Thrust Deduction - Holtrop Approximation

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

ThrustPropellerHoltrop

Block coefficientBeammLBPmPropeller diameterm

Thrust deduction t: 0.201 -

1 − t factor: 0.799 -

Changing the inputs requires JavaScript. The calculator above shows its default inputs and result. The formula, symbols, and regulatory sources are shown in the Formula section below.

Formula, assumptions, and limits

t \approx 0.25 C_B - 0.015 + 0.001 \cdot \frac{B}{L} \cdot 100

Symbol	Meaning	Unit
$C_B$	Block coefficient
$B/L$	Beam-length ratio

Source: Holtrop J. - Int. Shipbuilding Progress 1984

In short

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

Learn the theory Marine propeller