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extending Tornado's bows #219841
09/18/10 07:10 AM
09/18/10 07:10 AM
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pamusalas Offline OP
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I have started to think about winter projects (sailing season is quite short in Lithuania). One of the projects that i was discussing with my mates is to extend the bows.

I know it won't be a T anymore, but anyway we don't do any one design racing on this catamaran so who cares.

Basic idea of this project would be to make T even more efficient. Extended bow, would create finer entry, longer waterline, lower wave drag and because of that boat should sail faster. Am I right?

Has anybody done something similar? I know there is a thread somewhere in this forum, but i Can't find it anymore. Any info would be usable.

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Re: extending Tornado's bows [Re: pamusalas] #219842
09/18/10 07:44 AM
09/18/10 07:44 AM
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45degApparent Offline
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If it is a polyester boat you would be better off hacking the bows off and racing it as an F18.

Compared to modern designs the T have low volume hulls. Boat will need extensive surgery to be any faster than it already is if you want to modify the hulls. It would be much better to build new hulls!

Build new high aspect ratio daggerboards for the T and install T foil rudders. That should keep you busy, make the boat faster and easier to sail. You will still have the option of racing or selling the boat as a T if you want to at some point.

Re: extending Tornado's bows [Re: 45degApparent] #219851
09/18/10 01:30 PM
09/18/10 01:30 PM
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Asuncion, Paraguay
Luiz Offline
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Originally Posted by 45degApparent

If it is a polyester boat you would be better off hacking the bows off and racing it as an F18.


Will have to shorten the beams as well, among other details.


Luiz
Re: extending Tornado's bows [Re: Luiz] #219853
09/18/10 02:43 PM
09/18/10 02:43 PM
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pamusalas Offline OP
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Some quick renders:

Attached Files
tornado_bow.jpg (475 downloads)
tornado_bow_profile.jpg (474 downloads)
Re: extending Tornado's bows [Re: pamusalas] #219857
09/18/10 05:02 PM
09/18/10 05:02 PM
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Eastern NC, USA
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tshan Offline
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There was a guy on here a year or so ago from China (maybe?) that changed the bows on some sized ARC or Supercat - extended and changed them to wave piercing ..... he used to post a lot with A cat, F16 (?) and this metamorphasis project - I seem to remember maybe a storm or catastophic something destroyed or damaged it soon after completion. I'll search around some....


Tom
Re: extending Tornado's bows [Re: tshan] #219864
09/19/10 01:29 AM
09/19/10 01:29 AM
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japan
erice Offline
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japan
this would be my worry too

the forces on the old frp just forward of the beam by the leverage of the new bows would considerable

the major failure mode of long bowed old nacras and supercats seems to be 1 bow failing at the beam while on heavy seas or 2 on trap and flying a hull

i would think you would need 2 or 3 more layers of cloth forward of the beam for strength and possible a bridal foil like 90's nacras

Last edited by erice; 09/19/10 01:31 AM.

eric e
1982 nacra 5.2 - 2158
2009 weta tri - 294
Re: extending Tornado's bows [Re: erice] #225355
12/13/10 09:41 AM
12/13/10 09:41 AM
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pamusalas Offline OP
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I thought about this strenght issue and decided to do some measuring, so distance between bows is about 3cm (1") smaller then distance between centerlines near front beam. This difference is visible then rig is tightened then rig is loos this diference is significantly smaller. So my long bow idea is unusable on these hulls. On the other hand I think that strenghtening hulls would also increase performance. I looked inside my hulls and found that there is no horizontal bulkhead in the front part of the hull is it common in Tornados?
I thout that installing bulkhead would be great performance improovment, has anybody done something like this?

Re: extending Tornado's bows [Re: pamusalas] #225359
12/13/10 10:30 AM
12/13/10 10:30 AM
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sail7seas Offline
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>increase performance. I looked inside my hulls and found that there is no horizontal bulkhead in the front part of the hull is it common in Tornados?<
Common for '1970 ish fiberglass Tornados.

>I thought that installing bulkhead would be great performance improvement, has anybody done something like this?<
That is what developed say 80's fiberglass Tornados. A subdeck and bulkheads were added and obsolesced the older boats, perhaps someone can chime in with the details?

Re: extending Tornado's bows [Re: pamusalas] #225399
12/13/10 08:03 PM
12/13/10 08:03 PM
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South Florida & the Keys
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It would be easier to buy my ARC21 and extend the beams.


