We are working on a seastead design. The goal is to design our seastead such that all the parts can pack into a single a High Cube 45 foot container which has: width 7.7 ft height 8.9 ft length 44.6 ft max weight: 62,000 lbs (rated bouyancy at desired waterline is 27,500 lbs and we hope structure is enough under this that humans and their stuff can fit) Above the water there will be a big equilateral triangle frame, 44.0 feet on a side. The triangle frame is also the wall of the living area and will be 7 feet high (floor to ceiling). It will be enclosed and the whole inside the living area. Around the whole outside of the wall, except where the dinghy is in the back, will be a 3 foot wide walkway and railing that is bolted on and has some diagonal supports from below bracing to the wall (so walkway is 1 food higher than bottom of the wall). The walkway will have an aluminum grating that would let a wave pass through but you can walk on. Also two doors on the back side, one two feet in from left and one two feet in from the right side. There are 3 legs/floats/foils/wings/keels that provide the buoyancy, so it is a bit like a trimaran but with a very soft ride. Each leg/wing will 14.5 feet long and have a NACA 0040 foil shape with 8.5 foot chord except that the last 0.5 feet of the thinnest part will be cut short, so with foil does not come to a point at the trailing edge and fits within 8.9 feet hight of container. But the buoyancy is very close to that of an 8.5 foot chord foil. Each of the 3 legs will be attached to the underside of the big triangle near one of the 3 points. The center of the thickest part and going 1.5 feet in all directions from there will be within the area of the triangle, but within that constraint, each leg will be as close to the point of the triangle as possible. The legs will go down so that the lower half is in the water. This makes for a bit of "small waterline area" similar like a small oil platform but one that can move through the water easier because of the foil shape. It is not an extreme SWATH design as a 1 foot change in water level is about 1/7th of the total buoyancy, so still significant change. The 3 legs will all be parallel with the blunt or "leading edge of the wing" side facing forward so it is lower drag when moving forward than a typical cylinder on a semi-submersible platform. Each leg will be 50% under the water (so 0.5 * 14.5 feet) and the top 50% out of the water. On the top half of the front of each leg, so the top half that is out of the water, will be a built in ladder. The reason for these sizes for the triangle and legs is so they can pack into a container nicely and shipped to a shipyard anywhere for assembly. Imagine the 3 legs end-to-end with thin/trailing-edge of foil up and leading edge down on the right side of the container. So the right 3.4 feet of the container (width of legs) is used by the 3 legs. Then the 3 frame/wall sections will be upright (so 7 feet high) next to each other along the left side of the container. I am not sure the width of the walls but if they were 10 inches wide then 3 widths is 30 inches and some extra is 3 feet on the left side. There should still be lots of room in the center of the container for all the other parts. Connecting the mid points of the walls both at floor and ceiling level will be structural beams that make another triangle 22 feet on a side. Then all the remaining spans will be less than 22 feet. The rest of the floor and ceiling will be small pieces that are bolted in. On top of the roof there will be solar all over. With batteries and electric thrusters as the main propulsion system. There will be 6 RIM drive thrusters of 1.5 foot diameter, one on each side of the 3 legs/wings about 2 feet up from the bottom. These RIM drives will be all be fixed orientation to provide forward thrust. It will use differential thrust to turn. For slow movements in tight areas like harbors it can reverse thrust on one side and forward on the other to turn in place. There will be a conduit/pipe welded to the back of the trailing edge to take electrical wires down to the thrusters. There will not be any "through hulls" in the legs. The legs will also have multiple airtight compartments each for safety. Behind the back near the center will be two supports going out and 2 ropes going down to a dinghy. The dinghy is a 14 foot RIB boat (deflated for shipping) with an electric Yamaha HARMO outboard. It is sideways against the center of the backside of the living area. When the seastead is moving forward the dingy is shielded from the wind by the living area. On the lower part of each leg will be several bolt on heave plates. These will help dampen the response to waves. About 25% of the displacement will be for LiPo4 batteries which will be put low in the 3 legs. Each leg will have its own charge controller and inverter so there is triple redundant power on the seastead. Also, the thrusters for a leg will get power from that leg's inverter or batteries. So the 3 pairs of thrusters will have independent failure modes as far as power. When