stevenson project

[windbreaker]

Does anyone have any experience with the stevenson boats (american)? they are a very cheap way to get into boating. A 24' vacationer' can apparently be built for just a few thousand dollars. Has anyone done so? and if so what are they like to sail? are they more like a skiff or a keel boat? Any feedback, favourable or not will be welcomed.

[Boatmik]

Howdy,

Generally there are two ways of getting "cheap".

1/ The expensive way - is to use cheap materials - the boat ends up having poor resale and if you hold onto it the maintenance problems build up - if not structural problems.

Cheap materials can be OK if you don't expect the boat to hang around for a long time - so can be fun for something quick and dirty.

2/ The smart way - it is possible to design and build smaller boats these days with very little solid timber framing. The solid timber is just used to hold the ply together and there is little or no conventional framing.

I had a quick look on the net and Stevenson's boats do head down this route.

But the cost to build a 24ft boat is the cost to build a 24 ft boat - Clever design can get the building cost down 10 or 15% - for the hull - it won't make a boat half price over a sensible competitor!

But Stevenson's rigs (sails masts fittings) are pretty conventional - which means relatively expensive. The things that keep rigs cheap are free standing masts and no jibs/headsails.

On the other side a poorly designed boat (most free or cheap plans) can cost much more than its competitors.

Also you have to look at the quality of the plans relative to your experience. If you don't know a lot about boatbuilding yet - then detailed plans with step by step directions are worth every cent.

Also if you are new to sailing it can be worth building something smaller rather than going straight to a 24 footer if you are not sure whether you will like the boating thing. If you have sailed a bit and want to go for a 24 footer - go for it!

But it won't be just a couple of thousand dollars to get a largish boat like this on the water.

Best wishes
MIK

[Boatmik]

Just found some pics of a vacationer owned by the wonderful Andrew Linn - he picked it up really cheap - I think for a couple of hundred dollars and fixed it up.

http://andrewlinn.com/061021john/kohnen_photos_start.htm

The first thing that stands out is that the transom of the boat is draggng badly - and this is with only one person in the cockpit.

Having the back of the boat underwater like this causes a huge amount of drag and most designers go to great length to make sure it doesn't happen. This boat is going to be way out of trim by the time there is a second person in the cockpit.

Maybe that's why the boat isn't moving in the pictures even though the sails are full of wind. There is not enough wind to really get a boat going but there should be signs of life.

Maybe there was a problem with this particular boat.
______________________________

More added 10 minutes after -

Just found another picture attached below - the boat has little or no rocker - curve on the bottom that makes sure the bow and stern are above the water surface - fore and aft curve. Little or no rocker means the boat will have very poor performance - like I said any experienced designer knows that is the FIRST thing you design into a boat once you have worked out its approximate sailing weight.

The only exceptions would be canoes (which still need a little) some multihulls with canoe sterns (though you need some so the bot will turn ok) and planing powerboats whose bows will stick too high up in the air if there is too much rocker aft.

But all other sailboats - actually boats in general - need the correct amount of rocker to perform correctly. This boat would be sailing at double (triple) the speed in the Andrew Linn photos if it had the correct bottom rocker.

Michael

[bitingmidge]

A 24' vacationer' can apparently be built for just a few thousand dollars.

To be a little less polite than Mik: no it can't! Not in Oz anyway.

The PDRacer can be built for a thousand dollars using new materials - just, and it's an open 8' dinghy built with minimum materials. A typical 24 footer would have roughly 10 times the bult volume, and all the pieces will have to be scaled up because of the increased structural requirements.

Admittedly the 24' Vacationer is only 21' plus bow sprit, and it's a small volume 24 footer at that, which will give you some cost advantage, but it can't be built for just a few thousand dollars! :D

The trailer alone will cost you that! Of course if you are good at scrounging you'll get away with a lot less, but do the exercise first.

Why not get a hold of some study plans, and price the materials and fittings, then double that to allow for painting, disposables, tools and finishing.. at least you'll have a reasonable estimate of the project cost then.

I suppose it depends on whether to you a "few thousand dollars" is three or twelve, but I can't add anything else to Mik's posts above. They are both spot-on.

Cheers,

P:D

[Wild Dingo]

ahem... Im gonna stick me noggin in here as is my wont from time to time :;

First... the weekender may be a better first option rather than the vacationer... its similar designed and put together the same way just smaller. Check their site

Second the rocker that Mik talks about is inbuilt in the keel itself which is cut on a long taper the bottom ply is screwed and glued down onto the keel thus forcing the rocker into the bum.

third... from every report Ive read on these designs from those with them and those who have sold them they are good wee boats... not for long cruises but as the yanks call it gunkholing or coastal cruising in shallow protected waters... they have a forum at here (http://www.messing-about.com/forum/viewforum.php?f=1&sid=232aa39cfa0106e65e66606605c1f952) in which all facets related to this design are discussed and debated

There are some who have actually put a lead show on the keel to similate the keel on a "normal" sailboat while originally the weekender (first designed) had a centreboard it was subsequently deleted since very few people found them necessary.

