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Adding a center tube to a boat with elliptical saltwater performance package. Good or Bad?

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kblp

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I've searched the forums and I've seen where some have stated "you can't add a center tube to a boat with ellipticals."

I'm sure they probably mean you "shouldn't do it because" _______, fill in the blank.....

Does anyone know any of the reasons why it shouldn't be done?
 
Don't believe it will fit
 
There's a diagram on here somewhere of the spacing and distances. I think Link is right, there may not be enough room in between the outer tubes for a center tube.
 
KBLP, just wondering why you're posing the question? Is there something about your boat's handling characteristics that you're not happy with?
 
LINK and KAYDANO - from a purely physical dimension standpoint it will fit.. From a performance standpoint? I have no idea which is why I initially posed the question.

MICHIMAN - I love everything about the boat except for the characteristic inherent in the twin ellipticals with strakes/foils setup which is that it has a very wide turning radius when on plane, perhaps the widest of all the hull designs out there.

I wasn't shocked to discover this as I'd done my homework on the different hulls' capabilities and +'s and -'s before I bought the boat. It's plusses outweighed it's minuses for the majority of my use. However, I'd be on top of the world if I could come up with a reasonable way to significantly improve it's turning radius while on plane.

The solution if there is one very well may not lie in adding a center toon.
I've considered the possibility of what a deep V keel running on the bottom of each toon starting at the very back and running approximately half the length towards the front might do. Especially if that Deep V keel started at nothing on the forward end and progressively got deeper and possibly even progressively wider as you moved along it's length toward the back. Say like about 3-1/2" deep x 3" wide at the transom end of the toon.

I'm not trying to reinvent the wheel with this and I'm certainly not trying to get it to perform like a true full tritoon where it would rival the sharp turns of a V-hull. But if there was a reasonable way to significantly improve on it's turning radius without threatening physical integrity of anything or substantially subtracting from the current hulls inherent plusses I'd give it serious consideration. I still may not do it even if I knew beyond the shadow of a doubt that it would work. It's in my nature to look at the plusses and minuses of existing designs and try to determine and develop improvements. There isn't always a reasonable solution but sometimes there is. I'm just thinking and looking for input because group think always has it's benefits and usually brings things to the table that a single mind doesn't catch.

I appreciate you guys' input and am hoping for lots more so don't hold back with your thoughts and ideas.

Thanks
 
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In a static sense (standing still, on paper) it may very well fit, though not by much. From a dynamic standpoint (in motion) the lifting strakes and inside strakes for turning function in a very specific way with respect to each other (per the engineers I've talked with). I suspect placing them that close together would seriously impact the design intent in a negative way.
 
TomS I wondered about that and it's a very good point you make. That possibility is what led me down the path of wondering what if anything deep partial V keels might do if they were added to the two existing ellipticals.

But back to the tritoon conversion thoughts. Because of the possibility of lack of steering improvement due to the close proximity of the three tubes...my thoughts ranged toward definitely a round center tube rather than the addition of another wide elliptical and possibly the smaller diameter round tube in the center to get a bit more spacing between them.
I also tend to think that due to the wide surface planing area of the ellipticals it would likely always want to push in turns (slide) no matter what even with a center round toon addition, and even if there were sufficient distance between them.
That thought was another one that made me wonder about adding the tapered V keels on the existing ellipticals. Honestly I doubt anyone's ever tried it outside of possibly one of the pontoon manufacturers so I'm not holding out much hope that I'm going to get any input on that idea without speaking with a Bennington Engineer. And even if I did and he/she thought it had a decent chance at success I probably wouldn't attempt it just because of all the unknown variables.

It's a fun thought but that's probably as far as it will ever get with me, unless by chance I happen to run across a pair of elliptical pontoons laying around somewhere that could be had cheap enough that I didn't mind experimenting on them. The likelihood of that happening though is slim to none as they say.

Still, my desire was to improve the steering a reasonable amount in relation to the amount of cost and effort required to modify, not try to achieve the steering performance of a real tritoon so who knows, I may give it a whirl before it's all said and done.

Thanks for your input TomS, much appreciated.
 
Anyone remember CCanDo?
 
I'm too new here to remember him but I read through some of his posts and I'd certainly like to get his thoughts on this subject.
 
The rest of us would too...
 
I measured between the tubes today. 38" between the foil outer edges which appear to be in vertical alignment with the widest part of the toon. That would be a 7" space between tubes/foils if I added a 24" round center toon. My minds eye tells me that's too close together as has been suggested but who knows.
I've all but completely made up my mind I won't be modifying it no matter where the discussion goes but I'm going to speak with Bennington about this anyway and see what I can learn.
 
Our elliptical does not carve a turn like the ESP hull does but it will turn very quickly at speed. When I first got the boat, I tried high speed turns at WOT. It turns well but it is a flat turn and could be dangerous for passengers that are not hanging on and there is not much to hang on to on a pontoon. The few times we used it for watersports, I found it better to come off plane and kick the back end around to get back to the person in the water. We love it for what it does well.
 
I know what you're saying Remediation. I love this one for all the things it does well but...I'd love it more if it would turn better on plane lol.

Thanks for the response.
 
Does your twin ellipticals have performance foils and/or lifting strakes? I'm wondering if you would even get any "bite" on the ellipticals in a hard turn even with a center toon. With the bottoms being flatter as they are, to try to get one to dig in such as on an ESP, you would definitely need some help. My opinion is also that adding only a 23" center would be pointless as you need it in contact, unless you mount it 2" lower so it is level with the ellipticals, but not sure of the dynamics to where it can act as a pivot point on the tube on the inner turn.
 
Yes BulldogsCadillac it has both and I agree with everything you just said. I think the foils and strakes on the outside tunes are probably not conducive to turning and I think for a center toon to have any positive effect on turning sharper that it would have to protrude deeper into the water than the outside tunes, something akin to Manitou's V toon.

This would seem to set up two opposing forces working against each other and at some point while trying to force the turn I can envision something very bad possibly happening...outer toon connections failing...boat suddenly flipping...maybe that second one is an extreme and unwarranted concern but these thoughts have circulated through my mind as possibilities. Which is why I have all but written off the possibility that a tritoon conversion is going to yield the results I'm hoping for on this boat. Unless I removed the foils and strakes from the existing pontoons...but then I'd probably lose or negatively effect some of the characteristics I like about the current configuration. So it seems to be a catch22 and I think I'm going to call it a dead issue at this point unless someone has something to add that gets my wheels spinning again.

Otherwise thanks to all for your thoughts, ideas and input.
 
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