Dropdown Longshaft for Wharram Catamaran

[Chris Bretter]

Hi all
I am starting to build a 38 ft Wharram i would like to use a centre mounted Nissan SD22 with a 2-1 reduction box and a dropdown longshaft. All fairly simple Has anyone any ideas.Also perhaps a ducted prop with a rudder to assist low speed manouvering.You guys think out of the box.
Regards Chris South Africa :confused: :idea:

[boat fan]

Hello Chris , I don`t know if you have seen this :

http://www.themultihull.com/wharram/p52je2.htm

It`s a larger custom wharram , but may be of interest.

Another :

http://www.themultihull.com/wharram3/bk6.htm

http://www.themultihull.net/kd1.htm


Regards B F

[Chris Bretter]

Hi BF I had looked on the multihull site but not seen these pics.Have you tried anything like this thanks Chris

[boat fan]

Hi Chris ,

No have not tried ......

Some debate on wharram long tails here ,

http://www.multihullforum.com/forum/FORUM.asp?FORUM_ID=36

http://www.multihullforum.com/forum/topic.asp?TOPIC_ID=2761

http://www.themultihull.com/wharram3/photogallery/photo8528/am1_156.jpg

Personally I would mount an outboard in a drop down pivoting pod.

[Chris Bretter]

Will check it out now still a way off but i like my ducks in a row.Thanks for the help.Regards Chris

[Chris Bretter]

and a genset not a bad idea.Im a a bit wary of outboards and the lack of flushing .oriental air coolel outboards available now????????who knows.

[boat fan]

and a genset not a bad idea.Im a a bit wary of outboards and the lack of flushing .oriental air coolel outboards available now????????who knows.

The new generation four strokes are very good these days Chris....:)

[Chris Bretter]

the oriental ones are air cooled diesel who knows about quality and relaiability
I like low revs with big props sorta old school thing that coupled with being a diesel mech off earth moving machinery.

[Frosty]

Drop down engine on a Wharram means that the engine is right where you dont want it. It has to be covered by an ugly box where you dont want it. Dificult to get coolant water to the engine. Noisy, smokey, bloody awfull.

[Chris Bretter]

The idea is good but it seems to cause a lot of problems its just that i want a good power source as well.A lot of hassle though.

[boat fan]

The idea is good but it seems to cause a lot of problems its just that i want a good power source as well.A lot of hassle though.

Maybe a diesel / saildrive , or Shionning`s idea of vertically retracted outboards in wells. I hear what your`e saying about flushing them....and slow revs / big props....:confused:

[Chris Bretter]

a dilemma at the least.It makes sence to have a big diesel at 2200 rpm with a 15 inch prop. a 220 volt generator ,12v 200A charging,water pump, Raw water up and down the shaft all in one package .Ducted prop with rudder.
But ho to do it simply

[Frosty]

http://www.boatdesign.net/forums/powerboats/thai-boat-plans-needed-20398-3.html

I think there is something here for you

[Chris Bretter]

I surely hope there is.At least some light at the end of the tunnel ..Not a train please?

[Chris Bretter]

Hi Frosty.Raw water cooling but oh so simple.Perhaps the right way to mount it in a wharram on a pivot gets rid of the universal.use it for slow speed steering.Just put on a new sump and pickup.Auto disengage if the motor is pushed up.Not sure if there are any problems with a motor at 20 degrees.But its certainly worth some thought.
This is a wonderfull blog.Thanks Chris

[Manie B]

Hi Chris
welcome to BD.net

why Wharram ??????

i have done plenty homework - and there are MANY better options

[Frosty]

Manie ,---Oh brother do I agree with you.

I have known two friends with Wharrams and both boats have been lost on the beach. Rotted out and or broken up in a bit of surf.

I think the bit of string that hold them together come loose.

[Manie B]

It may sound a bit over the top

BUT why build a wharram when you can get them for virtually free - a dime a dozen

here is one at the Vaaldam in exelent condition :D

Chris - seriously look at Easy Cats if you want to build - and there are many more that are quality cats that could be built well on a strict budget

Wharram's are really for aging hippy dreamers - dont go there :D

with global warming the way its going now - only a solid dodger will do - biminis let too much sun thru -
the era of the "centre cockpit" and/or enclosed wheelhouse is well and truly on us for cruising :D

[Chris Bretter]

well its too late now .You makes your choices and then u gotta finish it.Thanks for the input i will use good string and stay away from bitches sorry beaches

[boat fan]

Manie ,---Oh brother do I agree with you.

