Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 15-03-2010, 10:08   #1
Registered User
 
UnlikelyVoyager's Avatar

Join Date: Dec 2009
Location: Huntington Station, NY
Boat: Tom Gilmer designed "Blue Moon"
Posts: 156
Send a message via AIM to UnlikelyVoyager
Size of Line For Towing Dingy?

I need to tow a 8', 100lb dingy behind my sailboat for a thousand miles or so (no room on cabin top).

The dingy tows easily but I'm sure to encounter some rough weather along the way, so I want to make sure the tow line doesn't part.

On the other hand, I want to minimize the width of the line to minimize drag.

Additionally, I want a line thick enough to handle, in case I need to let line out or haul line in, to adjust for an easy tow.

What's a good compromise size? I'm thinking 3/8", with about 3000 lbs breaking strength.

TIA: John
__________________

__________________

Check out my blog: UnlikelyBoatBuilder.com
UnlikelyVoyager is offline   Reply With Quote
Old 15-03-2010, 10:26   #2
Registered User
 
cdennyb's Avatar

Join Date: Jun 2007
Location: Northern California
Boat: finally a catamaran dive boat...
Posts: 505
Send a message via MSN to cdennyb Send a message via Yahoo to cdennyb Send a message via Skype™ to cdennyb
you might consider (2) seperate lines if it stays behind for a long time. One tight, the other slightly slack and ties to a seperate location. If one chaffs or has an issue and parts you havent lost your 'taxi'. your decision sounds reasonable.
__________________

__________________
the perfect dive boat is one you're on...
cdennyb is offline   Reply With Quote
Old 15-03-2010, 13:04   #3
Registered User
 
UnlikelyVoyager's Avatar

Join Date: Dec 2009
Location: Huntington Station, NY
Boat: Tom Gilmer designed "Blue Moon"
Posts: 156
Send a message via AIM to UnlikelyVoyager
Not a bad idea!
__________________

Check out my blog: UnlikelyBoatBuilder.com
UnlikelyVoyager is offline   Reply With Quote
Old 15-03-2010, 13:21   #4
Registered User
 
Hydra's Avatar

Join Date: May 2009
Location: Lorient, Brittany, France
Boat: Gib'Sea 302, 30' - Hydra
Posts: 1,229
I would recommend good chafe protection, inspected often.

Alain
__________________
Hydra is offline   Reply With Quote
Old 15-03-2010, 13:27   #5
Registered User

Join Date: Nov 2005
Location: Ohio
Posts: 2,311
We have a light painter for tying up and then use one of our dock lines for towing. 1" 8 plait, haven't lost the dinghy yet.
__________________
Joli is offline   Reply With Quote
Old 15-03-2010, 13:36   #6
Sponsoring Vendor
 
Tellie's Avatar

Community Sponsor

Join Date: Oct 2007
Location: Hollywood, Fl.
Boat: FP Athena 38' Poerava
Posts: 3,045
I've never had good luck towing the dingy over long hauls except in calm condtions. But I'm very intriged by this comment "On the other hand, I want to minimize the width of the line to minimize drag." Am I mising something here? I'm not trying to be a smart azz really, but you're wanting to tow a 100lb dingy and the diameter of the line is a concern? How so?
Tellie is offline   Reply With Quote
Old 16-03-2010, 07:34   #7
Registered User
 
UnlikelyVoyager's Avatar

Join Date: Dec 2009
Location: Huntington Station, NY
Boat: Tom Gilmer designed "Blue Moon"
Posts: 156
Send a message via AIM to UnlikelyVoyager
Quote:
Originally Posted by Tellie View Post
I've never had good luck towing the dingy over long hauls except in calm condtions. But I'm very intriged by this comment "On the other hand, I want to minimize the width of the line to minimize drag." Am I mising something here? I'm not trying to be a smart azz really, but you're wanting to tow a 100lb dingy and the diameter of the line is a concern? How so?
So, we are talking about a hard, flat-bottom Atkin-designed dingy that was designed to row and sail. Thus, the dingy itself has very little resistance.

On the other hand, when I'm towing a dingy even 5 or 10 miles off shore, sometimes you need to let a lot of line out to position the dingy in the right place, relative to the waves.

With more than a few feet of line out, the line is in the water, of course.

I don't have any science to prove this, but if you think about it, if the tow line is very short, it is not in the water and presents 0lbs of towing 'friction'. All the friction comes from the dingy.

But as you let more and more line out, the line dips into the water and starts to add its own friction.

At some length of line, the friction of the line must be greater than the friction of the dingy.

This is why people talk about towing lines behind them in storms, as a kind of sea anchor.

So, I can't say exactly how much friction 50 or 100' of towing line ads up to, but it's not 0.

Now... would you notice a difference between 3/8" and 1" line? I'm not sure, but my gut says you would see a difference if you dragged 200' of 1/4" line, vs. 200' of 5" line, so...

Obviously, I had too much time to think about this, yesterday! Time to get back to reality-based sailing!

-- John
__________________

Check out my blog: UnlikelyBoatBuilder.com
UnlikelyVoyager is offline   Reply With Quote
Old 16-03-2010, 11:21   #8
Senior Cruiser
 
FSMike's Avatar

Cruisers Forum Supporter

Join Date: Aug 2009
Location: Bahamas/Florida
Boat: Solaris Sunstar 36' catamaran
Posts: 2,654
Images: 5
Unlikely -
You might seriously consider a floating line (polypropylene) to keep the painter out of the prop when motoring. If you're going offshore investing in a good snug cover for the dink is a good idea to keep it from swamping from spray, waves, etc. Along that thought, if your dinghy has a daggerboard you need to seal off the daggerboard trunk to keep water from splashing up.
__________________

__________________
Sail Fast Live Slow
FSMike is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not 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 Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
What size line for sea anchor? Beneteau 50 bene505 Deck hardware: Rigging, Sails & Hoisting 7 22-04-2009 15:58
Advise for Preventer Line Size Firehoser75 Deck hardware: Rigging, Sails & Hoisting 27 18-02-2009 17:37
Towing bridle Aquah0lic Auxiliary Equipment & Dinghy 4 16-01-2009 09:47
Fuel Line size Charlie Engines and Propulsion Systems 8 28-06-2008 13:18
Dingy Prop Size Jon D Auxiliary Equipment & Dinghy 12 17-07-2006 10:20



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 09:09.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.