Seastead Thruster Performance Estimation

Seastead Characteristics: Approximately 30,000 lbs (13,608 kg) with high-drag configuration similar to a small oil platform, featuring 3 angled columns (4 ft wide, 13 ft submerged at 45°) with stabilizing cables.

Thruster Specifications

Primary Thrusters

Model: Shinmaywa SME-VR

Quantity: 2

Propeller Diameter: 2.5 meters

Material: Stainless steel (seawater compatible)

Performance Data (per thruster)

Maximum Thrust: 3,200 N (720 lbs) at 0 mph

Power Range: 2–3.2 kW

Thrust/Power Degradation: Provided in performance table

Performance Table (Given Data)

Speed (mph)	Thrust per Thruster (N)	Power per Thruster (kW)	Total Thrust (N)	Total Power (kW)
0	3,200	3.2	6,400	6.4
0.5	2,380	2.8	4,760	5.6
1.0	1,560	2.4	3,120	4.8
1.5	740	2.0	1,480	4.0

Methodology Note: The following estimations use linear interpolation between the provided data points. Actual performance may vary based on hull fouling, sea conditions, and battery voltage levels.

Estimated Performance at Specific Power Levels

Important: These estimations assume both thrusters operate at the same power level simultaneously. The "achieved speed" represents the equilibrium speed where thrust equals drag at the specified power input.

Power per Thruster (kW)	Total Power (kW)	Interpolated Speed (mph)	Estimated Thrust per Thruster (N)	Estimated Total Thrust (N)
1.2 kW	2.4 kW	~2.1 mph	~280 N	~560 N
2.2 kW	4.4 kW	~0.75 mph	~1,920 N	~3,840 N
3.2 kW	6.4 kW	~0 mph	3,200 N	6,400 N

Interpolation Calculations

Speed Estimation Formula (linear interpolation):
For 1.2 kW: Between 1.5 mph (2.0 kW) and extrapolated to lower power
For 2.2 kW: Between 0.5 mph (2.8 kW) and 1.0 mph (2.4 kW)
For 3.2 kW: At 0 mph (maximum power, zero speed)

Key Observations

Low Power Operation (1.2 kW): The thrusters operate in a highly inefficient regime, producing minimal thrust despite moderate speed. This represents about 37.5% of maximum power but only 8.75% of maximum thrust.
Mid Power Operation (2.2 kW): Provides a reasonable balance between power consumption and thrust. At this level, you get about 60% of maximum thrust with 68.75% of maximum power consumption.
Maximum Power (3.2 kW): All power is converted to static thrust with zero forward motion. This configuration would be useful for station-keeping or fighting strong currents.
Efficiency Consideration: The most efficient operating point appears to be around 0.5-1.0 mph, where thrust-to-power ratio is highest.

Solar Power Implication: With "lots of solar but not unlimited," running both thrusters at 3.2 kW (6.4 kW total) would require substantial solar capacity. The 2.2 kW per thruster setting (4.4 kW total) represents a more sustainable operating point for extended cruising.

Backup Propulsion Considerations

Given the high-drag profile of your seastead (similar to an oil platform), these estimates suggest that even at maximum power, speeds above 1.5 mph are unlikely with the current thruster configuration. For backup propulsion, you might consider:

Adding a retractable auxiliary propeller for emergency propulsion
Implementing a kite or sail system for wind-assisted propulsion
Using drogues or sea anchors to maintain position rather than fight currents
Considering a small diesel generator to extend range beyond solar limitations