Eric Arbogast
ARC 2101
Miami Yacht Club
Re: extending Tornado's bows [Re: arbo06] #225417
12/14/10 06:18 AM
12/14/10 06:18 AM
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japan
erice Offline
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i think the shipping to lithuania would kill the deal...


eric e
1982 nacra 5.2 - 2158
2009 weta tri - 294
Re: extending Tornado's bows [Re: erice] #225421
12/14/10 08:28 AM
12/14/10 08:28 AM
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South Florida & the Keys
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True...


Eric Arbogast
ARC 2101
Miami Yacht Club
Re: extending Tornado's bows [Re: arbo06] #225431
12/14/10 02:43 PM
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pamusalas Offline OP
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Shiping to Lithuania would definately kill the deal, but I don't mind getting my hands dirty.

Few questions keeps me from starting this project.
1. Hulls are made of two halves joined on the centerline. So to install this bulkhead i would have to cut a hole in a foredeck. Has anybody done similar holes? What is the technique used to do it?

2. Where and what size should this bulkhead be?


Re: extending Tornado's bows [Re: pamusalas] #225436
12/14/10 04:50 PM
12/14/10 04:50 PM
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japan
erice Offline
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you will probably get more and better info about cutting into an old tornado on 1 of the tornado specific forums

http://www.tornado-class.org/forum/index.php


eric e
1982 nacra 5.2 - 2158
2009 weta tri - 294
Re: extending Tornado's bows [Re: erice] #225441
12/14/10 05:45 PM
12/14/10 05:45 PM
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Found this from forum above, on widening old T bows.
http://www.aita.asn.au/tornado-info/hull-modifications

Re: extending Tornado's bows [Re: sail7seas] #225454
12/15/10 01:46 AM
12/15/10 01:46 AM
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japan
erice Offline
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japan
perfect!


eric e
1982 nacra 5.2 - 2158
2009 weta tri - 294
Re: extending Tornado's bows [Re: erice] #225480
12/15/10 04:25 PM
12/15/10 04:25 PM
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TurboCat Offline
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I installed bulkheads in my P19 which is very similar to the T. I did the subdeck just like the link above. Went from front tip back to the bulkhead in front of the beam. I used divinycell, west, etc. Turned out nice and its really stiff.

Re: extending Tornado's bows [Re: TurboCat] #225503
12/16/10 06:51 AM
12/16/10 06:51 AM
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pamusalas Offline OP
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Thanks for your help. Turbocat maybe you have some pics of your repair.

Re: extending Tornado's bows [Re: pamusalas] #226055
12/30/10 10:27 AM
12/30/10 10:27 AM
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pamusalas Offline OP
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I was downloading pictures from my camera and found this picture of chainplate inside my catamaran. Has anybody seen anything like this?

Outside the hull the chainplates can be turned around, forstay chainplates (or how are they called in english) ar also moving and leaking. Is there a tested way to fix this?

Attached Files
DSC00120sized.jpg (181 downloads)
Re: extending Tornado's bows [Re: pamusalas] #226058
12/30/10 10:54 AM
12/30/10 10:54 AM
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pamusalas Offline OP
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I thought that maybe somebody of you will be interested in the story of this catamaran.

So, 5 or 6 years ago I was invited to sail in a multihull regata in old wooden tornado. That T was awfull, it was leaking traveler was controled by puting the traveler car in one or another place and sheeting in (and it actualy stayed there) instead of trampoline where there a coton net wich streched then wet so then tacking we crawled in that net with our legs in the water. We managed to finish only once because it was more fight for life or death than racing. All in all I never looked back in the end of same season I bought an old polish fiberglass T. It had no battens, no runing riging, the standing rigging was unsafe to use and so on.
Because of job and other circumstances it took me 3 years to first time sail this boat. During these 3 years we replaced all riging, we have new'er sails and most important thing is that we started sailing this boat.
Till spring (mid april I hope) we should replace rudder blades (one rudder blade snaped then sailing), reinforce hulls, reinforce chainplates and replace inspection hatches.

Attached Files
DSC00086.JPG (174 downloads)
DSC00084.JPG (172 downloads)
Re: extending Tornado's bows [Re: pamusalas] #227172
01/21/11 06:57 AM
01/21/11 06:57 AM
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Posts: 185
Shanghai, China
Dirk Offline
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The old thread is still there...

http://www.catsailor.com/forums/ubbthreads.php?ubb=showflat&Number=92610&page=1

The SC 6.5 is still afloat. It was a fun project and turned an otherwise outdated boat into something more contemporary, which made it more pleasure to sail.


Dirk A-Cat GER 5 F-16 CHN 1 (sold) SC 6.5 CHN 808
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