rick willoughby, boat design .net

Torque and fuel effiency
This is what this site is all about, congrats on your post
I used to Work for Cummins, in 70,s but I learn from your posts regarding drives, props and other things, wanted thank you publically, as cant give you more points Keep up the good work

[Guest625101138]

I appreciate the comments.

The site provides a nice distraction from less meaningful work that I do to pay for my boating addiction and other bills.

I have found the web a rich source of information and there are some very useful sites that I am happy to recommend.

Looking at others' challenges is a constant source of learning and getting pulled up now and then for silly comments hopefully makes me a bit wiser and more knowledgeable.

Rick W.

Originally Posted by Rick Willoughby

I appreciate the comments.

The site provides a nice distraction from less meaningful work that I do to pay for my boating addiction and other bills.

I have found the web a rich source of information and there are some very useful sites that I am happy to recommend.

Looking at others' challenges is a constant source of learning and getting pulled up now and then for silly comments hopefully makes me a bit wiser and more knowledgeable.

Rick W.

Well, Rick, I and BhNautika are working on a new canal river, coastal boat design, and we have some interesting challenges, eg, we need 4 kts for canals, where most work is, The Rhine, mighty river runs nine knots in places, so we have to screw to suit , optimum, when we are done can we take liberty to run our drive train your way

[Guest625101138]

Originally Posted by lazeyjack

Well, Rick, I and BhNautika are working on a new canal river, coastal boat design, and we have some interesting challenges, eg, we need 4 kts for canals, where most work is, The Rhine, mighty river runs nine knots in places, so we have to screw to suit , optimum, when we are done can we take liberty to run our drive train your way

I will attempt to make some useful assessment and comment when it comes my way.

Rick W.

[tinhorn]

As a fairly new member here, may I echo lazeyjack's sentiments. This forum rocks, and Rick W. is one of the primary reasons why.

[Richard Atkin]

I couldn't agree more.

Rick, you obviously enjoy sharing your knowledge, and seeing others benefit from your help. Well, I have enjoyed receiving your help! If you managed to learn anything from me, directly or indirectly (I doubt it), then that would be great.

THANKS RICK

[Guest625101138]

Originally Posted by Richard Atkin

I couldn't agree more.

Rick, you obviously enjoy sharing your knowledge, and seeing others benefit from your help. Well, I have enjoyed receiving your help! If you managed to learn anything from me, directly or indirectly (I doubt it), then that would be great.

THANKS RICK

Richard
I am always learning and everyone has something to offer.

I learnt a long time ago, when I thought I knew most things, that simple observation by untrained people can give great insight if you are prepared to take heed. So I am loathe to dispel any honest observation.

I actually told a machine operator that what he observed could not possibly happen. I later determined he was spot on it was just that my brain could not readily comprehend the sequence of events that allowed the condition to occur. The fact that I ignored the observation meant a risk persisted longer than necessary that could have lead to many millions of dollars of damage.

Education and training usually provide a structured thought process that can constrain idea generation. I was once told that philosophy broadens the mind but it has not been an area of study for me. Your "different" outlook on design brings new perspective to importance of things I do not put much effort into.

I can recommend a good NA when you get around to detailing your design. I believe he is a bit too compliant to client's requirements but I guess it keeps him in work.

Rick W.

[Richard Atkin]

Rick,

It's nice to hear that my perspective has some value to you.

As for finding a good NA, I know you will only recommend a person who thinks things through properly. I am most likely to use whoever you recommend, when the time comes (assuming the NA is happy to accept the job).
The NA will discover that I am not a pain in the ass when it comes to safety issues.

I haven't ruled out the possibility of buying a boat that already exists, but it's unlikely because I'm so keen on seeing my drawings turn into reality.

Cheers

[Richard Atkin]

Hi Rick,

I didn't want to ask you for another optimised hull but i just can't get Michlet workiong on my computer.

if you get the time, would you mind sending me an opt hull to these specs:

20 ft LWL (6.1m)
8 kt boat speed
1000 kg displ

Hope i'm not being a hassle.

