DE23 raised Deck - Planing

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tobi
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DE23 raised Deck - Planing

Post by tobi »

After having bought the plans of the DE23 I am thinking about how to realise a raised deck version.

I would do the following changes:
1. Raised the deck in the front of the boat above the cabin.
2. Increased interior cabin height to approx 1.40 m to get more sitting head room by raising the sheer by 2“ in increasing the camber by 2“ compared to the camber of the deck (the camber of the original cabin is even bigger).

8231

If I would just extend the sides of the boat until the raised deck, the beam of the boat would exceed the legal width. So I will have to add one panel which is angled a little bit inward. If I would extend this panel with the same angle to the bow, I would get an (ugly) kink in the bow. If you take a look at raised deck boats like the rapsody 29 or the old petterson boats the sheer doesn't continue to the bow but ends about 2-3 feet before the bow. I would like to get one continuous side panel at the bow that is split afterwards frame A to the normal side panel and one panel that is increasing angled inwards (frame B 5°, frame C 10°). The panels will visually be separated by the sheer, so that the angle between the panel is less obvious.

8229

8230

The other possibility (which I don't prefer) would be to build the normal sheer and add one panel above as cabin side. To conceal the kink in the bow I would add a fake stem (just like in the discussion about DE23 klompen on this side). Any still visible kink would be just faired away.

Questions:
1- Is it possible to end the (outward) sheer before the bow?
2- Is it possible to cut the side panel in total height to the deck and just cut a slit from frame C to frame A to get the angle? (A small sailing boat called seggerling builds the total hull skin from just one big piece of plywood by just cutting away some areas and stitching it together afterwards).
Thanks for your thoughs
tobi

fallguy1000
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Re: DE23 raised Deck - Planing

Post by fallguy1000 »

Definitely a Mertens question.

Skoota 32 has a return to stay legal two hulls together.

You have to modify rubrail placements and ropes and lines can wear paint off those areas, so rub strakes are needed. It is more work as that is structural, etc.

I have not applied the strakes, yet.
4F3B4CF8-5DFD-4D23-939E-3DA353CC9F69.jpeg
C831CEBF-355C-4E27-B085-15E513AB7AF7.jpeg
My boat build is here -------->

viewtopic.php?f=12&t=62495

TomW1
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Re: DE23 raised Deck - Planing

Post by TomW1 »

I do not like it. You are making a lot of work for your self. How are you going to mate the changed sides to the bottom hull without also changing the bottom hull. You can't change the hull bottom without a total redesign of the boat. Just take the side panels as they are now and increase them by how many centimeters you need to raise them by. How many is that. I feel you are making an ugly boat out of what is very pretty boat.

The DE23 as designed has sitting headroom according to the study plans. If you need a little more raise it a little, but no reason to go to the extremes you are going to. 1.4M is 55" of headroom I am 6'3", 1.91M and need less than 39", 1.0M of sitting room from the waist up.

I do not normally bring this up, but at the bottom where you see my boats and achievements is Westlawn School of Yacht Design, Jacques and I have both had about the same amount of courses from the school so I sort of know what I am talking about. Some times if I answer correctly he will not waste his time or say Tom is right, or say Tom is right and add something.

I would think again about what you want to do.

Sorry to be so blunt, it is just that you are totally redesigning the boat from the hull up. With Jacques designs as long as you build it up to the deck you can then do any thing you want from there up. :D Raise the front cabin a couple of inches or so, take it out to the edge of the boat like you show. Just be aware that you don't add to much weight to the front that it is bow heavy. Also be sure in your planning you can launch an anchor from a hatch or some other method.

Tom
Last edited by TomW1 on Mon Feb 22, 2021 7:57 pm, edited 1 time in total.
Restored Mirror Dinghy, Bought OD18 built by CL, Westlawn School of Yacht Design courses. LT US Navy 1970-1978

Cowbro
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Re: DE23 raised Deck - Planing

Post by Cowbro »

tobi wrote: Mon Feb 22, 2021 4:21 pm
The other possibility (which I don't prefer) would be to build the normal sheer and add one panel above as cabin side. To conceal the kink in the bow I would add a fake stem (just like in the discussion about DE23 klompen on this side). Any still visible kink would be just faired away.
This seems like the best plan. Build the hull as designed and then simply modify above the gunnels. Does the hull as designed meet your width requirements?

