Eelco Hoogendoorn: Seastead Engineering Overview

Eelco Hoogendoorn’s talk entitled “Seastead Engineering Overview” is now available here.

Recent engineering graduate Eelco Hoogendoorn has done a lot of thinking about the technical pragmatics of seasteads. In his 2009 Seasteading Conference presentation, he lays out the fundamentals that a research plan must cover to begin to actualize TSI’s Poseidon Project goal of putting the first working seastead on the water in 2015. And as Seasteading Institute’s first engineering intern, this research plan is the one Eelco himself has been following, updating our Engineering Blog along the way.

Much of the engineering of feasible seasteads must revolve around economies of scale, as Eelco points out. Large platforms like cruise ships and flotillas (championed by Mikolaj Habryn and Miguel Lamas Pardo, respectively, whose presentation videos will be available soon) are proven living concepts, but will be better targets for business development, as the challenge will be to balance operating and maintenance costs to make them sustainable residences. Exotic projects like undersea hotels, while romantic, just aren’t practical.

Small boats — an ideal configuration for relatively cheap iterative development — are nearly as old as culture itself; yet in all of human history there has never been a stable, long-term settlement on the water. “Perhaps Ephemerisle will bring some innovation and new ideas as to how boats can help us,” Eelco muses.

The focus, then, will be on creating a “small hill” in the ocean, something of a compromise between the insecurity of the small vessel and the expense of the large craft, and developing compromises around wave drift, rocking motion, and maximizing the ratio of real estate to stabilization materials. Eelco’s talk leads gracefully and conversationally through a wide range of engineering challenges, from vessel clustering scenarios to seasickness, and provides great perspective as to the frontiers of seasteading-related technological progress.

Last week, the Seasteading Institute bid Eelco a fond farewell as he voyaged back across the Atlantic, having completed his three-month term of research for which he is presently finalizing the documentation.


4 thoughts on “Eelco Hoogendoorn: Seastead Engineering Overview”

  1. The technical problems of a “come together on water” can be split up in two challanges.

    1) Stay afloat, comfortable and spacy at reasonable cost.

    2) Avoid grinding  when connected with other units.

    So a seastead must be a floating structure that offers housing quality and space. And it must have a “fender and connection” solution.

    The necessary size of the minimum floating unit is given by the social needs of the occupants (family house size).

    The fender connection solution is given by the ocean – must be long and flexible or it breaks in moderate waves.

    The seastar design solves it both in a kind of “integrated way”. Once having a Grid that acts as flexible wavebreaker – any other floating solution can be hosted with no trouble.

    It is not clubsteading, or breakwater, or spar, or yachts, or cruiseship, or bottle islands, it can be ALL of them hosted in a reasonable tissue like GRID matrix that provides wave dampening and fendering for less tough solutions and connections. Keep the bunkesteads, the spars, the wavebreakers, on the outside – the soft solutions inside – allow them all come together .

    Like in a big friendly floating marina where club jacket is off – seagypsies are welcome, camping is a can be, and private floating space is available at 75 Euro per squaremeter. (maintenance free staying afloat 200 years)


  2. That’s an interesting idea. And I see you’ve inspired a lively conversation about grids over in the forums.

    Most formal engineering efforts we’ve been looking at involve steel — Clubstead being the most concrete example (perhaps the wrong adjective to use there, haha). It does seem like concrete would be advantageous in a lot of ways.

    So I’d be interested to hear about the downsides of concrete for floating structures. One paper I was reading said, “High-performance concrete containing fly ash and silica fume is most suitable for floating structures.” so clearly there are people thinking about optimizing the usage of concrete.

    What’s the counterpoint? I guess you don’t get shrinkage problems in the ocean…?

    Thanks Ellmer!

  3. Location:

    – Location: Choose the best place to locate the seasteading.

    – For example: in the Atlantic Ocean close to calm equatorial zone and southward. The best location is around latitudes -4º north, 17º south. I mean in terms of non ice, no hurricanes, and not so much stronger winds. Great rainfall during mostly part of year, so able to collect rain water, thus minimizing salt water treatment. No need of heating. Half of year natural ventilation will provide enough temperature comfort, ¼ of year forced ventilation, just the other ¼ will need some air conditioning.

