What if, instead of building a sea base in American ship yards, at great expense in both construction and maintenance costs, we could build the sea base from local materials on site where ever we wanted? What if once it is built we can change its shape and purpose whenever we want? What if you could pre-stage it, and then sink it, to be raised again when needed? All of this is possible with the use of expeditionary concrete fabrication. This will allow us to build modular, floating, concrete sections capable of being arranged in custom configuration to fit a variety of basing needs.
The Romans were the first to use concrete on an industrial scale and the durability of their construction can be seen today. They even pioneered the use of concrete for underwater construction. In 1848 the first ship was made of concrete. Concrete ships and more notably concrete barges served the Allied Powers in both world wars. During Operation Overlord the Allies relied heavily on concrete barges to move supplies across the English Channel. All of these vessels were built in concrete shipyards and then sailed under their own power or pushed by barges to the area of operations. What we propose is a little different.
The beauty of concrete as a material to build a sea base is that the bulk of the material required to manufacturer it is available on site. The aggregate (gravel etc.) which makes up 89% of the dry component of concrete can be dredged on site. Only the Portland cement which makes up eleven percent of the mixture has to be transported from home station. That is unless volcanic ash and lime is locally available in which case all materials can be sourced on site. The water is obviously readily available. Forms can be made on site to create hollow hexagonal columns of concrete. Built into these concrete columns can be mating devices which allow the hexagons to be attached to each other. Additionally, the walls of the hexagons would have filler ports which would allow air or water to be pumped into the columns to increase or decrease the buoyancy of the hex. Designed in this matter, a hex that has a surface that is 10 meters long on each side and one meter thick with side walls that extend 10 meters deep and 30 centimeters thick would weigh 1,055 metric tons. That same shape would produce 2,663 metric tons of displacement, providing for a useful load of 1,600 metric tons (that is more than the weight of 16 M-1 tanks).
By connecting multiple hexes together, the stability of the platform is increased by the distribution of the wave motion. Additionally, the hexes would be anchored in their desired location which would provide additional stability. Once the hexes are built, they can be towed around by barge to new locations. Once in those locations, they can again be custom configured into the design of choice. Matting could be added to the top of the hexes to create a runway for heavy lift aircraft to support the sea base. Because these hexes are made out of concrete, they could also be easily replaced if damaged by enemy A2/AD capabilities. Once the hexes are no longer needed, they can be slowly sunk to the sea bed for use at a later time.
This could be a flexible, cost effective method of establishing sea bases wherever necessary.