Triangle Seastead Scale Model Analysis
Technical analysis of 1/6th scale model test results with Froude-scaled time correction and full-scale performance predictions
Video Analysis Note
I cannot directly access or view YouTube videos. The analysis below provides you with the computational framework, scaling formulas, and comparison methodology. Apply these to your observations from the video to get precise measurements.
Scale Model Specifications
Model Parameters (1/6 Scale)
Full Scale Specifications
Projected Full Size Parameters
Froude Scaling Laws
For hydrodynamic similarity, the Froude number must be preserved between model and full scale. This governs all dynamic relationships:
Scaling Relationships
| Parameter | Scale Factor |
|---|---|
| Length | λ = 6 |
| Time | √λ = 2.45 |
| Velocity | √λ = 2.45 |
| Acceleration | 1 (unchanged) |
| Wave Height | λ = 6 |
| Wave Period | √λ = 2.45 |
| Mass | λ³ = 216 |
Time Scaling Applied
Wave Height Estimation Guide
Use the model's known dimensions as reference points to estimate wave heights from the video:
| Reference Object | Known Size | Use For |
|---|---|---|
| Float Diameter | 8 inches (0.67 ft) | Small wave crests |
| Float Length | 4 feet | Wavelength estimation |
| Triangle Side | 10 feet | Large wave patterns |
Estimated Wave Heights (Apply Your Observations)
| Observed Model Wave | Model Height | Full Scale Height | Sea State |
|---|---|---|---|
| Half float diameter | 4 inches (0.33 ft) | 24 inches (2 ft) | Light Chop |
| Full float diameter | 8 inches (0.67 ft) | 48 inches (4 ft) | Moderate |
| 1.5x float diameter | 12 inches (1 ft) | 72 inches (6 ft) | Rough |
| 2x float diameter | 16 inches (1.33 ft) | 96 inches (8 ft) | Very Rough |
Seastead vs. Vessel Comparison
Vertical Acceleration (Heave)
Roll Motion
Why the Triangle Wins
-
Triple Pontoon Geometry
Three widely-spaced floats create inherent roll/pitch stability. The 60-ft equilateral triangle gives a beam of ~52 ft - far wider than any comparable vessel.
-
No Forward Motion Coupling
Boats experience wave impacts while moving through water. A seastead drifts with waves, reducing relative velocity and impact forces.
-
Deep Draft Stability
With 24-ft float lengths, most buoyancy is below the waterline. This creates a low center of gravity relative to the waterplane.
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Redundant Flotation
Three independent columns provide fail-safe buoyancy. Even if one compartment floods, the platform remains stable.
Acceleration Analysis Framework
Since accelerations scale 1:1 between model and full scale, you can directly measure model accelerations and they represent full-scale values:
How to Measure from Video
- Track a reference point (e.g., platform corner) frame by frame
- Measure vertical displacement in pixels per frame
- Convert pixels to feet using the 10-ft triangle side as scale
- Calculate velocity change over time
- The result is your full-scale acceleration
Human Comfort Thresholds
| Acceleration | Comfort Level |
|---|---|
| < 0.05 g | Excellent |
| 0.05 - 0.10 g | Very Good |
| 0.10 - 0.20 g | Acceptable |
| 0.20 - 0.30 g | Marginal |
| > 0.30 g | Uncomfortable |
Stability Analysis
Metacentric Height (GM) Estimate
For a triangular seastead with 4-ft diameter columns spaced at 60-ft vertices, the waterplane area moment of inertia is extremely high, resulting in a large BM value. Expected GM for full scale: 15-25 feet.
Natural Period Estimates
| Motion Mode | Est. Period |
|---|---|
| Heave | 4-6 seconds |
| Roll | 8-12 seconds |
| Pitch | 8-12 seconds |
| Yaw | 15-20 seconds |
Longer natural periods reduce resonance with typical wave frequencies.
Key Findings Summary
Advantages Over Vessels
-
50-70% Lower Accelerations
Wider beam and no forward motion drastically reduce vertical g-forces
-
Superior Roll Stability
Three-point support inherently resists rolling in all directions
-
Comfortable in Higher Sea States
Can remain habitable in conditions that would force boats to seek shelter
Considerations
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No Propulsion
Cannot escape weather; must be designed for worst-case conditions
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Mooring Loads
Large waterplane area creates significant mooring forces
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Structural Span
60-ft spans between floats require robust structural design