Contact info: Catmando2, Dave ?

[Sinclair D-R]

Managua, 29.10.09.

Greetings to all,

How can i contact Dave, builder/owner of Catmando 2?
As i share a similar passage maker power cat concept and size in mind.

Thanks for your help!
Safe winds.
Sinclair

* Jeff: My first disappeared, with your anwer i never could read.

[catmando2]

Send a PM

[Sinclair D-R]

Managua, 29.10.09.

Greetings Dave,



Here are some of the specs for my to build Passage maker power cat 15.00

- LOA: 15.00

- LWL: 14.00

- BOA: 5.60

- D/L: 13/1

- Draft: 1.00 max.

- Wing clearance: > .90 @ lowest

- Power: 2x50 shp swinging a 600 mm 2 blade prop

- 2000 nm @ 10 kt +, loaded, 10 % reserve, heavy seas, strong wind, genset fuel burn, all included.

- Top speed: ~ 16 kt

- Cruise fast : 14 kt

- Range: 10 kt

- Displacement hull, raised pilot house.

- Accommodations: basically 15.00 hulls with the short bridge deck/accommodations of a 12.50 on top, utilitarian amenities for two

This boat optimized for about 12 kt.

Could you share your thoughts, thank you for your time Dave.
Who has a close design? Robin Chamberlin?

Safe winds.
Sinclair

You mentionned Jeff using same old tec building method as yours or Robin, would like to contact him.



Sinclair Dubier-Routier
Telefax: + 505 2265 7204
Cel.: + 505 8823 8943
Km. 12, Carr. Sur, 100 mts. al Sur Ex Embajada de Alemana,
Managua, Nicaragua C.A.

[catmando2]

Hi,
All sounds sort of similar to mine and 16 knots out of 50hp sounds pretty impressive, any pictures?


Not sure how current these details are for Robin

http://www.multihull-maven.com/Desig...bin_Chamberlin

And a site for Jeff Mcdavitt
http://www.mcdavitt.com.au/index.html

[Sinclair D-R]

Dave,

It seems i did not express my self clearly, you misunderstood me:
Firstly, I am looking for a disigner to draw her under the above specs, then a builder to give here life.
Any idea?

Sprint speed: rather slower than heavier.

Safe winds.
Sinclair

[catmando2]

Originally Posted by Sinclair D-R

Dave,


Firstly, I am looking for a designer to draw her under the above specs, then a builder to give here life.
Any idea?

Robin could be one to speak to, he designed the cat in this picture, though I think it has 100+ hp per side



as would Bob Oram who has done these with 50hp/side in sail, getting 10/12 from a 3 bladed folder
http://boboramdesign.wordpress.com/60-halcyon/


I think getting what you are asking for, 16 knots, with 50HP x 2 while using a 2 bladed prop may be a bit optimistic.

If it was very skinny, very light and minimalistic swinging a 3 or 4 blader it could well be achievable in the right conditions.

[Sinclair D-R]

Dave,

Catherine & John B. comissioned Foriegn Affair in 2002, i would vewry much like to contact them.
Sewnt mail to Robin and Jeff who built variuos 13.5 Chamberlin power cat, will keep you posted.

By the way i should thank Rick Willoughby who kindly offering me to crunch some of my numbers -for free- who also provided me with quoted sketckes and finally recommended me to get in touch with Robin Chamberlin as his power cat are close to my concept.
Thank you again Rick.

Bob Oram and i are in contact, i told him that his hands-on approach is refreshing and reassuring given his vast experience.

Sprint speed: around 16 Kt, well: rather lighther than faster, within reasonable limits.

Talking about numbers,
LOA has to be 50' minus one inch as marinas overcharge you above 50' LOA, Not that i intend to hang my hat in one.
BOA: Asked Leo Lazauskas about the criteria i should elicit to determine the most efficient beam after reading his 1988 paper as i did not find a satisfying answer, but he is to busy nowdays to work for free, understandble, Rick's Godzilla programm came with one figure.
Weight, LWL, and range speed are the three factors to take in consideration/
Any opinion, any ratio? else? Dave.

