35' cat concept for the inside passage.

its nuts that an engine/car that gets 95mpg can't be imported because of emissions. 1 gallon can only produce so much pollutants, for instance the CO2 component of that gallon wouldn't be more the sum of its carbon content plus two oxygen molecules for each. I think the multiple is something like 3.6 so if the carbon content of diesel was 6.1lbs then the total possible CO2 of the exhaust would be something like ~22lbs. since carbon is about the only thing that really maters coming out of that tail pipe then there's no way it shouldn't pass. I'm really not clear on how that could happen.

then again the emissions standards make no sense whatsoever

 

I don't think it is emissions. I think Americans simply don't want small cars and won't buy them until the fuel costs are the same as in Europe. Typically in the UK it's USD10 a gallon

I was going to suggest fitting the VW Golf diesel

Years ago I met someone who built his own plywood 35ft catamaran. He was driving a Morris Minor car. When he finished his boat he took the car engine out, including radiator, gearbox and propshaft (it was rear wheel drive) and mounted it on deck as an air-cooled motor with a "long tail" prop

He said that the 3 forward gears were very useful when motor sailing

Richard woods of Woods Designs

www.sailingcatamarans.com

 

I'd thought of maybe mounting one engine transversely and then using a simple length of pipe on pillow blocks to transfer rotation to the two hulls. I also thought of maybe having a nacelle suspended just above the water mounted between the two hulls. again with the lower leg of an outboard on it. But it seemed like ti would slam all the time.

The Kubota engines are fine by me as they do seem to have a good reputation and they are extremely easy to get parts for. I suppose I could just ask them what there most popular model is and go with that one. I'd rather use something out of a car just because auto parts stores are more common than farm and tractor part stores. But I'll go with reliability, weight, size, power, and then look at parts, as long as I can always get them, even if I might have to order it. Car parts are just easier tho.

My issue with the long tail deck mounted thing is its compatibility with charter operations, I want to be able to take folks out for a nice day on the water. Boats gotta look good and a deck mounted diesel just seems like its not real conducive to quiet operations. That and it makes the boat top heavy doesn't it ?

 

Hi Boston, did you download the PDF file? - all you need to know... and 332.9 pounds light - Where would you place "continuous rating? - around 2200rpm?

On the "gearbox" V-belts would be very nice and give you the 2:1 reduction in rpm for the propeller, BUT what about REVERSE ???

I also forgot about the 'common rail' injection system in the Mercedes, no good for CNO, (as I need that versatility), and dubious for any other 'home-made' diesel substitute...
The Kubota has "standard mechanical injector system" so remains OK for "our funny fuels"...

 

You will have fat americans standing/sitting in the same area and have not given a second thought about top heaviness there.

 

you seem to be enlightening Boston... a diesel mounted on deck would most likely be noisy and ugly... by the way your approaching this power/drivetrain issue, im envisaging a real mess, back deck looking like an agricultural shed... center mount engine, pulleys and what have you running everywhere, really? If you want something that looks nice, its not going to happen this way...

IMHO, if you want to keep this thing neat, this single engine thing is difficult - i refrain from using the word impossible, but id like to... the only neat way i can see it happening would be very expensive - which defeats your goals in the first place so i wont bother, 2 smaller engines is a better idea, has redundancy, is simpler, doubles as small genset, the list goes on...

Now, about that floor plan... hows that coming along?

 

I'm with Groper (and Richard Woods) here.

Get a couple of smaller engines and keep the boat simple. I went down all those paths of transferring power and putting together my own drive system from a single engine, from electric motors, etc... etc...

When it was all said and done, any change I made to a drive train cost thousands of dollars in parts and came with no warranty.

Be very careful there. Home made stuff is very tempting, but not very good for the wallet.

The VW engines are great, too. Check out trashed/crashed Jettas and stuff. The MB engines (I have one in a Sprinter van) are definitely a little more technical having both common rail injection and turbos. Very reliable though... I have 3,700 hours on my MB straight 5 engine with no sign of it getting tired at all. FYI: They run at 2200 RPM at 65MPH on the vans, full load. However, the VW engine would be cheaper. I also like the idea of twin Kubotas if you can do it. They aren't that much less than a Yanmar these days, but a couple of smaller engines, while a little more expensive out of the gate, will be much less money in the long run with longevity.

 

Maybe those "fat Americans" will loose their balance and fall off and drown - insurance could be wise, and also a policy with you as beneficiary - profit from the stupid overindulgent obesity... (make sure that person has a PFD1 on and correctly worn.....)

 

Here somebody built (or is building) a bit over 30' (iirc) strip-built catamaran with a single engine and a hydraulic drive. Comparing the price difference with 2 smaller diesels combined against one with a bit over their combined power, I would suggest that your additional drive train costs with the single engine will be well over the difference.

Also the efficiency gain with a single engine could be well lost in drive train.

Boston, btw; Did you notice the "save a classic" in the latest WB?

 

Hi liki,

is there a link?

 

It read about the project in a Finnish magazine way back in 2007 but couldn't find anything in the www with a brief search. I have the paper copy still somewhere, and you can buy a digital copy, but they are both in Finnish. Quite the same as encrypted text for a foreigner. ^_^

http://venenetti.fi/arkisto/lehtiarkisto?HaeNumero2=true&lehti=5335&number=09&year=2007
The article about the cat is titled
"Itserakentajan opas:
Katamaraani
Heitä ennakkoluulot nurkaan"

There were some pictures about it and a general description but nothing very specific.

In the "Save a classic" in the latest edition of Wooden Boat someone was looking a new owner willing to take good care of a converted 52' carrier.

 

I think your drawings have merit,i like them. There are so any cats on the market today that it's nealy impossible to settle on one.

 

Liki
Google translate of the webpage worked quite well, and got me to the point of ordering, but only choice seemed to be cellphone/SMS payment which doesn't work for my location. The pop-up message "Olet siirtänyt tuotteen ostoskoriin. Pääset ostokoriin palvelun yläosan linkistä" when clicking the shopping cart icon is saying I have moved the cart, so click on it at the top of the page... But I can't find it, seems I'm stuck.... Maybe you have to be logged in. Oh well, if you can post scans of your old paper version it would be good.

 

hmmm I kept getting the pop up and then a blank page.

I'm fine with two engines if its just the way it is on a cat. No sense fighting the nature of he beast. I think someone mentioned the hulls beam should be twice its draw so I'll figure it out for my displacement and what fits the engine's best. But those Kubota's are pretty thin so Im sure I can squeeze them in.

Someone also asked for a floor plan. Now there's something I've struggled with. Ok well once I get the shells balance worked out then I can locate the engines for and aft. Then locate the rest of the mechanical and the bulkheads. I gotta also center up the fuel tanks and then I'll jam the Lou, freezer, and a couple berths in down there and see where I'm at.

Oh and I'm going to try and combat the squatting my extending the hulls aft a few feet beyond that aft deck area. To bad that box keel looking thing didn't work out all that efficiently cause it looked like a great way to keep the prop shaft a simple arraignment

Also I think I'll aim for each engine having 40 hp each which should get me to ~12knots +. ~8 knots apparently is about my most efficient speed and although a bit of extra power is always nice at some point somebody suggested keeping this thing as light as possible

 

Ha ha, shopping cart doing it's own thing Brian ;-) , i try and order from amazon and when i find something i like 9 times out of ten it says there's no shipping to my county, It's gotta make you laugh someone said it had something to do with the price being to low, I then find another item that does ship to Australia and the price is $64 dollars Aus and then when i get to checkout it told me that the shipping was going to be $128, A total of 192 for a item advertised for originally 64 Arrr