THE FLOW OF WATER IN WOOD-STAVE PIPE, 



47 



Table 4. — Simultaneous discharge, elevation of water surface above weir, elevation of water 

 surface below weir, and head on weir. 



No. 



Discharge. 



Elevation 

 above weir. 



Elevation 

 below weir. 



Head on 



weir. 



1 



Second-feet. 

 106.6 

 446.1 

 724.9 

 749.6 



Feet. 

 8.752 

 9.539 

 10.123 

 10. 172 



Feet. 



7.77 



(not taken) 



9.62 



9.62 



Feet. 

 0. 515 



2 



1.302 



3 



1.888 



4 



1.937 







The mean elevation of the weir crest, 8.237 feet, was based on readings with level 

 and rod taken every 5 feet throughout its length. During measurement No. 1 the 

 hook gauge remained constant. During No. 2 water rose 0.142 feet on the weir. 

 During No. 3 water fell 0.020 feet on the weir. During No. 4 water fell 0.049 feet 

 on the weir. The mean gauge reading was accepted were fluctuation occurred. 

 Current-meter measurements were made by the two and eight-tenths depth 

 method. As the load carried (and consequently the discharge of water at a 

 power house) varies throughout the day, and since the discharge is controlled 

 by the load (by means of governors), the following method of testing the 12-foot 

 pipe for loss of head was adopted: The mercury manometers and the hook and tape 

 gauges were read continuously throughout the morning and afternoon. A synchronous 

 profile was then platted showing all gauge readings. From this profile periods of 

 comparatively uniform flow were chosen and each of these periods was designated as 

 an observation. These would necessarily vary in length of time. From the calibra- 

 tion curve of the weir the discharge for each reading of the hook gauge was taken 

 and the mean of these discharges was assumed as the discharge which held throughout 

 the observation. The capacity of tliis pipe was 2.4 per cent less than that computed 

 by the new formula. Since the pipe was new, joints smooth, and the curvature 

 gentle, the writer would estimate the capacity of this pipe to be greater than that 

 computed by the new formula. Tests by all experimenters show similar cases where 

 the observations indicate far different results than the conditions appear to warrant. 



No. 52, Expt. 8-14, 162-inch Continuous- Stave Douglas Fir Power Line, 

 Northwestern Electric Co., Condit Plant ^ on White Salmon River, Wash- 

 ington. — About 2 miles above the mouth of White Salmon River is located the 

 Condit Plant of the Northwestern Electric Co. Some 6,000 feet upstream a high 

 diversion dam raises the water above the intake to the supply pipe line. This, said to 

 be the largest wood-stave pipe in the world, 162 inches or 13^ feet in diameter, is used 

 to convey the waters of White Salmon River from the diversion dam to the surge tanlc, 

 a distance of 1 mile. Within the surge tank is a structure that divides the water from 

 the 13i-foot pipe between two 9-foot pipes with very little loss of head. Each of the 

 9-foot pipes serves 1 electrical unit in the power house. (PI. XI, fig. 1.) About mid- 

 way of the large pipe, upon which tests were made, is a bend of 83° with a radius of but 

 40 feet (less than 3 diameters) . In the opinion of the writer, such a bend would cause 

 an appreciable loss of head independent of the friction loss, and for this reason a 

 reach of pipe was chosen between this bend and the surge tank. Mercury manometers 

 were used for both gauges, the equivalent water column being just too high to be 

 feasible. (PL V, fig. 3.) Gauge No. 1 was located on the zone of neutral velocities 

 209.9 feet from the bend. Gauge No. 2 was located 2,378.9 feet from gauge No. 1 and 

 about 40 feet above the dividing tongue in the surge tank . During all of the runs the 

 load carried by the unit served by the right-hand 9-foot pipe was held constant, all the 

 fluctuation being thrown to the other 9-foot pipe. The time necessary for fluroescein 

 to travel from gauge No. 2 through the constant- velocity pipe was determined by 



J Eng. Rec, Oct. 11, 1913; Eng. News., voJ. 70, No. 15, p. 685. 



