. Journal of electricity, power, and gas . tower, thus throwing the lowest pointof sag in the span off the lineal center between the twotowers; in fact, this lowest point is. 2455 feet from thesouth tower and 1972 feet from the main tower, asshown in the drawing presenting the profile of thecrossing. A further reason for the arrangementadopted is found in the fact that the land north ofthe main tower falla away to a marsh at near tide level. January 22, 1910) JOURNAL OF ELECTRICITY, POWER AND GAS 75 which made it necessary to turn the cables down to an-chorages some 1700 feet back of the main
. Journal of electricity, power, and gas . tower, thus throwing the lowest pointof sag in the span off the lineal center between the twotowers; in fact, this lowest point is. 2455 feet from thesouth tower and 1972 feet from the main tower, asshown in the drawing presenting the profile of thecrossing. A further reason for the arrangementadopted is found in the fact that the land north ofthe main tower falla away to a marsh at near tide level. January 22, 1910) JOURNAL OF ELECTRICITY, POWER AND GAS 75 which made it necessary to turn the cables down to an-chorages some 1700 feet back of the main tower. Thiscondition compelled a great change in the dip of thecables between the main tower and the north anchor-ages, and necessitated the erection of the third or northtower, which, because of this change in direction ofthe cables, was built to lean toward the north. Itsinclination is at an angle of 13 degrees from the per-pendicular, and this has led to its being known asthe leaning tower, although the company terms itthe north The Soutli Tower. The three towers are of steel and iron through-out with the exception of the main cross-arms sup-porting the cable saddles, which were of course de-signed to afford an insulating support for the principal interest in the strains and stresses towhich these structures are subjected centers in themain tower, wherein compression and tension strainswere thus determined: Assuming that the maximumpressure exerted by the wind will be 40 pounds pers(|uare inch, the maximum strains of compression uponeach of the four curner posts of the main tower are: Wind strains 76,500 lbs. Live load 6,000 Dead load 50,010 On the other hand, the theoretical maximum ten-sion strains amount in the aggregate to 9400 pounds,while the practical maximum allowed is 17,600 pounds,affording an ample factor of safety. Twelve concrete piers with the corner ones ar-ranged in a quadrangle measuring 69 feet by 89 feetbetween the pier centers, support
Size: 1219px × 2049px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookidjo, booksubjectelectricity