Fourth... cheep? CHEEP?? We are talking about a bloody boat here mate it IS NOT going to be cheep... well then again cheep is rather ambiguous isnt it? Anyway Mike Stevenson states that they can be built with top shelf marine ply and all the fruit or it can be and seems mostly to be built using construction ply and cheeper materials... some have been built without epoxy and glass at all just put together and silicone of one type or another used with the aid of screws... the sails can be made with blue poly tarp and the plans include drawings and measurements for just that or by buying some sailcloth and making your own... the useful bits and bobs such as the wheel the blocks and the mast hoops the plans offer drawings and measurements of... cheep if you live and build it in the states yes but here where our ply and other gear is often up to three times as expensive to get no Id not say cheep but then comparitively to say Iain Outreds Grey Seal its very cheep!! :2tsup:

So in light of what Mik and Midgey both say I will add this... the plans are cheep $30US add a couple more and you get a video which I believe is unnecessary... so the plans themselves are cheep... depending on what you decide to buy decides how the plans arrive

1) Weekender plans come in a book type folder A4 size that give you EVERY concievable dimension for every part of the boat it also includes your build number and a log

2) Vacationer and Pilot boat come in 5 and 4 large sheets folded and printed on both sides a rather cheeper option in my view and not as good an idea as the Weekender method.

The pilot boat I think is actually the better option since it is doable as either sail boat or power boat and both look smart... like all these sorts of boats flat bottomed skiff types there will be some pounding into waves... but for all the seeming wrongs with the design there are and continue to be many many of these built around the world... mainly as one would expect in the States but also in NZ Aus England and other places... very popular.

Now weather that is simply due to the cheep cost of the plans or other reasons I dont know... what I do know is that the plans for all three are very detailed and with the forum and email to Mike himself you are never far from contact with either the designer or others building them.

OH... and my personal opinion of Mike Stevenson is that hes a bloody good bloke when we bought the plans of all three we received them less than a week before the flood which took the plans with it... I emailed Mike and within 2 weeks he had sent me a replacement set of all three... no other desinger or company museum or other that I had bought plans from did that or even offered a discount on another set to replace them (except Woodenboat who offered me a $5 discount on replacement ones)... with Mike it was simply "sorry to hear that Shane new set on the way" and they were

Anyways... tis a small ply boat its a simple boat that goes together easily... but dont expect it to be a sailboat like a Grey Seal cause its not and doesnt attest to be... its cost will be commiserate with how much you want to spend on it... the time it takes to build will be commisserate with how much effort and time you give to it... the details depend on you.

Cheers
Shane

[Daddles]

Oh bugger off ya bloody wombat ... yer supposed to be a mad dingo, not spreading good advice :D (dammit, I'm about to agree with the silly bastard again ... does that make me a silly bastard too? :oo:)

The Weekender fitted right into my own requirements for a boat and hence was closely looked at during the interminable months I spent researching this sort of thing. The question was solved by the premature purchase of Sixpence :wink: But I'm happy.

I'm not going to disagree with anything said above. None of it flies in the face of what I've read and I spent over three years on the Weekender Forum which is very active and passionate and full of good advice.

The Weekender and, I'm sure, the Vacationer, are very good boats for what they claim to be, and that is 'competent sailing vessels for amateur boat builders who want to have fun mucking about in boats'. There are far better boats out there ... but anyone who describes them as incompetent as a sailer has suffered a bad example of the class. They go together really well and those who love them are very passionate. The piratical looks help too :oo:

But, as Mik has alluded to, they are compromised as a sailing vessel, but not excessively so (according to those that love them).

The thing that turned me away from them was the size of the cabin ... or lack thereof. It's suitable for pygmies with a height problem and no fear of claustrophobia. Okay, I'm being mean, but it's intended to be a bit of shelter, NOT a cabin.

Should you build a Weekender or Vacationer?
Yes, but only if you have done a looooottttttt of research, looked at a looooottttttt of plans and just keep coming back to the damned things. They aren't the greatest, but as I said before, those that love them are passionate, which suggests to me they do some things very nicely thank you very much.

