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. Please used Froude scaling rules to give me the dimensions of a 1:4 scale model in feet/inches. If the full scale is 36,000 lbs, what is the target weight of the scale model in lbs. I am thinking that with Starlink and 2 trolling motors we could make a model that we could send out in the Caribbean. With a video camera onboard it could be fun. Making our own solar unmanned surface vehicle (USV). With batteries down in the legs it seems it could be ok as long as there is not a tropical storm or hurricane. Of course we can easily take it out of the water if there is any kind of storm coming. But imagine we sell this and some customer has it out in waves that are too much more it, how would you describe the waves that could tip this over? With current weather forecasting and the speed of this drone, and it stays out of hurricane zones, is it practical to avoid such waves 999 days out of 1000? It seems the high solar power to weight ratio and stability that makes the full scale nice could also make a model this size nice. The weight scales with the cube and the active stabilizer area scales with the square. The solar scales with the square. So a model that is 1/4th scale can have much better power/weight ratio and better stabilizer thrust / weight ratio that the full scale. With high power it can go faster than scale speed, so the stabilizer will have very strong impact for the very low scale weight. Also, if there is a limited time of high waves the drone can use extra battery and go faster, making the stabilizers work even better. And for high waves the drone legs acting like keels/dagerboards can make running from the wind at some angle work well. If we can get this 1/4th scale model to be "safe" in the actual ocean then it should be easy to have the full scale be safe as the model is sort of testing in waves 4 times higher than the full scale version would experience. So it seems like fantastic stress testing of the control algorithms. The stabilizers could even be used a bit like hydrofoils and lift the vessel, and so reduce the amount of drag from the legs, and go faster. Please try to analyze the potential for increased speed by doing this. If we had a full battery and tried to do efficient foiling how fast could this go for how long, and so how far? We might want to put the thrusters below the stabilizer wing if there is good possibility of foiling on the surface. The legs/floats, triangle frame, and stabilizers are all made out of marine aluminum. The triangle can be made out of extruded marine aluminum "2 inch angle" (at this small scale we don't need a truss). We can have cross supports parallel to the back (short side of triangle) to support the solar panels. Near the center will be a small pipe, maybe 1 inch diameter, going up 4 feet supporting a 360 camera mounted on top. We want solar panels that are light, cheap, efficient, and can tollerate an occasional splash from a wave. What solar panels would you recommend? If increasing the triangle size a small amount makes more solar fit we can do that. How many watts will that be? I am liking 6 of the Blue Robotics M200 thrusters, so we can get the high level of redundancy planned for the full scale version. These are better at handling sargasso seaweed than the T200 enclosed thrusters. Can you find a MTBF rating for the M200 in continuous ocean use? If you have the option use a average power usage level about what we expect this design would use. If we need at least 2 thrusters not on the same leg to do differential trust and make forward progress, how long would be expect to be able to go before enough thrusters failed so we could not use 2 thrusters to make forward progress? Is there some other thruster you like better? I wish there were cheap small RIM drives, but I don't think there are any. The Blue Robotics Navigator Board has compass and acclerometers, as well as 16 PWM outputs, so it is easy to drive 6 ESCs for the 6 motors. If we turn the tail on the stabilizer airplane to some angle it should rotate the wing to a certain angle, so we don't need any sensor on the stabilizer wing, right? What would be a good actuator for the stabilizer tail control? For locking the stabilizer I want the pin to be on a spring so that when the waves move the stabilizer so the whole lines up the ping can snap into place. When locked a stabilizer turns into a heave plate, which is still helpful. But I also want to be able to pull out the pin to unlock the stabilizer. How should this work exactly and what parts should we use? What do they cost? We could use a number of them to patrol Anguilla's territorial waters for illegal fishing. They should not cost to much each. Try to estimate the cost if we get the parts made in China and order 5 sets of parts. We will assemble the models ourselves, and my boys work for free, so don't worry about assembly cost. Please estimate the weight of all the parts for this drone and check if we are making the weight budget. We have 3 part plan to recover damaged drones. 