aNoual Archives ia fic uthwest Region NCS TING U HOLMES & NARVER, A hy GeGy INC, “ Engineers=Constructors NATIONAL REPOSITORY PACIFIC #2319 DiNdreys 8 a Ph =~53 To: ARCHIVES SOU TAWES §F REGION ® yy COLLECTION BE346 ATomic EMEREY CovaA \v BOX No. 129624 (#60¢} AIGISH 206 ~6S Voy Lt SURVEYS = §, Py Howell Je FO AVCUS T ! Job: 88h BEPARTME ahE FEVIEW A , ? ue DETERMINATION [CIRCLE NUMBER(S) Ree: d4 1. CLASSIFICATION RETAINED 2. CLASSIFICATION CHANGED TO: “CONTAINS NO DOE CLASSIFIED INFO 4. COORDINATE WITH: CLASSIFICATION CANCELLED CLASSIFIED INFO BRACKETED ~@ 2 Date: Alignment of Stations 1203, 2220, 2230 August 28, 1953 The following procedures are recommended for alignment of the pipe arrays at Stations 1203, 1220 and 1230 to a horizontal and vertical tolerance o: plus or minus 1.0 inch from a line of sight between working points at the extremities of the lines. The procedure con- sists of establishing horizontal control from an offset line parallel to the centerline of an array and bench marks at convenient intervals for vertical control, The alignment of the pipes is made by hori-= zontal and vertical measurement from reference marks on the supports transfered from these control points. Procedure for the 7500 foot line at Station 1203 is outlined herein and can be modified to accomplish the alignment of the shorter lines at Stations 2220 and 2230. With precise equipment and qualified personnel the accuracy which can be obtained in establishing the alignment controls is dependent on the methods used and the atmospheric conditions during the alignment operations. As the alignment of the pipe lines will be subject to additional factors affecting the accuracy of the results including construction tolerances of the pipe itself, Temperature distortion and wind deflection, it is imperative that the controls be established as accurately as is possible under the existing field conditions. Horizontal Cortrol Horizontal refraction is the most likely source of error in this operation and as it is an indeterminate quantity as related tothe alignment, it will be necessary to accomplish the work under the most favorable conditions that can be obtained. As refraction is caused by variations in the temperature and density of the air and may be increased by unequal movements of air crossing the line of sight, alignment of the control stations should be accomplished at night when these variations are at a minimum. The hours just before daylight should approach the ideal conditions. Gusty, windy weather is unfavorable as it will be necessary to shelter the alignment equipment. However, a light breeze may help to minimize the conditions causing ~efraction. The line of sight should be as high as practica: anove the ground as the density of the air decreases with the elevation of the line of sight. The line should be cleared of vegetation and it is desirable that there be a free movement of