Kampon boilers

[marcelo_malara]

As promised. A compilation of Hood´s two speed trials as found on Man o´war 6.

In the top line, some data, water line length, and the theoretical max speed for a displacement hull of that length.

Below, displacement, power measured, speed, propellers rpm, the variation of speed between two consecutives values, the variation of power for the same.

The last column is the (mathematical) exponent that has to be applied to the speed variation to get the measured power variation. It has been obtained with the formula:

log (base 10) variation_of_power / log (base 10) variation_of_speed

It shows that cube variation of power with speed holds approximately true for the lower values of speed, but that beyond certain values (about 25 kt in this case) the exponent shots up to the 4th or even 5th power.

[marcelo_malara]

Another set of data, this time from the carrier Soryu. Same columns as before.

In this case, Soryu was a shorter ship than Hood, so the maximum hull speed is down to about 36 kt and the maximum speed of the trials is closer to it. The effect is a massive increase in the power needed, with the variation of power being up to even the 7th power of the speed increase.