Seastead Manufacturing Facility Requirements

Floats: 4 units per seastead. 4ft diameter, 20ft long. Dished ends (1/2" thick), Cylinder walls (1/4" thick).
Material: Duplex Stainless Steel (High strength, requires specialized welding).
Superstructure: Corrugated duplex panels (2-3mm) and framing.
Goal: In-house manufacturing of pressure tanks (floats) and corrugated skin.

Scenario A: Low Volume (1 Seastead per Week)

Production Goal: 4 Floats and 1 Superstructure per week (approx. 1 float per day shift).

Building Size: Approx. 6,000 - 8,000 sq ft

Layout includes: Raw material storage, cutting zone, rolling/forming zone, welding stations, and assembly area.
Clear Height: 20-25 ft (to accommodate 20ft long tanks and crane manipulation).
Crane Capacity: 5-10 ton overhead bridge crane recommended for handling 20ft tanks.

CNC Plasma Cutting Table: For cutting plate blanks. (Laser is preferred for thin corrugated sheets, Plasma for thick heads).
3-Roll or 4-Roll Plate Rolling Machine: 4ft width capacity, capable of rolling 1/4" duplex (high yield strength).
Dished Head Forming Press: 500-1000 Ton hydraulic press with specific dies for 4ft diameter dished ends. (High Cost Item)
Welding Automation (Orbital/Tank Welder): Automated tractor system for long seams to ensure consistent quality on Duplex.
Roll Forming Machine: Custom roll former for corrugated skin profiles.
Post-Weld Heat Treatment/Polishing: Area for passivation and polishing of Duplex.

Machine / Item	Estimated Cost (USD)	Notes
CNC High-Definition Plasma Table (5x20ft)	$120,000	Handles plates for floats and skin.
Heavy Duty Plate Roller (4ft x 1/2" cap)	$80,000	Duplex requires higher torque than mild steel.
Hydraulic Dishing Press & Dies	$250,000	Specialized tooling for tank heads.
Automated Tank Welding System	$75,000	Column and boom or tractor system.
Corrugated Roll Former	$45,000	Custom profile rollers.
Material Handling (Cranes/Flatbeds)	$60,000	Essential for safety.
Tooling & Safety Gear	$30,000	Grinders, jigs, fixtures.
TOTAL ESTIMATED MACHINE COST	$660,000	Excludes building construction/lease.

Production Goal: 4 Floats and 1 Superstructure per day (approx. 1 float every 2 hours).

This requires an assembly line approach to prevent bottlenecks.

Building Size: Approx. 25,000 - 30,000 sq ft

Fiber Laser Cutting System: Faster than plasma; handles thick plates for tanks and thin skin sheets simultaneously.
Automated Panel Lines: CNC controlled roller lines for corrugation and cutting-to-length.
CNC Spinning Machine: For dished ends. Faster than pressing for high volume.
Robotic Welding Cells (x2-3): 6-axis robotic arms for seam welding floats. Consistent heat input critical for Duplex.
Longitudinal Seam Welders: Multiple stations for tank bodies.
Automated Material Handling: Vacuum lifters and conveyor systems to move sheets.

Machine / Item	Estimated Cost (USD)	Notes
Fiber Laser Cutting System (Large format)	$450,000	High speed, automated loading/unloading.
CNC Metal Spinning Lathe	$350,000	Rapid production of dished ends vs pressing.
Industrial Plate Rolling Line	$200,000	Automated feeding and cone-rolling capability.
Robotic Welding Cells (x2)	$400,000	Includes positioners and Duplex-specific weld packages.
Automated Corrugation Line	$180,000	Continuous feed and cut.
Heavy Material Handling System	$200,000	Cranes, conveyors, lifters.
Quality Control / NDT Equipment	$80,000	X-ray or Ultrasonic testing for pressure vessels.
TOTAL ESTIMATED MACHINE COST	$1,860,000	High efficiency line.

Duplex stainless steel (likely grade 2205) differs significantly from standard 304/316 stainless:

Welding Sensitivity: It requires precise heat input control (typically lower heat input than austenitic stainless) to maintain the 50/50 austenite-ferrite balance. Automation is highly recommended to maintain these strict parameters.
Springback: Duplex has higher yield strength. Bending/forming machines must be 20-30% stronger than those rated for mild steel.
Cutting: It work-hardens quickly. Laser cutting is preferred for speed and edge quality.