radius chine == radius bilge ?

[greenwater]

Hey all,

I've been looking at a few different designs for many years and think it's almost time to start building.

My question is about a Ted Brewer design that I really like, the Orca 45'. The website says it's a radius bilge type hull. I've been comparing this to some Bruce Roberts designs which have radius chine hulls which are suppose to be much easier to build than a round bilge (Bruce differentiates these in his books). Yet even Ted seems to make a difference between his radius bilge and a true round bilge. Are these two processes just different names for the same construction process from each designer? Will a standard metal shop be able to provide me w/ radius bilge pieces?

Does anyone have experience building a radius bilge from Ted's designs? Is radius bilge same as radius chine? I'm wondering how much of a difference this is from the radius chines which I think I find quite easy from reading Bruces books and how much the steel process changes.

[PAR]

Yep, just two different terms describing the same thing. Both are developed, flat panel builds, but have a rounded over chine areas. This is also known as a "soft chine" type as well.

and in my opinion they are neither fish nor fowl, they look horrible, a serious compremise

[JeroenW]

Originally Posted by lazeyjack

and in my opinion they are neither fish nor fowl, they look horrible, a serious compremise

But besides the looks, are there any other reasons to not use this technique?

[Wynand N]

Originally Posted by lazeyjack

and in my opinion they are neither fish nor fowl, they look horrible, a serious compremise

I beg to differ from you Jack If designed by a designer that knows his stuff, it is just as pleasing to look at as any other boat...

A little tale that happens to be true as told to me by Dudley Dix; In the early 90's, a very well known designer (now residing in NZ) and the doyen of SA designers at the time, looked at one of Dix's radius chine hulls on the dry about to be launched, and made the remark that it is one of the best round bilge steel hulls he has ever seen. Was he flabbergasted to learn that it is in fact a radius chine hull.

Yes, I had seen some less than nice radius chine hulls in my time and the Robert's version comes to mind. Some American designers also make them look sad and this is mainly due using different radius along the hull...

The website says it's a radius bilge type hull. I've been comparing this to some Bruce Roberts designs which have radius chine hulls which are suppose to be much easier to build than a round bilge (Bruce differentiates these in his books). Yet even Ted seems to make a difference between his radius bilge and a true round bilge. Are these two processes just different names for the same construction process from each designer?

A round bilge is not a radius chine. Most fibreglass hulls are round bilge designs as you have ever changing curves all over the hull so to speak which makes it difficult to duplicate in steel unless you are a very skilled steel worker.
Radius chine hulls are actually a single hard chine hull with the chine "softened" as pointed out by Par. As said before, if it is properly designed, it CAN be more pleasing to look and at as a proper round bilge hull...in fact, without being biased, I think it looks better overall.
And the beauty of this type of construction is that it is well within the ability of amateur builder and actually very easy to build

But besides the looks, are there any other reasons to not use this technique?

Just to put your mind at ease regarding the "looks", I attach a few photos of Dix designed radius chine hulls. Three photos are of the Dix43 now under construction at my shop and as a matter of fact, one of Dix earlier - 1987 - designs and his later ones are much more pleasing if I may say so.
The other two are of a Dix65, designed in 1990/1. I had build the Dix38 (which I actually commissioned in 1991) and the Dix57 and both are just as nice.

As for the looks, study the pics and you be the judge...

[PAR]

Wynand is correct, especially in modern hull forms. Well designed soft chine designs look quite good and most amateurs would be hard pressed to tell the difference from round bilge.

[JeroenW]

Wynand, I am following that Dix43 project of yours with admiration.
Thanks for clarifying.

I assume that strength wise, a well designed radius chine hull is not inferior to a (multi) chine or round bilge hull?

[PAR]

Curved panels are always stronger then flat ones.

[tugboat]

i am building a John G Alden tugboat Circa plans from around 1952. when i look at the hull form(i have a model) It looks like a round bilge to me- there is only on section that would be a compound curvature. the bottom appears to imitate a chine hull but there is no chine. the bottom is slighlty vee'd. and the sides plumb(for towing on the hip. would this be classifed as a round bilge?http://www.boatnerd.com/pictures/tug...ndianab-th.jpg
http://www.tug44.org/tugboats.trawlers/tug-8th-sea/

[viking north]

Well designed double chine construction hulls are certainly not ugly and there might actually be a little spinoff. There is an ongoing study and debate that a properly designed chine hull in certain situations might actually be faster than her non chined sister.The theory being that the chine ridge actually creates lift resulting in less wetted surface and possibily a little gain to winward ability. Anyhow food for debate. Geo.