    – This location means is at international waters between Brazil and Africa coasts. No pirates at this region, remember, e.g, Somalia, is far in the east African coast.

    – Doubt. I haven’t check places for anchoring/mooring the structure. If you want to live far from governments authorities, must stay out of the continental shelf, it means no shallow waters. Must be checked in navy charts.

    – If the structure can’t be anchored/moored, drift will be happen, or it must have motorized propeller to control it. It would require more fuel, so much cost, much maintenance and much danger.

    – Though I think it is possible to find a place in shallow waters near to some reefs or some small rocky Islands. Some are within government’s jurisdiction, but it will not difficult to get a permission, e.g, from Brazil’s government.


    Fernando (retired civil engineer/wants to cooperate/structural and general technical issues

    fcfernandquintanilha@hotmail or

    55 48 3334-5711

    PS: Just in case you want, call me. If you talk slowly I can get you in my “fake” English. Please warn me previously, by email, so I will be able to wait the call at home.

  4. Reproducing some comments I did about concrete: “Hello all, first time in here. I haven’t read any topic previously, so I could sound repetitive. Sorry for not using an English text corrector, cause I’m in a hush. In the book was mentioned Reinforced Concrete. I recommend you using, at least, in the main floating structure, Prestressed Concrete. It’s not an innovation, PC, has been used in the last 50 years in several structures, including off shores platforms. A prestessed concrete structure can install a previous compression in the structure, which will not allow cracking and so, virtually no infiltration, seeping, etc. Quite different of reinforced concrete when the structure must crack (inside a minimum value defined in codes and standards, sure). Feel free to comment it, cause I am too old for joining such challenge, but I dare to say I am able to cooperate with you in the structural design as well in other subjects.

    Best regards,” In fact, it seems to me you’re right having chosen prestressed concrete, at least for the hull. I am talking as civil structural engineer. Why usual ships use steel? Ships needs lighter structures cause they are transport structures which needs performing the better in hydrodynamics, not only for floating but to allow a reasonable speed. They need maintenance in dry docks at some 5 or 8 years. Not by chance the new generations off – shore oil platforms are built in prestressed concrete. Well, prestressed concrete is a wider denomination of a process the high strength steel cables are tensioned, introducing stress and strain in the concrete mass. It can be “pre” or “pos” tensioning. In floating structures, is usual post tensioning, for some reasons, it could take too much time to explain now. The basic calculation of prestressed concrete deals with the so called losses. These losses consider: Stress and strain due to shrinkage, creeping, temperature, etc. I dare to say it will be a waste of time if you keep trying to find a different material, at least for the hull. The structure above the water line, the decks etc, can be built in steel, for sure. I think you need to advance and propose at least a sketch for such structure. I would like to cooperate with you, within my possibilities. My problem is I’m retired (but it could be an advantage too) and I don’t have softwares as AutoCAD at hand, and I am not familiarized with it. I think my main cooperation, with be to define some basic specifications as well to check some issues. It would be great if some more structural engineers join the team. It would be rather people who know concrete than naval engineers. Of course, we will need data for currents, waves, etc, but as far as I know you have these experts. Think about getting some consultancy works too. Yes, it could be expensive, if you think just getting it at USA or Europe. The important is at least, producing a basic sketch for 30/50 people. Roughly as I imagine a basic sketch that would be reproduced in drawings for a start to a basic design, that allows you, at least, a preliminary budget: My basic “sketch” about such structure is as follows: – The main floating structure in Prestessed Concrete. It allows, virtually, no maintenance on the hull if correctly designed. – The decks could be in steel, cause concrete is too heavy (though in the main structure is important for stability) – Steel with at least 1 inch (25 mm) special mortar coating for fire resistance as well against corrosion (though maintenance above the water level is not a hard task). – Solar Photovoltaic cells on decks as well, at least, 2 eolics generators (the power and the kind we can discuss later) – 2 diesel generators (same comment as above) – A battery group, for sure. – Valves, pump systems, etc, would be defined in another step of the design. Regards


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