Popular Science Monthly 



533 



The "Hump" cut passed through the very heart of the City of 

 Pittsburgh The work took eighteen months 



city and to the base- 

 ments of the large 

 office buildings. 



The particular 

 conduit line leading 

 into the "Hump" 

 district which had 

 to be rebuilt con- 

 tained seventy ducts 

 where it left the cen- 

 tral vault, thence 

 sixty ducts in Straw- 

 berry Alley, and 

 branched out via 

 Grant Street, 01i\'er 

 Avenue, Diamond 

 Street and Tunnel 

 Street. It was necessary 

 rebuild the cable vault 

 question. Where the 

 seventy-duct line was lo- 

 cated on Pentland (formerly Fountain) 

 Street, the "Hump" cut was only a few 

 feet down. The new grade was cleared 

 by removing thirty-five ducts off the top 

 of the seventy-duct line and building 

 them down on the side, thus making a 



Cables were placed in a plank box, shown 

 at the right. The ditch is twenty-two 

 feet deep, cut mostly through blue rock 

 and limestone by means of steam drills 

 and dynamite 



the wdrk was eighteen months, costing 

 the telephone company about $75,000.00. 

 This is the largest jol.) of the kind ever 

 attempted and successfully accom- 

 plished. At the rear of the telephone 

 company's main exchange, located at 7lh 

 Avenue and Grant Boulevard, there is a 

 central cable vault or underground room 

 about eighteen feet square, extending out 

 under the street, from which radiate in 

 various directions the underground con- 

 duits leading to different parts of the 



Cables systematically arranged and hung 

 in the trench preparatory to being low- 

 ered into the solit ducts 



