Clubstead Design

TSI Clubstead


Engineering Details / Reports
Pretty Stuff
Questions and Answers



This is TSI’s first seastead design, for a hotel/resort built to withstand the waves off the coast of California, also known as a “Floatel”. The base platform draws from traditional oil platform designs such as pillar platforms and semisubmersibles, but with the addition of a a deck suspended from steel cables, inspired by Tensegrity concepts, which saves on material costs. On top, we’ve designed a 200-guest resort around the inherent geometry of the four pillars (one can imagine them being themed Air, Fire, Water, and Earth).




Specifications and Key Stats

TSI ClubsteadTSI Clubstead

• 400’x400′ (200′ span between pillars), so 160,000 ft^2 footprint. Pillars are 30′ in diameter.
• 368,200 ft^2 of room space for 200 guests with staff quarters to accommodate up to 70 staff
persons: Floor layouts
• Draft is 75′, Airgap 40′.
• Total weight 20,908 short tons.
• The platform’s strength comes from a 40′ high steel truss which encases the first two floors of the buildings.
• Target location: 12-30 miles off Southern California (San Diego or LA).
• Total cost of $114,333,000. This cost includes all structural elements, the hotel, generators, thrusters, fire safety, HVAC, fresh water system, and sewage, as well as installation. This is $311/ft^2 of area,or $715/ft^2 of solar footprint. Maintenance costs are estimated to be about 3%/year ($3,430,000, or 9$/ft^2/yr)/



TSI Clubstead

These reports from Marine Innovation & Technology contain the most up to date information about the ClubStead project.
Download the final ClubStead reports in a single .zip file, or as individual PDFs:

  • Executive Summary – Describes the design requirements and included reports.
  • Architectural Design – The layout of the buildings and rooms on the platform, including the mechanical tower containing the power, water, waste, and propulsion systems, and the square footage figures for each level.
  • Global Design – The dimensions, mass properties, stability, structure, energy needs & propulsion system, and cost estimate.
  • Hydrodynamic Analysis – A long report describing the methodology, hydrostatic characteristics, and frequency characteristics of the structure’s motion in both normal and extreme sea-states. Also includes industry standards on acceptable motions for passenger comfort and comparisons of ClubStead’s motions to those of a ship encountering the same waves.
  • Construction and Installation – The philosophy of the construction and installation plan, shipyard requirements, and stages of construction and installation, with diagrams showing how to assemble the structure.
  • MetOcean Analysis – Data on the weather conditions (wind, waves) at the operational location, both regular and extreme conditions.
  • Structural Analysis – Finite-Element analysis of the primary deck structure, including the main truss, truss for cantilevered buildings, suspended light-weight areas, and towers, as well as a brief overview of the column design.


NEW – View Dominique Roddier’s ClubStead talk at the 2009 Seasteading Conference:

Dominique Roddier – The Seasteading Insitute 2009 from The Seasteading Institute on Vimeo.


Why did you choose to patent your seastead designs?


The patent that we filed for the Clubstead design – along with any patents we will file going forward – are intended as defensive patents only. It’s not our goal to use patents to prevent others from building seasteads based on our designs, or to extort money from those who wish to. We intend to make our patented material available freely (or for a nominal fee if this better suits the legal and business requirements of the organizations who wish to make use of the patents), and our maintenance of patents is intended to protect the seasteading community as a whole. For more thoughts on patent philosophy, see the book.



Pretty Stuff

Still Views on Flickr:

TSI Clubstead



3D Models





Simulated wave motion in 15′ (5 meter) H_s waves.


Fly-by of the model, rendered in Rhino:


HDTV video download


Questions and Answers


See the Clubstead Interm Report (Pre-May 2009) for Q&A.





The platform engineering design was by Alexia Aubault, assisted by Dominique Roddier and Christian Cermelli (all from Marine Innovation and Technology), and the architecture by Wendy Sitler-Roddier. Wayne Gramlich, TSI’s Director of Engineering, coordinated the effort. Funding came from Peter Thiel’s founding grant.


TSI Clubstead

TSI Clubstead