What would it take to build a semi-submersible seastead community?
One promising seastead design based in existing technology is the semi-submersible – a very stable floating platform, most often used in the offshore drilling industry. Our engineering team, led by George Petrie, set out to determine the feasibility of this design for an early seastead platform in terms of costs and logistics, while factoring in the necessary amenities to sustain a small residential and commercial community. The study is part of our Floating City Project, but is not the only design under consideration. We are also partnering with Dutch aquatic urban design firm, DeltaSync, to engineer a novel architectural seastead design. We will release the design in the Fall of 2013.
The top-side residential and commercial space was designed by naval architect Lina Suarez, whose full report can be viewed here.
In order to produce realistic estimates for the seastead – the semi-submersible hull and deck structure – our director of engineering George Petrie rendered a hull design based on industry standards, and submitted it for bidding to several shipyards. As of May 2013, only one shipyard – located in Texas – returned a bid. While the figure quoted represents the single largest expense for a semi-submersible seastead, there were numerous other costs which needed to be estimated based on educated estimates, previous research, and quotes from maritime professionals in our network. Estimates for the structure and basic systems were based on existing technologies, at current market rates and employing standard installation protocols used in offshore industries.
Simultaneously, Petrie worked with a Naval Architecture intern, Lina Suarez, to produce a novel top-side design for residential and commercial units, which can be rearranged to fit the Institute’s vision of a modular seastead. In turn, the cost of these units was estimated to produce full plans and cost figures for a complete seasteading community. The specifications, estimates and visuals for the platform are one part of our Floating City Project, and are available to anyone looking to actualize this vision through collaboration with the Institute, potential customers, and outside sources of financing.
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 Eight (8) 120-person enclosed lifeboats, $125,000 each, from Alibaba.com
 180 duplex modules at $96,000 each
 Capacity ~ 20 people, speed ~ 30 knots, docked at platform
Overall OpEx Estimate:
Total square footage: 230,800
Annual maintenance per square foot: $36.22
Average apartment size: 640 sq. ft.
Monthly maintenance per unit: $1,932
Annual maintenance per unit: $23,181