Seastead Design Recommendations for Shippable Modular Body

Core Design Principles

• Modular Segmentation: Divide the 40' x 16' living area into 4 modular sections (e.g., two 20' x 8' sections + two 16' x 8' end caps) for container compatibility.
• Container Optimization: Design all modules to fit within standard 20' or 40' shipping containers:
  • Internal dimensions: 20' (L) x 7.5' (W) x 7.7' (H)
  • Packaging approach: Lay modular frames flat, stack panels vertically

Material Recommendations

Structural Engineering

Modular Frame System

• Perimeter Beams: Segmented box beams (10' segments) with internal sleeve connections
• Internal Structure: Hybrid truss-frame (4' grid) with bolted node joints (T-connections)
• Corrugated Panels: 0.125" thick sheet with 6" corrugation for stiffness

Assembly Sequence

1. Assemble perimeter using 4 modular corner units (each 8' x 8')
2. Install floor framework with pre-welded beam pockets
3. Clip-in modular wall panels (10' wide x 8' tall)
4. Install roof with overlapping panels for weatherproofing

Manufacturing Requirements

• Chinese Fabrication: Recommend CNC plasma cutting + MIG welding for precision
• Surface Treatment: Aluminum: chemical conversion coating + marine paint Stainless: electrolytic polishing
• Quality Control: Preassembly checks in China with test joints Salt spray testing (ASTM B117 certified)

Ship-to-Site Preparation

• Container Packout:
  • Frame segments: 12 per 40' container
  • Panels: 20+ per 40' container with vertical racks
  • Hardware kits: Vacuum packed in 2 per 20' container
• In-Container Protection:
  • Non-abrasive separators at contact points
  • Moisture-barrier wraps
  • Shock indicators on container doors

Cost & Schedule Comparison

Factor	Aluminum	Duplex SS
Material Cost Ratio	1	1.5
Structural Weight	100%	300%
Corrosion Management	Moderate	Low
Shipping Volume	60% container use	70% container use

Recommended Approach

Hybrid System: Duplex Stainless Steel for structural frame connected to aluminum decks via composite transition joints.

Implementation Checklist

• Develop full 3D CAD model with all connection details
• Create mockup container pack plan
• Secure Chinese fabricator with DNV-GL certification
• Run finite element analysis on modular connections
• Order shipping containers with lifting eyelets and skid rails