Anonymous wrote:

Howard, 

bi plane trimaran!  Have you been smoking herbal cigarettes?  Can’t think why such weird  concepts should be aired on the website!!

....but seriously, it might work, but not many trimarans would suit it.  What the effect of the large separation would have on the balance is intriguing 

 Mark:

    I don't use mind altering substances of any kind... used to use alcohol in moderation but I don't even do that anymore   ;-)    I just like to toy with outside the box ideas...  Speculation is harmless I think.    What good are ideas and "weird" concepts if they are not aired / shared?

     I keep forgetting that the JRA is a den of conventional thinkers ;-)

Seriously, the Tristar series is probably better suited for this kind of thing than most trimarans.   If you take a look at the structure.   It is fully decked all the way to the gunnels.  The interior wing deck contains berths and extends all the way out also with a substantial structural bulkhead at both the head and foot of the wing berths.  Note that you can see the forward bulkhead in the photo below, the aft one is the aft end of the cabin.  The bury potential in the amas is greater than most trimarans due to this full wing,  the logical mast location would be just forward of this bulkhead, and a bit of "creative engineering" could result in a very strong mast step and partner relative to the mast height and loading.

     The advantages of the biplane are fairly obvious in this case where a large mast trunk would block access forward.... Not to mention having the entire deck clear during trade wind sailing wing and wong.  The Tristar has a beautiful full unobstructed deck except for the mast.

      Arne's comments about handling sails "way out there" is no different than on a biplane catamaran.... with the full deck and width, nor is "catching things" a valid observation IMHO.  With a biplane rig you can fly just a single sail over the deck depending on the tack if that is a concern. It really differs from a biplane cat ONLY in the fact that you get a little more heel.  

     Later note:   The fact that there are two masts, one in each ama, counteracts any concerns about putting the mast weight out on the ama... the opposite mast balances it out so that it is carried on the main hull effectively.  I see few obstacles in this particular case at least... other than thinking mired deeply in convention.

      I have to confess that every time I see a tristar and think about a junk rig on it, my thoughts go in that direction.  I'm not known for doing conventional things or thinking conventional thoughts.... I have a bit of a "mad scientist" reputation.... deserved.... and my home and shop are full of different and innovative solutions.  

                                                      H.W.

Howard, 

bi plane trimaran!  Have you been smoking herbal cigarettes?  Can’t think why such weird  concepts should be aired on the website!!

....but seriously, it might work, but not many trimarans would suit it.  What the effect of the large separation would have on the balance is intriguing 

The narrow accommodations on a trimaran would likely result in the mast being in a bad place as you would naturally want it next to a major bulkhead for lateral support.   That bulkhead would be the one between the saloon and the heads compartment putting it right in the middle of a doorway forward.   I looked at this on the Searunner 31 a few years ago, and determined that the mast (at Arne's suggestion) should be offset to one side enough to provide access.  

The Tristar 24 has only about 30M of sail area... I wonder how a biplane rig would work out on a trimaran like this.  Masts could be kept fairly light weight due to small sail area, lower air draft, perhaps even using readily available carbon fiber masts for the upper sections.  The downward pressure on the amas when heeling would probably be less than  with a single taller mast, making ama displacement a non issue in that respect.  Imagine having that big beautiful deck completely or mostly clear of sails and rigging much of the time.

    I've never seen or heard of a biplane trimaran.... Conventional thinking would be that since nobody's done it, it's a bad idea, but in my experience that is not necessarily the case.  

                                     H.W.

Mark wrote:

To keep more cash for the conversion, if anyone could help out with accommodation close to Emsworth (if I need an early train)  or another close by train station, that would be appreciated.  I also will have to get a pilot book and back up paper charts, which I am unlike to use again, but photo copies would suffice if anyone could help out.

You can have my old copy of the Lundy and Irish Sea Pilot, by David Taylor, (1994), borrow such of the Martin Lawrence pilots for Scottish waters as you need; and borrow such paper charts as I have (but with iSailor chart app on an iPad for reliable navigation, I can't remember when I last looked at them).

What a fantastic project Mark.

At 1st glance it looks like the new JR stick may be right in the crapper. :-)

Yellow is either a popular livery for these boats or this might be the one you bought.

Tristar 24 on Yachtsnet

As others have said this is going to be a great project to follow.

I wish you fun and good fortune.