Station 54 - Runit and Engebj - NBS. The first sketches were furnished on February 8, 1950. On May 16, 1950, a representative of NBS was in Los Angeles and furnished H&N with the necessary design data to complete engineering for Station 54, Engebi. Three days later the data was furnished for Runit, The buildings were constructed of limonite concrete above the foundation level. The foundations were made with coral concrete, The thickness of walls and roof was specified by the User as being the minimum required for shielding purposes; the front wall being 6 feet and the roof 5 feet thick. Some structural failure was considered likely to occur in Stations 54, since it was considered impractical to design this station for the full pressure. Because the basic collimator tubes extending through the face wall had to be set to relatively close tolerances established by the User, it was considered advisable to bolt them to the wood concrete forms and then tie them together and support them from the foundation with a steel rack fabricated in the field to suit the conditions encountered, Also, because the stations were to be mounded over with earth, it was necessary to construct a timber framed tunnel to the entrance doors, This timber tunnel was considered to be expendable, The final collimator tubes were made from stainless steel tubing in accordance with sketches prepared by the User. These were "dry packed" in place in the basic tubes with limonite concrete after proper alignment. A wooden tunnel over 26 feet long to act as battery storage was constructed under the fill in back of the stations. The studs in the tunnel were spaced to fit the batteries to be used, and the spacing was given on June 9, 1950. The plans were approved by NBS on July 18, 1950, after minor changes, i.e, increased power requirements, and paving of the ramp. The ramp had to withstand 500 pound wheel loads and have a maximum slope of less than 15 per cent, Station 55 - Engebi and Runit ~ NBS, Sketches for this building were furnished H&N by J-Division on February 8, 1950, The building's inside dimensions were 28 feet, 5 inches by 1)’ feet by 6 feet, 6 inches high, The 15 inch walls and roof were of coral concrete, In order to be able to fasten equipment any place in the building, a system of con- tinuous slotted inserts on 1+ foot centers was provided on all four walls and ceiling, This made it possible to alter the User's gear up to the time of installation. The final building changes were received on March 23, 1950. The drawings were completed March 31, 1950. In May 1950, the station assigned to Aomon was moved to Runit, In July 1950, a change of location on Runit was made, 5-165