CHAPTER Ii, SECTION 3 Stations 311.01, and .02 and .03 were also steel trussed with corrugated asbestos roofs, but the siding was 8-inch thick reinforced concrete with a 7’ high continuous opening 7’ off the ground. The ends of the buildings were left open. On 18 December 1955, a combination of high tides and a storm caused inundation in the vicinity of Station 311.03, Dog. All of the work accomplished on the station to date, even to the stakeouts, was lost. The criteria covering the size of the manmade islands and the location of the stations were furnished by the User. A description of the islands and problems involved in their con- struction are found in this report under the sub- heading of Man-MadeIslands. A total of 55 cubic yards of concrete at an average 28-day strength of 5,300 psi was poured for Station 310.01, 55 cubic yards at 3,800 psi for 310.02, 62% cubic yards at 5,000 psi for 310.03, 180 cubic yards at 4,600 psi for 311.01, 204 cubic yards at 3,200 psi for 311.02 and Figure 2-57. Station 312.04 Form for Precasting 167% cubic yards at 4,025 psi for 311.03. measures were required to prevent leakage. Since the finished grade on the man-madeislands was only two feet above the high water line, a portion of the structure was constantly submerged in saturated soil. This posed two problems: first, the buildings might necessitate cassion shafts of sufficient size to accommodate construction and heavy enough to remain submerged when set in place; secondly, was the need for sealing the porous concrete from the water ~— ' Oecower Ee Figure 2-56. STATIONS: PURPOSE: SITES: USER: Stations 311.03 with 313.06 in Foreground 312.01 thru 312.04 Instrument Shelters Man-MadeIslands (Charlie-Dog Reef) (312.01-312.03) Dog 312.04 DoD Program 3 Project PARTICIPATION: 18 CONSTRUCTION: 2-13-56/4-20-56 OCCUPANCY: 4-11-56 These stations were reinforced concrete buildings 10’ x 15’x 10 high with walls and a floor slab 10” thick designed to withstand expected overpressures. The tops of the structures were 2’ above finished or natural grade. Proper Page 2-72 that would seep in the sides and bottoms of the building. The best solution appeared to be precasting each building and then setting it in place. The structures were therefore designed to be as light as possible and yet strong enough to withstand expected pressures. The bottoms and about four feet of the sides were encased in 1%” steel jackets with watertight seams. The jacket served in part as the outside form for the con- crete pour. The entire form was erected adjacent to the excavations. At Dog, an attempt was made to lower the form with only the floor precast. It floated and had to be raised; walls were added, which provided the weight necessary to help the structure set in place. Precasting of the floor slabs for the stations on the man-made islands was also necessary. Three 8-inch pipe vents extended through the roof and at each end of the battery room, and one was installed opposite the shelter entrance. Blank flanges on each vent covered the openings prior to the experiment. The entrance was a 2’-6” square hatch with a blast resistant, watertight, steel cover. Power to each station was supplied by a portable 25 KW diesel-driven generator which