Richard

[Wild Dingo]

DAMN!! yer gotta love that!! :2tsup:

Actually after I wrote that post above I raced out through the rain to the shed where I have put all things boat so they dont get muddled up with her gear or the hoons :roll: and bought them inside to have another look at

As I said earlier have a close look at the Pilot boat... it has that chubby roomy Catboat look about it and is somewhat shorter in length but is a good looking boat either way you decide to go... as a cruiser or sailboat... and from the materials list would be the cheeper option of the three if thats a main consideration.

The plans are the same price but dont come in the folder like the Weekenders do but rather in two large double sided sheets (sorry I got the number of sheets wrong in the first post its 2 for the PB and 3 for the Vacationer) but when unfolded they come to 16 x A4 pages per sheet thus 32 pages of information pictures and diagrams of the complete boat even down to the shelf in the cabin :2tsup: and 48 pages for the Vacationer and an extra A4 page with the materials list the weekender ends up being 45 A4 pages

In some ways when comparing with other designs Ive bought these are far more complete for an amature home builder the only other designs Ive seen that are as full and complete are as I said earlier Iain Oughtreds Grey Seal and Al Masons Oskust design both directly aimed at the home builder one from recent years and the other from the 1930s... none of the more recent designs Ive seen have been as comprehensive and detailed some do come close but most dont... mind you this is the same for many of the old time boat designs as well so nothing unusual or exceptional about it... just as a note for Mik and Midge on the level of detail contained in the plans.

For a "cheep" set of plans they are worth somewhat more than what you pay for them and if you build one then worth a damned sight more... and given the amount of help available through the forum that I linked to above and Mike still breathing (something that really does help at times!) and accessable by email phone or mail something of real importance if you find a question or two that confounds you... hint the first one will have something to do with the keel :;

Now I can hear the resounding question banging and clanging its way around the collective minds of those reading this... that being "So? Why havent you built one then Shane if theyre so good?" Well to answer that question honestly I have made several attempts since I recieved the second set and have actually had the keel and stem made for some months along with the wheel and some other bits... just the same as Ive had the keel and tiller for Atkin's Valgerda for many months and 2 sets of canoe moulds and backbones ready in the seatainer and cause of that I wont mention all the bits and bobs for a 1930s houseboat :o ... Other things get in the flamin way!! generally but not restricted to work family other projects available finance and other factors called... life? Probably why daddleydaddles is still muckin about with his boat instead of havin it finished and having fun... life gets in the way :~

So... I would suggest 1) really go over the Stevensons site... 2) go to the forum and lurk for awhile read back through the posts and 3) Ask questions!!

Actually if you do REALLY go over the Stevensons (http://www.stevproj.com/) site check out the free wee "Sportfoil" plans down the bottom of THIS (http://www.stevproj.com/Planlets.html) page its something Ive been thinking of getting Midgey to make... Personally I reckon it would be an absolute hoot!!... also on that page you will find extra plans for different things for the weekender like the salty looking deadeys and the cockpit drain but theres also a sewing centre that your missus shouldnt see... mine did and it cost me an arm and a leg to alter her thoughts of me making one (I ended up having to buy her a wang dang doodle of a sewing machine that wouldnt fit the thing in a chinese fit! I gots enough on me plate without adding a sodding sewing centre to it) but the site is a wealth of information.

With the forum... you will find some people get rather anul about the "fruit" of their boats one bloke from if I remember rightly Ireland went totally spaz with his wheel and did some gaelic knots instead of the usual rings!! beautifull so theres a heck of a lot of info there.

Anyways... for the price Id say buy them even if you just get an idea or two but dont build it you could change the plans and just make a skiff from what it will give you... but whatever enjoy it.

Cheers again!
Moi the legendary dingo wombat of the west :U

[Boatmik]

Howdy,

So we all agree that it will be more expensive.

But the question that just keeps coming into my mind is why he didn't get the bottom rocker right.

Like it sounds like the boats have a lot going for them - good construction - detailed and accurate plans - even a nice bloke as the designer - but why compromise on the sailing performance?

It probably only means another 3 inches of rocker in the bottom and the boats will sail at three times the speed in light winds (under 5 knots) and 50% faster in 5 to 10 knots of breeze - particulary upwind.

It is so easy to get right.

Dingo, perhaps you had better send me part of the plans to have a look at as you offered - maybe I've got it wrong and Andrew Linn's boat was built wrong or something. If there is a lines plan that would be interesting to see. But it looks like such a basic mistake with huge repercussions that don't need to be there.

Like selling a car with only three wheels. Send em to me and I'll have a look and see if I'm wrong.

So you can all know for the moment that I'm not sure about what I'm saying - at least as far as this boat goes. I know that I'm right about the performance aspects of having so much of the transom and bow dragging in the water - but maybe there is more than meets the eye in the photos I've been able to find.

