Longtail Evolution

Wikipedia claims the " Long-tail boat" was invented by Sanong Thitibura in Sing Buri province Thailand in the 1930's. Further study though, would indicate the longtail was invented in France by Gabriel Trouche in 1904. These early longtails were mounted on rowboats and can only be assumed run subsurface due to the power restrictions on turn of the century powerplants. Furthermore, the same could be thought of the 1930's engines. My question is when was a surface piercing propeller first introduced on a longtail making it a true surface drive?

 

I'm surprised you didn't find this even earlier example in Wiki-P

Propeller - Wikipedia https://en.wikipedia.org/wiki/Propeller#:~:text=Robert%20Hooke%20in%201681%20designed,power%20for%20ships%20through%20water.



Edward Shorter - Wikipedia https://en.wikipedia.org/wiki/Edward_Shorter



And concerning Surface Piercing props



https://web.itu.edu.tr/takinaci/dersler/advpropsys/Week_14/SurfacePiercingPropellers.pdf

 

The 1800 Edward Shorter design although technically a "long tail" has no means of steering and would rely on the ships rudder for such. I am aware of Hickman but, had never heard of Admiral DW Taylor an interesting read. The Motogodille has all the components of a modern longtail with one exception the surface piercing prop. This was all just an exercise to segue to the modern longtail popularised in South East Asia namely Thailand. I realize now I asked an impossible question as to when they went to surface propulsion over there as you would have to have been part of the scene to know that. They have a fantastic canal racing scene with classes ranging from glorified surf boards with 150cc 2 strokes to hot rodded 4 cylinder car engines up to 800 hp turbo diesels reaching speeds of 100 mph. There are half a dozen American longtail manufacturers that have developed their own designs popular in the southern U.S. The design has stood the test of time.

 

Any of those ancient props could be run @ half submerged on a pivoting surface adjustable long tail. I don't think that means they were the first true surface piercing designs (useable for the forerunners of the racing boats you posted).

Performance improvement of surface piercing propeller at low advance coefficients by aeration https://www.sciencedirect.com/science/article/abs/pii/S0029801821009410

 

Hello neighbour!

I'm curious what you're really after here if not this:

I've had opportunity to skipper a few surface drives, very impressive.
The rooster-tail alone is spectacular!

BB

 

I was just curious as to when the surface piercing prop was first used on a longtail motor. All indications would lead me to believe this occurred in Thailand and was linked to longtail boat racing. There is very little information regarding the history of the sport. The 150 cc motorcycle engines used on these boats would be one indicator as they have probably been around since the 60's. The Thais manufacture these propellers.

 

What/who is JTR Surfacedrives?

 

I am. (Jeff Thompson Research) It's just a fun thing I had done when I built my boat and surface drive. See my other post.

 

The Zundapp Delphin 303 circa 1954 made in Germany. In 1957 Songsak Sriprasertying began manufacturing the first commercially produced longtail in Thailand first under the KKK brand and later SPS.

 

Which one?

 

"Inboard Air cooled Surface Drive". Lots of pictures and video.

 

I think the two types will overlap in various aspects, JMHO.

Some of the American ones can run in surface piercing mode or subsurface; I think the Thai can also run in both modes, depending upon what someone is wanting to do, (neither one runs very well in reverse for parking a boat)

https://mud-skipper.com/surface-drives.html#
(See video)

My guess is that a direct drive flex shaft design can more efficient than either one of the two above, as the prop will automatically adjust and align perfectly with the flow, when run Beyond some minimal power level. But Flex shaft systems may not work well at high HP power levels..

 

Pictured is a typical American longtail with universal joint and ride (cavitation) plate. The shaft length is 58". A comparable Thai longtail has an 85"shaft. I don't know much about the "flexible multi-cored" shaft so I will reserve comment. I will however, put my trust in my 3/4" dia. round solid 4140 shaft to get me home.
I have studied the American longtail and they run with the prop submerged and the ride plate on the surface.