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rKLKTYPFAVRITER EXCHANGE SYSTEM 509 



vision of a teletypewriter shelf the lower ed^e of which was at the same 

 height as the lower edge of the adjacent keyshelves. The depth of 

 the teletypewriter made it necessary to recess it in the jack field. This 

 recess was obtained by cutting off one stile strip and adding a longi- 

 tudinal detail the entire width of the section to support the lower end 

 of the cut stile strip. The teletypewriter shelf was placed on rollers 

 to permit its sliding out easily for maintenance accessibility. 



The teletypewriter, being the operating center of the position, has 

 nine cords on each side to locate all 18 cords within easy reach of the 

 operator. Because of this arrangement it was not possible to make the 

 position boundaries coincide with the section boundaries as this 

 would require two keyshelves of nine cords each per section with the con- 

 sequent waste of equipment space for the supports between adjacent 

 keyshelves. This loss of space was reduced by providing one 18-cord 

 keyshelf per 2-position section and associating one half of the cords 

 with the teletypewriter to the left and the other half with the teletype- 

 writer to the right. This caused an overlap of the position and 

 section boundaries so that the nine cords on the left end of each section 

 form a part of the right position of the adjacent section to the left. 



No. 1 Switchboard Multiple Equipment 



The primary objective in the design of multiple equipment is the 

 provision of line terminations in a form that will make each line 

 readily accessible to every operator, taking into consideration the 

 physical limitations imposed by the operator's reach. Previous 

 experience in the design of telephone switchboards has determined 

 that, for a subscriber switchboard, satisfactory operating conditions 

 may be obtained in respect to the horizontal reach of the operator by 

 the multipling of the line terminations on an 8-panel basis (using the 

 standard 8^ inch panel) giving a distance of 68 inches from one appear- 

 ance of a line to the next. The maximum reach in each horizontal 

 direction will then be half of this distance, or 34 inches. This was, 

 however, reduced to a 6-panel multiple giving a maximum reach of 

 25| inches to insure operating efficiency. 



In determining the maximum vertical reach for the operator, the 

 standard practice was followed of limiting this reach to 30 inches for 

 line terminations which are to be answered, and to 34 inches for lines 

 to which calls are to be completed. The line terminations to be 

 answered by the operator are kept lower than the lines for completing 

 purposes because the operator's attention must be attracted to the 

 line by the illumination of the line lamp. The line capacity of the 

 switchboard is limited by the number of line terminations that can be 

 provided within the above dimensions. 



