Wendy Sitler-Roddier on Seasteading Architecture

ClubStead’s architect Wendy Sitler-Roddier answers a number of questions about the ClubStead design:

1) What parts of the ClubStead Project were you specifically part of, and who was responsible for the other (building and architectural) details?

MI&T designed and engineered the platform for the proposed ClubStead structure and I was commissioned by MI&T to conceptualize the architecture on the 400’-0” by 400’-0” square deck. Alexia Aubault was the lead engineer with Dominique Roddier as principal engineer overseeing the design.

The program for the platform is an offshore resort with a luxury hotel and club casino intended to accommodate up to 270 people at a time. Although this first conceptual design is charged with spaces rendered for the hospitality program, the design of the platform and the conceptual form of the architecture can be used for a variety of business and residential functions. The flexibility is inherent to the form of the architecture. Some components such as major columns and truss systems, the operable boat landings and seaward machinery are central to the design for life at sea and will remain unchanged regardless the function of the final ClubStead. Independently of the business purpose of the ClubStead, the program layout is optimized to include recreational outdoor surfaces as well as indoor community spaces, such as dining hall, shopping areas, fitness facilities and offices.

2) How did you get involved?

I guess you could say I was in the right place at the right time. My husband, Dominique Roddier, is a principal at MI&T and he invited me to work on the project with his engineering team for the project. I was on maternity leave at the time the project started and had the time to work with The Seasteading Institute on this exciting conceptual project.

3) How does one go about planning a floating structure that people are supposed to live in? Are there precedents you could use as a basis?

The precedents that were studied for this project were the cruise liner, the Freedom Ship, resort style architecture, concepts of other floating cites and cable stay bridges around the world. It really is an interesting concept, living on the open sea, and an idea that I am sure will be realized in the next 10 years. I have attached a little info on The World cruise ship, the Freedom Ship and a floating city concept. If you google “floating cities” you will find many more.

The World is a floating residential community owned by its residents. The residents, currently from 40 different countries, live on board as the ship slowly circumnavigates the globe — staying in most ports from 2 to 5 days. Some residents live onboard full time while others visit their floating home periodically throughout the year.

Freedom Ship was a floating city project initially proposed by Norman Nixon in the late 1990s. It was so named because of the “free” international lifestyle facilitated by a mobile ocean colony, though the project would not have been a conventional ship, but rather a series of linked barges.

The Freedom Ship project envisioned a 1400m-long integrated city with condominium housing for 30,000 people, duty-free shopping and other facilities, large enough to require rapid transit. The complex would circumnavigate the globe continuously, stopping regularly at ports of call.[1]

Lilypad – floating city

4) What were the main technical and otherwise challenges that the ClubStead structure would have to broach, and how did you solve them? (For instance: tropical storms)

The engineering technical challenges for the design of the platform that MI&T faced had to take into account factors otherwise not so challenging to structures designed to sit on land.

Mobility and location

The ClubStead is located all year long about 100 miles off the coast of San Diego, California, in the Pacific Ocean. The platform is not permanently moored to avoid permitting issues. Instead it is dynamically positioned, keeping station using a diesel electric propulsion system. It is allowed to drift within a defined zone.

Passenger comfort and safety:

The ClubStead available square footage for living facilities is maximized and the architecture intends to convey an impression of ample space. Because the ClubStead passengers may not be professional or even recreational mariners, the level of discomfort, measured by the proportion of sea-sick passengers, must be minimized in all operational conditions.

The ClubStead is designed to withstand extreme environmental conditions on site without affecting the integrity of the platform. It must also ensure the safety of the passengers and equipment in case of damage to the hull. It must be equipped with fire fighting and emergency medical material. Emergency and evacuation procedures follow international standards for passenger vessels. Access to the platform must be possible by boat and helicopter.


The ClubStead community is not fully self-sufficient and relies on some goods and services such as food, medicine and diesel to be imported every month via a supply boat. The platform is however fitted with systems such as water making, waste and garbage treatment and utility power production to minimize the complete dependency of a land-based station.

Calculations of Weight and Engeneering the Platform:

The design of the buildings are integrated in the engineering of the overall structure because it uses the allocated payload of 7,705 short tons and the weight repartition on the 400ft by 400ft square deck. To control the cost, the submerged volume of the floating structure is minimized. The submersible-type hull of the ClubStead, which consists of four columns, provides an optimal stability at sea with a minimum submerged volume. A footing at the base of the column lowers the center of gravity and increases the natural heave period for maximum stability of the platform in waves. Cable stayed light-weight surfaces are suspended from the top of towers at the deck level to maximize the available surface area. The dual use of cable stays is inspired from modern bridges where a design element is associated with the lightweight tension supports. This is an innovative solution in the design of floating platforms. When surfaces are supported by cable stays, the primary structure of the deck is lighter. This is critical to keep the weight of the submerged structure small and contributes to lower the construction cost.