1) We will do most of our early long range testing upwind of home. If one motor fails the drone can still do differential thrust steering with the one working motor by having it do forward and reverse. This can keep the vessel pointed toward home, so legs/keels/dagerboards track in that direction as the wind pushes it. Even if both motors are out the active stabilizers can also make a differential steering system and keep the vessel pointed home. Can have one side be in a high drag angle to make that side of the vessel go back. So this solar drone can self rescue by acting like a sailboat, as long as it is upwind of home port. 2) We can have something under the drone toward the font that is either very light weight or balanced on a hinge so that when the drone is moving forward the water pushes it and it swings toward the back and mostly out of the water but if the drone stops and goes backward it lowers down into the water and makes lots of drag and keeps the drones nose and long direction pointed into the wind. It is sort of an emergency water-break that goes on automatically if the drone goes backward. This increases the chance of rescue if a drone breaks (by humans or another drone). 3) We would like a working drone to be able to rescue a disabled drone so we don't have to send humans far out in the ocean to rescue a broken drone. The current/draft idea is that the front each drone will have a bright red rope with a bright float on the end, maybe 4 feet of rope as the front is around 2 feet above the water. On the back of each drone will be a something that goes down near the surface and has a V shape to sort of funnel the rope into the point where there is a U shape that the rope can go into the the float can not pull through. There will be 360 cameras on the front and back so the operator can focus his view on the target rope. We don't send the whole 360 camera data, only the portion of current interest over Starlink. With this system it should even be possible for one drone to rescue another drone that had tipped upside down (after waves were back to normal). Once the rescue drone has hooked the rope of the other drone it then slowly heads for home port. With Starlink video an operator can probably do this (can try again and again if needed). At some future time we will get AI on the computer to drive and do the hooking. Does something like this make sense or do you have a method you like better or improvements for this idea? No need for a dinghy or dinghy mounts on this model. No living area or glass, or floor, or roof. Triangle just has one layer for solar. No tension legs for this either. We would want some LiPo4 batteries that we can fit down in the legs. If we have 30% of our weight in batteries, how much total is that in lbs and kwh? If we have a Starlink mini, raspberry pi, a couple cameras, some LED navigation lights, and an AIS transmitter, what would you estimate the "base load" or "hotel load" will be in watts? I am guessing we will typically have more solar than we can put in the batteries so we will probably go faster during the day and slow at night. Please estimate the watts we can have for the motors during the night and during the day. Don't use the last 20% of the battery. Given the leg area and drag coefficient, what sort of speed do you think we could get with those wattage numbers during day and night travel? Estimate for into the wind, across the wind, and downwind directions. The batteries will be down in the legs, and everything else will be very flat, so hopefully the wind drag is not too bad. The wind drag of the legs in the direction we are moving is low, as they are foil shape, and they act like keels or dagerboards to counter wind pushing sideways. I worry about salt spray accumulating on the cameras, solar panels, and Starlink. What would you recommend for that issue? We will probably a raspberry pi. I think I want a 2-part soft thermally conductive silicone elastomer (like Sylgard 184) to pot the computer so there is no chance of salt water getting to the computer. Maybe we can't run the raspberry too hard, but we really don't expect to. Which model raspberry pi would you recommend? We will put tall heat-sink on the raspberry pi and have it stick out above the potted macterial. The the computer can be put down in one of the legs, which are always cooled by water. The Raspberry Pi Compute Module 4 (CM4) eMMC should last better than ones booting from an SD card. Are there competing products (Orange PI etc) that offer better low power reliability for our use case? Do you think potting this way is a good way to go? I am in Anguilla in the Caribbean. There is lots of Sargasso seaweed these days. Probably we will want onboard vission/AI that will avoid the seaweed. Does not seem too hard during the day. At night will we want a an IR camera I guess? One danger is that the occasional wave hitting the bottom of the solar panels may eventually damage something on the solar panels. I wonder about extra protection at the wire joints by using heat-shrink-tubing over the solar pannel wiring joints (which are supposed to be waterproof but maybe not expecting to be hit by waves this often). What do you think on this issue? Along with patrolling for illegal fishing, it might be useful for ocean research or something else. What sort of market might this drone sell to? How big a market might it be? Please describe the top 2 or 3 current long distance/endurance open ocean solar/wind/wave powered USV that this drone might compete against. How fast are the? How long can they stay at sea? What sort of range per mission? What do they weigh? What do they cost? Can you run your own code on the computer and connect your own instruments to it? I am guessing they are all self righting? This is one thing we will not have. If we sold ours for twice what the parts cost, how competitive would our USV be? It seems like the other solar/wind/wave powered open ocean USVs have much high prices. What is the reason for the difference? Do they come with warrenties?