HomeCalculatorsThrust Deduction - Holtrop Approximation

Thrust Deduction - Holtrop Approximation

Thrust-deduction fraction t from the Holtrop-Mennen resistance regression - used to convert propeller thrust to ship resistance.

ThrustPropellerHoltrop
Thrust deduction t
0.201 -
1 − t factor
0.799 -
Formula, assumptions, and limits

Rough single-screw estimate. Holtrop-Mennen original formula uses more terms including stern shape coefficient. Hull efficiency η_H = (1-t)/(1-w).

Symbol legend

SymbolMeaningUnitSource
Block coefficient - hydrostatics
Beam-length ratio - ship particulars