IMPORTANT! Calling all Tiki 38 Builders & Owners

9 Responses

  1. Edward says:

    Neil,
    The first question I would ask is.. were the two failures actually built to specification and of high quality materials? It appears to me that too many builders make serious changes to the designers plans without thinking through the possible long term issues.
    But seeing as JWD has made changes I would incorporate those as the best current design. Good luck

  2. I haven’t seen any problems with my mast case… 😉

  3. Jacques says:

    From the begining i have been watching this piece. So far so good.

  4. Adrian Hall says:

    Hi Neil,
    Scary stuff! Thanks for bringing the matter to the attention of the Wharram community. As it happens I have recently been thinking hard about the rig for Kira. So far I have stuck to the plans believing JWD knows best, but I am now minded to move to the “dark side” and am contemplating fitting a junk rig. An unstayed mast fitted in each hull would avoid such stresses that have been the undoing of Marabu and Jumpa Lagi. I am re-reading Practical Junk Rig, and will discuss my plans further with Sunbird Marine. I recall following a Belgian couple building a Tiki 46 a few years ago who went down the same route; I am also thinking of going to electric hybrid propusion too!
    As an update, I am now on a sabbatical for the next 3 months. Kira’s starboard hull is now parked in my garden, and I am now working on the port hull. I have nearly completed fitting the lower hull panels, and will shortly start glassing. I am getting faster; it has taken me 3 weeks this time to get to the same position as it took 7 months for the first hull!
    My web site is still down, but I want to use all available time to build Kira rather than fiddling about with technology.
    Keep going
    Adrian

  5. Dave says:

    My mast case has not shown a problem and now I think about it I raised the mast be 1 meter and increased the sail area of the jib and foremain accordingly – thus increasing the laoding!!
    One thought comes to mind and that is if you allow the foremast to rest against the back plate, that is going to put enormous pressure on the aft mounting arms. Think of the leverage of the mast against it and the dynamic loads as you bash into the seas going up wind. So keeping the forestay tight enough to prevent this from happening is important.

    Regards,
    Dave
    Dragon

  6. Neil says:

    Hi Dave good to hear from you!
    Interesting though about the foremast putting pressure on the tabernacle like that, I’m glad you’ve had no problems.
    Definitely something to keep a weather eye on though eh?

  7. Andre Gietl says:

    Hi Neil
    I’m still building my tiki38 which I started many years ago. The tabernacle has made me scratch my head from the beginning and the aft end in particular has always made me think it looks like a joke. The documented failures are exactly what my common sense structural engineering insight has been telling me! It looks like it can’t work and it doesn’t. I look at this flimsy plywood box suspended in mid air, forward, with the added stresses from the jib and fore decks and compare it to the half beam that carries the aft mast. That one is built like it is part of a railway bridge. It makes no sense to me. Years ago I already heard of a case of a foremast punching its way through the tabernacle. That time it appeared to be the builders fault for using a boomed jib and bottle screws instead of the recommended shroud lashings. Lashings, screws, doesn’t matter, both can deliver tension to braking point. All that load is transferred down into the tabernacle and gets concentrated at the mounting points over the cross beams, with the added problem of a substantial lever. And two hardwood sticks glued along the outside as added strength does not convince me either. It’s a makeshift and makebelieve improvement to a poor design. I built a tiki26 over 20 years ago and the mast beam support there is standard accepted engineering, like on performance and small cats: a dolphin stay, countering the downward pressure through the dolphin striker. It’s simple, reliable and very rigid, it looks like it works and it does!
    How can a flimsy three sided suspended ply box without such support be expected to perform?
    I built my tabernacle to plan but closed the fore and aft ends so stuff doesn’t just fall out and I added a hardwood pad under the mast location. My intention is to fit a dolphin striker there and add a stay that runs fore and aft. I haven’t decided yet if I will attach the stay to the cross beams or the tabernacle itself.
    This to me is another learning exercise. Don’t always just accept what the experts come up with, more often than not your instincts are right! I sailed professionally with a great guy who skippered a big oyster. He never took for granted what the specialists and experts declared as the best solution and the result of decades of experience: he redesigned the transom of that boat and turned it into a folding bathing platform with rotating steps, and the whole lot closes up and folds away at the push of a button. Now a showpiece for oyster marine!
    He considered the counterintuitive behaviour of the jet driven Williams inflatable as “lazy engineering” and designed and made the relevant modifications to make the tender behave ” normal”.
    During races the big Lewmar electric primary winches used to overheat and cut out for half h, not so useful when short tacking. He singlehandedly designed and made and fitted watercooling to those winches. Lewmar said it can’t be done. Yes it can! …..
    Anyway, I’m rambling. this is in memory of Philip who died last year on passage to the Azores.
    He was my friend and a great inspiration to me.

  8. Neil says:

    Hi Andre

    Thanks for your thoughtful and interesting comments, wise words indeed and confirmation if any were needed that we builders shouldn’t be afraid of making changes to what after all are extremely personal objects.

    I’ve yet to finalise my preferred method for strengthening the mast box/tabernacle but whatever I do I’ll guarantee it will be far far stronger than the Wharram design.

    My condolences for the loss of your friend.

  9. Emil says:

    I am in proses of purchasing tiki 38 Tanoa, lying Richards bay South Africa. She suffered loss of fore mast and broken up step. Need to re- build the whole structure. Is it possible to obtain plans for improved/ strengthened step / box ? Also need proper specs for replacement masts. Any asvice would be appreciated.
    Emil Gaigher

Leave a Reply

Your email address will not be published. Required fields are marked *