities 

 between each auxiliary and main repeater station over a loaded cable 

 pair. The various alarm signals are terminated in lamps which are 

 mounted in the sealed test terminal bay at the controlling main office. 

 These alarms are arranged to indicate such happenings as fire, open 

 door, high-low battery voltage, main discharge fuse operation, a-c 

 power failures, etc. When an alarm signal is received at the main 

 station, it is rechecked and upon its reappearance an attendant may be 

 dispatched at once or later to the auxiliary station involved, depending 

 upon whether the signal is of major or minor importance. 



The auxiliary stations are not always controlled by the nearest at- 

 tended station. For example, in several cases it has been thought 

 better to have them controlled by a station located in a small town 

 rather than a city, because in cases of necessity an attendant should be 

 able to drive to the auxiliary station in less time than required to drive 