I have known two friends with Wharrams and both boats have been lost on the beach. Rotted out and or broken up in a bit of surf.

I think the bit of string that hold them together come loose.

Now, now ...Frosty .....Wharrams don`t fall apart that easy actually...IF Maintained.

Having said that , I do agree there are many better choices out there.

Regards , B F.

[boat fan]

It may sound a bit over the top

Wharram's are really for aging hippy dreamers - dont go there :D





What`s wrong with aging hippy dreamers Manie?:D

[Frosty]

Boat fan , can you change your Avatar, it frightens the life out of me --its real creepy weird. You to Manie ---creepy stuff.

[Chris Bretter]

Well it seemed like a good idea at the time.Only time will tell now.I have a few friends with Wharrams and im wondering if i should delete them off my xmas list.Too late will have to see it through.I havent seen many Tiki 38s for sale a few on multihull thats about it.thanks for your help thusfar if you have any ideas about a motor ,trans or drive drop me a line.

[boat fan]

Boat fan , can you change your Avatar, it frightens the life out of me --its real creepy weird. You to Manie ---creepy stuff.

You must frighten easily Frosty...:D

Have you actually looked at yours lately ? :)

[catsketcher]

Hello

I have a friend who has a 50ft Wharram that he loves. He drives it with a longtail. The water is picked up in the hulls which is a fine method. The weight of the engine is on the middle - good for pitching, the engine is very easy to work on and very easy to use for watermaking etc. If he wants he can make the prop go deeper in the water to stop it ventilating in rough conditions.

A guy on the lake here has a Fitzgibbon with a longtail. He loves it - big three bladed prop for motoring and out of the water for sailing. The whole assembly rotates to get the prop in the water. He has a pushrod to hold the thing down in reverse.

As to the Wharram's merits - Wharrams make great boats. A dodger or bimini will almost certainly be added by you but the Tikis I have seen have sailed well.

I met a couple of guys who each had a 31 and they did get a little exposed. One sold the Wharram and got a tri the other is probably half way around the world. Build some sun and wind protection and have fun.

cheers

Phil Thompson

[Chris Bretter]

Hi Phil Thanks for the reply does the guy with the long shaft have a E-Mail i would like to get a picture of his system

[Chris Bretter]

Hi Phil we are modifying the deck pod to be a little larger with a bimini and a lot of shaded areas.Seemed like a good boat to me.There are a lot of horror stories with old boats not only Wharrams,Im happy with my Choice.Just want a nice diesel longshaft.People have been very helpful.Regards Chris

[Manie B]

Chris how far are you?

post some pics - would be nice :D :idea:

[Chris Bretter]

Hi Manie We are starting in January 2009. Just got the plans 2 weeks ago (R22750.00)A friend of mine has built 5 Tiki 38s this will be no 6.I am plan 118.Should be an interesting project he will allow me to assist with the minor work and the motor/s which is more up my street.I am a diesel Mac by trade but have been customising and selling bikes.I can weld Tig,arc,gas operate mill,lathe have built bike frames,tanks etc first big project in wood tho.Need to do somthing different.

[Manie B]

Chris best of luck - all should be ok :D
its frightening to see what plans cost with our poor exchange rate

however please keep us posted - i am very busy with all my "experiments" and so is Wynand - Fanie and Butch

we could probably save you a bundle on materials and extras

i am going to see Butch in Pietermaritzburg now during the holidays - maybe we can join for a beer :D

[Chris Bretter]

Hi Manie what line are you in.If you come down to gateway in Durban i will be working right through.Pop in for Coffee Regards Chris

[Manie B]

Chris we will pop in - cool bananas :D

i am in building and construction - that is why i am so f@cked in the head :D :D :D

anyway i have done a sh1tload of research and it is honestly a case of the further i travel the less i know - however feel free to post any question and i will give my 2 cents worth - please list your suppliers BEFORE you pay good money, we may be able to steer you in better directions :idea:

[Manie B]

Hi Chris

I am always fascinated / intrigued by what and why somebody wants to build a certain type of boat. I fully understand that there are strokes for folks - everybody has got their own specific needs and budget AND application.