Best wishes
MIK

[Wild Dingo]

Mik... you have mail :2tsup: and a pm to apologize :B read the pm FIRST!!

[Boatmik]

Howdy Dingo,

I got the pm fine but the big email didn't arrive - I think my mailbox is too small.

you could send it to [email protected]

Don't send anything else to that email address - all other correspondence needs to go to
[email protected]

Cheers man
MIK

[Wild Dingo]

Yep just got the rejection slip mate... will try the yahoo one... if that doesnt:2tsup: work maybe scan and send a few pages at a time eh?

[Boatmik]

No probs - I really only need the body plan or lines plan - the Plan view is most useful as well as a side view. I can scale.

Probably don't need most of the instructions.

Sailplan and interior layout too will allow me to see if a centreboard is useful/responsible.

MIK

[Wild Dingo]

:2tsup: I think we have a landing Mik... well no rejection slips yet anyways so thats gotta be good right! :2tsup:

Im actually VERY curious as to your thoughts and views mate... as I said from my contact with Mike Stevenson they initially did design it with a centreboard but he says that a lot of builders found that it was unnecessary... as to weather or not thats a reflection on the boats abilities or the sailors abilities Id not say... but sufficed to say they revised the plans and left it out... and in their reworking of the plans for the Vacationer they left it out altogether... that being said the plans of the Pilot Boat I have show an offset bilge board so although that boat is but 15ft LOA apparently it needs one... dont know if that makes some sort of comparision difference or not but seems curious to me that they leave it off the Weekender and the Vacationer but put a bilge board on the other... just strange is all... Ive also read that some other builders have made lead keels and attached them but have yet to find a result thread or site that gives a reasoned view of if it actually improved the boats performance or not.

So if you can post or email your findings or thoughts to let me know Id appreciate it :2tsup:
Cheers

[Boatmik]

Howdy Dingo,

The Weekender plan got through this time and I downloaded it all via broadband at the place I am staying and drew up the bottom part of the hull on my program ...

For the transom to just touch the water the curve of the bottom of the hull will displace around 404lbs.

Ideally with boat design this should be equal to the weight of hull, rig, ballast, masts, sails, rigging, outboard and crew - plus any other payload.

So its WAAAAAY under what it needs to be for the boat to sail well and explains that deeply immersed transom in Andrew Linn's photos.

I'll work out what it needs to be if you can find a reasonably accurate all up weight for the boat.

With the revised bottom it will sail like a witch - compared to the standard version. Or at least a lot better.

Most of the improvement will be upwind and on all points in all light and medium weather sailing - ie Average conditions.

I would also suggest a centreboard or offcentreboard - that keel won't work too well when there is a chop and ground to cover upwind. I'll work out where to put it so it doesn't intrude - probably off centre. I reckon put up with the standard upwind performance when the water is a bit thin, but where it is deep whack in the board to give some real bite and performance upwind.

If you don't get three or four times the speed shown in Andrew Linn's pictures for the same windspeed (ie light winds) then I'm no boat designer.

At a heel angle of 0.000 deg
Pitch angle is 0.000 deg
Volume displaced is 6.310 cu ft
Displacement is 404.229 lb
Righting moment is 70.478 lb ft per deg.
Mass per unit immersion 2602.774 lb/ft
Moment to change trim (MCT) 13.252 lb ft per inch

The other slightly worrying thing is the centre of buoyancy is right in the centre of the boat.

X-centre of mass (LCG) 7.634 ft
- distance forward of midships -2.112e-02 ft
Centre of buoyancy (LCB) 50.196 %
- at 7.634 ft
- distance forward of midships -2.112e-02 ft
Centre of flotation (LCF) 50.906 %
- at 7.711 ft

In little boats like this the biggest concentration of weight is the crew - so the centre of buoyancy should be more towards the back of the boat. Thats why a lot of Bolgers smaller box boats have straight lines in the front third then flatten out for the second third and finally curve up to the transom with a rush at the back end of the boat - making the bum end the one with all the bottom curvature.

But yep, I can fix this too - or at least move into a more correct position - to find the absolutely correct position requires an extensive weight edit of every part in the boat.

You'll have to redraft the depths and widths of all the frames - but the depth above the water and the deck width will be unchanged - but I can work most of that out for you with a little bit of follow up measuring once the bottom is attached to the curve of the keel.

Have a bit of a check through and see what else might be changed by redrafting the rocker.

The only downside of all these changes is that you will end up with slightly more draft As the hull is deeper - the keel has to be made deeper too to keep the correct lateral plane.

Michael Storer

[Boatmik]

Howdy Dingo (again!)

