Design and drawings were practically camplete on this basis when the User requested that the column ce shielded with lead only and that the pipe used for encasing the coaxial cable be changed fram 12 inch diameter to 8 inch diameter. The new plan of installation, and the one that was actually used, involved hanging the top 180 feet of the § inch pipe from the lower structure and pulling the coax cables up through the pipe as the cables were welded together. The bottom 20 feet of the pipe was 10 inches in diameter, and it was slipped over the 8 inch pipe before the placing of the cables began, The coax cable was of the rigid type and was shipped in 20 foot lengths. A length of cable was pulled up into the 8 inch pipe and a second length soldered on, This was pulled up and this operation was repeated until all coaxial cables were in place. After all of the cables had been placed, secured, and tested, the 10 inch pipe was lowered into place, and the placing of the lead blocks began, The lead, in the form of split doughmts, was placed to a height of a little more than 124 feet; then the first section of the flanged steel casing was placed in two parts and these parts welded together, This series of operations was repeated until the column was completed, The grouting of the one inch space was done section by section. To retain the lead, it was decided that the flanged welded steel casing sections would be employed as contemplated in the original requirements, A clearance space of one inch would be allowed between the lead and the steel retaining shells which would be pressure grouted as the construction of the column progressed, Holes and nipples for the grouting hose connection were provided in the walls of the shell, Designs and drawings were completed on this basis and material placed on order, but after the User reviewed the plans, he requested that the steel grillage supporting the column at the base over the coaxial cable trench in the foundation be designed so that it could be installed after the coaxial cable was in place, including the bends into the trench in the foundation. Design therefore had to provide a hole in the grillage for passing the coaxial cable. On checking the status of the material on order it was found that the grillage as originally designed had been shipped. Because field changes on these to meet the later requirements would have been diffi- cult, a new grillage was immediately designed which could be installed in halves around the coax, This was ordered and shipped to the Jobsite. The coaxial cable and the lead were furnished by NRLK and installed by H & N under the User's direction. H & N designed, furnished, and installed the remainder of the column, A portion of the test gear for the UCRL experiment involved the use of a vacuum tube system which extended from the top of Station 131, located at the base of the 200 foot tower, to the floor of the 5-143