The admiralty coefficient

The admiralty coefficient is now available in NavalToolbox starting with the version 0.3.4. Like every new version, there is some new features. You can find it in the page Design, in the tab Speed.

The admiralty coefficient was develop to easily compare several vessels. You can compare vessels with different dimensions or shaft powers. On the other side, it can be used to estimate the power need for a vessel with a similar speed and displacement. In this case, the coefficient can be considered as a constant.

As there is some variant, we choose to use the following formula and units in the app: $$C = \frac{D^{2/3} V^3}{P}$$ With $C$ the admiralty coefficient, $D$ the vessel displacement in metric tons, $V$ the forward ship speed in knots, and $P$ the mechanical shaft power.

The literature indicate that the coefficient should be between 400 and 600 (link to Wärtislä websitä). The vessel will be considered as more efficient and economic if the coefficient value is higher.

Moreover, this new version also introduce the possibility to switch the units and values in the converters. You can click on the two arrow on the other side of the title in each converter.

To improve the effectiveness of the app, we change the method to print structure calculation results. They are now exported in png file instantly by clicking the printer icon at the top right. You will obtain the picture of the profile with its dimensions and the calculation results.

To access the web app, go to or download the mobile app on iOS or Android.

Send us your suggestions for the next features to add by email in order to make it more useful: .

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