BTW there is a bit of work involved in working it all out - so please don't let me do it if you change your mind! If something serious intervenes when you really think that you are going to do it - no probs - after all I love you like a brother.

But if you aren't going to do it then don't let me go ahead.

MIK
hehehehehehehehe

[RossM]

Slightly off topic & not wood, BUT...

Why not a concrete submarine yacht!! :oo:

http://imulead.com/tolimared/concretesubmarine/image/ax-crane.jpg

http://imulead.com/tolimared/concretesubmarine/

:U Couldnt resist - it was jumping out of the forum Dingo posted earlier!

[Wild Dingo]

Howdy Dingo (again!)

BTW there is a bit of work involved in working it all out - so please don't let me do it if you change your mind! If something serious intervenes when you really think that you are going to do it - no probs - after all I love you like a brother.

But if you aren't going to do it then don't let me go ahead.

MIK
hehehehehehehehe

:U :U Gawd mate Im glad you laughed at the end of that!! had me worried for a bit you did :C
All this is only going to really change a) the performance and b) the draft?... if the performance changes make for a better sailing performing boat then go ahead... if the draft is but a few inches then go ahead hell it could be increased a foot and compared to other boats of a similar nature it wouldnt be too deep... as long as it retains the trailerability and better sail performance then I say go for broke!!

Of course this will mean I have to toss the keel Ive made up... sigh... BUT on the good side no worries I can use it elsewhere!! and thats a good thing cause so far its simply been driving me knuts :roll: a few boxes a nice sideboard its all good

Cheers
and Im glad they got through... so aside from all that above the plans package isnt to bad is it! very thorough in the details and explainations... and the deadeyes make it soooo salty it gives you sunburn :U

[Boatmik]

Howdy Dingo,

The changes will increase the draft probably around the 3 to 4" mark - it won't be that much.

But don't scrap the keel - the extra depth can just be laminated on the bottom. and the curve recut.

The bottom panel will need to be rejigged slightly in length to make everything work.

Consider replacing the wheel with a tiller so you can move more forward in the boat when steering - that will also help get the weight out of the back.

We are talking a lot of performance here!

But I need some information about a realistic weight for the beestie - can you plunge into their forum and see what you can find out. I'd rather work with real data rather than something like the following estimate I just worked out.

The ply sheets come to around 300 lbs so I would guestimate
ply - 250
timber, glass, glue - 250
rig - 60 and sails
fittings and bits and pieces - 80
So around 640lbs.

This could EASILY be out by 20% either way.

starts to make the displacement of the original design 404lbs look pretty sick particularly when there is another 350 lbs of crew for an all up sailing weight around 990 lbs.

Does the boat have ballast? That would be extra.

But an actual trailer weight would be great to get.

MIK

[Wild Dingo]

Rightio... thought Id already done this last night but seems Im having some issues with the forum software... (server too busy at 2am??? get a grip... but then I seem to be unable to get on at all for at least several periods a day with the data error page coming up)

Anyway...

1) No ballast

2) Weight of boat dry as designed with rig 600 - 700lbs

3) include trailer 1000 - 1500lbs depending on trailer make style and whatever else influenced them at the time

Re Ballast... Some have made a lead shoe to fit over the keel of up to 250lbs or in one blokes case a lead bulb of roughly the same weight... others have made a box and installed it inside the cabin and this gets lead bags of anywhere between 160 - 250lbs some like it that way rather than fixed so that it could be moved with trim but thats more rare from my reading most make it fixed

Tiller... not an issue I have both a wheel and a tiller the wheel can easily be made into a sexywexy clock and the tiller can be reshaped to fit easily.
Cheers

[Boatmik]

2) Weight of boat dry as designed with rig 600 - 700lbs

I'm not bad am I - estimated 640lbs above!!!


Re Ballast... Some have made a lead shoe to fit over the keel of up to 250lbs or in one blokes case a lead bulb of roughly the same weight... others have made a box and installed it inside the cabin and this gets lead bags of anywhere between 160 - 250lbs some like it that way rather than fixed so that it could be moved with trim but thats more rare from my reading most make it fixed

Do you want to do that? I'd have to add it to the rocker - and it would make the boat more seaworthy.


Tiller... not an issue I have both a wheel and a tiller the wheel can easily be made into a sexywexy clock and the tiller can be reshaped to fit easily.
Cheers

What about making the wheel into a hat?

MIK

[Boatmik]

ACtually Ding, you blessed canine ...

Have a think about the ballast. It will make the boat a bit more laborious to get up on the trailer etc.

But it would add to the safety factor - do these boats ever go over? How easy are they to get back up again?

MIK

[Wild Dingo]

ACtually Ding, you blessed canine ...

