New type of propller that is 20 percent more thrust

[JumbleDuck]

Similarly with HMS Warrior. Unbelievably, they could haul the prop out of the water at sea to reduce the drag while under sail. They could even raise it to deck level and replace a blade as they carried a spare!

The Great Britain got a prop like that later on. They have the frame of it on display, together with some handles with which the young (or young minded) can unclutch the prop, lift it out of the way and then put it back. The Discovery in Dundee also has a lifting prop.

 

[JumbleDuck]

The academics aren't easy to cooperate with unless what you want help with happens to be exactly what they feel like researching.

I'm afraid that's how it is these days. Academic time is pretty narrowly allocated and there is little spare for speculative research. That's particularly the case when big kit like wind tunnels and water tanks is involved - these things are VERY expensive to run.

 

[JumbleDuck]

Didn't Archimedes (something BC) expound the principle of the screw?

He did indeed, but nobody successful propelled a boat with a screw till the 1830s (iirc). Anyway, archimedean screws are generally spirals rotating in a tube, and they don't work at all well for propulsion ... much better two use two or more hydrofoils whizzing round in circles.

 

[cliff]

Didn't Archimedes (something BC) expound the principle of the screw?

Aye, you cannot beat a good screw.