How to find a rudder design? - Page 2 - SailNet Community
SailNet FAQ This forum is specifically on the Sailnet Website and how to do certain things on the website. Please note - any other threads will be deleted.

 1Likes
Reply
 
LinkBack Thread Tools
post #11 of 17 Old 04-27-2019
Senior Member
 
Join Date: Oct 2011
Location: Nanaimo B.C.
Posts: 4,427
Thanks: 5
Thanked 135 Times in 134 Posts
Rep Power: 8
 
Re: How to find a rudder design?

If it's anything like Canadian rules and regs, Overnight guests are passengers requiring things like watertight bulkheads ,all sorts of fire alarms and gear ,just for starters.even if the boat never leaves a dock. Dept of Transport doesn't hand out the ticket easily Getting legal may be more work than getting the boat to sea. I was licensed for 18 day passengers and 6 overnight so got good at jumping hoops.building the boat was easier.
Capt Len is online now  
Sponsored Links
Advertisement
 
post #12 of 17 Old 04-28-2019
Dirt Free
 
boatpoker's Avatar
 
Join Date: Jul 2008
Location: Toronto
Posts: 2,498
Thanks: 22
Thanked 141 Times in 136 Posts
Rep Power: 11
 
Re: How to find a rudder design?

Quote:
Originally Posted by Capt Len View Post
If it's anything like Canadian rules and regs, Overnight guests are passengers requiring things like watertight bulkheads ,all sorts of fire alarms and gear ,just for starters.even if the boat never leaves a dock. Dept of Transport doesn't hand out the ticket easily Getting legal may be more work than getting the boat to sea. I was licensed for 18 day passengers and 6 overnight so got good at jumping hoops.building the boat was easier.
I don't know about US rules but that's not the case in Canada. A friend has been running a B&B on a boat in Toronto harbour for 7 or 8 yrs. without having to follow TC passenger carrying rules as he never leaves the dock with passengers. I did his survey and have worked with TC on several Toronto tour boats approvals.

The hysterical laughter you hear as you drive a way in your"new" boat ..... is the seller.

Last edited by boatpoker; 04-28-2019 at 12:10 AM.
boatpoker is online now  
post #13 of 17 Old 04-28-2019
Member
 
Join Date: Feb 2014
Posts: 56
Thanks: 2
Thanked 3 Times in 3 Posts
Rep Power: 6
 
Re: How to find a rudder design?

Tall Ship, since your goal is having a vessel for sailing and chartering, and your goal does not seem to be restoration of a historic vessel, then have your naval architect design the new rudder in steel. Nice NACA airfoil shape. Semi balanced if necessary. It will be many times more effective than a wood rudder.
makobuilders is offline  
 
post #14 of 17 Old 04-28-2019
██▓▓▒▒░░▒▒▓▓██
 
Join Date: Apr 2006
Posts: 13,643
Thanks: 11
Thanked 253 Times in 248 Posts
Rep Power: 15
   
Re: How to find a rudder design?

tallsip, if you aren't lucky with dice and don't want to totally bodge the job (at a high price) then try to contact the builder or designed and find out what the rudder had been designed as. Otherwise spend the money on a naval architect or designer. It will be cheaper than getting it wrong--which is VERY easy--and then having to redo the job multiple times until you can it right.

Similarly on the prop. If you can't figure out what the transmission is, get a mechanic who can figure it out. You will need to know the engine, the transmission, and the weight of the vessel before a prop shop can even guess at what you need, and even then it may not be right on the first try. The same mechanic or prop shop can probably tell you what kind of shaft you need, and whether that also needs a shaft log and support, and just how long it should be to keep the prop clear of the hull and rudder.

"Close" is good enough for horseshoes, but you will find it often is simply an expensive mistake on something like a 100' long ship. Things come back to bite you, if they aren't right the first time. And finding good help is not easy--at any price.
hellosailor is offline  
post #15 of 17 Old 04-29-2019
Member
 
Join Date: Feb 2014
Posts: 56
Thanks: 2
Thanked 3 Times in 3 Posts
Rep Power: 6
 
Re: How to find a rudder design?

Quote:
Originally Posted by Tall ship surprise View Post
It would Portland Oregon. I'm hoping to get the big lady ready to sail down the west coast and set up down in Chula Vista CA this winter as a Air Bnb.
If I were more experience, I wish I could go around the world, and end up in maine. maybe catch lobster off the boat
I might get crucified for saying this, but here' a suggestion for your AirBnB...

If your engine/shaft/prop works are exorbitant (likely) then how about just pull the engine out and sell it for a couple grand. Plug the holes in the hull, fair the deadwood, install the high lift steel rudder that your naval architect will easily design... and go engineless.

It's a floating hotel that doesn't move. If you want to go for a sail then take your two launches and use them as tugs to tow out of the marina into open water. Then sails up!

Might make some good marketing points on the brochure as well.
makobuilders is offline  
post #16 of 17 Old 05-09-2019
Moderator
 
MarkofSeaLife's Avatar
 
Join Date: Nov 2010
Location: London!
Posts: 6,018
Thanks: 61
Thanked 277 Times in 250 Posts
Rep Power: 10
 
Dock
Re: How to find a rudder design?

I spose it's all to late as the OP hasn't been back and said he was buying this 100ft ferrocement "tall ship".

But I chuck my warning in that the rules change when the boat is over 24 Meters/80 feet internationally.

I don't know about the USA but I feel they would be in compliance with it.

A private person can't captain a boat 24 metres and over unless they have a pretty good license.
To employ a skipper to do it the boat would need to be seaworthy.
For it to be used as a commercial enterprise the USCG would want it inspected, even as a 'dockside attraction' or whatever BS word they used for the Bounty.

As most ferrocement boats are home built (probably in the 1970s) no naval architect will look at designing a new rudder, or if he wanted to, could.
One wonders how the old rudder disappeared, along with the prop and shaft, except for some weird misadventure.

The word 'misadventure' rings clear in my mind... of this boats past and its future.

Finally I think everyone here has written very politely in response to this guy's endeavour.
I hope he has reconsidered buying this huge boat and perhaps jump a bus to safety


Mark

Sea Life
Notes on a Circumnavigation:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


People can say they want freedom, but offer them the keys to what chains them, a map to where they want to go,
And they'll turn it down for the cell they know
MarkofSeaLife is offline  
post #17 of 17 Old 05-09-2019
Member
 
Join Date: Feb 2014
Posts: 56
Thanks: 2
Thanked 3 Times in 3 Posts
Rep Power: 6
 
Re: How to find a rudder design?

Yes the OP seemed to have disappeared and I'd be curious to know how he is progressing, or what his final decision is.

BTW, if I recall correctly, that 23.8 length barrier is measured as the load line length, similar to length between perpendiculars. A creative naval architect could conceivable measurement and document the boat's LLL as 78ft even thought the overall is 100ft.
makobuilders is offline  
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Barn door rudder design bmwdude Sailboat Design and Construction 13 03-03-2017 09:40 PM
Drop rudder design basssears Gear & Maintenance 2 11-20-2010 06:56 PM
AC / DC Lighting – a stylish design solution for the design obessive DIY… artbyjody Electronics 0 11-03-2009 02:33 PM
Weather Helm/Rudder Design tschmidty Sailboat Design and Construction 9 11-13-2008 01:25 PM
Perry on Design Piper one Design Jeremy Monk General Discussion (sailing related) 0 05-14-2006 07:53 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome