Row & cougar
you are very right, the J Class shall stay a J Class.
My hands where going to fast and deformed what instead is a myth.
I certainly go back to the spirit and forget what I was doing for Endeavour and Ranger.
Pity, because technically I was happy to reduce the wet area and get deeper ballast, just too late since someone before me found the same thing many years before !!!
I go back to the right path and tank you for your talks.
Cheers
ClaudioD
Claudio,
I don’t think scrapping what you’ve done is the way forward. Certainly from the ‘J’ point of view I think they need to stay as the full keel hopefully with the additional draft (eg: your original ‘Enterprise’ drawings from a few years back) - although I’m sure some purists would argue even that would be wrong. However, I do firmly believe that there is a place for your fin & skeg drawings - but rather than being passed off as scale 'J’s, they could be ‘marketed’ as ‘inspired’ by the 'J’s of the 1930’s.
While I think the perception of this could be seen as selfish for the many out there who enjoy scratch building purely for the sake of it, they also benefit from your phenomenal talents. At the end of the day, there are plenty of extremely accomplished scratch builders around the world but very few with your design skills. So, if you do have the energy and time, please do ‘publish’ the fin & skeg drawings - if nothing else it extends the limited choice out there (with a few notable exceptions!).
Regards,
Row
Hi Row,
I’m back to work, and the final Endeavour design with deeper keel up to 150% draft
…
To improve the righting moment I decided to increase the ballast weight. Of course an increased displacement is necessary and I redraw all shadows after changing also the Beam from 202mm to 210mm.
As a result the model has 5869g and the bulb is 4042g. The Ratio is also good with 0.68%.
The Displacement is now close to the 12Metres Columbia with 5768g and Australia with 6300g.
As is the Endeavour should sail with 8.5kt and 30° heel and up to 11kt with 45° heel.
Hope people will like it ! apparently not !!!
Cheers
ClaudioD
I hate to say this, but I think this design may be too stiff. Universal Rule boats were designed to sail “on their ear” and as a previous poster noted, holding them there is part of the skill and enjoyment of sailing a boat like an EC12. There really isn’t a prettier sight in model sailing, IMHO, than watching a Universal Rule boat lean over, stretch out on her lines, and accelerate. I really don’t see that a greater righting moment than a Canterbury J or EC12 is necessary. Also, for recreational sailing, if someone goes with the non-overlapping double foresails a la Yankee III, removing the jib and sailing on staysail only gives a sort of “A-” rig.
Cheers,
Earl
Hi Earl,
probably I was exaggerating with the RM bee !!
I go back to my desk and clean up my “polluted” mind !!
Thank you
ClaudioD
I totally disagree. Especially within the M-Class.
A J is a J, and should have the traditional hull-form lines. Anything else is not a J. That’s a given.
But the “deformed” plan with Madcap keel is not a trash-can plan. It’s just another Marblehead.
You can do ANYTHING you want for hull form design in the Marblehead Class. the design criteria is WIDE-OPEN.
So while this design is not a 50" J. It’s also very, very far from a “Stupid” design.
Infact, if the data proves to be faster than other VMs, It’s quite the opposite. A very USEFUL Vm.
Your idea here was originally to build the 12s and Js on a open and relitievely even playing field (The M-Class) and you should stick with that. But don’t lose sight that you have complete design freedom inside of 50/800.
100% agreement
0% agreement.
If you are within the class rules, in this developmental class your mind is very far from polluted. The design might not work, but it’s not your creativity that is the cause of the problem.
If your design extends past the rule-set, then yes, time to re-assess.
Hi Breakwater,
I appreciate what you say, but I think I was pushing too far and I shall come back to a reasonable shape in spite of a reduced righting moment.
Finally I do not need to go deep, a good ballast and sufficient displacement shall do the job.
The point is that I spent a lot of time sailing with fin blade and bulb models like Class M and I’m always afraid about RM. Just like a bee in my hat !!!
