392 CONFERENCE ON NATURAL BEAUTY 



To accomplish further and more rapid progress in the future, we 

 would recommend that collaboration between electrical utilities and 

 their suppliers be intensified, on both an informal and formal basis, 

 to develop products and methods which will improve the aesthetics 

 of transmission and distribution networks on the most economical 

 basis. Both utilities and manufacturers commonly apply value 

 analysis methods to increase their performance and reduce costs. By 

 linking their value analyses together as it applies to this problem, 

 they can achieve faster progress towards the goal. 



L. F. LISCHER.* In addressing ourselves to electric transmission 

 lines (those operating at 66,000 volts or higher) and not to under- 

 ground distribution, the problem is of much greater magnitude. In 

 underground distribution great strides are being made so that in 

 the near future such service may be provided at costs economically 

 competitive with overhead distribution. For Commonwealth Edi- 

 son last year 50 percent of all new residential subdivisions were sup- 

 plied by underground distribution, and the total number of customers 

 served from underground lines is now 140,000. 



The problems in underground transmission are far from simple. 

 For example, Commonwealth Edison figures show that to provide 

 the same line capacity underground as overhead at 138,000 volts, 

 costs on the average 1 6 times as much ( about $400,000 per mile for 

 a single underground line); at 345,000 volts this ratio jumps to 

 45 times as costly for underground. A fact sometimes not readily 

 apparent is that when underground transmission lines fail, as much 

 as five days may be required to locate the point of failure and to make 

 repairs. This, of course, necessitates duplicate facilities to avoid long 

 interruptions and thus adds to the cost. 



Many metropolitan areas already have extensive underground 

 transmission systems. Taking the Chicago area as an example, we 

 have today 50 percent of all our transmission investment in under- 

 ground lines, and on a mileage basis this represents 15 percent of all 

 transmission line miles. 



There is need for considerable research on two fronts. One is 

 how to build cables economically for voltages higher than 345,000 

 volts (which is the highest voltage cable we know how to construct 

 today) ; and second, how to provide lower cost cables and installation 

 methods for those voltages for which cables are currently being built. 



*This is an extension of the remarks made by Mr. Lischer during the panel 

 discussion. 



