My previous post is cut short, something something computers :(
The same engine in a longer waterline may have some effect. The underlying physics is that the length of the waterline influences the wake system that a boat creates between its bow and stern wave. Those waves interfere constructively and at a certain speed, they start adding up to significant waves - the bow wave starts to pile up more and more. The boat needs to ride up the wave. Drag rises sharply at that point - so a stronger engine helps little at this point.
This used to be called the “hull speed”, the maximum speed that a hull can achieve. (It’s grossly simplistic and outdated concept, but a workable estimate).
Going beyond requires either a longer waterline or switching from displacement to planing. Some hull shapes can exceed their nominal hull speeds somewhat, but not indefinitely. Some hulls (keelboat for example) can never transition to planing.
Hull speed is a concern if you tow a small vessel with a larger vessel that can run faster than the small vessels hull speed. You can sink a boat by creating a large enough bow wave.
> Hull speed is a concern if you tow a small vessel with a larger vessel that can run faster than the small vessels hull speed. You can sink a boat by creating a large enough bow wave.
This explains something that didn't make sense to me when I first encountered it 25 years ago.
There's a board game, Star Fleet Battles, which is superficially set in a fork of the (original) Star Trek animated series[0], but the mechanics are all much closer to ~WW2-to-cold-war naval combat[1].
The specific mechanic you've just explained is that if you grab a small vehicle like a shuttle craft in a tractor beam and drag it along the map too fast, the shuttle will be destroyed by going too fast.
[0] and therefore has Kzinti
[1] Q-ships named as that; "drones" that act like torpedoes, photon torpedoes that act like missiles
The speed of sound in water is 1480 m/s (at 20C), and is independent of the length of the vehicle.
Ships are sort of special because they operate at the surface of the water. Submarines operating submerged have no such "hull speed", and their wave-making resistance is insignificant.
The same engine in a longer waterline may have some effect. The underlying physics is that the length of the waterline influences the wake system that a boat creates between its bow and stern wave. Those waves interfere constructively and at a certain speed, they start adding up to significant waves - the bow wave starts to pile up more and more. The boat needs to ride up the wave. Drag rises sharply at that point - so a stronger engine helps little at this point.
This used to be called the “hull speed”, the maximum speed that a hull can achieve. (It’s grossly simplistic and outdated concept, but a workable estimate).
Going beyond requires either a longer waterline or switching from displacement to planing. Some hull shapes can exceed their nominal hull speeds somewhat, but not indefinitely. Some hulls (keelboat for example) can never transition to planing.
Hull speed is a concern if you tow a small vessel with a larger vessel that can run faster than the small vessels hull speed. You can sink a boat by creating a large enough bow wave.
https://en.m.wikipedia.org/wiki/Hull_speed