As i am deeply involved with my own building program and vast experimental comings and goings (which comes at a price as well) - i keep a constant lookout for new things because i am petrified that i have missed something crucial. I am working on the ultimate folly -which is going alone - because either i go alone or not at all, as my family does not share my views / dreams. In short what turns me on leaves them cold. My children are adults, my wife a corporate career girl and i am an entrepeneural party boy:D

I am totally committed to epoxy and plywood - all my experimentation - as well as my final build which will start next year - is committed to ply and epoxy.

I am very curious as to why you have gone Wharram.
I have just gone over the TIKI 38 website - looked at most of it - and still ask why???

For the benefit of the doubt maybe you guys have picked up on something we dont comprehend - so I would love to know more from you and your actual usage of such a vessel

I fully understand that this becomes a VERY personal issue however we are all still boat fanatics with by and large the same dreams.

So here goes a couple of basic questions

Cruising across the BEEEG pond or day sailing in and out of the harbour
How many souls on board and ages (kids are special)
Simple budget - empty hull/deck - sails/mast - navigation/electronic equipment - living/household equipment - motors

dont worry about accuracy, just get a general feel first

and very very important - is resale value important to you or not

last but not least - how much sailing have you done?
and your mate, that will build for you, can he get you onto a Wharram for a couple of days?

Hopefully i will be starting from step one next year with Chris Bonnet, Sunsail there in Durban - to do my proper licences - the whole flippen lot from yacht hand up to Yacht Master and so on. So yes i could buy you a beer every now and then, who knows:D My minicat is actually a half scale model of my basic thinking in line for my 12m cat next year. i am learning every day:D

[Chris Bretter]

Well firstly i am a poor white boy so i need to keep costs down really low,I am good with my hands and being an old diesel mac need a simple wet sleeve motor and mechanical trans.I sailes Hobi 16s for a while other than that not much past day sailing.I like the simplicity of the wharram and have watched my friend Mushroom build 5 of them over 15 years all are still sailing with no sea worthy problems.I know one guy who is old cruiser who sails anything but will only own a wharram.I have sailed on his one only.
Only for 4 people at a push.Will be sailed by my girlfriend and I.Minimal electronics.12 v electrics solar panels big charger.I will have to earn cashola as i go so will have to carry my tools of the trade.The current costing on the bare boat with no sails,head,cooker ,anchors,rode R340K.Which i think i can afford in the current situation.(barely)Just recieved my plans last week.Ease of maintainance is what i like as well as the flexing hulls.Mabe i am an ageing hippie(really im a metal head but whos to know)Perhaps its his brochure with the neked chicks)

[Manie B]

Chris to me it all seems ok:D

i dont particularly like your choice of boat - but however the fact remains that there are a lot of them sailing around the world, if there were serious fatalities it would have been all over the web by now.

i am an EASY fan but that doesn't mean that that is right either - i just feel that a bridge deck cat could be set up very well for single handling, and that is what i am experimenting with my half scale minicat5.

i like your budget - i think it is do-able
ply and epoxy is priced OK in RSA
rigging can all be gaivanized including steel mast
keep interiors simple
i for one am going to stay away from extravagant over the top "creature comforts"

i know that the world has gone crazy on "electronics" - half of which belongs on a "volvo racer" not a cruiser

anyway start a new thread called building a Wharram when you are ready to order materials and i will post web pages of what i have found - experimented with - and recommend

here are some posts showing all the mischief i get up to with epoxy and ply and pics of a boat AND trailer i built last year

http://www.boatdesign.net/forums/boat-building/epoxy-second-layers-solution-25128.html

http://www.boatdesign.net/forums/boat-building/minicat-5-a-24096.html

http://www.boatdesign.net/forums/open-discussion/what-have-you-done-weekend-23233-29.html#post238127

[Chris Bretter]

I like a sextant and a sounding lead.A big anchor with chain.Lots of water and bean sprouts.I dont drink and eat little meat.The bouat comes with an ally mast and Galv Rigging.Price is really important as i really cannot afford this.But i got to do it afore im old.Older!!!

