And the winning design is…

I feel like I am writing this post prematuraly but I feel as if I am going around in circles and that I just need to make a decision. Both the Schionning COSMOS 1750 and the Tennant VEGA are the short list. Everything else has been removed. So is there a big difference between them? The Schionning is a nicer looking boat….NO QUESTION. The VEGA on the other hand has a really special layout, I really like it. Cost wise they will both be within cooee of each other to build so that is not a big differenciator. I like the way SCHIONNING can organise for the bits to be delivered in stages so its not a big hit the first day. On the other hand the up front cost of the plans etc are very different in price, much lower for the Tennant (because its an older design). After sale value…I think the SCHIONNING would be better value. So what to do????

The good thing is that which ever I pick I don’t feel that I will be let down.

(have come back to this thread after two days in draft)

No I can’t make the decision yet. i need more time to find out the true costs of the Tennant Design changes. If you held a gun to my head and said pick, I think I would choose the Tennant…why, only the up front design costs. But I’ll be back.

Mick

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And the Schionning…

When I read the last post back I didn’t realise that i put a spin in there that I was fixed on the VEGA design. The fact is that the VEGA design is the most suitable I have seen but I should also mention the SCHIONNING COSMOS 1750. This is a lovely design that I am still playing with. As I write this I have jsut finished writing to Tony from Tennant Designs and Jeff from Schionning to get a handle of what the changes I am suggesting might cost in terms of redesign costs.

Anyway, the Schionning is cool and here is a couple of sketches with what I am looking to change. Also I have stuck in a perspective view of an aft mast rig to give you a better idea of the rig, regardless of designer.

See you later…

Mick

A lovely sunny day

Well today is a lovely sunny day and that is good, we seem to have started the climb back out of winter towards spring. But Melbourne weather will assert its authority again later this week with 14 and raining. But as we say here…”did you don’t like the weather…wait 10 minutes, it will change!!”

So progress on the boat.

Design wise…I have lots and lots of drafts of lots and lots of varients on a theme. Sound familiar?? There are, as is normal, a number of competing aspects to the design.
So whats settled? The size to a large extent is settled for me. Somewhere between 17~18 meters. I think the cost structures of bearths and the layout will determine the actual length. The width of the hulls are settled. I want to be able to place a full Queen sized bed at 400mm off the hull sole so I’m aiming for a width of 1700mm at 400mm over waterline at the rear bulkhead. The maximum hull width will be 1950mm located near the centreline of the hulls. The bow will be an axe face shape or possibly an 8 degree slope forware from top to bottom. The beam will be 8.5~8.6 Meters. I am not a fan of the long sloping windows i some cats and will change them for windows at about 8 degrees to the vertical. Additionally these will have the salon roof overhanging to provide shade. Another aspect that I am fully behind is the main bed being on the bridgedeck. The actual location is still fluid but we are working on it.

OK, so what are my design problems to be solved/decided.
AS is the way of things a lot of the design aspects are interdependant. A change in one alters many others. Which is the first decision, well due to the interdependancies there is not a first decision, there are scenarios to consider.
So lets start with the mast scenarios. There are basically two that I am considering. The traditional bermuda setup and the aftmast concept being championed by a good bloke called Brian Eiland.
Scenario 1. This can be summerised by Malcolm Tennants Vega design with the traditional bermuda rig. I really, really like it and with a few updates I think it is a winner. Updates would be the bow, the windows adn a change to the rear bedrooms, I would just have one large one with a rear access. And possibly some different deck access arrangements.
Scenario 2 Aft mast config. This makes some significant changes to the Vega. Because of the location of the aftmast base (on the vega close to the middle of the aft bedroom) there will need to be changes to the layout. So what changes? I like the large open front area salon that the vega has so maybe its just a swap of the centre cockpit to the aft location so that the bedroom moves forward to accommadate. When I say just, this is a major change to the structural layout and will mean a full structural redesign. The hulls skin will stay the same shape but the bulkheads will move. Access from the rear cockpit to the front salon is a challenge given the location of the aft bedroom but that is just a layout efficiency problem. Anyway that is secnario two.
Scenario 3 Aft mast config 2. Similar to Scenario 2 but swap the bedroom to the front salon location and vis versa. I have a location sketch of this and although there are problems with this layout it will create a super master bedroom which I beleive is very important both for us living abard AND resale…rememebr its the woman that makes most of the buy choices!!! Anyway thats scenario 3. Just a note on 2 and 3, the cockpit at the back will be a dual level thing. There will be part at the bridgedeck level and there will be part which will be at a similar level to the standard VEGA cockpit level, maybe a little higher. But it will be in the same area as the lower cockpit so communcations will be cool and the skipper will be part of the group.

So they are the big design considerations I am working through. The standard is cheapest, but if I go Aftmast (which I would really like to) it will cost money to get the redesign done.
Credit for VEGA design see here..http://www.tennantdesign.co.nz/index.php?page=vega

The Model: Well the model has started. See the model page. But what design am I going to use, what layout. Well that will evolve as the model evolves. Right now the hulls are common so will be the starting point. Have a look at the model page for an update.

