CHAPTER II, SECTION 3 STATION: SITE: USER: PURPOSE: PARTICIPATION: DESIGN PSI: CONSTRUCTION: J-1810 Johnston Island NRL, LASL Recording Shelter J-40, J-41 None 5-8-58, 7-7-58 This station utilized a new structure in joint occupancy with Station J-1030. The building was 48x64 feet, varying in height from 8 to 12 feet. A 12-inch-thick concrete slab supported the timber framed structure. The roof was insulated with fiberboard sheets, and the exterior walls were covered with plywood on the outside. Station J-1810 occupied an area 25x64 feet and one additional room. The room, Electronics Room “A,” was 10x23 feet located adjacent to the Photometric Room of Station J-1030. It con- tained a double door at each end, one to the out- side was was was and one to the Camera Room. The framing exposed on two walls, but insulation board placed on the two exterior walls. The room air-conditioned. The remainder of Station J-1810 was divided into two 64-foot-long rooms. The room adjacent to and behind Station J-1030 and Electronics Room “A” was the Camera Room. The walls and ceiling of the room were covered with insulation board. The room behind was the Tracker Room, and the wall separating the two rooms was constructed of 12-inch thick concrete to a height of 5 feet. The wall contained thirteen 14-inch steel pipe sleeves 4 feet 144 inches on centers with flanges on one end. Three sleeves had flanges on both ends. A stud wall above the concrete was sloped 1:1 toward the Camera Room. This was done to provide sight from points within the Tracker Room through the roof to Stations 40 and 41. A light-tight entry from outside was provided in one end of the Camera Room, and the Camera Room was made light-tight. The Tracker Room floor was 1% inches lower than the remainder of the building. The walls and ceiling consisted of exposed framing. The roof included a series of removable panels over 4x9-foot openings which were lined with 14-inch pipe sleeves of the concrete wall. Wood shutters, 3x4 feet, were placed in the rear wall of the Tracker Room to providesight alignment from the mirrors in the Tracker Room to Station J-1812 light array on Sand Island. A track assembly was provided on the floor of the room to support User-furnished mirrors. The track was constructed of steel angles the length of the room. Entry to the Tracker Room was provided at each end from the outside. This was the only room of the building that was not air-condi- tioned. STATION: J-1811 SITE: Johnston Island USER: NRL, LASL PURPOSE: Thermal Radiation Measuring PARTICIPATION: J-40, J-41 DESIGN PSI: None CONSTRUCTION: 5-11-58,'5-30-58 This 6-inch-thick concrete slab was 20 feet square. User-furnished shelters and motor generator sets were located on the slab. STATION: J-1812 SITE: Sand Island (Johnston Island USER: NRL,LASL PURPOSE: Aiming Light PARTICIPATION: J-40, J-41 DESIGN PSI: None CONSTRUCTION: 4-14-58, 7-7-58 A 13-light array was placed 15 feet above grade. It was utilized to provide a light source for aligning the mirrors in Station 1810. The array was mounted on three guyed wood poles. Power was supplied from a 10-kw generator placed at the station. STATION: J-3230.01 SITE: Johnston Island USER: SC PURPOSE: Recording Station PARTICIPATION: J-40, J-41 DESIGN PSI: None CONSTRUCTION: 5-1-58/7-7-58 Occupying a portion of existing Building T-249, this station was located within the same area as Stations 3241.01 and 3440.01. The space was adjacent to that occupied by Station 613 and was 21x25 feet. Work benches were provided along the walls for a length of 46 feet. Power receptacles were located over the benches 2 feet on centers. The room was air-conditioned by a ceiling-hung unit which also fed air through a duct passing Station 613 and into the equipment room on the other end of the building. The end room adjacent to the 21x25-foot room was 21x11 feet in size and was used to house instrument racks. Existing wood studs in the area were removed, and three power receptacles were added, as well as lights in this and other rooms of the building. Page 135