Boom twists while reefing... - SailNet Community

   Search Sailnet:

 forums  store  

Quick Menu
Boat Reviews  
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Hatches and Portlights
Interior And Galley
Marine Electronics
Other Items
Plumbing and Pumps
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here

Go Back   SailNet Community > On Board > Gear & Maintenance
 Not a Member? 
Old 01-08-2012
MedSailor's Avatar
Closet Powerboater
Join Date: Mar 2008
Location: Anacortes PNW
Posts: 3,326
Thanks: 204
Thanked 103 Times in 93 Posts
Rep Power: 8
MedSailor is on a distinguished road
Boom twists while reefing...

A question that has plagued me for some time. Why does my boom twist up to 90deg when I reef?

My reefing setup a "jiffy reefing" setup I believe (tack is hooked separately to the boom near the gooseneck) and is as follows: I have a winch on the starboard side of the boom and a cleat to affix the working reef line. The reef line goes inside the boom and exits at a sheave at the AFT END of the hollow boom.

The reefing line then exits the aft end of the boom, goes through the leech reefing cringle and back down to the the port side of the boom where it is fixed to an eye with a bowline. The eye it is fixed to is part way up the boom, about the same fraction forward as the reef cringle is forward.

When I crank down on the reefing line the boom lifts and the line snugs the cringle up to the boom as it should, but the whole boom rotates/twists at the gooseneck. The starboard, or winch side, of the boom ends up facing the sky.

The boom is a Spartec spar and they were supposedly a really good spar maker/designer, but I wonder about the reefing lines exiting at the aft end of the boom. Other boats have the reefing line exit part way aft at a block on the starboard side instead of the aft end.

Anyone able to give hints at what's wrong (if anything at all)? If so you get extra points for doing it without the help of pictures or a diagram.

I have a sauna on my boat, therefore I win.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Quick reply to this message Share with Facebook
Old 01-08-2012
Faster's Avatar
Just another Moderator
Join Date: Sep 2005
Location: New Westminster, BC
Posts: 16,219
Thanks: 100
Thanked 294 Times in 284 Posts
Rep Power: 10
Faster has a spectacular aura about Faster has a spectacular aura about Faster has a spectacular aura about
Any chance your boom was originally a 'roller reefing' (around the boom) setup? Plenty of boats in the 60s and 70s seemed to have been set up that way. If so there will be a 'hex' type of gear drive built into the boom at the gooseneck.. if it's been converted to slab reefing the original crank handle may well have long disappeared.

In any event there's no need for the boom to have that much rotational freedom of movement and I'd be looking at the gooseneck arrangement to see if you can 'pin' the boom to prevent that rotation. 90 degrees, esp, seems an awful lot of 'free play'...

1984 Fast/Nicholson 345 "FastForward"

".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)
Reply With Quote Quick reply to this message Share with Facebook
Old 01-08-2012
Senior Member
Join Date: Apr 2003
Posts: 4,192
Thanks: 50
Thanked 38 Times in 37 Posts
Rep Power: 15
knothead has a spectacular aura about knothead has a spectacular aura about knothead has a spectacular aura about
That's a very common system. It sounds to me like maybe you're just cranking it too tight. Your mainsheet should keep the bottom of the boom down.
After you set your reef and snugged up the halyard, try easing the reef line slightly.

You might also simply tie the reef line off at the cringle instead of bringing it back down to the boom. You will lose the purchase, but with a reefing winch, that shouldn't be a problem. Then there won't be any forces trying to twist the boom.
Reply With Quote Quick reply to this message Share with Facebook
Old 01-08-2012
tap tap is offline
Senior Member
Join Date: Apr 2009
Posts: 176
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 7
tap is on a distinguished road
I've seen plenty of booms where the reefing line exit at the aft end of the boom. Often there are two or three sheaves side-by-side for the outhauls. The center is the normal outhaul and the outside sheaves are for reef 1 and reef 2.

Does the reef line exit on the starboard side of the aft end? Normally what you do is have the reef line exit on one side of the centerline (stbd), go through the leech cringle, entering on the same side (stbd) and exiting on the other (port). Then it goes down to the boom on that side (port), wraps under the boom and up the other side (stbd), and is tied to itself. E.g., tie a bowline in the end of the line around the line as it comes down to the boom on the port side. This works with a loose footed main or a one with holes for the line to pass though in the foot shelf.

There are a number of advantages to wrapping the line under the boom instead of going to an eye.

You don't have an eye that the reefing line is trying to twist off the boom. You don't even need the eye.

It's much stronger as the entire boom is taking the force of the reefing line vs just the attachment point of the eye.

The loop will slide for and aft on the boom to be positioned directly under the leech cringle, where it belongs. The eye can not move to match the sail.

How does the reefing tack attach exactly? I wonder if that's the thing that is twisting your boom and not the leech.
Reply With Quote Quick reply to this message Share with Facebook
Old 01-08-2012
travlineasy's Avatar
Morgan 33 O.I. Perryville
Join Date: Dec 2010
Location: Maryland
Posts: 3,138
Thanks: 3
Thanked 122 Times in 107 Posts
Rep Power: 5
travlineasy will become famous soon enough
I had the same problem with my 33 Morgan O.I. and the problem turned out to be a loose bolt in the end of the boom near the connection to the mast. I added a star type lock washer, torqued it down and it hasn't happened since.

Hope this is helpful,

Reply With Quote Quick reply to this message Share with Facebook
Old 01-08-2012
RichH's Avatar
Senior Member
Join Date: Jul 2000
Location: Pennsylvania
Posts: 3,270
Thanks: 20
Thanked 126 Times in 116 Posts
Rep Power: 15
RichH will become famous soon enough
Your leech reef cringles are probably adding a LOT of friction to the reef and forcing the unreefed portion of the sail to be 'principally' attached to the side of the boom or nearer to the reef line terminal attachment than the centerline.

Several things can lessen this ... SLIPPERY reef line and/or Goļot 'reefing blocks' / blocks that fit inside the ID of the reef cringles .... OR mount a 'secondary' cheekblock on the 'other' side of the boom opposite the terminal connection ... boom aft sheeve --> cheekblock --> reef cringle --> reef line terminal connection.

Goļot reefing cringle blocks:
Reply With Quote Quick reply to this message Share with Facebook

Quick Reply

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:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Frozen roller-reefing boom spin1012 Gear & Maintenance 4 06-20-2010 08:15 AM
Old tyme roller reefing by boom rolling.. groundhog Gear & Maintenance 9 04-30-2010 06:24 AM
Reefing your mainsail by rolling the boom.. groundhog Gear & Maintenance 9 06-25-2008 05:22 PM
Rooler reefing boom for Morgan 49 OI JSOUTO Morgan 2 04-04-2008 02:20 PM
Profurl In-Boom Reefing/Furling Sailormann Gear & Maintenance 7 02-10-2007 07:39 PM

All times are GMT -4. The time now is 04:48 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2015, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) LLC 2000-2012

The store is owned and operated by a company independent of the forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.