Have a think about the ballast. It will make the boat a bit more laborious to get up on the trailer etc.

But it would add to the safety factor - do these boats ever go over? How easy are they to get back up again?

MIK

aaaahh the question no one wants to admit to!... Given the constant references that they "are tippy" and "would go over" "have no floatation" hat have come up on the forum over there over the years... although Im yet to see someone say directly "my weekender turned into a turtle today" :doh: Id say mmmm yeah! :roll: Easy to get back up? probably maybe along the lines of a small cat? although probably more difficult due to lack of floatation ergo rather full of the liquid stuff!! :o

Although Id say people would stand on the keel and with halyard in hand walk up the hull as they pull the masthead up... of course this entails some superhuman effort on said keel/hull walker but doable Id think... more so if theres a couple of bods.

Id rather the lead if you can mate... safety bein me middle name and all :q and internal flotation if possible would be good Im thinking... now about that transom end of things... now Im the kinda bloke that likes some nice curves on the bum you know? so Im wondering how difficult hard it would be to turn the transom into a nice upsweeping round stern?

Longer doesnt matter a hell of a lot to me as I will be using the underbody from an old 24ft caravan (with a few mods as needed) for the trailer anyways so if it stretched out a tad thats okay but that transom just doesnt look right to my luggerish mind :no: so a nice upsweeping curved bum... now lets look at that stem... mate what about we bring that out and straight up like say... well like a luggar you know?

oooh Im bad man Im bad as!!... can you see what Im doin here huh can yer?? I WILL GET MY MINI LUGGAR!! :U

A wheel hat?? mmmm Im thinkin here... may have to make some wee modifications I think... but well doable!! Talk about makin that Capn Sparrow (Pirates of the Carribian) look a right woos!! :U

[STEPHEN MILLER]

Looking at the pics of the boat Mik cant see that its 24' long even with the bow sprit.
The rig on that particular boat would not be that expensive with its set up looking at it all galv turnbucles shakles etc poly rope for the stays so it would not be to expensive to use that type of rig
As for dragging its transom in the water looking at the pictures that appears to be the design .By the way our boats transom sits in the water it does not effect its performance [as Daddles has been sailing in her, he can confirm this]as this is its design its sister boat at Port Adelaide Sailing club same design of hull just built in aluminium wins most of the races at that club every year so if its designed correctly wheres the problem. As for no stays etc the rig on Charlie Fisher is unstayed but is an expesive sentup because of the aly masts and type there of.
So what have you got against BERMUDA rigs apart from the cost:D

[STEPHEN MILLER]

Better the a sub just re attach wings and there youy go

[Boatmik]

Looking at the pics of the boat Mik cant see that its 24' long even with the bow sprit.
The rig on that particular boat would not be that expensive with its set up looking at it all galv turnbucles shakles etc poly rope for the stays so it would not be to expensive to use that type of rig

Compared to what I guess. I've done the maths too many times working out the prices of jibbed boats - there is a lot more hardware required compared to something that doesn't carry a jib.

I agree - choose the level of technology you want and set up the rig that way. If you want to go for polytarp sails any rig - both the freestanding rig and the bermudan sloop will both become cheaper.


As for dragging its transom in the water looking at the pictures that appears to be the design .By the way our boats transom sits in the water it does not effect its performance [as Daddles has been sailing in her, he can confirm this]as this is its design its sister boat at Port Adelaide Sailing club same design of hull just built in aluminium wins most of the races at that club every year so if its designed correctly wheres the problem. Sorry, you are against the whole knowledgebase of boat design. Go ask any reputable designer on the planet. The lower the power and the lower the speed the bigger the difference.

The the depth and the width of the transom both make a lot of difference - if the transom is immersed the shallower and narrower it is the better. Maybe your boat doesn't have much immersed transom in both width and depth. A hint - in light winds move the crew forward so the transom is out - you will go faster.

If I was drawing up a sailing or rowing boat and had to accept some degree of transom immersion to get the displacement and other numbers that I wanted I would try to keep the difference between the displacement where the transom is just touching the surface and the designed immersion down to 10% of displacement. This is just a number I'm picking out of the air because I know the less there is - the better it is.

The weekender has a difference of 100% between these two figures. Even more if we are talking about ballast.

Immersed transom increases drag at low and medium speeds
Basically if the transom is immersed there will be a swirl or turbulence trailing behind the boat. It takes energy to create that turbulence. The boat can only generate a certain amount of power from engine or sails. Lose some in turbulence and it is energy that could be used to propel the boat.

Look over the back of your boat sometime - get rid of the swirls by getting the transom above the water and there is more energy for driving the boat.