There were many challenges in designing the architecture for the ClubStead. The primary challenge was the size of the platform and also the prescribed structure that was in place as I joined the team. Due to the intrinsic nature of the ClubStead hull and platform design, the architectural design and the naval architecture / engineering studies are closely related. Iterations were necessary between the architectural and engineering studies to determine the global characteristics of the ClubStead.

Typically when planning a building or a campus of buildings, the ground is a blank slate and it is not moving. In this case, the ground already had a given structure that enables the platform to float and it was this structure that prescribed the placement of the architecture and vertical circulation like elevators and stairs. In a typical design problem, the structural ideas usually come to fruition just after the basic form of the building is realized. In this case, the structure was in place before the architecture was even envisioned.

The second issue was that the ground was floating and this was unusual for a design problem. For building sites on land, there are some given environmental forces that could be studied to inform the overall architectural layout. For the ClubStead, the environmental forces acting on the site (platform) were in flux and the typical orientation forces of directionality, light and wind for building layout were in flux as well. At sea, the views are all around the platform, along with the light and the wind.

Another design challenge was approach and arrival to the platform. How were guest to arrive at the ClubStead, how would they move from ferry boat to the platform, how would we sequence this event, and what would this experience really feel like. The ferry landing and walking plank had to be moveable as well as any other landings and walkways that would take guests down to the water level.

The mechanical and safety components for the program were large and took up a lot of area on the platform. These types of program elements are large, noisy, smelly and an eyesore at times. On the platform of 400’ x 400’ (a little larger than a city block), it was hard to figure out how to hide them. We ended up screening these mechanical elements at the fourth tower by buffering them with the casino element of the program. The casino, noisy in its function, does not have to have quite spaces, nor does it need views out to the sea. The main views from inside the four level casino are facing onto the main public central court.

Figure 1, the mechanical column as we called it is located at the bottom right hand corner of the plan.

5) How difficult was it? How long did it take and what problems did you encounter?

I think that the most challenging thing of all was envisioning spaces that would be comfortable, different and yet familiar all at the same time for life at sea. Making public spaces and private spaces that guest would enjoy was the focus. On the limited space of the platform, we had to provide a ground plane that resembled a resort atmosphere that included pools, open space and recreational spaces like tennis courts and landscaped gardens.

The concept phase of the project took approximately four months.

6) Do you have diagrams or something to explain which parts of the structure are which? (This would be a lot easier if we could actually be in the same room, looking at the pictures!)

General Layout:

The architectural program for the ClubStead takes into account a number of constraints and the layout of the architecture is driven by the engineering considerations of the platform. The allocated area of the platform is limited to a 400’-0” x 400’-0” square deck surface. The maximum structural support for the architecture is provided between columns of the platform which are located 200’-0” apart from each other in plan as illustrated in Figure 1.

The architectural program for the ClubStead is as follows:

  • 100 room luxury boutique hotel (approx. .200 guests) with staff quarters to accommodate up to 70 staff persons.
  • A club casino
  • Fitness and Spa amenities
  • Meeting and flexible function spaces
  • Retail spaces
  • Food and Beverage Venues
  • Rooftop spaces and vegetation gardens
  • Rooftop areas for solar panels
  • Outdoor public spaces for leisure and sporting activities
  • Operable boat landings and leisure water access
  • Building Mechanical and Seaward Mechanical spaces
  • Desalinization spaces
  • Fire and Life Safety spaces
  • Trash and Recycling spaces
  • 2 Helipads

Figure 1: Top View of ClubStead Deck (building in yellow, open spaces in white)

The buildings and the outdoor spaces provide a large available surface area for living Facilities and recreational use. A total of 368,200 ft2 is available for passenger use on the ClubStead. It includes 90,000 ft2 of open recreational surfaces.

The use of the available surface area of the platform must be optimized and the architecture must provide to its guests a sense of openness and space comparable to that of an onshore resort and give a more spacious sense to that of a typical cruise ship.

The buildings are organized on the deck around the 4 main structural columns that connect to the submerged columns below the deck. It is these columns that carry the structural load for the architecture at the deck and continue below the platform as the submerged columns that enable the balance of the platform in the water. The cruciform plan of the architecture at each column is supported by the primary 40’-0” box trusses. A pyramidal form at each column was realized to maximize the surface area at the deck level. It also keeps the center of gravity low, by minimizing the weight at the upper levels of the buildings. A low center of gravity is critical to the stability of the platform.

3 of the 4 columns are dedicated to the program of the hotel for hotel rooms, staff quarters, function spaces, restaurants and bars and spa and fitness areas. The fourth column is a mechanical tower that houses the equipment and spaces needed for operations of the building and for life at sea. The club casino is located near the mechanical tower and separated by sound and safety isolation walls.