[Chris Bretter]

That picture is your minicat. really cool.Designed and built by you.The wharram has a high bridge deck to stop pounding.but the construction method very similar.Lower hulls upside down then turned and topside fitted.
your garage looks to neat to build boats.

[boat fan]

I like a sextant and a sounding lead.A big anchor with chain.Lots of water and bean sprouts.I dont drink and eat little meat.The bouat comes with an ally mast and Galv Rigging.Price is really important as i really cannot afford this.But i got to do it afore im old.Older!!!

Sounds like a good plan Chris , just do it !:D

[marshmat]

I concur.

Build, sail, enjoy. That's what it's all about.

As to Wharrams: Well, yes, they're weird. Wharram-bashing has been trendy ever since he built the first one in, what was it, 1955? But there's nothing terribly new or unorthodox about them. All he did was to apply some modern materials and mathematics to designs that have been criss-crossing the Pacific for thousands of years.

Wharram himself cautions that a lot of his designs (there are a few thousand examples out there) have been built badly; see page 72 of his design book:
Built roughly, Classic designs may leak, leading to rot. Unfortunately, some Classic designs have been built roughly, but the surplus of timber in their construction give a strength safety margin allowing rough builders in the first years of ownership to successfully sail long distances before rot develops. (Beware of such boats on the secondhand market.) But the same could be said for any design that appeals to home-build, low-budget adventurers.

I don't see anything wrong with a lack of electronics, the use of galvanized rigging, etc. as long as you build a sound, solid hull. Longstanding commercial practice, not current trends in racing, should be the guide for someone planning to build a cruising boat on a tight budget.

Best of luck, and do keep us posted :)

[Chris Bretter]

Hi Matt
The friend who is building it has built 5 already in 15 years only Tiki 38s This will be 6.He really understands the design.To many builders modify the boats radically.there are pieces that are structural which dont appear to be and weight is also an issue They are solid simple boats which flex We are raising the cabin height 4 inches all thru Regards chris

[sabahcat]

I have a tiltable/steerable Yanmar S2 leg that I was going to use in a sailing cat.

These are used on boats that have a centre pod with diesel engine and works like a sonic drive.

It is a bit short for a vessel with high bridgedeck clearance, but an appropriate sized mast section is used to extend the leg and then shafts get cut and sections added in.

These have been commonly used on Fastback (Australian) sailing catamarans with great results

If interested, I can be contacted on sabahcat@gmail.com

[marshmat]

That might work, sabahcat.

Chris- good to hear you have someone who knows Wharrams. His design philosophy works, but it's a bit unorthodox and seems to stump some builders who are expecting more 'conventional' ways of doing things.

I'm still trying to figure out, though, how one would handle a single-engine cat that's as wide as these things. Everything I've read about handling big cats under power says that the primary method of controlling them in harbour is to oppose the shifters, and steer with gearshift and throttle....

[sabahcat]

One I have sailed on in Brisbane, ten years ago arguably the fastest around (a 40ft foam kevlar epoxy suppershockwave with pre-bent rotatating carbon mast) has the single leg with linkages coming up to a vertical lever that travels port to starboard.

This is at foot level at the steering position and they stuff it into a fairly tight berth, sometimes in big crosswinds seemingly with ease.

They steer the motor with the foot and can have rudders and engines in opposing directions allowing some impressive crabwalking and pirouettes.

Pics of boat and berth, pink line is about where the mud dries to at low tide

[Chris Bretter]

Hi Matt.The wharram is all i can afford really but i am fortunate to like them and have a friend who can build them.I was hoping to be able to use a ducted prop with a balanced rudder to steer.the rudder could be linked to the Steering system.I was hoping that someone could give me some advice on this site.regards Chris

[sabahcat]

the rudder could be linked to the Steering system.

Makes sense:confused:

[FAST FRED]

I was hoping to be able to use a ducted prop with a balanced rudder to steer

If the prop and ducting is underwater while attempting to sail , the results will be like sailing with huge buckets towed astern.

FF

[Chris Bretter]

The drive unit lifts out of the water for most of its life whilst sailing.Can still charge ets while up.

[sabahcat]

The drive unit lifts out of the water for most of its life whilst sailing.Can still charge ets while up.

If you're asking about that leg of mine, yes as the water intake would be in the hulls.

Would you? probably not, no load on an engine is not good for it, and solar would be the go IMHO