The effect is immediate and obvious with smaller racing dinghies. Drag the transom and you get passed - move a bit further forward and you match speed. Instantaneous and obvious - same displacement - same waterline length - same sail area.

Immersed Transom reduces nett drag at higher speeds
Interestingly it changes a bit when the boat gets up to planing speed. An immersed transom reduces drag by increasing the lifting force on the hull. Theres a lot I could say here about the pressure distribution along the hull and how the breakaway increases the vertical lifting force acting directly on the hull but it would take too long.

Oh - b*****r it! Here goes...

At the front and back of the disturbance around the boat the water has to be at the same level. At the front the water is being pushed down and out. The two sides push out in equal amounts so those effects cancel. The water being pushed down under the boat has an equal and opposite force that pushes the boat upwards reducing its displacement. ie the boat's bottom will experience a positive pressure above the non moving state.

At the back the energy is reversed - the water moves back up to the surface level - to make this happen the forces operate in the opposite sense - so the back end of the boat is pulled down into the water. Negative pressures.

If the transom corner is out of the water these positive and negative forces are, as near as spit, equal. There are some losses but they are minor - I can explain most of them as well if you like.

But if the transom is in the water and the boat is going fast enough for the water to break smoothly away from the transom and continue the hollow the boat is travelling in a few metres behind the boat then a lot of that negative pressure is not pulling the boat down any more. So you end up with more force pushing the boat upwards than pulling it down.

So rowboats and small sailing dinghies have transoms at or slightly above the surface and if they are immersed pains are taken to keep the transom narrow and/or shallowly immersed.

AND planing powerboats - which are godawful to row or sail because of their wide deeply immersed transoms - look at all those swirls at subplaning speeds are very efficient at planing speeds.

These things happen for a reason - so we design boats different ways for different speed regimes.

Summary regarding transom drag
The amount of immersed transom has to be carefully calculated for different speed regimes.

Most "normal" sailboats spend most of their time at speeds less than hullspeed so it is worth their while to have little or no immersed transom or if immersed it is shallow and narrow.

As sailing vessels get faster - cats and 18ft skiffs - the rules are changed. They are optimised toward speeds higher than hullspeed and they get around the excessive transom drag at lower speeds by having both narrow transoms (compare 18s of the early 70s with their big wide sterns to the modern ones and the difference is obvious) and relying on moving the crew a long way forward in the light stuff to sink the bows and get the bum out.

Some higher speed ocean multis and monos can use water ballast to get the weight forward but with the increased sophistication of weather routing extensive computer modelling is done to get the degree of immersion optimum for the mix of speeds expected.

Boats that operate almost purely in planing regimes have well immersed transoms in terms of both depth and width.

Rig costs - apples with apples

As for no stays etc the rig on Charlie Fisher is unstayed but is an expesive sentup because of the aly masts and type there of.
So what have you got against BERMUDA rigs apart from the cost:DThe Charlie Fisher (norwalk Island sharpie) setup is at the high end of both cost and sophistication for unstayed rigs. You may also note that I don't specify alloy spars on any of my own designs for this reason.

Don't put me in the position of defending a particular boat - I have nothing to do with them these days - the last bit of work was to design the yawl and ketch rigs for the little cat rigged NIS18.

But if you do the quote to compare a sloop rig with a similar level of equipment the unstayed rig is so much cheaper it is a joke.

If both have wooden spars - it is cheaper.
If both have untapered alloy spars - it is cheaper
If both have tapered alloy spars - it is cheaper
If both have carbon spars - it is cheaper.

But only for similar levels of equipment. If you are talking about a sloop with galv turnbuckles, well, I'll downscale the equipment level on the unstayed rig that I'm comparing it with too and still undercut you.

There ARE some disadvantages to unstayed rigs though - the major one is it puts the weight of the mast up in the eyes of the boat where there is a serious increase in pitching moment.

I've done the quotes both at Duck Flat when the NISs were first being developed and for three years in retail chandleries spending a lot of time quoting different rig and sail combinations for a vast range of boat sizes.

And look how the cost of the number of sails and the amount of gear on a sloop multiplies as soon as racing rears its "ugly" head.

A caveat is that I don't know what NIS boats / Spunspar are charging for the mast/tabernacle arrangement these days. But with the tabernacle you are paying for a level of convenience that a sloop just can't match - the NIS's if set up properly can rig in a few minutes - <10?

But like I said - thats the top end if you don't count carbon - compare like quality with like quality and the freestanding rig will almost all the time be cheaper.

MIK

Er, I mean ..
Best wishes
MIK!

