KEVOS® MAKEOS · Hydraulics
Sluice Gate Lift Check (Water Force, Seal Friction, Screw Torque, Handwheel Effort)
For a screw-operated sluice or penstock gate holding back water, what force does the water put on it, what force lifts it against seal friction, and can one person turn the handwheel?
Check of a vertical sliding gate opened by a screw spindle: the water force on the gate and where it acts (as the hydrostatic force tool), the lifting force from the gate weight and the friction of the seals and guides under that force, the torque to raise the load on the spindle thread and thrust collar and whether the screw holds without a brake (as the power screw torque tool), and the rim effort on the handwheel through any reduction gearing, against your effort limit.
Open the calculatorRuns in your browser. No account needed.
How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Water depth on the gate | m | Depth of water against the gate, from the gate bottom. |
| Gate width | m | Width of the gate across the opening. |
| Water density | kg/m³ | Density of the water or liquid. |
| Gate and spindle mass | kg | Mass of the gate leaf and the part of the spindle that moves with it. |
| Seal and guide friction coefficient | Friction between the gate seals and guides and their seats under water load. | |
| Spindle | ||
| Mean (pitch) diameter of thread | mm | Mean diameter of the spindle thread. |
| Lead | mm | Lead of the spindle thread. |
| Thread form | choice | Thread form. |
| Thread friction coefficient | Thread friction. | |
| Mean collar diameter | mm | Mean diameter of the thrust collar or bearing. |
| Collar friction coefficient | Collar friction (small for a ball thrust bearing). | |
| Handwheel | ||
| Handwheel radius | mm | Radius of the handwheel rim. |
| Reduction (handwheel turns per spindle turn) | Handwheel turns for one turn of the spindle nut (1 for direct drive). | |
| Gearing efficiency | % | Efficiency of any gearing between handwheel and spindle. |
| Largest handwheel effort | N | Largest rim force one person should apply. |
Method and formulas
- Water force = ρ g w h² ÷ 2, acting h ÷ 3 above the bottom (as the hydrostatic force tool).
- Lifting force = gate weight + friction coefficient × water force.
- Spindle torque to raise (thread and collar) and self-locking (as the power screw torque tool); handwheel effort = torque ÷ (gearing × efficiency) ÷ rim radius.
- Example: 23.536 kN of water force; 8,531.8 N to lift; 157.58 N at the handwheel.
Limitations
- Gate fully closed with water on one side only; the first crack open, with flow under the gate, can be harder.
- Static friction taken as the coefficient given; silt and corrosion raise it a lot.
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Check a manual penstock or sluice gate
- Size the spindle and handwheel for a channel gate
- Decide whether a gearbox or actuator is needed
Who it is for
- Civil and water engineers
- Maintenance engineers
- Plant engineers
What you get
- Water force and its height
- Lifting force
- Spindle torque and handwheel effort
Interpreting the result
- The water force grows with the square of the depth, so the effort can double for a modest rise in level.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 3024–3027, 1921–1928. Topic reference; no source tables or recommended settings are reproduced.
WORKOS tools are screening and decision-support utilities. Verify important financial, engineering, safety, legal or operational decisions using appropriate professional standards and your organisation’s approved data.