I don't hate the look of your model, however I would stretch out the curve where the sheer drops down beside the helm about twice what it is now to make the change slightly less abrupt. I would also move the round port light to the outside of the hull and go with something more oval or rectangular.

Cowbro.

Matt Gent
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Re: DE23 raised Deck - Planing

Post by Matt Gent »

If you're going to build a boat, might as well build the one you want. The cabin mods are more effort to make (and to design the adjustments) but in the grand scheme of building a boat this size its not that much. That entire area has nothing to do with the stability (if kept light), performance, or structure of the boat.

Looks like what they'd call a "bass boat" in the NorthEast US, but not what we call a bass boat in the south. Those can be handsome....the CAD image looks faceted for some reason. If I follow your description properly, I think you can taper the angle so there is no kink at the stem to get what you want. How strict is the legal beam limit? I'm certain in FL I could get away with just having the boat be a few inches wider than the towing restriction. A long time I go I sketched up a modified DE25 (before finding mine to buy) which had a raised deck not so different than your image.

I think what you are calling a shear, I would call a rub strip. And the "broken shear" would follow up the step to the raised deck, up to the stem. Pretty clever to put that rub rail/strip right over the panel intersection to hide the angle, but I think it would still be visible in shadows. I've seen boats built with the split plywood as you describe - it was called "butterfly" technique. That can make the transition less abrupt:

Image

I might guess that the panel layout will be a challenge to get that to fit with the extra height on top of the standard topsides.

For what its worth in my DE25, there is 34.5" from the v-berth seat (without a cushion) to the cabin top, and 31.5" to the rib structure. I am 5'10" and I cannot sit upright, and its not really that close. For rainy days I wish I could sit in there.

tobi
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Re: DE23 raised Deck - Planing

Post by tobi »

I measured that I need at least 1.0 m above the sitting surface to be able to sit upright. To achive this I have to raise the deck by approx. 10 cm or 4 inch, split in a shear raised 5 cm and an increased camber of 5 cm. This results in an cabin height of 1.4 m. It is a small change to the design but important for the usability of the cabin (the freebord of the DE29 in the netherlands is raised by 15 cm or 6 inch). I will fine check the needed space with a cabin mockup later.

The side panels of the hull are not changed despite raising them by 5 cm, the hull stays the same (the facets in the rendering are just because of the used very old CAD-system or my capabilitis). The only question is how to join the new upper side panel to the normal side panel. Either use the butterfly technic for a smoth transition (it may be possible that the twist in the upper panel could create some distortion in the side panel, but I don't think so) or just add one panel. I think adding one panel could result in an uneven surface at the joint. A bigger panel should be no problem, there is some space left an the nesting drawings.

Thanks for your comments, tobi

Cowbro
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Re: DE23 raised Deck - Planing

Post by Cowbro »

tobi wrote: Wed Feb 24, 2021 2:44 pm A bigger panel should be no problem, there is some space left an the nesting drawings.

Thanks for your comments, tobi
If you can just leave the side panels long on the top side until after the flip, then you can trim them down afterward to the desired height/shape. I was thinking about it and you might be okay on width since the extended side are mostly forward of the max beam.

rick berrey
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Re: DE23 raised Deck - Planing

Post by rick berrey »

Your best option would be to buy 5'x8' or 5'x10' ply and you would not have a joint .

TomW1
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Re: DE23 raised Deck - Planing

Post by TomW1 »

There is no problem with either method. Just bring frames A, B and C up high enough to define the shape of the higher sides. If you have to tape and epoxy a higher piece on to the side it will follow the main side pieces as they curve around the bow. Or if you want them to slant them in put them on after you put the regular sides on just slant A, B and C in the amount you want and use plastic ties to hold them to the lower piece and the frames while you tape them and glue them on.

Good luck to you

Tom
Restored Mirror Dinghy, Bought OD18 built by CL, Westlawn School of Yacht Design courses. LT US Navy 1970-1978

jonnymac
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Re: DE23 raised Deck - Planing

Post by jonnymac »

I know this is from 8 months ago, but when I look at the renders I see the LB26 just a little smaller. Maybe take design cues on how Jacques handles the small details there, and just scale accordingly.

i also wonder if a bulwarks detail that would let you hide the height some and make the various curve transitions easier.

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