Calculator Inputs
Plotly Graph
The chart shows the estimated corrected reaction and corrected energy across deflection. Use it for quick comparison, not final manufacturer verification.
Example Data Table
| Project | Fender Type | Corrected Reaction (kN) | Available Energy (kN-m) | Demand/Fender (kN-m) | Utilization (%) | Status |
|---|---|---|---|---|---|---|
| Pier A | Cone Fender | 841.92 | 99.71 | 70.00 | 70.21 | Adequate |
| Jetty B | Cell Fender | 1,175.42 | 140.33 | 92.50 | 65.92 | Adequate |
| Harbor C | Arch Fender | 483.56 | 44.95 | 35.00 | 77.86 | Adequate |
Formula Used
This calculator uses a preliminary nonlinear estimate for marine fender behavior. It is useful during screening, option comparison, and early berth planning.
The exponents provide a simplified response curve. Always check final fender sizing, reaction, panel loads, anchor loads, and tolerances using manufacturer performance data.
How to Use This Calculator
- Enter the rated reaction, rated energy, and rated deflection from the selected fender data sheet.
- Set the actual working deflection expected during vessel contact.
- Apply velocity, temperature, angle, and shear factors for the project condition.
- Enter total berthing energy, active fender count, and the design safety factor.
- Press the calculate button to view corrected reaction, available energy, utilization, and adequacy.
- Export the result as CSV or PDF for estimates, reviews, and design records.
FAQs
1) What is fender reaction?
Fender reaction is the resisting force developed while the marine fender compresses under vessel impact. Designers compare it with hull, panel, anchor, and support limits during early selection.
2) Why are correction factors included?
Correction factors adjust catalog values for actual temperature, impact speed, berthing angle, and shear effects. They make the estimate closer to site conditions before detailed supplier checks.
3) Is this calculator suitable for final design?
Use it for screening, comparison, and early layout studies. Final design should confirm energy absorption, reaction, tolerance, and hardware loads using current manufacturer performance curves and project requirements.
4) Why is energy divided by active fenders?
Total berthing energy is often shared by several units. Dividing by active fenders estimates the demand on each one before applying more detailed contact and distribution analysis.
5) What does the safety factor do?
The safety factor reduces usable energy capacity before adequacy is checked. Higher factors create more conservative selections and help account for uncertainty in operating conditions.
6) What if utilization exceeds 100 percent?
That means demand is higher than the available corrected capacity. Increase fender size, add active fenders, reduce demand assumptions, or review the selected correction factors.
7) Why is deflection so important?
Reaction and absorbed energy change nonlinearly with deflection. Small increases in compression can raise loads sharply, so operating deflection strongly affects panels, anchors, and supporting members.
8) Can I export the result for reporting?
Yes. The page exports the current calculation as CSV and also creates a PDF snapshot for project files, estimate reviews, and design coordination records.