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Thread: Lifting cabin top construction thoughts/tips

  1. #1
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    Default Lifting cabin top construction thoughts/tips

    I decided to keep my 1987 Rob Roy 23', but need to modify it some before it is the perfect boat for me. For those not familiar with the Rob Roy 23, it was designed by Ted Brewer to be a modern version of the British Humber canoe yawls that started to take shape just before the end of the 19th century.

    I'd like to modify the cabin top to lift while camping overnight, similar to some Norfolk Broads yachts. I've searched the web unsuccessfully trying to find construction methods for the Broads yacht pop-tops. Anybody know of a link, pics, plans, or a book to assist me in this modification? Anybody chopped up their fiberglass cabin before, and can pass-on some tips?

  2. #2
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    Default Re: Lifting cabin top construction thoughts/tips

    You should look at how they do van conversions for pop tops. You could use an old VW pop-top mechanism. Bassicly 4 ex braces. Some of these just lift at one end.
    Seems to me the old Kells had pop up cabin tops as well.
    http://www.camperize.com/build-your-own-poptop/
    http://www.poptoproofs.co.uk/index.php
    Last edited by navydog; 08-01-2018 at 09:32 PM.

  3. #3
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    Default Re: Lifting cabin top construction thoughts/tips

    Front hinged or lifting both ends?



    This one uses wooden props pushing against the tension in the canvas.


    after lifting it with the gaff halyards.
    It really is quite difficult to build an ugly wooden boat.

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  4. #4
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    Default Re: Lifting cabin top construction thoughts/tips

    I'd like both ends to raise. I'm guessing some the front hinged coach roofs, will unpin and raise as well. It would be nice to see construction photos, but every photo helps. Thanks for the above photo's and links.

    Currently, I'm thinking I could cut the existing cabin top. Add a wood frame around the bottom edge of the cut out section (the lifting section of the roof). Add a wood frame along the inner edge of stationary section of the cabin top. The throughway and drop board arrangements may get tricky.

  5. #5
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    Default Re: Lifting cabin top construction thoughts/tips

    Quote Originally Posted by Okiebobby View Post
    I'd like both ends to raise. I'm guessing some the front hinged coach roofs, will unpin and raise as well. It would be nice to see construction photos, but every photo helps. Thanks for the above photo's and links.

    Currently, I'm thinking I could cut the existing cabin top. Add a wood frame around the bottom edge of the cut out section (the lifting section of the roof). Add a wood frame along the inner edge of stationary section of the cabin top. The throughway and drop board arrangements may get tricky.
    You will need to consider keeping the rain out when you design your coamings.
    The last photo suggests a roll down canvas screen to bridge the gap between the companion weather board top edge and sliding hatch. It is probably laced to the side canvasses with lachets through grommets.
    It looks as though the props are pivoteded at the bottom end, stow horizontaly in clips, and are swung up into housings under the pop top to deploy.
    It really is quite difficult to build an ugly wooden boat.

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  6. #6
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    Default Re: Lifting cabin top construction thoughts/tips

    The schooner "Nelly Bly" had a telescoping deck house the was raised by a couple of halyards and then locked in place with trunnels. She was a lovely little boat that had no head room and needed that trick set up to give the much needed head room.
    Jay

  7. #7
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    Default Re: Lifting cabin top construction thoughts/tips


    This?
    How much of the cabin top are you thinking of removing? I would be concerned about compromising the structure if too much is removed, with special consideration to how the mast is supported no what remains.

    I have a VW Westfalia vanagon, the top is remarkably heavy for what is and there are some serious springs in the pop-up mechanism to assist with the lift.
    Steve

    Boats, like whiskey, are all good.
    R.D Culler

  8. #8
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    Default Re: Lifting cabin top construction thoughts/tips

    Chris Cunningham, editor of Small Boats Monthly, has built a barge like camping boat that has a pop up top. He's described it in SBM. I'm not remembering which issue.

    Jeff

  9. #9
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    Default Re: Lifting cabin top construction thoughts/tips

    Quote Originally Posted by Okiebobby View Post
    I decided to keep my 1987 Rob Roy 23', but need to modify it some before it is the perfect boat for me. For those not familiar with the Rob Roy 23, it was designed by Ted Brewer to be a modern version of the British Humber canoe yawls that started to take shape just before the end of the 19th century.

