Single Family Platform | Caribbean Deployment | Chinese Fabrication / Caribbean Assembly
Platform Specs: ~14ft x 60ft footprint | 14ft freeboard | <0.1G acceleration (90% time) | High Salt/UV Exposure | Weight Critical
| Strategy | Est. Cost (Shell Only) | Lead Time | Marine Suitability | Logistics Fit | Verdict |
|---|---|---|---|---|---|
| Chinese FRP Sandwich Panel Kit (Custom Design) | $60k – $110k | 3–5 Months | ⭐⭐⭐⭐⭐ (Purpose-built) | ⭐⭐⭐⭐⭐ (Flat pack containers) | WINNER |
| Used Offshore Living Quarter (Refurbished) | $80k – $200k+ | 2–6 Months | ⭐⭐⭐⭐⭐ (Certified) | ⭐ (Heavy, wide-load, shipping nightmare) | High Risk / High Effort |
| New Build Offshore Module (China Yard) | $250k – $500k+ | 6–12 Months | ⭐⭐⭐⭐⭐ (DNV/ABS Class) | ⭐⭐ (Oversize modules) | Over-spec / Expensive |
| Modified Shipping Container | $40k – $80k | 2–4 Months | ⭐⭐ (Corrosion/Fatigue issues) | ⭐⭐⭐⭐⭐ (Standard logistics) | Not recommended for 20yr+ life |
| Yacht-Style Composite Build (Local Yard) | $150k – $300k+ | 6–12 Months | ⭐⭐⭐⭐ (High quality) | ⭐ (Labor cost in Caribbean) | Too expensive |
This matches your "yacht company" intelligence. You engage a Chinese engineering firm (or panel manufacturer with design capability) to design the structural box (floor, walls, roof) as a kit of large panels. You handle interior fit-out, windows, and MEP at the Caribbean shipyard.
| Component | Recommended Spec | Rationale |
|---|---|---|
| Core Material | Divinycell H80/H100 or PVC Foam (80-100 kg/m³) | Best strength/weight/cost. Closed cell = no water ingress if skin breached. |
| Skins | E-Glass / Vinyl Ester Resin (Infusion) | Vinyl Ester essential for osmotic blister resistance (salt water). Polyester will fail. |
| Panel Thickness | Walls: 30-40mm | Roof: 40-50mm | Floor: 50-60mm | Floor needs higher core density (H100/H130) for point loads. |
| Structural Framing | Integrated FRP hat-stiffeners / bulkheads (no steel) | Avoids thermal bridging & corrosion. Panels act as stressed skin. |
| Joint Design | Puzzle joints (scarf/step) + Structural Adhesive (Methacrylate/Polyurethane) + Glass Tape | Waterproof, structural continuity. Shipyard welds not required for shell. |
| Windows/Portlights | Pre-cut openings with reinforced edges. Supply standard marine portlights (Freeman, Bofor, Lewmar) separately. | Do not let panel factory glue in windows. Install at shipyard for watertight warranty. |
| Item | Low Estimate | High Estimate | Notes |
|---|---|---|---|
| Engineering & Mold/Tooling (NRE) | $8,000 | $15,000 | One-time. Can be amortized if building multiple units. |
| FRP Sandwich Panels (Material + Labor) | $45,000 | $75,000 | ~3,500-4,000 sq ft panel area. $12-$18/sq ft FOB. |
| Structural Adhesives / Tape / Consumables | $3,000 | $5,000 | Plexus MA530 / 3M DP460 + Biaxial tape. |
| Marine Portlights & Hatches (Qty ~10-12) | $12,000 | $25,000 | Standard sizes (e.g., Lewmar Ocean, Freeman 600). Buy direct. |
| Entry Door (Watertight / Fire Rated) | $3,000 | $6,000 | Marine aluminum or FRP. |
| Subtotal (Shell Kit) | $71,000 | $126,000 | |
| Shipping (2x 40'HC Containers to Caribbean) | $6,000 | $10,000 | Panels nest flat. Fits in 2 containers easily. |
| Total Landed Shell Cost | ~$77k | ~$136k |
You asked specifically about this. Modules exist (e.g., from decommissioned North Sea rigs, GoM jack-ups), but "Family Friendly" is the contradiction.
