Winch Power Ratio Calculator
Compute ideal winch mechanical advantage as the handle-to-drum radius ratio multiplied by the dimensionless gear ratio. Real handle force is higher because this ideal model excludes friction.
Description
Compute ideal winch mechanical advantage as the handle-to-drum radius ratio multiplied by the dimensionless gear ratio. Real handle force is higher because this ideal model excludes friction.
Winch Power Ratio Calculator is a focused tool for the following task. Compute ideal winch mechanical advantage as the handle-to-drum radius ratio multiplied by the dimensionless gear ratio. Real handle force is higher because this ideal model excludes friction. It reports Power ratio from the values you provide rather than inventing measurements, coefficients, or professional judgment that are not part of the input.
When to use Winch Power Ratio
Use this sailing calculation for planning or education when the vessel, units, reference directions, environmental conditions, and assumptions are explicitly known.
- Drum diameter (mm)
- Required number in mm. Effective diameter of the winch drum.
- Gear ratio
- Optional number. Dimensionless output-to-input gear ratio for the selected winch speed.
- Handle length (mm)
- Optional number in mm. Length of the winch handle from center to grip.
The cited overview of Sailing supplies background for the terminology and domain context used by this tool.1
How Winch Power Ratio works
Compute ideal winch mechanical advantage as the handle-to-drum radius ratio multiplied by the dimensionless gear ratio. Real handle force is higher because this ideal model excludes friction. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.
- Power ratio
- Returned number. Mechanical advantage of the winch; each newton at the handle holds this many newtons on the sheet.
Limitations and assumptions
- Vessel design and loading, sea state, wind, current, tide datum, weather, chart accuracy, equipment, crew, and safety margins can make real conditions differ from a simplified result.
- Gear ratio must be at least 1.
- Gear ratio must be no greater than 20.
- Handle length must be at least 150.
- Handle length must be no greater than 400.
- Use finite inputs in the displayed units, preserve source measurements and assumptions, and independently verify consequential decisions.
Alternative or Complementary approaches
Cross-check current charts, tide and weather services, instrument data, vessel manuals, and applicable navigation rules, and retain a conservative alternative plan.
References
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Sailing — Wikipedia contributors
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