As noted in Part 4, there are currently 17 plants routinely producing 
in excess of 500,000 cubic yards per year. Any number of these can be 
assembled at the construction site to obtain virtually any production 
rate. It is reasonable to assume that any multiple or fraction of the 
above can be achieved by a system composed of equipment whose outputs have 
been scaled up or down the appropriate amount. The only limitation appears 
to be the problems of finding adequate manpower (both in skill and 
numbers) for exceptionally rapid construction. 
There are a large number of feasible and practical alternatives 
for establishing a concrete-mixing plant, thus making it relatively 
safe to reason that the problem can be solved in all but the most 
remote locations. While it is difficult to estimate the total cost of 
equipment, it was determined from various sources on heavy construction 
that a one million-cubic-yard per year plant, newly purchased, would be 
slightly less than $4 million. This dollar figure includes purchase 
price, installation cost and dismantling cost, and zero salvage value. 
Materials 
The technical literature includes much information on mix design, 
laboratory investigations, and production of concrete for waterfront 
structures and ships. The extent of information is too great to report 
here. Comments on material specifications applicable to MOBS are 
offered in Appendix B, together with a selected reference listing. 
CONSTRUCTION TIME AND COST 
At a production rate of one million cubic yards per year, the time 
necessary to construct any of the platforms is indicated in Table 5.2. 
The maximum time noted is approximately 3% years for the elevated plat- 
form with multiple decks. As was discussed in Part 3, the table values 
represent the extremes, the final platform will probably be a combination 
of single and multiple decks. On the other hand, the shortest time is 
only 0.03 years, which suggests that a baseline plant producing con- 
siderably less than one million cubic years per year would suffice. 
Cost 
Table 5.3 presents the estimated construction costs of the platform 
exclusive of power systems, machinery and personnel support facilities. 
The costs of mixing and placing the concrete, fabricating and installing 
the forms, and purchasing and installing the reinforcement are included 
in the figures. 