    I'd like to modify the cabin top to lift while camping overnight, similar to some Norfolk Broads yachts. I've searched the web unsuccessfully trying to find construction methods for the Broads yacht pop-tops. Anybody know of a link, pics, plans, or a book to assist me in this modification? Anybody chopped up their fiberglass cabin before, and can pass-on some tips?
    Important question, what sort of water do you cruise in. Broads yachts are all on rivers and small lakes, no fetch to knock up big waves. If you cruise in anything rougher than that, be very careful with your design work.
    It really is quite difficult to build an ugly wooden boat.

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  10. #10
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    Default Re: Lifting cabin top construction thoughts/tips

    I'm picturing the lifting top to be about 3' wide x by 6' long. Not real big, but will probably have some weight. Much smaller than the Broads yachts. I saw a training video on youtube for a much larger Broads yacht. I don't think springs were involved.

    watch

    Hopefully the above link works. I haven't learned the tricks to add pics and video on this forum yet. Sorry!
    Last edited by Okiebobby; 08-09-2018 at 08:14 PM.

  11. #11
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    Default Re: Lifting cabin top construction thoughts/tips

    Quote Originally Posted by Jay Greer View Post
    The schooner "Nelly Bly" had a telescoping deck house the was raised by a couple of halyards and then locked in place with trunnels. She was a lovely little boat that had no head room and needed that trick set up to give the much needed head room.
    Jay
    I would love to see this. If anybody knows of a link, please post it.

  12. #12
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    Default Re: Lifting cabin top construction thoughts/tips

    This is a fun video, plus it has some great shots of the Broads yachts lifting cabin tops. Oh, the British have some nice boats.

    https://www.youtube.com/watch?v=0Qr5...eCUfl&index=10

    The frame around these tops is just how I'm picturing the modification to Bilgewater. I am still having trouble picturing how to handle things at the companion way bulkhead. I guess there is no two ways around it, it will requiring some orthopedic and cosmetic surgery in this area. The results could make this boat look way more traditional; more wood, less plastic. Very exciting!

  13. #13
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    Default Re: Lifting cabin top construction thoughts/tips

    Look at a 90s vintage MacGregor 26. We sailed one for 9 seasons. The poptop was dead-simple, and never failed.

    It converted a dark small tunnel into a tall, sunny room. In seconds.

    There was a vinyl enclosure that slipped over the raised roof, with 4 lashing points. It needed a bit of modification to be mosquito proof, but then worked well.

  14. #14
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    Default Re: Lifting cabin top construction thoughts/tips

    Cool idea. Some thoughts:

    I would say build it like a hatch, with sides that overlap a coaming and that can be dogged down tight against a gasket.

    For lifting, you could do it without any mechanism at all. Utilize removable corner posts that secure with wingnuts, or mount using keyhole fixtures, or opposing wedges, or etc: lift the top manually--or with a line from the mast. Then emplace the supports, drop the top on, and, finally, snap or Velcro on the canvas or bug screen all around.

    Kevin
    There are two kinds of boaters: those who have run aground, and those who lie about it.

  15. #15
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    Default Re: Lifting cabin top construction thoughts/tips

    here's a fellow that built a pretty nice but basic one for his volkswagen,
    plywood + fiberglass
    seems like it would translate to boat..

    http://subagonsouth.com/one-of-a-kind-custom-poptop/






  16. #16
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    Default Re: Lifting cabin top construction thoughts/tips

    You may want to check an early mfg Catalina 25 fiberglass boat for ideas too. They had a large lifting roof section with vinyl fabric sides to keep weather out. A friend had one and I remember it was very easy to raise and lower. There's an active Catalina forum that may also gleen info.

  17. #17
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    Default Re: Lifting cabin top construction thoughts/tips

    B23B19EB-80B0-4CC3-BE3A-CA0FDB283F31.jpg

    http://thunderbirdsailing.org/

    This is how the hatch lifts on a Thunderbird. The solid front panel is interesting. I am not too sure how the lifting works but I bet if you researched the Thunderbird world you could get some info. There are plenty of active boats out there. My intial thought would be to build a new top entirely, for ease of modification and it would look and feel nice out of wood.
    "Yeah, well, that's just, like your opinion man"
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  18. #18
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    Default Re: Lifting cabin top construction thoughts/tips

    Look at the Farrier trimaran details. (F22, F24, F27, etc.) I had one of these and the pop top worked extremely well. It was simple and versatile because you'd lift one end at a time. The lifting mechanism is almost all stainless bimini top hardware.
    The aft end of the top is on stainless tubes. You lift it to whatever height you want and slide pins through holes in the tubes to keep it up.
    The forward end has sliding, hinged posts. The top end ride in a light traveler track so that the height there can be set variably also.

