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Thread: Open jawed boom with a tabernacle on a bermudian rigged cutter.

  1. #1
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    Default Open jawed boom with a tabernacle on a bermudian rigged cutter.

    The wooden Bermudan cutter rigged Flicka I'm restoring came with an open jawed boom. I've installed a tabernacle and need advice about supporting the mast - boom connection whilst lowering the mast forward. Would a gooseneck downhaul be sufficient. Any ideas welcome

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    Default Re: Open jawed boom with a tabernacle on a bermudian rigged cutter.

    Probably, depending on the angle. pictures would help, do you really lower the mast forward?

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    Default Re: Open jawed boom with a tabernacle on a bermudian rigged cutter.

    Your boat is small enough to allow you to unship the boom and lash it to the mast for lowering.

    Or are you using the boom as an "A" frame to use the main sheet and topping lift as a lowering system?
    It really is quite difficult to build an ugly wooden boat.

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    Default Re: Open jawed boom with a tabernacle on a bermudian rigged cutter.

    Thanks guys.

    I haven't mastered photo uploading yet. Yes, I hope to use the boom as a gin pole braced by the topping lift, for passing under the bridges on the New South Wales east coast rivers but not for transporting. Lowering forward means only the back stay needs detaching. The cap shrouds pivot level with tabernacle pivot while the rear lower shrouds are loosened with hyfield leavers. The back stay detaches and the mast is lowered using a main sheet. A similar system is used on Westsail 32s I think. I haven't done a lot of sailing with this boom set-up but like the idea of being able to use the boom weight and downhaul to tension the main rather than the halyard. One drawback is having to lean out to release the backstay on the bumkin that is largely supported by the backstay !! The mast is pretty heavy douglas fir and the rig generally robust 1/4"wire & stalok type. I've searched the web for years without sighting any open mouthed goosenecks on anything other than gaffers - so maybe it's impractical - I don't know.

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    Default Re: Open jawed boom with a tabernacle on a bermudian rigged cutter.

    There is a whole lot of tension when the mast is getting horizontal, mostly compression on your boom jaws. Your gooseneck downhaul will obvioulsy have to be on the mast itself and not on the deck or tabernacle, but i would like a spare halyard on the opposite side keeping everything tight.
    I had a scaffold pole i used on may Waterwitch mast , but that was pinned through the mast base after leaning the mast back slightly from the tabernacle, basically the same jaw set up, but with a pin (alloy mast) and used just the forestay and mainsheet tackle, no reason it would not work in reverse if your tabernacle is set up for it.

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    Default Re: Open jawed boom with a tabernacle on a bermudian rigged cutter.

    Thanks Skaraborgcraft for your thoughts. You're obviously a serious contributor to this forum. Where are you residing now ?

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    Default Re: Open jawed boom with a tabernacle on a bermudian rigged cutter.

    Quote Originally Posted by flicka View Post
    Thanks Skaraborgcraft for your thoughts. You're obviously a serious contributor to this forum. Where are you residing now ?
    I gained most of my knowledge through books ,screwing up and the occasional truly talented that actually enjoyed sharing knowledge, and that was before i really got into boats seriously. If anything i share helps to avoid someone making a mistake then everyone benefits, the learning never stops and the internet has made sharing knowledge even more accessable...though i make no claims about being an expert in anything. Currently in Sweden and those days of white nights and 20hrs of light outside.
    I did have some photos (pre-digital) of my tabernacle set up somewhere. How is your mast secured? Using your boom as a lever is one way, i also used much lighter wood booms either side of the mast, with the deck ends pinned through the rigging deck plates, as an "A" frame, for hoisting a keel stepped mast in and out single handed, certainly a bit more "rigid" than an all-rope set up.

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    Default Re: Open jawed boom with a tabernacle on a bermudian rigged cutter.

    Sweden in summer sounds good

    It would take pages to describe my rig details - if only I could upload photos

    I've made a strong ply tabernacle that should detach from the cabin top in the event of a roll over / dismasting, rather than rip a hole in it. The cap shrouds are attached to braced stainless rods about 900mm long that rise from the chain plates and kept from leaning forward by wire braces shackled to their tops and back down to the rear lower shroud chain plates. The tops of the rods align with the pivot bolt in the mast so that shroud tension is maintained as the mast lowers. ( It all sounds good in theory ) The mast is almost ready for raising but we had a set-back in February when a 47c day and extended heatwave caused blisters to form under our beautiful topside paint job and the 30 year old fibreglass external sheathing - 20 blisters on the sunny side ! A 2 inch chisel; dynel; epoxy and days of work to fix. Anyway, drifting off topic here.
    Thankyou for your thoughts.

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    Default Re: Open jawed boom with a tabernacle on a bermudian rigged cutter.