the seastead is going to be staying in one place for awhile, we can put down 3 helical mooring screws and give the seastead tension legs so it becomes nearly stationary when parked. Near each corner there will be a pair of helical mooring screws with a motor unit between them. We only plan to do this in the Caribbean where tides are very small and in protected places where the saves are small, so pulling down 3 feet will be sufficient to never go slack. Two seasteads will be able to connect together with a walkway, one behind the other, so that while underway people can move between seasteads, enabling a real community. The two computers for the two seastead will both work thrusters to minimize the movement of the walkway, particularly when warned that someone will be on it. We want the above seastead to be able to go to someplace where the water is less than 50 feet deep and do "GPS hold" after pointing into the wind/waves and then "screw in tension legs" and have it automatically lower stuff down that screws in and then tightens the tension legs the right amount without. The human will watch a camera will start the motors one by one and for at least the first few seconds for each to make sure screws get started correctly. They can watch all 3 going at the same time once they are started. The captain will usually pick a location that if not "inside a harbor" is at least somewhat protected on the downwind side of some land. Also, probably they will usually pick closer to 15 feet deep deep locations. Assume for now it is a location known to have nice Caribbean sand. The seastead is expected to be about 25,000 lbs. We may want about 3,500 lbs down pull on each of the 3 legs. The current idea is to have a "auto screw unit" (ASU) under each of the legs that is lowered down to the sand. Each unit will have two helical mooring screws, some legs, and a motor. The screws will have hex shafts so they can be rotated from any point along the shaft. The motor will be attached to both shafts but able to slide up and down. It rotates both shafts at the same time in opposite directions. With the two screws it can keep from spinning itself around (torque from one screw goes into other). The motor stays just above the surface of the sand as the screws go in. Our hex shaft is like "Kelly Rod" and our motor rotating it is like a "Kelly Drive" and between the Kelly Rod the Kelly Drive there is normally a "Kelly Bushing" so the rod can move up and down while still letting the drive turn the rod. We will also want something like the "Kelly Bushing" in our system. Other names for the bushing are "hex broach bushing", "hex drive sleeve", "hex bore bushing", "hex drive coupling", "hex bore hubs", "hex sprockets", and "PTO hex adapters". Normal mooring screws are just regular steel with a galvanized coating; however, these are designed to just be screwed in once and left there. For our use case, where it gets screwed in and out many times, this would not work as the coating would get worn off by the sand. We must use screws that are solid 2205 Duplex or 316L stainless steel. I think that something along these lines can be engineered to work realiable for a reasonable price. Do you agree? Please describe the solution in more detail. What sizes for things would you recommend? How far apart should the 2 screws in a pair be? What would the parts cost if made or purchased in China? If we order enough for 20 seasteads, so 60 "auto screw units" with a total of 120 screws, that would the cost for each seastead come to? Each of the screws will have a float at the top so that when the motor is lowered down the shafts to the sand they do not fall over. The tops of the screws will have something that mechanically transfers the load from the central part of the unit to them once they are screwed in. So the cable for power and force only has to go down to the central part of the unit. For each unit there will be a winch mounted a couple fee out from the top of each corner of the seastead. For storage it will lay down horizontal and about floor level in a cradle that has rubber lining so there is no electrical connection between the duplex mooring screws and the aluminum seastead. The operator will use the winch and some hand guidance to get it in and out of the storage cradle. When How long would each pair take to screw in? And how long to screw out? If we wanted to hire a person or company to do more detailed enginnering analysis and drawings so we could send the drawings to a Chinese company to have them built, how do we find the right person or company to hire? What sort of fees would be reasonable? How long would you expect it takes? I am wondering if some of the parts we need are already available "off the shelf". Are there "Kelly bushings" (or by any of the other names) of a reasonable size that we can just order? Are there duplex stainless helical mooring screws already available? There are hex shaft helical mooring screws so there must be devices for sale for driving them in. Can I just get two of those and connect them together to make my ASU?