    Your boat is one of my favorite commercial designs. I would suggest removing the sliding hatch and cutting out the top between the hatch rails. No more than that. A pop top will give standing headroom enough to move around. A canvas cover can be made to snap over the top (standard on the F27) for good ventilation and to keep the rain and bugs out. I think the key here is to not get carried away and make something that's impractically big and heavy. Also, as noted above, cut out to much and the entire top will loose its rigidity. Good luck with the update.

    -Dave

  19. #19
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    Default Re: Lifting cabin top construction thoughts/tips

    Quote Originally Posted by Woxbox View Post

    Your boat is one of my favorite commercial designs.
    Dave, I'm glad I decided to keep the Rob Roy 23. Recently, I have seriously compared it to many of the boats on my wishlist. Each time it won out. So now, I'm focused on customizing it for my purposes. The more I learn about this boat, the more respect I have for the designer Ted Brewer and the builder Marine Concepts.

    For somebody that has been boat whoring like I have, trading boats about every other year, this is a big relief to know I can stop looking for the next boat and focus on THE boat.

    Today I spoke with Jim Leet, the owner of Marine Concepts. He was helpful and generous with his time. Hopefully I didn't waste too much of it. I contacted him to inquire about ordering a new mizzen sail, and to explore a mizzen mast furling method similar to the Sea Pearls. After speaking with him, and hearing some possibilities in aluminum and carbon fiber, it hit me that I don't really want more modern materials. What I really want is more wood. So that is the direction I'm headed, starting with the mizzen spars. Brewer's plans also have a Gunter option for the main. I think it is viable in wood. The Gunter rig should be similar sized to Dylan Winter's KTL Hunter Minstrel, which I think is a masterpiece. Dylan demonstrated how versatile the rig was, and then some.

    From my perspective though, I see the used GRP boat as a sturdy reliable low maintenance foundation to house the transformation that may likely lead to a completely new wood boat within the old hull. That old GRP hull is going to outlast me, so I might as well protect my handiwork within it. Plus my handiwork may not always be so handy; therefore it is nice to know the foundation that keeps it from sinking was built professionally. I also feel a since of pride in rescuing one of these old GRP hulls that last so long, we can buy them dirt cheap. Most of these old GRP hulls have no market value. The value of an old used production boat is in the trailer, the outboard motor, the sails, and the lead in the keel. The old GRP hull may very well have negative value. Jim told me the Rob Roy molds were cut-up and burned intentionally because they had no market value, and needed to cut the company's storage costs.

    In a sense, I'm envisioning a homemade classic wooden boat encapsulated in a rescued production GRP hull. I think it could be the wave of the future in homemade boat building. There definitely is a large supply of inexpensive GRP hulls around to choose from. Pick a boat size and shape, and then furnish it to your hearts content.

    Sorry to get off topic. Well back to the lifting top. Great ideas fellows. Please keep'm coming. The bolder the better. I'm not worried about hurting the old boat. If I screw-up too bad, I'll replace the whole GRP deck mold with a wooden one. Not a bad reward to that risk, but I don't think it will come to that.

  20. #20
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    Default Re: Lifting cabin top construction thoughts/tips

    I think you're going to have fun with this project. But watch the weight gain! That's been the performance death of many a customized boat.
    -Dave

  21. #21
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    Default Re: Lifting cabin top construction thoughts/tips

    I've sailed two different arrangement of lift top broads cruiser.

    First one had th cabin top hinged at the forward end - just abaft the mast.

    The second one had the whole cabin top lift on four spring loaded poles and pinned - this was gaff rigged and having a low boom needed a secondary gooseneck.....

    In both cases canvas dealt with the infill.

    I've seen one other - where the whole cabin top hinged sideways.
    Someday, I'm going to settle down and be a grumpy old man.

  22. #22
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    Default Re: Lifting cabin top construction thoughts/tips

    Quote Originally Posted by P.I. Stazzer-Newt View Post
    I've sailed two different arrangement of lift top broads cruiser.

    First one had th cabin top hinged at the forward end - just abaft the mast.

    The second one had the whole cabin top lift on four spring loaded poles and pinned - this was gaff rigged and having a low boom needed a secondary gooseneck.....

    In both cases canvas dealt with the infill.

    I've seen one other - where the whole cabin top hinged sideways.

    I'm jealous. Any pictures???

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