BIZOMAT MAKEOS · Mechanics
Ramp Winch Pull Check (Pull, Holding Force, Power)
What pull does my winch need to haul this load up the ramp on wheels or skids, will the load run back if released, and is the winch power enough at the haul speed?
Check of a winch hauling a load up a ramp: the effective friction from rolling resistance of the wheels (coefficient of rolling resistance ÷ wheel radius, as the rolling resistance tool) or sliding friction on skids, the pull up the slope and the force to hold the load against sliding back (as the inclined plane tool), the power at the haul speed with the winch efficiency, checked against the winch rated pull, its motor power and its brake for the holding force.
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How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Load mass | kg | Mass of the load and its cart or skids. |
| Ramp angle | ° | Angle of the ramp from horizontal. |
| Load moves on | choice | Whether the load rolls on wheels or slides on skids. |
| Coefficient of rolling resistance | mm | Coefficient of rolling resistance (lever arm) for the wheel and floor. |
| Wheel or roller radius | mm | Radius of the wheels or rollers. |
| Sliding friction (skids) | Sliding friction coefficient of skids on the ramp. | |
| Haul speed | m/s | Speed the winch hauls at. |
| Winch | ||
| Winch efficiency | % | Efficiency of the winch gearing and drum. |
| Winch rated pull | N | Rated line pull of the winch on the layer used. |
| Winch motor power | kW | Rated power of the winch motor. |
What each input means
Open an input to see what it is, its units, the worked example and the common mistakes, with a small diagram.
What this means: Load mass
- What it is
- The total mass hauled up the ramp: the load plus its cart, skates or skids.
- Units and format
- Enter a number in kg: kilograms. The form accepts 0.000001 kg to 10000000 kg. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 2000 kg as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- Pull, holding force and motor power are proportional to it.
What this means: Ramp angle
- What it is
- The angle of the ramp surface from horizontal.
- Units and format
- Enter a number in °: degrees of angle. The form accepts 0° to 60°. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 10° as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A steeper ramp raises the holding force and, over normal ramp angles, the pull.
- Get it right
- If you know rise and run, the angle is the inverse tangent of rise divided by run.
What this means: Load moves on
- What it is
- Whether the load rolls on wheels or skates, using the rolling resistance inputs, or slides on skids, using the sliding friction input.
- Units and format
- Choose one of 2 options from the list: Wheels or skates; Skids (sliding).
- Example
- The form opens with “Wheels or skates” selected as a worked example. Choose the option that matches your case.
- Get it right
- Only the inputs for the chosen mode are used.
What this means: Coefficient of rolling resistance
- What it is
- The rolling resistance lever arm of the wheel on the ramp surface: how far ahead of the wheel centre the contact force acts. Used only for wheels.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 100 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 0.8 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Get it right
- It is a length, not a friction coefficient; the tool divides it by the wheel radius.
What this means: Wheel or roller radius
- What it is
- The radius of the wheels, skates or rollers the load runs on. Used only for wheels.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 5000 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 100 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A larger radius lowers rolling resistance in proportion.
- Get it right
- Type the radius, half the wheel diameter.
What this means: Sliding friction (skids)
- What it is
- The sliding friction coefficient between the skids and the ramp surface. Used only for skids.
- Units and format
- Enter a plain number with no unit. The form accepts 0 to 2. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 0.3 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Get it right
- Wet, greasy or worn surfaces can change it a lot; use the lowest value for holding.
What this means: Haul speed
- What it is
- The speed of the rope and load up the ramp while hauling, from the winch data at the layer used.
- Units and format
- Enter a number in m/s: metres per second. The form accepts 0 m/s to 10 m/s. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 0.2 m/s as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- Motor power rises in proportion to speed.
- Get it right
- Type metres per second, not metres per minute.
Winch
What this means: Winch efficiency
- What it is
- The share of the motor’s power that reaches the rope after losses in the winch gearing, drum and sheaves.
- Units and format
- Enter a number in %: percent: the number is read as a percentage, so type 8 for 8 %. The form accepts 10% to 100%. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 80% as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- Lower efficiency raises the motor power needed.
- Get it right
- Type the percentage itself, not a fraction.
What this means: Winch rated pull
- What it is
- The rated line pull of the winch on the drum layer used, from its nameplate or maker’s data. Both the pull and the holding force are compared with it.
- Units and format
- Enter a number in N: newtons. The form accepts 0.000001 N to 100000000 N. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 6000 N as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Get it right
- Line pull falls on outer drum layers; use the rating for the layer the rope is on.
What this means: Winch motor power
- What it is
- The rated power of the winch motor, from its nameplate. The power needed at the haul speed is compared with it.
- Units and format
- Enter a number in kW: kilowatts. The form accepts 0.000001 kW to 100000 kW. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 1.5 kW as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Method and formulas
- Effective friction μ_e = f ÷ r on wheels (as the rolling resistance tool) or μ on skids.
- Pull = W (sin θ + μ_e cos θ); holding force = W (sin θ − μ_e cos θ) (as the inclined plane tool).
- Motor power = pull × speed ÷ efficiency.
- Example: hauling 2000 kg up 10° needs 3,560.3 N and 0.89008 kW; released, it needs 3,251.3 N to hold.
Limitations
- Steady haul; starting needs extra force for breakaway friction and acceleration.
- Rope angle assumed parallel to the ramp.
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Check a winch for loading a machine onto a trailer
- Plan moving a load up a ramp into a building
- Decide between skates and skids
Who it is for
- Riggers
- Millwrights
- Maintenance supervisors
What you get
- Effective friction and pull up the ramp
- Holding force against running back
- Power at the haul speed
Interpreting the result
- Wheeled loads almost always run back down a ramp: the winch brake or a second line must hold them.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 165–171. Topic reference; no source tables or recommended settings are reproduced.
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Open the Ramp Winch Pull Check (Pull, Holding Force, Power) calculator