Other Uses of Cement Pipe 



159 



has been much more satisfactory for our use than the hand-tamped. 

 Have purchased and used both and very much prefer the machine- 

 made." 



In answer to an inquiry some months later as to how the cement 



pipe culverts were withstanding the traffic, the county engineer 

 states* : 



"These culverts are in good condition and show no signs of 

 weakness. After being laid, heavy rollers and motor trucks have 

 run over them. Since road has been completed heavy motor trucks 



Fig. 36. — Carrying- capacities of cement pipe and corrugated iron culverts 

 of equal diameters. 



weighing, when loaded twenty-two thousand pounds, including load 

 and weight of vehicle, have been operated over road and have not 

 injured the concrete pipe culverts in the least." 



For culverts for special service, where great strength is required, 

 reinforced concrete pipe can be used. (See page 93.) 



3. Capacity: The smooth interior of cement pipe has a great ad- 

 vantage over the corrugated interior of metal culverts. Every cor- 

 rugation causes eddies with consequent loss of head. The carrying 

 capacities of long pipe lines of corrugated iron have been found to 



•From a private communication from C. M. Hindman, May 11, 1917. 



