New Tunnel Hull Design ????

[RonShaw]

All,
I saw the hydro design below and being a tunnel head I’m thinking, why can’t I mount an outboard on the back and run in the outboard tunnel class? The two continuous sponsons are there and the center tub is lifted creating the “tunnel” of air. This is right from the IMPBA rule book on boat design:

g. Tunnel Hulls: The tunnel hull will have two continuous keels or "sponsons", thus creating a tunnel or air trap along the length of the hull.

My outboard hydro is a three point design so thats what makes it an outboard hydro but this??? I am looking forward to the feedback. Thanks.

 

[HTV Boats]

Kinda like the outboard lower Otto ran. Legal yes but not in the spirit of tunnel purists. Could be a can of worms but I may have a Covid building project now.
Mic

 

[Carl Van Houten]

It is going to come down to the interpretation of "creating a tunnel" as far as it being a legal tunnelboat. It will be controversial that's for sure. I would run that one past the Contest Director before you tried to throw it out there in the tunnel class.

 

[Geraghty]

Illegal in NAMBA

Namba rule book.....
h. No hull will be allowed to have a recessed or picklefork bow which exceeds 30 percent of the overall boat length. Airslots in the center hull must be subtracted from the overall hull length.

 

[Brandon Atwell]

I’d think the only problem with it would be the fact the sponsons are continuous but do they create a tunnel since they aren’t joined directly to the center section? The gap would dissipate air rather than force into a tunnel
I think a design similar with boom tubes to remove different sponsons would be killer, but close off the center section.

 

[Jerry Dunlap]

Well, the good news it is a legal IMPBA(B)/NAMBA(A) Outboard Hydro.
JD

 

[RonShaw]

Great feedback everyone. OB Hydro candidate for sure unless I connect the center section to the sponsons. Its an interesting design for sure.

 

[RonShaw]

It is going to come down to the interpretation of "creating a tunnel" as far as it being a legal tunnelboat. It will be controversial that's for sure. I would run that one past the Contest Director before you tried to throw it out there in the tunnel class.

Hahaha. I would not even attempt that one LOL. Was looking for feedback on what everyone thought. Notice I didnt even mention NAMBA because their tunnel class rules are much cleaner and leave very little room for experimenting.

 

[RonShaw]

Kinda like the outboard lower Otto ran. Legal yes but not in the spirit of tunnel purists. Could be a can of worms but I may have a Covid building project now.
Mic

Great points. I hope you and Jay are doing well.

 

[Mark Poole ModVP]

Not a legal tunnel by any stretch. With an outboard it would probably not make a very fast hydro. The drag of continuous sponsons without the air lift of a closed tunnel would make it run wet unlike a true hydro which suspends itself on 'points'.

 

[johnsteltzer]

I had don build me a set of sponsons in the 90’s that I sent him a drawing my sponsons that drew up looked just like those I made a center section and I skinned the bottom with one sheet of 1/16 ply and the top was 2 pieces and they bolted on the top it had a dumas 45 cowling and it ran pretty good I didn’t get to do a lot of testing with it I was in a crash in Atlanta and it was in bad shape I can’t remember what I did with that boat but it will work

 

[Wasted wages]

What about sheeting the sponsons to the center tub and then holesawing the appropriate amount of "speed holes" to "balance" it ??

In other words....for looks...

 

[michael faszcza]

I had the same thought when i seen those pictures.

 

[rumrunner]

I couldn’t leave this alone , that would be perfect with my turntable on it. rules are rules .

 

[Wasted wages]

You don't race cars, you race the rule book

Smokey Yunick

 

[ACTION JACKSON]

Well Ron I like your thinking & even though it won't be able to run as a tunnel let us all know how it performed. By the way I'm pretty sure years back someone made that design & I think they called it a coyote but do t hold me to the name. But boat has been tried