Props: ready to learn plenty, please!
Thought about starting a thread on thsi subject: Beam for long range power cat.
Thanks for your time.
Sinclair

[catmando2]

Originally Posted by Sinclair D-R

Dave,
Sprint speed: around 16 Kt, well: rather lighther than faster, within reasonable limits.

Not sure if I understand this, are you saying you would rather a lighter boat that kept 50hpx2 even if speed was 10knots
Compared to a 16 knot boat that needs 100hpx2 to get it?

Any opinion, any ratio? else? Dave.

Not really, just keeping it simple and doing what has worked relatively well before.

Props: ready to learn plenty, please!

Dont know enough to knowledgeably comment and rely on the prop guys for recommendations.
For mine they recommended an 18 inch 4 blader or a 19 inch 3 blader (or the other way around)
No mention of a 2 blader so I assume they are not efficient enough.

[masalai]

In my gallery is a couple of images of the Chamberlin 10 (10 metres=32.8ft) that had twin 50hp with a max of 16knots - I doubt the ability to get same top speed out of 50 ft and range (3tonnes of fuel?) - "Foreign Affair" could achieve 1.3litres/NMi (from a failing memory) and top speed around 20Knots but good sized engines...

I responded to an email from Rick Willoughby today, give him time, he may find a link... The 'Icecat' website is closed.

[Rick Willoughby]

Sinclair
As far as the beam that GODZILLA came up with it should be subjected to a sensitivity analysis. I doubt the hull drag will be a compelling factor in what works out best. A few values over the likely range should be compared.

As far as props go you go for the largest diameter you can reasonably fit and protect. From there you go to the lowest BAR consistent with strength and cavitation limits.

If you look at the Wageningen data you will find a 2-bladed props with 20% BAR achieves best efficiency of 90%. You will not get to this with your current loadings but it shows what can be achieved with light loading.

I think once you start talking to designers they may be able to get the weight down from what you have in mind as I gauge you are not after a floating palace but rather a competent sea boat for small number of people.

Rick W

[Sinclair D-R]

Managua, 31.10.09.
Quite a lot of rain recently, everything is lushly green around!

Dave,
- Propulsion:
Weight being such a drag and given the choice i would rather have a slower than heavier boat. 50 rated -crank- shaft hp. should do.
Which

- Beam:
Still in the mist!

- Props:
Same as above

-Props:

[Sinclair D-R]

Dave,

Which Cummins did you choose? i only remember 65 hp @ 2600.

Interesting post:
http://www.boatdesign.net/forums/sea...archid=1560930

[Sinclair D-R]

Masalai,

Chamberlin 10 m Sea trial, Rick gave me this link:
http://catchcryhamm.com/?q=node/19
Sent the Hammonds a mail a couple days ago.

Foreign Affairs:
Nice efficient boat,
http://thecoastalpassage.com/papers/tcp30.pdf
Page 12.
"73 hours for the 816nm" Wonder how much engines fuel the Brosnans burned.
Which make, model, etc.

Whish you plenty of NRG for your beautiful cat coming to life.
Sinclair

[Sinclair D-R]

Rick,

Thank you for your time and insights.

About props:
History & Design of props by: Jimboat, Canada,
Part 1
http://www.boatbuilding.com/article....nofpropellers1
Part 2
http://www.boatbuilding.com/article....nofpropellers2

"BAR" What does this acronym stand for?
"Wageningen data"? Where, what, when, how, why? New to me, can you enlighten me?

Keeping all things light, thinking about your 11 kg for 6 m.!
C'est magnifique.
Sinclair

[catmando2]

Originally Posted by Sinclair D-R

Dave,

Which Cummins did you choose? i only remember 65 hp @ 2600.

Interesting post:
http://www.boatdesign.net/forums/sea...archid=1560930

http://www.cummins-sp.com/engines/in...b33_engine.htm