[Wild Dingo]

And dont you go gettin Mik started!! :slap2:

ever felt like this? :pop:

:rotfl:

No seriously... hows things goin? I mean hows yer day? Bloody ducks knutz of a day over here in the West :wtg:
:repplus:

[STEPHEN MILLER]

Ar Mik you are a wealth of info sometimes getting you riled up is a good way to extract it in a direct easy to understand form.
Every little bit helps:D
I have attached photos of our boat out of the water the water line is about 20mm below the antifoul line and dont mind one of the photos has been coloured in with blue texta didnt it tosee how the hull would look in Royal Blue before we repainted her in that colour.
When we sail we get no swirl as you say out the stern form the transom, flow is straight out , the boat is well balanced moving crew forward makes little difference 200 hundred litres of water up front balance up 10hp of Bukh diesel sail drive up back, 4 people in the cockpit does not lower the transom into the water anymore then one does .
The keel is all steel with 750kgs of lead on the bottom, rudder skeg and rudder are all steel as well, hull is garbon ply Dynel sheeted as is the deck and cabin.

[STEPHEN MILLER]

Ar Mik you are a wealth of info sometimes getting you riled up is a good way to extract it in a direct easy to understand form.
Every little bit helps:D
I have attached photos of our boat out of the water the water line is about 20mm below the antifoul line and dont mind one of the photos has been coloured in with blue texta didnt it tosee how the hull would look in Royal Blue before we repainted her in that colour.
When we sail we get no swirl as you say out the stern form the transom, flow is straight out , the boat is well balanced moving crew forward makes little difference 200 hundred litres of water up front balance up 10hp of Bukh diesel sail drive up back, 4 people in the cockpit does not lower the transom into the water anymore then one does .
The keel is all steel with 750kgs of lead on the bottom, rudder skeg and rudder are all steel as well, hull is garbon ply Dynel sheeted as is the deck and cabin.
Dingo its lovely and wet over here at present and the sun is shining at present

[bitingmidge]

Oh dear Stephen! :oo:

20mm below the antifoul line means you've got bugger all transom in the drink. See up there when Mik said apples with apples?

The boats in question have 100 mm or so of their entire flat transom submerged.

Cheers,

P
:D

[STEPHEN MILLER]

There is a 100mm of transom in the water that antifoul line is about 150mm above the the lowest point, the transom is at the waterline is around 1200mm, beam is 3metres LWL is 9.5 metres, draft 1.075
and I thought apples were oranges mate, I know its not flat across as in the transom as the Stevenson boat I havent seen the plans so I dont whats below the water.
But Mik can explain the difference and where the hull shape makes a difference in this case:D

[Daddles]

I think it's time Steven invited Mik and myself out for an afternoon sail on his wee boatie - I'd need to be involved because you need someone to bring the boat back after all the bloodshed and besides, I don't like to miss chances to go sailing.

Richard
actually, I'm serious about the invite - I reckon Mik and Steve would get on well together :D

[STEPHEN MILLER]

I would luv to one day when I can find the time and you make great shark bait Daddles that would be the only bloodshed

[Boatmik]

Ar Mik you are a wealth of info sometimes getting you riled up is a good way to extract it in a direct easy to understand form.
Every little bit helps:D

Howdy Stephen

Thought that was what you were up to!!!

Happy to oblige. :-)

Yep, compare the immersed transom with the displacement of your boat and the sail area. Also note that as your transom is veed the outer parts are only very slightly immersed so you can probably discount a large part of the width.

Then compare the much greater immersed transom of the weekender with its much smaller sail area and displacement.

I'm sure too that if I look at a dozen or so light wind photos of your boat that it will cranking along just fine.

And I'm sure Daddles is right - that we'd get along fine.

I'm serious about information but not too much else!

Best wishes
MIK

[STEPHEN MILLER]

Thanks for the info Mik
Its is slightly underpowered it can have bigger mainsail [to much cost new boom sail etc] but it sails well as is those photos are from when we first bought her there have been a few mods mainly running all the halyards for the main etc back to the cockpit and making the roller reefing operation for the main from the cockpit. The boat was designed and built by Peter Dowding went in the water in 1993 its classified as a Dowding 30 we have hadsince 2002 there are two more in the eastern states somewhere seen them in tradeaboat with slightly different deck and cabin set up and two more of his design at Port Adelaide Sailing Club but one is simalar hull design but as raiseable keel its a go fast machine the other a cruiser similar in design to Spartas
If we did go sailing we can always toss Richard over if he starts waffling to much :D
Are you at this years working with wood show might be able to catch up there:)

[Boatmik]

Howdy Stephen,

My route for displaying at the woodworking show is via Duck Flat. So If they are there I'll be on the bludge (once again) and ask them to be on the stand as well.

MIK