Comparing the late C-class cruiser Cairo with Danae shows that the new design was intended for a different operating pattern. Danae gained roughly 650 tons at standard displacement and 730 tons at full load, about 77 centimetres of beam, and eight centimetres of draught while retaining 40,000 shaft horsepower. Maximum speed fell slightly from 29.5 to 29 knots, but range at ten knots rose from 5,900 to 6,700 nautical miles. The fuller, more capacious hull exchanged a small speed margin for eight hundred additional miles of economical endurance. The D class gave up a little top speed for much greater reach instead of relying on extra power.
Notable Point · 7:47-10:16
A broader hull bought eight hundred more nautical miles
The comparison between Cairo and Danae shows the D class accepting more displacement, beam, and draught in exchange for much greater economical range and a small loss of maximum speed.