The hotel buildings have 7 floors of interior spaces. The first floor houses a hotel lobby and back of house service spaces, retail spaces, 3 restaurants, the spa and fitness amenities and public circulation. The second floor houses the staff quarters, function and meeting spaces along with additional spa and fitness level spaces. There are four levels of rooms above level two. There are varied sizes of rooms at each level with the more spacious rooms and penthouses located at the end bays. The seventh level, or rooftop level, houses the specialty restaurant, the observation and learning center for life at sea, and the rooftop lounge. Vertical circulation of elevator and stairs for each tower are located inside the columns. There are also enclosed walkways at levels 2, 3 and 4 to provide cross-tower access.

At the deck level, light-weight surface areas at the platform perimeter and center are suspended off the columns with cable stays; they provide recreational space for gardens, tennis courts, exterior dining areas, lookout points, etc. (Figure 1).

The form of the architecture at the end bays of the hotel towers are shaped with sail-like transparent surfaces that echo the shape of the arch beams supporting the stay-cables. They are visible in Figure 9. These surfaces provide large window bays for the penthouse room and maximize the views of the sea. The cable stays are integrated to the landscape.

The following text is from the final Engineering report that outlines some of the mechanical requirements for the platform. The more we thought about what was needed on the platform to allow it to be autonomous at sea for 30 days, the list got longer and longer.

The mechanical components needed for life at sea vary slightly from that on land. While dome components are similar, a few additional components must be integrated in the design.

The electricity is generated with Diesel generators (2 operational and 2 for backup) and its distribution is controlled with utility power controls. Each operational Diesel generator has a maximum available power of 2,000 MW. It provides enough electricity to feed the propulsion system to maintain the platform position and the local grid for domestic use.

The platform is dynamically positioned to avoid the expense and administrative constraints (permits) of a mooring system. The energy for the propulsion system is derived from the Diesel generators. The Diesel electric propulsion system consists of components like a switchboard, converters, motors in the machinery room and thrusters in the columns.

An advanced water distribution and treatment system is necessary to optimize the energy use on the platform and prevent pollution of the surrounding waters. Freshwater, grey-water and black water should be duly separated and treated. Fresh water is for drinking and domestic use only. To maximize autonomy, it is produced onboard, out of the pumped sea water. A desalination system is needed to produce 20,000 gallons of fresh water per day[1]. Grey-water needs less treatment and may be used for surface washing, gardening, etc. Pools will be filled directly with salt seawater to avoid spending unnecessary energy on desalinization.

The black-water is treated as part of the waste and water treatment system. Compactors, separators and a number of black water treatment units are necessary to sort garbage, destroy the non-recyclable and store the pollutants. Three or four black-water units should suffice to treat the estimated 7000 gallons per day produced on the platform.

Recyclable goods are taken to the recycling center adjacent to the tower and other non-recyclable trash is burned in the incinerator.

The heating and cooling system consists of a boiler and chiller system with piping and water pumps laid out as required. The water ballast system at the bottom of each column under the deck is fed by pumps and pipes. It is used to adjust the displacement of the platform.

In addition to a machine room, the platform must be equipped with a sound safety system for fire prevention and fighting, evacuation, and medical emergency. Recommendations on equipment and plans to provide passenger safety at sea were drafted at the International Convention for the Safety of Life at Sea (SOLAS) organized by the IMO (International Maritime organization) in 1974 [1].

There is a medical treatment center on the ClubStead and one of the helipads on top of the towers can be used for emergency medical evacuations.

A fire-fighting room, next to the mechanical tower, is equipped with pumps, hoses and gear for trained staff members. Additionally, small fire-fighting sub-stations with emergency gear and light equipment are located as required on the platform. Fire alarms and small extinguishers and sprinklers are installed in all rooms to increase the chances of fast detection and containment. The construction of fire doors and the use of thermal and structural boundaries in the building plans will take into account recommendations by Chapter II-2 of SOLAS. The machinery should be well insulated and where necessary the mechanical equipment should be redundant to prevent failure of the safety system.

Chapter III of SOLAS and amended sections outline the recommendations for the life-saving equipment, including rescue boats, life jackets and gathering areas. As typical on passenger ships, rescue boats are located on each side of the platform and have enough capacity to carry twice the number of passengers and crew. Additional self-inflating life rafts are located at other extremities. Gathering areas for evacuation have easy access to the life rafts and are located in a structurally safe part of the platform. A safety center with access to the internal communication system including audio equipment, the fire monitoring system and the alarm system is developed.

7) What’s the timeline as regards the building of the ClubSteads? What can we expect?

Well this is a good question and one that should probably be targeted to Patri. However, my answer would be that if The Seasteading Institute would get the funding to build the ClubStead within the next year, we could see the realization of the ClubStead by 2013. What a fantastic thought!


[1] According to the US Geological Survey website, freshwater consumption per capita varies between 80 and 100 gallons per day. This includes activities for which the use of water may be minimized aboard the ClubStead (ex: dry flushing system) so the lower bound is considered in this case.


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