Give Tahoe 23 a more racing look.

A forum for contacting other builders of Ken Hankinson designs. These designs are now a part of the Glen-L family.

Moderators: Bill Edmundson, billy c

Daniel79
Posts: 38
Joined: Sun Sep 21, 2014 9:37 am
Location: Netherlands (Europe)

Give Tahoe 23 a more racing look.

Post by Daniel79 » Mon Sep 22, 2014 11:43 pm

Hi everyone,

I'm thinking of redesigning the Tahoe 23 to give it a faster look. I think the cockpit is too far to the front of the boat and I want to eliminate the cockpit at the front. The steering will be situated in the middle cockpit. The front cockpit will be replaced by decking so a beatiful long sleek nose is obtained.

Any thoughts on if this is possible, if there are balance issues by doing this and maybe tips and tricks on this adjustment are greatly appreciated.

With kind regards,

Daniel van Straten. (Enthousiast from The Netherlands)
Boat-design.jpg
example.jpg

User avatar
Bill Edmundson
Posts: 11134
Joined: Wed Nov 23, 2005 6:45 am
Location: Birmingham, AL, USA
Contact:

Re: Give Tahoe 23 a more racing look.

Post by Bill Edmundson » Tue Sep 23, 2014 7:08 am

I don't think it would have much affect. You might need to add some weight up front or trim tabs.

Bill
Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
Tahoe 19 Build

User avatar
Bob Perkins
Posts: 452
Joined: Tue Mar 29, 2005 6:28 am
Location: North of Boston (MA)
Contact:

Re: Give Tahoe 23 a more racing look.

Post by Bob Perkins » Tue Sep 23, 2014 11:07 am

By the top view - you also changed the shape of the forward frames - and therefore the shape of the bow and the displacement and the front part of the boat.

That part matters.. at rest.. you can add bow weight and get it on the designed water line.. I'm concerned about how it would cruise and plane.

Not moving the motor is good since that is the largest mass..

Handling is my concern more than balance with your modifications.
Regards,
Bob Perkins

All the Fun Stuff
https://bperkins.wordpress.com/

sands35
Posts: 61
Joined: Tue Oct 16, 2012 5:30 am

Re: Give Tahoe 23 a more racing look.

Post by sands35 » Tue Sep 23, 2014 12:54 pm

As long as the motor stays in the same place, taking out the seats from the 1st row and replacing it with deck will likely be CG neutral. If you need to trim it, you will have a big battery you can move around. Narrowing the sheer doesn't do much to buoyancy as long as the chine (at or below the water line) and keel stay in the same place.

CG is CG - If the boat trims at rest, the CG won't move at speed (assuming it stays sort of level), so it will be fine at speed. On balance, it is probably better to have the CG a bit aft of designed as that can be corrected with trim tabs. A forward CG can't be corrected with trim tabs. A planing boat has the additional complexity of a changing LCB with speed changes.

User avatar
Bob Perkins
Posts: 452
Joined: Tue Mar 29, 2005 6:28 am
Location: North of Boston (MA)
Contact:

Re: Give Tahoe 23 a more racing look.

Post by Bob Perkins » Tue Sep 23, 2014 1:03 pm

I agree with "below the water line"

If you leave the shape the same from the designed water line down - should be pretty close to neutral.
I would be more concerned with a shape change down below if that were the case.
Regards,
Bob Perkins

All the Fun Stuff
https://bperkins.wordpress.com/

dmac
Posts: 54
Joined: Fri Jun 21, 2013 8:46 am

Re: Give Tahoe 23 a more racing look.

Post by dmac » Tue Sep 23, 2014 1:14 pm

If you can make it work functionally, your proposed new side profile certainly does look fantastic IMHO. The longer bow area that you have in mind makes the boat look very sporty and sleek. Very nice!

User avatar
Bill Edmundson
Posts: 11134
Joined: Wed Nov 23, 2005 6:45 am
Location: Birmingham, AL, USA
Contact:

Re: Give Tahoe 23 a more racing look.

Post by Bill Edmundson » Tue Sep 23, 2014 2:40 pm

I agree with the above comments. Leave it alone below the chine. The Tahoe has a lot of flair in the bow from chine to sheer. If you reduce that flair, I think you can get the look you want with out affecting the boat. I would make the forward frames per the design. only deeper. Then fair them down to what you want them.

If you open the link below you can see the flair in the frames.

Bill
Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
Tahoe 19 Build

sands35
Posts: 61
Joined: Tue Oct 16, 2012 5:30 am

Re: Give Tahoe 23 a more racing look.

Post by sands35 » Wed Sep 24, 2014 5:53 am

OP - have you looked at some of the older Hacker designs? He has some in the 18-26' range that are about what your design is.

Even changing the lofting for the above the chine work is not trivial. Best that you have a 3D CAD program to help you like DELFTship or something. DELFTship is free and purpose built to loft boats.

(not my picture) I'm pretty sure this is a Miss APBA design.
Image

There is a book out there called Forty designs for postwar boats , by Atkin, William.

LCCN 44008397 (Library of congress control number)

You can get it via inter-library loan. They have all the loftings and construction details - assuming you have a basic level of woodworking competency. They where all batten seam construction, but nothing says you can't do them with a cold molded method.

Daniel79
Posts: 38
Joined: Sun Sep 21, 2014 9:37 am
Location: Netherlands (Europe)

Re: Give Tahoe 23 a more racing look.

