It is desired at this time to present in summary form a factual history of the Building 234-5 operations, encompassing not only the immediate pre-start-up period from April to July, 1949, but including the major obstacles encountered in the succeeding interval to the end of 1949. This report is intended to serve not only as a review of 234-5 operations during this period but also as a documentary evidence of the difficulties experienced and the manner in which they impeded the start-up. This report presupposes a certain familiarity with the background of the 234-5 Building. To one unacquainted with the scope of this project, or for those desiring a background review, reference should be made to Document HM-253, ``234-5 Building Program Review``, by D.D. Streid, dated April 22, 1949. It must be realized that any attempt to discuss in detail all the circumstances and difficulties contributing to the start-up period would be disconcerting to the reader, and would very likely be repetitive. Therefore, although it is far from the writer`s intent that a cursory review will suffice, the presentation will be as nearly as practicable, chronological and comparative. For the sake of clarity it will be necessary to present several …