Surface piercing props in action

[zul8tr]

Interesting visuals of high speed operation of dual Arnesen drive sync with rotating props. Action starts at about 1 min in

https://www.bing.com/videos/search?q=Surface+Piercing+Drives&&view=detail&mid=42BDAE36514F7D0205CA42BDAE36514F7D0205CA&FORM=VRDGAR

[filthy phill]

thats is a very good view of whats going on.
mesmerising too.

shows just how high the props are running, great video.

[zul8tr]

thats is a very good view of whats going on.
mesmerising too.

shows just how high the props are running, great video.

Makes one ponder just how the thrust can be effectively delivered by the prop with half a wack at full speed.

[filthy phill]

yes it is a bit weird.
you would think that they need twice the rpm once they get half out the water, very strange how they work.

[Fastjeff57]

One can imagine how over-propped that rig must be at plane off if the rpm is correct at high speed with so little prop in the water.

That's supposed to be the knock on Arneson drives, though the Germans (who else?) came up with an adjustable pitch prop arrangement to overcome that deficiency.

Jeff

[zul8tr]

One can imagine how over-propped that rig must be at plane off if the rpm is correct at high speed with so little prop in the water.

That's supposed to be the knock on Arneson drives, though the Germans (who else?) came up with an adjustable pitch prop arrangement to overcome that deficiency.

Jeff

Jeff

But once it gets going what a ride. Over prop pitch is what it takes for high speed. The A drive can be lowered for take off but over pitch will load the engine and as you say that is bad. Definitely not a hole shot boat.

Pete