Post by thebastidge on May 17, 2017 17:16:30 GMT
discuss.seasteading.org/t/experimental-small-hexagonal-platform/2377/37
discuss.seasteading.org/t/landlubers-guide-to-seasteading-feasibility/2392/51
A tool for thinking about hexagons:
rechneronline.de/pi/hexagon.php
This thread draws from original discussions over and TSI and summarizes and focuses the conversation on a particular concept I have developed further. Specifically, open-bottomed variable buoyancy hexagon platforms with or without spuds.
The structures themselves are to be made of basalt fiber-reinforced alumino-silicate geopolymer concrete, a material with significant structural strength and longevity, as well as favorable chemical composition for providing coral substrate. Each island is constructed as a hexagon approximately 8 meters per side with 5 to 10 meter height for grounding in 3-7 meter depths. The internal deck is permanently supported by blocks of sealed EPS foam and the walls are pre-formed geopolymer concrete. At each angle of the hexagon, mechanisms are mounted to extend concrete spuds downward through the internal deck to act as legs for leveling the platform in place. A seventh spud is centered in the structure and serves to support both the lower and weather deck. The deck and center of the hexagon remains supported by buoyant EPS foam blocks even after gravity placement, resulting in near complete elimination of dead load. The internal deck is elevated to a minimum of 1 meter over mean high tide and the weather deck is approximately 3 meters higher. Walls extend below the waterline and permanently contain the EPS foam blocks, as well as providing last resort defense against complete submersion should the spuds fail. Dead load on the spuds is minimized by the same technique of buoyant EPS foam placement that eliminates dead load on the deck. The depth should be adjusted such that the weight of the internal deck is neutralized by buoyant foam, the weight of the walls rest on the spuds, and the spuds rest on seabottom.
Placing the "bottom" (deck) in the middle of the upright walls kills two birds (buoyancy and internal space) for the weight penalty of one deck and greatly eliminate the complexity of design and construction implied by the internal structure shown in most closed displacement hull structures. The vertical cross-section would look like an "H" in a cut-away drawing. Internal buttresses could be added to the H design to provide structural strength between the walls and deck.
The displacement under the deck can still be EPS. If the walls extend above the deck (bulwark) and below the water line (hull) then you get a starting place for building out living and working space.
You could even deliberately scuttle for stability in shallow enough locations, using the below-waterline hull walls as legs. Could possibly design for initial towing to final placement as a gravity structure. Enclosing the bulwarks above the waterline allows for in-filling as a true artificial island, if you abandon the floating requirement.
Individual Hex Island units are arranged into a Honeycomb Archipelago to enclose a lagoon. Unlike many natural lagoons, water flow under the Hex Islands maintains a clean and fresh lagoon with healthy sea life while calming the lagoon waters at the surface for use as a marina.
discuss.seasteading.org/t/landlubers-guide-to-seasteading-feasibility/2392/51
A tool for thinking about hexagons:
rechneronline.de/pi/hexagon.php
This thread draws from original discussions over and TSI and summarizes and focuses the conversation on a particular concept I have developed further. Specifically, open-bottomed variable buoyancy hexagon platforms with or without spuds.
The structures themselves are to be made of basalt fiber-reinforced alumino-silicate geopolymer concrete, a material with significant structural strength and longevity, as well as favorable chemical composition for providing coral substrate. Each island is constructed as a hexagon approximately 8 meters per side with 5 to 10 meter height for grounding in 3-7 meter depths. The internal deck is permanently supported by blocks of sealed EPS foam and the walls are pre-formed geopolymer concrete. At each angle of the hexagon, mechanisms are mounted to extend concrete spuds downward through the internal deck to act as legs for leveling the platform in place. A seventh spud is centered in the structure and serves to support both the lower and weather deck. The deck and center of the hexagon remains supported by buoyant EPS foam blocks even after gravity placement, resulting in near complete elimination of dead load. The internal deck is elevated to a minimum of 1 meter over mean high tide and the weather deck is approximately 3 meters higher. Walls extend below the waterline and permanently contain the EPS foam blocks, as well as providing last resort defense against complete submersion should the spuds fail. Dead load on the spuds is minimized by the same technique of buoyant EPS foam placement that eliminates dead load on the deck. The depth should be adjusted such that the weight of the internal deck is neutralized by buoyant foam, the weight of the walls rest on the spuds, and the spuds rest on seabottom.
Placing the "bottom" (deck) in the middle of the upright walls kills two birds (buoyancy and internal space) for the weight penalty of one deck and greatly eliminate the complexity of design and construction implied by the internal structure shown in most closed displacement hull structures. The vertical cross-section would look like an "H" in a cut-away drawing. Internal buttresses could be added to the H design to provide structural strength between the walls and deck.
The displacement under the deck can still be EPS. If the walls extend above the deck (bulwark) and below the water line (hull) then you get a starting place for building out living and working space.
You could even deliberately scuttle for stability in shallow enough locations, using the below-waterline hull walls as legs. Could possibly design for initial towing to final placement as a gravity structure. Enclosing the bulwarks above the waterline allows for in-filling as a true artificial island, if you abandon the floating requirement.
Individual Hex Island units are arranged into a Honeycomb Archipelago to enclose a lagoon. Unlike many natural lagoons, water flow under the Hex Islands maintains a clean and fresh lagoon with healthy sea life while calming the lagoon waters at the surface for use as a marina.