Floating Wind Spar Stability Calculator
Deepwater offshore wind engineering: Calculate spar-buoy hydrostatic metacentric height (GM), pitch restoring stiffness, surge natural period, and wave resonance.
Spar Platform & Turbine Mass Properties
Hydrostatic Stability & Natural Periods
Recommended Tools & Equipment
Tested hardware and components for high reliability
Frequently Asked Questions
How does a floating spar-buoy achieve hydrostatic stability?
A spar-buoy relies on deep "ballast stability." By loading high-density magnetite/iron ore ballast near the bottom keel (70 to 100 meters underwater), the platform's center of gravity (z_G) is positioned far below the center of buoyancy (z_B). This creates an immense pendulum righting arm (GM > 10 m) that keeps the turbine upright without relying on waterplane stiffness.
Why must the pitch natural period stay outside 6 to 20 seconds?
First-order ocean waves carry almost all of their energy in periods between 6 and 20 seconds (e.g. typical North Sea JONSWAP spectrum). If a floating spar's natural pitching frequency matches wave periods, dynamic resonance will cause violent pitching oscillations, resulting in extreme blade tip accelerations and fatigue failure.
What is the role of catenary mooring lines in spar surge motion?
The slender vertical spar has virtually zero hydrostatic restoring force against horizontal surge drift. Heavy catenary mooring lines (chains with clump weights or polyester tethers) provide the horizontal spring stiffness (K_x), tuning the surge natural period to 70–120 seconds—well into the slow-drift second-order wave regime.