APPENDIX. 



The following pages are devoted to abstracts of the descriptions of 

 experiments made by agencies other than the Irrigation Division, 

 Bureau of Public Roads. The first part covers tests made on pipes 

 under pressure while the last portion covers tests made on pipes and 

 conduits but partially filled. The number before each description 

 refers to the corresponding numbers in column 1, Tables 3, 4, and 11. 



PRESSURE PIPES. 



No. 12, Experiment N-l. — 16-inch jointed concrete pipe, Z a , siphon, 

 Umatilla project, United States Reclamation Service, Oregon. — In 

 1911 and 1912 Herbert D. Newell, manager of the Umatilla project, 

 conducted a series of experiments on several of the concrete inverted 

 siphons under his charge. For the sake of brevity the descriptive 

 matter pertaining to all the tests will be abstracted from his extended 

 article, 1 and placed under this number. Matter pertaining to indi- 

 vidual pipes will be placed under the proper reference number. He 

 states: 



During 1911 and 1912 a number of experiments were made to determine the coeffi- 

 cient of friction. The quantity of water was generally determined by meter meas- 

 urements. Difference of water surface elevation between the inlet and outlet ends 

 were determined from bench marks carefully established on the inlet and outlet struc- 

 tures. 



Regarding the 16-inch pipes he adds: 



No information exists as to whether or not the 16-inch pipes are somewhat ob- 

 structed near the bottoms of depressions. It will be noted that the 16-inch pipe show 

 discharges relatively much smaller than the 30 and 46 inch pipe. The 16-inch are 

 made by the dry process and have joints every 2 feet. At every joint there is una- 

 voidably a slight irregularity in the cross section. The mixture used in making the 

 30 and 46 inch pipe is distinctly a wet mixture. All sizes are grouted on the inside, 

 but the grouting on the large size is more smooth, as a man can work inside the pipe 

 and it is possible to do a better job. 



The nominal size of the pipe appears to have been accepted as the 

 true size. In the experiment on this particular siphon the quantity 

 of water for the first observation was taken as the mean of two meter 

 measurements, one indicating a discharge of 3.78 second-feet and the 

 other 3.70 second-feet. For the second observation the mean of three 

 measurements, ranging from 4.78 to 4.97 second-feet was accepted. 



From the amount of the friction loss the writer would judge that 

 some debris had accumulated between the time this pipe was laid 

 and the date of the experiments. The retardation factors are not 

 consistent. 



No. 13, Experiment N-2. — 16-inch jointed concrete pipe, Z c siphon, 

 Umatilla project, United States Reclamation Service, Oregon. — In 

 addition to the information given under reference number 12a for the 

 series of tests conducted by Newell, the following pertains to this pipe 

 alone: 



'Studies of Coefficient of Friction in Reinforced-Concrete Pipe, Umatilia project, Oregon. ByH.D. 

 Newell, Eng. News, vol. 69, May 1, 1913, p. 904. 



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