Sure with your help, I will come to an acceptable solution technically and aesthetically.
I shall say that a too deep keel is not for me a very nice looking outside water…
What I miss is the practical aspect and the filling on the behavior of such models against the wind speed.
Probably I focus to much on pictures showing large deep keels as shown below.
Cheers
ClaudioD
I agree completely, the Draft went too far.
As Earl has said extending the keel on these style hulls this deep would create a boat that is too “stiff” whereas these Universal Rule yachts were designed to Lay-Over.
But, As I mentioned you weren’t processing stupid thoughts. All of that was within Marblehead Class rules. And so long as it’s with class rules it’s atleast a good idea.
Just because you can, doesn’t mean you should. But don’t loose sight of the fact that it’s not a matter of you can’t
The EC-12 really is a fine sailing Model Yacht.
I would reccomend taking your ballast ratios off of that model. It’s a very well rounded design.
Without having sailed one, or seen one sail I would venture to say that the Canterbury J is a little on the Stiff side, with it’s extended keel.
Endeavaburra?
This one is for real…a F-class yacht.
Claudio,
I was wondering why in the drawings of the extended keel that you added area pretty far forward, almost up to the #1 shadow, rather than extending from where the keel starts normally, (at about shadow 3 or 4)?
Is it to attempt to retain the same center of lateral resistance?
Todd
In terms of Marblehead design you are of course 100% right, after all, that’s the whole point of a development class (although I’m not familiar with the ‘Vintage’ rules). I think that where we may differ in opinion is that my perception was that Claudio was attempting to create a J class that would fit into the 50/800 rules but also retain the ‘essence’ of what made it a ‘J’, whereas your approach appears to be purely working within the development idea of the Marblehead class. While this is commendable and creates additional choice within the vintage marblehead fleet (which has to be a good thing) it doesn’t necessarily retain (what I think) was Claudio’s original idea.
Regards,
Row
Claudio… dont get me wrong… you have me sold on endeavour. that boat is going to be build this coming june… I like the lines and the only suggestion i had. was the dept of the keel… not a remodel of it… I was thinking it has such great lines. and would make for a beautiful model undersail and at a pond…Now i have drawn a J Class boat. ( dont ask. i am a amature) and following club suggestions.( is 1300 cm loa and 160 keel dept… so i dont know the righting moment…) my test boat has been made… and i would like to put in a 1500 cm mast. with around 900 sqr inches or sail… If this works. and i have had many failures. If this works… your endeavour at 140… would only need a 20 mm increase… and that could easy be hidden. .
dont give up on the desing. you have done a great job.
i realy liked the design…
good job
i just thought of something… I was watching a guy with a bluenose. ( very tough to build) and he came up with a idea. that might just work here…
could we leave the drawing with the shallow keel… and put in a dummy fin? just put the fin in… when the boat is in the water…??? then when on shore we take the fin out. and nobody knows?
I personal will build the boat with a 160 draft… like the plans you posted
Hi Breakwater and Row,
I’m still puzzled about the Draft I should consider !.
My intent is to satisfy 2 conditions :
1 - being fully compatible with Marblehead Rules where the draft can be as high as 12" and 16" for the Traditional and High Flier models and
2 - allowing separate racing of J Class and 12Metres designed models since their displacements are relatively different but using of the original Sail Plans/Rigs with the possibility to include different Ballast techniques like for instance the removable sliding fin/bulb. In this case art of the keel should be interchangeable. Some sketches will explain.
I do not have difficulties to match the Marblehead Rules.
Instead, the righting moment necessary for the increased SA or even a taller mast, can be achieved in various way, among these, the ballast can be increased in weight by modifying the hull draft and keeping the same water line, or increase the draft and consequently the volume to.
All that, with the desire to have the highest ballast ratio as possible !
