Design and Operation of a Cantilevered Traveling Fish Screen 



(Model V) 



By 



DANIEL W. BATES, Fishery Biologist; ERNEST W. MURPHEY, 



Laboratory Mechanic; and EARL F. PRENTICE, Fishery Biologist'' 



Bureau of Commercial Fisheries Biological Laboratory 

 Seattle, Washington 98102 



ABSTRACT 



Model V was installed within the Stanfield Irrigation Canalnear Echo, Greg. The 

 Bureau of Commercial Fisheries developed the screen to meet the need for improved 

 guiding of juvenile fish of all sizes and to reduce capital and operational costs. 



Field tests with the model V screen showed a head loss of only 9.1 mm. with 

 waterflow of 73 centimeters per second. From 97 to 100 percent of the juvenile 

 migrant coho salmon, Oncorhynchus kisutch , and steelhead trout, Salmo gairdneri , 

 that entered the Stanfield Irrigation Canal were diverted into a bypass. 



The self-cleaning screen, supported by a wire-rope suspension systenn, 

 traverses the 8. 5-m. wide, 1.8m. deep, earth-lined sectionof the canal at a 20 angle 

 to the waterflow. Torsion induced in the structure by water forces on the screen is 

 resisted by a main torque tube with track support arms placed at intervals along the 

 tube. The support arms are tied with wire rope to anchors on shore. To minimize 

 drag, the speed of the screen in the water can be matched to water velocity and the 

 screen returned upstream above the water. Screen panels are cantilevered from 

 carriers on a continuous track. 



INTRODUCTION 



The prototype-size traveling screen dis- 

 cussed here (model V) was placed in an earth- 

 lined section of the Stanfield Irrigation Canal 

 (a diversion of the Umatilla River) near Echo, 

 Oreg, (fig. 1). Here it was exposed to the 

 debris in the river and to the runs of juvenile 

 steelhead trout, Salmo gairdneri, and coho 

 salmon, Oncorhynchus kisutch, that had been 

 drawn into the canal. The canal at the instal- 

 lation site was 8.5 m. wide and 1.8 m. deep. 

 Flow discharges were 3.7 to 4.3 c.m.s. (cubic 

 meters per second). The only modification in 

 the canal floor was the construction of a 

 6ll-cm. wide concrete sill. The traveling 

 screen was placed on a 20° angle to the 

 direction of flow; it extended 23.2 m. across 

 the canal. 



The use of a wire-rope suspension system 

 in place of piers is generally considered less 

 costly. To demonstrate the practicability of 

 this type of support system in rivers, the 



wire-rope suspension system was adapted at 

 Stanfield. 



This report describes: the design and oper- 

 ation of a traveling screen in which screen 

 drag is reduced by lifting the panels out of the 

 water before their return upstream and the 

 results of mechanical and biological tests 

 (trials with coho salmon and steelhead trout) 

 of the system. 



DESCRIPTION OF TRAVELING SCREEN 



The structural and mechanical design of 

 this screen was based on loading values in 

 which consideration was given to the material 

 from which the screen was constructed-- 19- 

 gage, spiral-wound, carbon steel wire with 

 6.35-mm. openings and a 68-percent effective 

 open area. The loading values were: 



Wind load on screen--48 kg. per square 

 meter (10 lb. per square foot) 



'Present address: Battelle Northwest Memorial Institute, Richland, Wash. 99352 