I'm looking at scaling down my original to design to one that fits with certain Californian regulations. I have discovered the 28 footer is a logistics nightmare, and is not the most ideal size for my purposes.

Thanks yet again for your time, if you have time. I'm in no rush.

[Guest625101138]

Originally Posted by Richard Atkin

Hi Rick,

I didn't want to ask you for another optimised hull but i just can't get Michlet workiong on my computer.

if you get the time, would you mind sending me an opt hull to these specs:

20 ft LWL (6.1m)
8 kt boat speed
1000 kg displ

Hope i'm not being a hassle.

I'm looking at scaling down my original to design to one that fits with certain Californian regulations. I have discovered the 28 footer is a logistics nightmare, and is not the most ideal size for my purposes.

Thanks yet again for your time, if you have time. I'm in no rush.

Richard
The attached is the Freeship file for the underwater portion direct from the Godzilla offset file. I doubt that the bumps have much bearing so I would just iron them out.

This has the typical shape of a displacement hull designed to operate well above hull speed.

Rick W.

[Richard Atkin]

Hi Rick.
Thanks very much for the hull you sent me. I haven't been at Boatdesign.net for ages and missed your post.

I did a 20 foot design and crudely guessed the shape of the hull. The Godzilla hull is much more narrow and deep. I will see how it marries with my design.

Hope things are going well for you.

Cheers

[Guest625101138]

Richard
Good to know you eventually got it.

I am back home and into paid work after some interesting pedal boating in North America.

Thought I should take my wife on a long holiday from home while planes still have the fuel to fly.

We plan to visit NZ next May if I am still in paid work. I hope to have a lightweight inflatable pedal boat for touring while there.

Rick

[Richard Atkin]

Hi Rick.

Man you must be fit....all that pedalling. Have you been to NZ before? The most extreme scenic places are only accessable by helicopter and boat. Dead quiet....perfect for canoeing or pedal boat. You do NOT want to use a motor.
May is a deathly cold time to go though....unless you are just visiting the north island. Your wife would need to do some pedalling too just to avoid hypothermia.

I want to be in California by then, so probably won't be able to offer you free rent in Wellington (If I am still here, the offer is there....maybe you already have that sorted out....whatever).

I tried to integrate the opt 6.1m hulls with my design but it created too many compromises with functionality, so I am sticking with my final (probably)design which is now 22 feet long (not posted yet). It won't be fast but wave-making doesn't seem to be such a problem at slower speed. The non-optimised hulls have slightly better wetted surface and better room to sit and stand etc.

It's interesting to me that displacement hulls designed to exeed typical hull speed, are shaped more like a straight tube with blunt ends. This is weird to me. I know that large aeroplanes have a blunt nose because this creates beneficial turbulance. The turbulent air close to the surface of the nose acts like ball-bearings which reduces friction for the outer airflow. I am just wondering if the physics is similar for fast displacement hulls.

If you don't know the answer or it takes too long to explain...don't bother


All the best

[Guest625101138]

Originally Posted by Richard Atkin

....

It's interesting to me that displacement hulls designed to exeed typical hull speed, are shaped more like a straight tube with blunt ends. This is weird to me. I know that large aeroplanes have a blunt nose because this creates beneficial turbulance. The turbulent air close to the surface of the nose acts like ball-bearings which reduces friction for the outer airflow. I am just wondering if the physics is similar for fast displacement hulls.

If you don't know the answer or it takes too long to explain...don't bother


All the best

Richard
The physics that you describe are not taken into account with the hull.

Without looking through the entire optimisation results the main factor that comes into play is trading off energy from the transverse waves to the diagonal waves. This is achieved through reducing beam and increasing buoyancy in the ends by making a blunter entry.

At some point with increasing speed it is more efficient to go for a planing hull.

Rick W.