A wharf crane moves cargo between a vessel and the dock. This simplified calculator compares load and counterweight mass-radius products about one pivot, using a multiplier and counterweight share you enter.
Wharf Crane Interactive Calculator
Enter load, outreach, dynamic multiplier, assumed counterweight share and counterweight radius. Results are moment comparison only—not a load chart or stability certification.
Equation Used
- Load and counterweight are represented as point masses at horizontal radii.
- The dynamic factor and counterweight share are entered assumptions.
- Results use tonne-metres; mass has not been converted to gravitational force.
- Boom, machinery and platform self-weight are omitted.
- Stability, structure, fatigue, wind, slew, braking, rope and foundation checks are omitted.
Wharf-Crane Moment comparison
The NASA Glenn torque reference defines moment as force times perpendicular distance. Here the comparison uses mass times radius in tonne-metres. The multiplier and counterweight share are assumptions you supply.
What This Calculator Represents
It compares a load-side moment with an assumed counterweight contribution about one illustrated pivot.
Moment Allocation
M_d=D M_s
m_c=fM_d/R_c
M_res=(1-f)M_d
D and f are assumptions, not predictions.
Worked Scenario
At 20 t and 64 m, the mass-radius product is 1,280 t-m. An assumed multiplier of 1.5 gives 1,920 t-m. Allocating 40% to a counterweight at 16 m gives 48 t, leaving 1,152 t-m outside that counterweight contribution. These values do not establish crane stability.
Assumptions and Limits
- Calculated: entered mass-radius products and share allocation.
- Illustrated: boom, load line, pivot and counterweight arms.
- Not calculated: rated capacity, stability, structure, ropes, wind, motion, fatigue or safety.
Frequently Asked Questions
Is this a crane load chart?
No.
Is dynamic factor predicted?
No.
Does counterweight share prove stability?
No.
Are boom and platform weights included?
No.
Are tonne-metres force moments?
No. They are mass-radius products. Convert mass to gravitational force to express a force moment in units such as kN·m.
Can this approve a lift?
No.
References
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