Post by Daniel79 » Thu Sep 25, 2014 1:45 pm

Thank you all for your comments so far.

My appologies for the rather late reaction. It's a bit hectic at the company at the moment.

Good to know that the general idea is that there will be no problem in replacing seats with decking. In understand that it's crucial to maintain the original design below the waterline. Narrowing the sheer might alter the handling of the boat. Is there a big difference in the way a Tahoe goes and the way a boat like the one from Miss APBA design (see post of Sands35) goes?

@Sands35: could you please educate me a bit more on the CG (Center Gravity?) and especially changing LCB (don't exactly know what this abbreviation means)?
@Bob: you are worried about cruising and planing. Is that due to the same issue Sands35 raises?
@dmac: Thanks for the compliment!
@Bill: thanks for the picture of the frames. Still have to get used to the english words like flair and chine. Pictures always help :D

@Sands35: Thanks for the Miss APBA design. I like it a lot, must look into this design a bit more. The book you are referring to doesn't contain the boat in the picture. I don't think I can get this book at a library in The Netherlands. Amazon also hasn't got it for sale. :(
Have to try something else to obtain the plans for this boat so I can study it better.

You guys are the best. Here in Holland there are no serious sites for boat builders like this one. Weird with all the water we have here and our history in boat building....

Pullie
Posts: 63
Joined: Sat Aug 31, 2013 11:09 am

Re: Give Tahoe 23 a more racing look.

Post by Pullie » Fri Sep 26, 2014 12:06 pm

Daniel79 wrote:Thank you all for your comments so far.

My appologies for the rather late reaction. It's a bit hectic at the company at the moment.

Good to know that the general idea is that there will be no problem in replacing seats with decking. In understand that it's crucial to maintain the original design below the waterline. Narrowing the sheer might alter the handling of the boat. Is there a big difference in the way a Tahoe goes and the way a boat like the one from Miss APBA design (see post of Sands35) goes?

@Sands35: could you please educate me a bit more on the CG (Center Gravity?) and especially changing LCB (don't exactly know what this abbreviation means)?
@Bob: you are worried about cruising and planing. Is that due to the same issue Sands35 raises?
@dmac: Thanks for the compliment!
@Bill: thanks for the picture of the frames. Still have to get used to the english words like flair and chine. Pictures always help :D

@Sands35: Thanks for the Miss APBA design. I like it a lot, must look into this design a bit more. The book you are referring to doesn't contain the boat in the picture. I don't think I can get this book at a library in The Netherlands. Amazon also hasn't got it for sale. :(
Have to try something else to obtain the plans for this boat so I can study it better.

You guys are the best. Here in Holland there are no serious sites for boat builders like this one. Weird with all the water we have here and our history in boat building....
That's why I am here ;-)

I built a 14 foot flying saucer with some modifications, if you ever want to look and see what the plams and instructions are like you're welcome to drop by, i live in the east region (Zutphen)

Daniel79
Posts: 38
Joined: Sun Sep 21, 2014 9:37 am
Location: Netherlands (Europe)

Re: Give Tahoe 23 a more racing look.

Post by Daniel79 » Fri Sep 26, 2014 3:33 pm

No way... I live in Zutphen also.
Je houdt me voor de gek, of niet?

This would give new meaning to the phrase:
It's a small world...

sands35
Posts: 61
Joined: Tue Oct 16, 2012 5:30 am

Re: Give Tahoe 23 a more racing look.

Post by sands35 » Fri Sep 26, 2014 6:42 pm

LCB = longitudinal center of buoyancy
CG = center of gravity

The boat will change pitch until the cg and the lcg line up. Of course that is at displacement speeds.

I can post the table of offsets for a 25' version next week. The plans are in the public domain.

Daniel79
Posts: 38
Joined: Sun Sep 21, 2014 9:37 am
Location: Netherlands (Europe)

Re: Give Tahoe 23 a more racing look.

Post by Daniel79 » Sat Sep 27, 2014 1:00 am

Hi Sands35,

I'm curious about the table of offsets. If you could post or email these that would be great.

What about the cg and lcg at planing speed?

What do you mean by "the plans are in the public domain" Are the plans for the Tahoe available for free? I doubt that this would be the case. If so, any idea where I can find them?

Kind regards, Daniel.

sands35
Posts: 61
Joined: Tue Oct 16, 2012 5:30 am

Re: Give Tahoe 23 a more racing look.

Post by sands35 » Sun Sep 28, 2014 2:43 pm

Tahoe plans are not free to use. Many of the early Hacker, Gar Wood, etc. designs are not copyright protected, so are free to use.

Basically, you want the CG to be behind the LCB. There is a reason why most modern boats have the engine mounted as far aft as possible. But you can't just arbitrarily move the motor around.

khundley
Posts: 252
Joined: Fri Aug 13, 2010 11:12 am
Location: Wilmette, IL (Just outside Chicago)
Contact:

Re: Give Tahoe 23 a more racing look.

Post by khundley » Sun Sep 28, 2014 7:27 pm

Not that I have any real experience with this, but I would be concerned that, trim and CG issues aside, would there not be too much bow in front potentially obstructing the driver's view when moving the driver back one cockpit? There is a reason the cockpit openings are spaced out in this design the way they are. Again, forgive me if I am incorrect.
Ken Hundley
http://www.nocturnalguitars.com

So, my big brother was playing guitar and I figured I'd try it too.
- Stevie Ray Vaughan

Post Reply

Return to “Hankinson designs”