FIGURE S-2.-SHELTER ENTRANCE SHOWING BLAST BULKHEAD, DOOR, AND INTAKE VENTILATORS FIGURE S-3.-VIEW LOOKING FROM REAR TOWARD SHELTER DOOR FIGURE S-4.-VIEW LOOKING TOWARD REAR OF SHELTER WITH BUNKS STORED ALONG WALLS Analysis of cost information from the general contractor, subcontractors, and suppliers has been exceedingly difficult and it has been only very recently that actual costs that could be compared to those in the design study have become available. The tentative results are given in table S-2, which I have reproduced. TABLE S-2.-Cost summary of USNRDL experimental shelter Item Description Cost 1 As estimated by USNRDL-TR-366. $16, 096 Did not include profit, overhead, latent costs peculiar to site, performance bond, or labor fringe benefits. 15,830 Actual costs of construction on same basis as item 1 except that analysis was not completely successful in removing all profit and overhead charges. 1, 560 Includes tests of water and electrical systems, use of select material for backfill, and minor changes in design. 4 Estimated profit and overhead. 7,959 25, 349 Sum of items 2, 3, and 4. The first item is the cost as estimated by USNRDL-TR-366, which was the design study already submitted to the subcommittee at previous hearings. I would like to reiterate that the estimated cost did not include profit, overhead, latent costs peculiar to the site or performance bond, labor fringe benefits, and the like. The cost of the shelter, as estimated in the 1958 design study, was $16,096. The analyzed cost for comparison, on the same basis as item 1, except we do not believe that the analysis has been completely successful in removing all profit and overhead charges, is $15,830. So it can be seen that the estimates of the design study were well borne out by the actual construction of the prototype. In addition to this amount, there was about a 10 percent increase, $1,560, in latent costs of construction. By far the largest amount of this came about because it was found that the adobe clay soil excavated at Camp Parks was not suitable for compaction around the installed shelter as is required for a 35 pounds per square inch blast protection. This shelter obtains its performance against blast by deforming under the blast loads and pushing out against the earth at the sides, and in order for this to occur the earth must be carefully compacted upon installation. In this case, suitable earthfill was purchased and hauled to the site at a cost of about $1,000. This cost would not have occurred in most building sites or at any site where a pure fallout shelter was being installed, one where you were not insisting upon this sort of blast protection. There were other latent costs of tests of water and electrical systems and minor changes in design that contributed to this $1,560 cost. The combined base costs and latent costs; that is, the combination of items 2 and 3, totaled $17,290. The estimated profit and overhead of the general contractor and subcontractors is obtained by subtracting this cost from the total actual expenditures of $25,349. Therefore, the estimated profit and overhead is in the order of $8,000. This 46-percent margin did include some labor fringe benefits and the California sales tax on material procurement. So that is about the status of the knowledge of the costs of this type of shelter. COST SAVINGS DUE TO LATER RESEARCH AND DEVELOPMENT WORK Subsequent experimental work with this prototype shelter has, among other things, resulted in a known cost saving of about $2,000. In other words, if the results of the experimental work had been available at the time the prototype was built, the cost in item 2 of table 2 would have been about $14,000. In addition, possibilities of additional savings through further research and development are indicated. Specific research results that have contributed to cost reduction will be mentioned in subsequent paragraphs. All shelter research projects have been funded by the Office of Civil and Defense Mobilization. SIMULATED OCCUPANCY EXPERIMENTS I would first like to discuss the simulated occupancy experiments. One of the critical problems in fallout shelter design is the provision of adequate ventilation to maintain a habitable environment for a period of 2 weeks. Maintenance of normal oxygen and carbondioxide concentrations is not a serious problem compared to control of temperature and humidity. Each person in the shelter gives off about 500 B.t.u. (British thermal units) per hour; 100 persons produce 50,000 B.t.u. per hour, about half the output of the average home heating system. Part of this heat is liberated as sensible heat and part is liberated as evaporated moisture-latent heat. The proportion of latent heat increases with increased shelter temperature. Heat prostration occurs if the environment exceeds 93° effective temperature. (Effective temperature is a standard index that includes the physiological effects of both temperature and humidity.) Since the heat capacity of ventilating air is small, practically all sensible heat must be absorbed through the shelter walls into the surrounding soil. On the other hand, the moisture produced by the shelterees must be removed by the ventilating air so as to prevent condensation of water on the shelter walls. The calculation of ventilation requirements under these conditions is a complicated process that has not been satisfactorily resolved for shallow buried structures, such as fallout shelters. To aid in assessing the habitability of the USNRDL experimental shelter and to provide data on which to develop a calculational technique that would permit assessing ventilation requirements in all climates and soil types, a series of experiments were undertaken in late 1959 and early 1960 in which the heat and moisture output of 100 shelterees was simulated and environmental conditions were measured under various amounts of ventilation. To simulate the occupied shelter, each shelteree was represented by a 5-gallon paint can, painted black, within which was located an electric heating element. Each paint drum was draped with cheesecloth on which a metered amount of water was dripped. The amount of water evaporated was adjusted as the shelter temperature changed so that the proper proportions of sensible and latent heat were produced, as if 100 real people were in the shelter. I have two figures that show the nature of these experimental devices in the shelter. (See figs. S-5 and S-6.) |