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/Designers/Robin_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]

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
http://img338.imageshack.us/img338/6942/foreignaffair.jpg


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/
http://boboramdesign.files.wordpress.com/2009/03/halcyon03.jpg

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]

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/search.php?searchid=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.php/designofpropellers1
Part 2
http://www.boatbuilding.com/article.php/designofpropellers2

"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]

Dave,

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

Interesting post:
http://www.boatdesign.net/forums/search.php?searchid=1560930

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

[masalai]

At 250kg dry that is quite heavy... The Mercedes 1400cc diesel from their "smart car" and used in several home-built aircraft in USA (several fixed wing experimental) & Eu (Ramphos) weighs 75Kg and delivers 75 ~ 100 hp...

[sabahcat]

At 250kg dry that is quite heavy... The Mercedes 1400cc diesel from their "smart car" and used in several home-built aircraft in USA (several fixed wing experimental) & Eu (Ramphos) weighs 75Kg and delivers 75 ~ 100 hp...

1400cc, thats about as much power as what, an electric toothbrush or blender? :D
How many million RPM does it spin, who marinises them and what gearbox does one use?
Found some details on what I think is the same motor
MINI One D: 1,364cc chain-cam diesei: 55kW (75bhp) at 4,000rpm / 180Nm (133 lb ft) torque at 2,000rpm.
Thats not very good ^^

Where do I get them worked on in remote locations?

At the end of the day I wanted reliability and parts wherever I went

I wanted something that was slow spinning, high torque and high displacement that would last, just like the Gardners, JD's etc, but they are to large and very heavy.

lightweight fast spinners I don't believe would last.
I definitely didn't want little black computerised boxes or turbochargers to cause me additional problems

The Cummins stacks up fine if comparing to a
yanmar 2 litre 75 hp turbocharged at 237kg that spins at 3200rpm (http://www.yanmar.com.au/marine/jh3_series/jh3_series.htm#specifications) :eek:

or an Isuzu 69hp Turbocharged at 320kg (http://www.isuzuengines.com/products/product_I.asp?series_id=2&model_id=59)?

or a Nanni/Kubota Turbo at 85hp and 285kg (http://nannidiesel.com.au/Marine-Engine/Shaft/5-250-TDI/) These only came in a 2L 60hp or 2.5L 85hp.

or perhaps a John Deere 84 hp at 437kg (http://www.deere.com/en_US/rg/ESC/QuickSpecs/MarineProp/4045DFM50_A_S0_R0.html)



edit: Catmando2 was my old user name, I forgot the password (but fluked it again recently) and opened a new ac. as sabahcat a while back if anyone was wondering.

[masalai]

http://www.ramphos.com/e/03_s.html the middle image on the left is the "smart turbo" diesel engine from the 1400cc 4 door "smart series" Mercedes cars... http://www.dieselveg.com/smart.htm is the 800cc engined Mercedes car conversion to burn veg-oil, the 4 door version of that car uses a 1500cc turbocharged engine and can be chipped to deliver 100hp in car form, but detuned to 75hp and weighing naked some 75kg worthy of a look? I was looking at it for a 15 knot 40 ft power-cat before I felt I could not do without sail... Also difficulties turbo+ watercooled manifold and wet exhaust... :o :D

[sabahcat]

I'm thinking I needed some weight in the bum as the tip of the prop is churning away about 250 mm below DWL

I would still be worried about longevity of those lightweight fast spinning electronically controlled low torque engines.

[masalai]

It had sufficient torque for my concept as that is also the 'aircraft needs' criteria, (1200rpm at the propellor in the water) but surface piercing/ventilating at displacement (15 knots max) was not resolved as draft & beam wl were 750mm with 7500kg displacement on 40ft lwl (12m) Earlier stages with Rick were looking appealing but too many issues that needed resolving...

Sorry I am distracting discussion from the original objectives - I will but out...

[Sinclair D-R]

Dave,

Thanks for the info about your engine's choice.

Masalay,
Quote:
* Foreign Affair *:

- LOA: 14.25m
- LWL: 14.00m
- BOA: 6.75m
- L/B ratio: 16:1.
- Power: 2x100hp Yanmar 4JH3. 4 blade 19x19" props.
- Fuel tankage/range: 2000L diesel. Av consumption over 22,000nm is
1.1 L/nm. So with 10% reserve, at 12-13kts, range is 1600nm.
- Top speed: 20kts.
- Cruise fast : 15kts @ 1.3 L/NM.
- Range: No figures but estimate less than 1 L/NM. So range 1800.

Hull/fuel efficient!