Contrary to my model’s culture (deep fin/bulb combination see Class M) where the boat righting moment/stiffness is accepted up to 30°/35° heel, in the JClass/12Metres case as was written above, it is accepted that the models being more “gentle” and probably going up to 45°/50° of heel.
Of course watching the pictures presented above, it is understood that there is still the need to have an acceptable righting moment while being still “gentle”…
In the 1/16 JClass Rules it is agreed the use of a deeper keel to a maximum of 2 inches. If this it is done is because there is a good reason…
Form stability at model level is negligible.
From the interest expressed and exchanges made so far, I recognize that I was “pushing” too far the idea with the last presented drawing, although compatible with the Marblehead Rules, therefore I will come back to the previous approach by increasing the draft from 140mm average to 165/170mm, half of what it is allowed for the 1/16 JClass Rules.
I appreciate a lot this wide discussion with different opinions, this is exactly what I’m expecting from a serious Forum like this one.
The story is not finished yet …
All the best
ClaudioD
Hi Cougar,
one should respect the Rules if any. Some category do accept the added prosthesis with removable fin/bulb as shown earlier in this tread.
Let see what happen next !
Cheers
ClaudioD.
These images resume what is my intent :
…
Of course the Fin/Bulb option is a solution when the Rules accept it for racing, otherwise any one is free to use it. Not nice to see, but the problem disappears when removed.
Another solution I’m thinking seriously is the “interchangeable” keel as depicted below. Very similar as Fin/Bulb function, but rather more elegant. Further the Wet Area increase is not excessive !
Options not limited to two Keel !!
…
ClaudioD
Hello,
This is how I got my Schooner to sail very well, a drop Keel !!.
Not seen at all while sailing - - no Rules to keep to, boat sails just like the real one.
Folk understand why the keel is required, wind and waves will not Scale!.
At an Exhibition, the keel is removed for display.
John.
Claudio,
I seriously like the interchangeable keel option and as I mentioned previously, does it really matter if the wetted area increases (assuming it’s not excessive) to enable the yacht to carry on sailing in moderate as opposed to light winds? Or for that matter allowing an increase in sail area?
I remember reading a series of posts from approximately 4 years ago where you were trying to decide how to improve the righting-moment of ‘Enterprise’. If memory serves me well, I think Earl mentioned about some J class skippers over ballasting their boats and accepting that it would sit 1/4" or so lower in the water. If I also recall correctly, he went on to say that although it may have an unwanted effect in terms of aesthetics when the boat is upright, as the ‘J’ was designed to be sailed on her ear it should never really be an issue.
You really are working overtime on this one!!
Cheers,
Row
Hi Row,
I will work on the assumption of 2 keels. I think is a workable solution for what wrote some post before.
I just recall you mentioned the Rival.
I 1978 I ordered to Rival company a Rival 38C (today Bouwman company) fully rigged with several sails but almost empty inside except the major 2 bulkhead and water toilets already installed. All kit bought separately like galley, central heating, all electronics including VHF radio, all teak marine plywood of Bruyinzeel assembled from the same tree, etc.
Got to Holland in December 78 after sailing from Southampton. Started building the inside.
Transferred to south of France few months later and crossed the Channel down to the entrance of Gironde river (Bordeaux) and joined the Toulouse city via the waterway “Canal du Midi” after some 70 locks maneuvered by hands. This was my place for several years where I was working the WE.
I went down every holiday seasons in the Med although the inside work was still in progress. We enjoyed a lot, fantastics boat when force 5 was coming up, at force 2 was almost a buoy, very slow.
My wife never managed to avoid to be seasick, finally some one decided to take over and I sold the boat in 82 when finally I got a mahogany planked Dragon.
Here the two boats
From a M standpoint, this design type is still acceptable in the M-Class, but because of the dropped keel it would now be pushed forward into a More modern category. At that stage it’s still a “Legal” M, but one would expect it to not be able to compete against the More modern designs… such as Claudio’s AZUR.
It still should be built… Not every boat has to be the fastest that design can possibly create.