The discussion centers around the comparative speeds of large ships and large aircraft, particularly in the context of historical military vehicles before and during World War II. Participants explore why large planes tend to be slower than their smaller counterparts, while large ships can achieve relatively high speeds.
Participants express differing views on the relationship between size and speed in military vehicles, with some agreeing on the principles of displacement hulls while others challenge the practicality of large tanks and planes. The discussion remains unresolved regarding the specific reasons for the speed differences observed historically.
The discussion includes references to specific historical models and their capabilities, but lacks consensus on the implications of size on speed for both ships and planes. There are also unresolved assumptions about the effectiveness of large military vehicles in combat scenarios.
russ_watters said:A ship that doesn't plane has what's called a "displacement hull." Displacement hull ships have a top speed that's proportional to the square root of the water line length. At "hull speed" (the max speed for that ship), the ship sits in a trough between the bow and stern waves and going faster means lifting the ship out of the water to ride up the bow wave. So while a frigate tops out at 29 knots - and I know from experience that doubling the engine output at 25 knots only pushes you up to 29 - a carrier actually tops out at about 45.