Cheers.
Sinclair

Sinclair

[masalai]

Sinclair,
That sounds about right, The statistics I had relied on the data at the "ice-cat challenge" website which is now closed... That was where the original "sea-trial" for Foreign Affair was documented... A well designed boat... Thanks for the info...

[Sinclair D-R]

Masalay,

Bill who commisisoned this motor cat around 2003
gave me those datae yesterday.
So very close to my specs.

Sinclair

[masalai]

And please DO NOT put a flybridge on it... That would spoil the lines and is totally un-necessary... I would hope the Robin Chamberlin design is your choice?

[Sinclair D-R]

Mas,

- Fly: Nope, thank you! No wedding cake!
Would even like this one to be more integrated somehow.

- Design: 20000 + nm. later...
Bill told me he would not change much to his original requirements:
less steps, details really.

He also recommends Jeff Shionning who has a similar approach to motor cat.
But i definately like Robin's design more than the Prowlers i saw with flys in yachtworld.com
Weeks ago Jeff told me to get a good look at his Alaskan models:
http://www.schionningdesigns.com.au/www/page.cfm?pageID=206
Perhaps stretching the hulls of the 41' to 50', just the hulls not the deck,
I do not know;
then his 52' is too big, could he shrihk it some?


Getting close.
Sinclair

[sabahcat]

And please DO NOT put a flybridge on it... That would spoil the lines and is totally un-necessary... I would hope the Robin Chamberlin design is your choice?

Depends on where you plan to cruise

You will appreciate the raised position and superior visibility if traveling in hot reef strewn areas, where the inside helm station will be severely lacking in visibility and steering from behind those sloped surfaces can be like being baked in a hot oven.

If your cruising grounds will be somewhere it is predominately wet , cold and windy, I agree the inside position is more appealing.

I will have both.
Up top with a wheel and Autopilot remote for the hot calm days enjoying the superior view and a cold beverage and less pleasant days and cooler nights when on passage inside with secondary engine controls and just an autopilot for steerage.

I recently helped on a powercat delivery to Vanuatu and the whole trip, due to leaking hydraulics at the wheel, were done using the Autopilot control head for steerage and it worked a treat.

Thankfully its helm position was about 3 metres from the front windows, so the heat was manageable.

When approaching reef, a higher vantage point would have been invaluable.

[Rick Willoughby]

Rick,

......
"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

BAR is blade area ratio. The ratio of the area of the blades to the area of the disc swept by the blades.

Wageningen is a well known series of water propellers that has a large amount of test data in the form of charts that allows you to work out what a particular propeller will achieve in open water conditions.

The simplest way to get an idea of the best prop to suit your application is to use JavaProp. It is quite easy to use and can be run from this web site:
http://www.mh-aerotools.de/airfoils/javaprop.htm
Click on "The Applet" and it will start a jave application. I can tell you how to set the parameters similar to what your cat requirements are per attached.

This allows you to quickly appreciate the interaction of the variables. For example what is the sensitivity to diameter and RPM. You need to check that the resulting shape will have the required strength. Also at higher speed, cavaitation can be a factor and JavaProp does not cater for this condition.

In the past there was not a lot of attention paid to efficiency on recreational power craft but that is shifting. The hull design you are chasing will be reasonably easily driven. The best prop is likely quite different to what is regarded as typical.

The props I make for my own little craft and design for, or recommend to, others are able to get efficiencies well over 80%. This is a recent example of one:
http://www.youtube.com/watch?v=jh_RhkejWLw
Not too shabby for less than 1HP.

Denny also posted some interesting test data at post #252 on this thread:
http://www.boatdesign.net/forums/boat-design/efficient-electric-boat-27996-17.html
It compares a model aircraft prop with a standard Minn Kota prop along with a few other efficiency improvements not directly related to the prop. However anything you do that can improve efficiency can have indirect benefits like reduced power, lower engine weight, less drag from lower engine/gearbox weight and so it goes on.

Low hull weight is desirable where it does not compromise integrity as it will reduce overall costs up to the point where you start to use exotic materials or spend more money on designing detail than just sticking with something more robust.

More exotic reinforcements like carbon fibre that I use on my boats can save significant weight but they come at a high price. I doubt that you would want to go to these. Some of the weights being achieved with large boat hulls amaze me but they cost a king's ransom.

One last thing - interesting that Foreign Affair has a beam of 6.75m - close to GODZILLA result.

Rick W

[Sinclair D-R]

Managua,
Rick,

My apologies for answering your last post a tad late, discovered it now!

Thanks for the infos: BAR, Wageningen,
"Javaprop" in which i will dwell soon;
80 % effiency: what an achievement and a saving in all aspects.

Similarities: Beam of Foreign Affair and your results for my project, Thanks again.

Safe byci-cat!
Sinclair