| Factor | Reality |
|---|---|
| Availability | Surplus yards in Houston, Singapore, Rotterdam, UAE. "Accommodation Modules" come in 12ft/20ft/40ft widths. |
| Dimensions | Standard ISO width (8ft / 2.44m) is standard. **14ft wide modules are NON-STANDARD.** You would need two 7ft wide modules side-by-side (complex join) or a custom wide-load. |
| Condition | Most are 20-30 years old. "Refurbished" often means paint & carpet. Structural fatigue, hidden corrosion (CUI), and asbestos/lead paint are major risks. |
| Layout | Corridor + small cabins (bunk beds). Low headroom (often 7'6" - 8ft). Tiny portholes. Not "family living." |
| Weight | **Heavy.** Steel frame + corrugated steel cladding + concrete ballast deck. 15-25 lbs/sq ft vs 3-5 lbs/sq ft for FRP. Kills your platform payload. |
| Logistics | Heavy lift vessel or jack-up required to load. Wide-load permits for trucking. Draft restrictions at Caribbean shipyards. |
| Certification | DNV 2.7-1 / ABS / SOLAS. Great for insurance, but expensive to maintain class if you modify structure (cutting windows). |
Chinese yards (COSCO, CIMC, smaller yards in Nantong/Rugao) build *new* offshore modules to DNV 2.7-1 for ~$300-$500/sq ft.
Standard 40ft HC containers (2x = 16x40ft = 640 sq ft, close to your dims).
| Issue | Impact on Seastead |
|---|---|
| Corrosion | Corton steel rots fast in splash zone / salt spray. Requires full blast & epoxy coating (expensive). |
| Fatigue | Corner castings designed for static stacking loads, not cyclic racking/torsion of a floating platform. Cracks propagate at door headers. |
| Thermal | Steel skin = massive thermal bridge. Condensation city. Spray foam helps but adds weight/VOC risk. |
| Modifications | Cutting sides for windows destroys structural integrity (corrugation carries shear). Requires massive steel reinforcement framing. |
| Weight | ~9,000 lbs empty per 40HC. + Reinforcement + Insulation + Interior = ~15-20 lbs/sq ft. |
Welded aluminum (5083/5086/6061-T6) frames with insulated sandwich panels (PU/PIR core, Aluminum or FRP skins).
Do not rely on the housing module vendor for solar. Integrate it at the **Platform Level**.
| Criteria | FRP Panel Kit (China) | Used Offshore Module | New Offshore Module | Aluminum Kit | Container Mod |
|---|---|---|---|---|---|
| Capital Cost (Shell) | $80k - $140k | $100k - $250k+ | $300k - $500k+ | $150k - $250k | $60k - $100k |
| Weight (lbs/sq ft) | 3 - 5 | 15 - 25 | 12 - 20 | 5 - 8 | 12 - 18 |
| Marine Durability (20yr) | ⭐⭐⭐⭐⭐ (Vinyl Ester) | ⭐⭐⭐ (Corrosion risk) | ⭐⭐⭐⭐⭐ (Classed) | ⭐⭐⭐⭐ (Anodes/Coating) | ⭐⭐ (Fatigue/Corrosion) |
| Logistics (China -> Carib) | ⭐⭐⭐⭐⭐ (Flat Pack) | ⭐ (Heavy Lift) | ⭐⭐ (Oversize) | ⭐⭐⭐⭐ (Flat Pack) | ⭐⭐⭐⭐⭐ (Standard) |
| Customization (Windows/Layout) | ⭐⭐⭐⭐⭐ (Total Freedom) | ⭐ (Structural limits) | ⭐⭐⭐ (Costly changes) | ⭐⭐⭐⭐ (Easy) | ⭐⭐ (Reinforcement needed) |
| Shipyard Assembly Skill | Composites (Resin/Tape) | Steel Fit-out / Heavy Lift | Hook up / Minor Fit-out | Aluminum Welding / Bolting | Steel Fab / Welding |
| Fire Rating | Class A / B (Core dependent) | A60 (Standard) | A60 (Standard) | A60 (Mineral Wool) | Difficult / Expensive |