```html Seastead Tensegrity Scale Model

Seastead Tensegrity Semi-Submersible
Scale Model Calculations

Scale Factor

Scale Ratio: 9.6 : 1 (Full scale is 9.6× larger than model)

This scale was determined by matching the model leg diameter to your 5-inch cylinders:

Full scale leg diameter: 48 inches
Model leg diameter: 5 inches
λ = 48 ÷ 5 = 9.6

Dimensions

Component	Full Scale	Model Scale
Body Length	720 inches (60 ft)	75.0 inches
Body Width	168 inches (14 ft)	17.5 inches
Body Height	96 inches (8 ft)	10.0 inches
Leg Diameter	48 inches (4 ft)	5.0 inches
Leg Length	420 inches (35 ft)	43.75 inches
Leg Submerged Length (60%)	252 inches (21 ft)	26.25 inches
Leg Angle	45° (both front and side views)	45° (same)

Geometry Note: All angles remain 45°. The front and rear isosceles triangles formed by the underwater cables, and the four stabilizing cables running from the bottom of each leg to the center underside of the body, should all be built to the scaled lengths above. Cable lengths scale linearly by 1/9.6.

Weights & Displacement

Item	Full Scale (Seawater)	Model Scale (Fresh Water)
Total Displacement Volume	1,055.6 cubic feet	1.193 cubic feet
Total Weight / Displacement	67,557 lbs	74.5 lbs

Calculation basis: 4 legs × π × (2 ft)² × 21 ft submerged × 64 lb/ft³ seawater.

Model Weight Note: The completed model (including legs, body, cables, and any added ballast) should weigh approximately 74.5 pounds in fresh water to float with the legs 60% submerged. If testing in salt water, target ~76.4 lbs.

Model Body Using 2 × 55-Gallon Barrels

If you use two standard 55-gallon plastic barrels connected end-to-end to form the model "body":

Barrel Model Body	Model Dimensions	Represents Full Scale
Length	70 inches (2 × 35")	672 inches = 56.0 feet
Diameter	23 inches	220.8 inches = 18.4 feet

Comparison to Original Design:
Original body: 60 ft long × 14 ft wide × 8 ft high
Barrel-derived body represents: 56 ft long × 18.4 ft diameter
This is a reasonable approximation for length but wider than the original 14 ft design.

Summary for Construction

Use your 5" diameter cylinders cut to 43.75 inches for the legs.
Build body approximately 75" long × 17.5" wide × 10" high (or use the two barrels at 70" long × 23" dia).
Target total model weight ≈ 74.5 lbs for correct flotation.
All cables and attachment points must be scaled by factor of 9.6.
Froude scaling is preserved: speeds should be scaled by √9.6 ≈ 3.1.

Generated for seastead tensegrity model • Scale 1:9.6 • Froude Scaling Applied