View Full Version : Self-Tending Jib Boom

06-13-2015, 03:04 PM
First, thanks for checking out this posting. I recently came across this forum as I was trying to find articles/photos of small sailboats that were rigged with jib booms. While I haven't yet been able to find anything like the setup on my 1976 Melges X-boat (I know, I know, it's a glass boat), even after inquiries with the factory rep's, I have been able to deduce that it is likely a self-tending jib. Unfortunately, when I bought the boat a couple of years ago, it was mostly disassembled, so I don't know how things are supposed to be attached and rigged.

I've taken photos of the jib boom with it's mounted hardware, and a photo of an assembly of a snap hook and two blocks that I think figures into the self-tending scenario. If anyone knows how I should be setting this up to function as intended, I would be extremely grateful.

I've spent over an hour trying to post the photos to this thread (no wonder I can't figure out the jib), with only frustration to show for it thusfar. So, instead of looking at photos in this posting, if you would be kind enough to just view the 5 photos I have up on Flickr at https://www.flickr.com/gp/134062344@N04/yWC78Y I would be very grateful.

If photos of anything else would be helpful, I'm very happy to provide them as well.

I appreciate your understanding.

Howard Henneman

George Ray
06-13-2015, 03:49 PM
Can't stop, just passing through and had only a moment to do a search....
Good luck on your project.
I love searching google and wooden boat forum for stuff.
This might be useful (club jib)

And This (posting pictures)

06-13-2015, 04:00 PM
Something like this?



06-13-2015, 04:05 PM
This is an old ad, but this one seems to have one. Keep Googling. Good luck.

Ian McColgin
06-13-2015, 04:15 PM
Not a balanced club. The earliest Melges X boats had a club attached to the foot of the sail but that's been dropped. The current boats have no club and you might double check the cut of the jib you have to be sure it and the club match. It does not appear that the clubbed rig was laid out to be self-tending. That sort of club won't set well if sheeted to a midships place. Even clubs pivoting on a deck post a bit abaft the jib's tack need either a track or horse so that there can be good down pull. The clue from that pair of clew bocks is that you are meant to have a sheet on each side.

The shape with that taper is a little odd. So's the end fitting. And that thin bale around it. And the lack of fittings at the other end, just the hole. All in all, I'd see how the jib sets without the club first.


06-16-2015, 08:08 AM
While the spar is functionally a boom, its proper name is "club". A jib boom, jib-boom or jibboom (depending on where you went to school ;) :d ) is an extension of a bowsprit, in the same way that a topmast is an extension of a mast.

Anyone who's shared a foredeck with the spar under discussion will know why it's called a club!

Jay Greer
06-16-2015, 12:14 PM
Indeed it is called a "Club" as well as a "Widowmaker". A well set up self tending club footed jib, needs an athwart ship control line to adjust its angle to the center line of the boat in order to not over flatten it by taking out the draft by too much down pull.

06-16-2015, 01:45 PM
These are great for smaller boats, where you don't go forward much. The tension on the clew varies depending on how much you slack the sheet, so the sail is pretty tight when hard on the wind and pretty full when running off. The are self tacking, basically you just put the helm down, staysail and main change sides on their own and then start sailing on the other tack. Note the club is not attached to the stay, but set on a post on the deck a little aft of the stay, so it turns around a different centre.
You lose a bit of effective area or drive, because it is not overlapping, and the club is in the way at times, like when anchoring...there is always tradeoffs.

Tom Hoffman
06-16-2015, 05:56 PM
Take a look at Model Yacht sailboat building they use a jib boom for a very practical reason, no crew. I would think it would be very easy to rig one. I have one on my 1 meter Sea Wind boat.

http://i90.photobucket.com/albums/k276/slvrgost/tall-sailboat-remote-control-model-sailing-boat-seawind-6_zps56iihtc7.jpg~original (http://s90.photobucket.com/user/slvrgost/media/tall-sailboat-remote-control-model-sailing-boat-seawind-6_zps56iihtc7.jpg.html)

Todd Bradshaw
06-16-2015, 08:04 PM
The biggest advantage to that sort of rig with the jib attached to the deck partway aft on the spar (used on a lot of old iceboats as well as model sailboats and others) is that it is self-vanging. Despite having minimal control lines that may not be sheeted to a place which would generate good jib shape, the clew stays down, avoiding twist and keeping the whole jib working.


Tom Hoffman
06-17-2015, 10:42 PM
On our RC boats we installed what I believe would be called a topping lift to the aft end of the jib boom, It ran up to the top of the sail shackle and then through a piece so you could adjust the tension and by doing this pull the jib boom up and give a fuller jib shape.

We also installed a weight on the bow end of the jib boom that helped when tacking to snap the jib over to the opposite tack very quickly as the boat starts to take the new tack.