CHAPTER Il, SECTION 3 STATION: PURPOSE: SITE: USER: PARTICIPATION: CONSTRUCTION: 1524 Vacuum Array Yvonne LASL 24 11-5-55/4-25-56 This station consisted of a two-story build- ing 324’ x 12’-6” wide and 17 high, forming a pump and mirror house from which a 38 va- cuum pipe array led to the working point of Station 24, a distance of 500 feet. The first story of the building consisted of six pump houses spaced along the length of the building; the second floor consisted of a 313’x10 room which housed the vacuum manifold and mirrors for each pipeline. The mirrors, located at elevation plus 20’-6”, reflected light from the mir- rors at the 38 pipe ends and in tur sent this reflection to camera Station 1520 through open- Figure 2-84. Page 2-96 ings in the front wall of Station 1524. Beginning at Station 1524 and progressing toward Station 24, the 38 pipes were 12-inch diameter for a distance of approximately 410 feet, later changed to 10-inch diameter for an additional distance of approximately 76 feet, and then reduced to 7-inch pipe for the remaining distance of approximately 25 feet, to the working point of Station 24. The mirror house structure rested on the pump houses and on intermediately-spaced columns at the rear wall facing away from Station 24. The second story roof and floor and rear walls of both stories were wood framed. Since the pump houses were 32 feet apart, the secondstory rear walls were suported on 12-inch Ibeams which spanned to 6-inch steel pipe columns spaced between the pump houses. The front walls of both stories consisted of 18-inchthick reinforced concrete, and the span between Interior Mirror Shed - Station 1524