    Quote Originally Posted by flicka View Post

    It would take pages to describe my rig details - if only I could upload photos
    The FAQ page tells you how. First you have to put the photos on a web site like Photobucket.
    Then
    POSTING PICTURES
    Control yourself. Avoid posting BIG pictures. Keep them 500 pixels wide OR LESS. That way the dial-up folks aren't bogged-down, and the width doesn't make the page hard to read in a standard sized window. If you don't have Photoshop, try the freebie from gimp.org. We do NOT host your images. You need to have a place like Flickr, Imagestation, Photobucket, DropBox, or one of the free other hosting outfits... or your own site. Per Thorne's 'How-to', here's how to post photos on this forum:



    ...FIRST - Don't attach photos. Only a tiny version will display.
    ...SECOND - Post the photos on the web. Use your own website or a free image hosting service like www.flickr.com, picasaweb.google.com, picturetrail, photobucket, etc. Images posted on Facebook must be set to "Public" access via the Edit option, not limited to "Friends".

    ...THIRD - Once posted on the web, right-click the photo to "Copy Image Location", or drag the photo to another browser window, then copy the image URL (web address) which will end in ".jpg". You can test by pasting the photo URL into the location field (http://* ) of a web browser and see if the photo displays. Remember that this process will not work for photos located just on your computer, on members-only Yahoo groups, or on Facebook unless set to "Public" view. (In Flickr - You usually have to first click the photo to bring up the black-framed viewer, then click the "View All Sizes" link near the top right. Then you can get the image URL by right-clicking the image. Alternately you can go to the Actions menu on the upper left, then select "View All Sizes".

    ...FOURTH - DO THIS EVERY TIME TO POST IMAGES IN THREADS: A. In any "Reply" window you can click the "insert image" icon --> a little yellow square icon with a dot at each corner, a tiny tree in the center. Depending on browser version and Reply/Edit status, this may bring up a simple window with a field to paste the URL into, or the "Add an Image" window described below.
    B. If the window titled "Add an Image" comes up, click the "From URL" tab, paste the URL of the photo in the field, deselect the box for "Retrieve remote file and reference locally", then click the "INSERT IMAGE" button. The Forum software will resize some large images, so look at your post to see the actual displayed images.


    It really is quite difficult to build an ugly wooden boat.

    The power of the web: Anyone can post anything on the web
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    Default Re: Open jawed boom with a tabernacle on a bermudian rigged cutter.

    Thanks Peerie Maa

    I'm not computer savvy & using the www.flickr.com link, the second step is to insert the key number that's emailed to me. After retrieving the email number & left arrowing back to insert the number, I'm told the page has expired. I use Pacasa normally but I gather you can't upload photos to the web on pacasa anymore.

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    Default Re: Open jawed boom with a tabernacle on a bermudian rigged cutter.

    Quote Originally Posted by flicka View Post
    Thanks Peerie Maa

    I'm not computer savvy & using the www.flickr.com link, the second step is to insert the key number that's emailed to me. After retrieving the email number & left arrowing back to insert the number, I'm told the page has expired. I use Pacasa normally but I gather you can't upload photos to the web on pacasa anymore.
    I use Picasa, sold out to google. You have to go to options tab to re-save it or post on the web (edit in google option), i think this is when google takes over the rights of your photos...Picasa didnt, as far as i know.

  12. #12
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    Default Re: Open jawed boom with a tabernacle on a bermudian rigged cutter.

    Another issue with the solid 8.5 metre douglas fir mast & 1"ply tabernacle -- I had intended using a stainless bolt as a pivot, thru stainless tubes set in the mast & tab. cheeks. I'm now thinking a snug fitting rubber tube, at least in the mast may make raising & lowering smoother.

    The mast foot slopes to reduce friction, so should there be a pad of some sort between mast & tabernacle to ease the landing especially when coming vertical ?

    Should the bolt be taking some of the strain after the mast is raised & is an vertical oval hole in the mast a better idea ?
    Last edited by flicka; 07-12-2017 at 02:50 AM.

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    Default Re: Open jawed boom with a tabernacle on a bermudian rigged cutter.

    I have seen masts supported by 2 large pins, one pivot and one securing the foot, the load being on the pins and the pins oversized for that job. I think Bolger did a few like that, you might find some details by looking for "Black Skimmer". My mast had an oak wedge driven under the foot when raised to take the pressure of the pivot bolt, which was only a small diameter.
    I dont know how tall you are intending your tabernacle to be, but 1in sides will still require some substantial side webs/braces.

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    Default Re: Open jawed boom with a tabernacle on a bermudian rigged cutter.

    Thanks skaraborgcraft

    My tabernacle has 12"high cheeks through bolted to a solid 3"high block at the bottom.

    What do you think of the rubber tube insert idea ?

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    Default Re: Open jawed boom with a tabernacle on a bermudian rigged cutter.

    Personally i would go for the stainless tubes and pin. I think there is more chance of flex and possible binding if using rubber, unless it was of a highly rigid type. The stainless set up is well proven.

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    Default Re: Open jawed boom with a tabernacle on a bermudian rigged cutter.

    I take your point about binding, and using Teflon wouldn't allow movement to soften the landing either.

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