Hull Efficiency η_H
η_H = (1 − t) / (1 − w). Usually 1.05–1.15 for single-screw full-form hulls - the wake gain outweighs thrust deduction.
Hull efficiency η_H
1.171 -
Formula, assumptions, and limits
Single-screw tankers / bulkers with w ≈ 0.3 and t ≈ 0.18 give η_H ≈ 1.17 - a free 17 % bonus. Twin-screw ships are closer to η_H ≈ 1.0. Fine-form containerships 1.02–1.08.
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| Thrust deduction fraction | - | wake-thrust calculator | |
| Taylor wake fraction | - | wake-thrust calculator | |
| Hull efficiency | - | result |