Materials:- This has been an interesting journey. I have learned so much about materials in the last couple of years. Materials and composites. I now realise that you have to be very very careful with checking the date of any article as the technologies in both materials and composites have changed quite a bit. Acceptance of change talkes a very long time which at face value might seem to be a bit stoggy BUT when you dig further there is a very valid point to this. A new material or combination needs at least 10 years of real world application before we can truely understand the good and bad of it. Therefore when going with “new” materials like corecell we are to some extent covering untested ground. Thats not to say that it is wrong….just had limited real life experience. There seems to be two components that stand out in the discussions, below waterline usage and Heat distortion. The below waterline one is very very valid. How does a material/combination react to long term submersion and as importantly is the QA of the workmanship going to jepordise the material through little fault of the material perse. Quality of layup seems to come up time and time again when discussing boat hull faults. So my conclusion is that whatever material is decided that is only half the story, ensuring true quality of the layup is even more important. I wonder if the hull shoe should be treated differnetly when it comes to construction…don’t know, will eb exploring.
Regagrding Hear distortion, this one got me by surprise. A particularly good boat surveyor source focused on this and I was surprised witht he results. A boat hull or deck left out in the sun (and Australia’s got plenty of that) gets up to the mid 200 degrees F. Wow. But I can understand that. I have tried to walk across a hot deck only to do the beach bunny hop to stop the soles of my feet from burning. So this IS an important factor for Australian boats. I was then surprised to see that some of the excellent core products only go to the low 200 degrees F in their Heat distortion ratings…!!! Wow again.
POLYCORE. Current my favourite material for part of the construction….why? no factual reason but it seems to be a very sensible approach. Weight wise it seems to be similar to corecell, so no big advantage there, strengths, somewhat lower than corecell. Resin soak, seems about the same?? So right now I am trying to compare Polycore (or any equivlent) to Corecell (or any equivelent). Boy is that hard to do. Try to get some small samples of either and a sales prson who actually knows both well. Its very hard to do and I am struggling. But I will persist. Regarding Polycore, I have the name of a guy who is building a polycore boat about 5 hours drive from me here. I am goign to try to get over to have a good look at the stufff. i really dont understand enough about it to decide what is best. Mark from Compositepanelsaustralia has been very good to be and has chatted about things freely. I like that.

AFT MAST. Oh boy has this been fun. First of all big cudos to Brian Eiland who is a good bloke. He has been very much a champion of this and freely discusses with anyone who wants to hear. I have created a discussion document that I will upload discussing aftmast configs. I am trying to mimic luffing jib construction cranes with fling jibs. Thi sis along way from being settled. The ONLY thing that is stopping me from deciding today to go AFTMAST is cost. Two components…the cost of the redesign of the VEGA design and the cost of the loss I will make due to lower resale value because of the “unusual” mast configuration. But I want to take the chance if I can afford to. Regardless I want to help develop this concept with Brian.

MONEY:- I still dont have the money to complete the project, but I am going to start anyway…if I dont its guarnteed not to finish but if I do start it has a change…

So there you have the latest gossip on the boat. Talk soon.

Mick

The design continues…

Hello all again…

As you know I have been developing the Malcolm Tennant VEGA design using the information available on the web site. I bought the study plans but disappointingly they still have not arrived. I’ve been told that they were posted so still waiting. One of the issues I have been trying to design around is keeping the main bedroom on the main level and having lots of room there. The VEGA gave me this at the back which is one of the reasons I really like it. One of the main constraints in cat design is the point at which the mast is supported. The forward bulkhead which takes the main load becomes “untouchable” and is a main layout constraint. So I have focused on the alternate mast designs which then changes the design constraints. Two that have interested me were the non-stayed double carbon masts (see Schiolling Radical Bay setup) and the Aftmast arrangement.

The Aftmast I must say is the one that catches my eye most. There is a discussion paper here.
The key things that attracted me is that it removes the forward bulkhead constraint and creates the possibility of a forward main bedroom. Additionally it adds a simplier control rigging and I like that. I have redrawn an accommodation layout based on an aftmast.

I have started to look for Australian based designers around this concept and have chatted to Jeff Schiolling and his COSMOS 1750 could be altered to suit this need. We are just in the beginning of looking at that….still very early days.

So that is where the design work is up to.

The model is started and I will post some progress photos on that.

Needs analysis

The nice to have analysis

All designs require a needs analysis adn here is mine. Should not be called a needs analysis more like a nice to have analysis…but here goes…
I added a usage analysis jsut to try to develop some reletive priorities. Yes I know that we could drive a truck through the gaps in this but its something for me to work with.
Also not that I have really focused ont eh accommadation side. The rigging etc will take care of itself when I talk to a designer.
Mick