Boom Clutches / Jammers

[rajjes]

The goosneck end of the boom has 3 jammer handles for the outhaul and reefing lines which pass through the boom and exit via small sheeves and pass above the jammers. When the jammer is tightened it grips (or should) the line.

Unfortunately these do not seem to be gripping the lines well and I have to make the lines fast to the mast winch/cleats. As the mast foot is quite busy this tends to get messy and I would prefer if I could use the jammers reliably.

The handles seem to very loose and I'm wondering of there should be some sort of spring arrangement to tighten the jammer against the lines?

The mast/boom are proctor 1980 vintage and hopefully there's a pic attached.



Duncan

 

[geem]

Normally with these you need to lift the handle to make the rope grip whilst you release the tension on the line. They don't have springs.

 

[rajjes]

Thanks, for reply.

I was hoping that springs could be fitted as browsing the Selden brochure seems to show that similar (albeit more recent) jammers are spring loaded.

First page on: http://www.seldenmast.com/products/pdfdownload/__file_excerpts/595-808-E-78-78.pdf.html

 

[Spirit of Glenans]

As a keelboat instructor, I constantly have to explain these jammers as succinctly as possible from first principles, so here goes:
1. Using the mast winch, tension your outhaul/reefing line to the amount required, then harden it up a little more, perhaps two or three of clicks of the ratchet.
2. Put down the winch handle and hold-in the turns of line round the winch barrel with the hand you used for winching.
3. With your other hand, the one you used originally for tailing the line, hold in the jammer, while gradually releasing tension on the line by turning the line back anti-clockwise on the winch-barrel.
The teeth of the jammer will engage with the line, and friction, combined with the tension in the line, will keep it in place.
A sharp tug should release it, or if that doesn't suffice use the winch.
If the above technique still fails to hold these lines securely, I would suspect that your outhaul/reefing lines are worn in the relevant area and would suggest you replace them or at least 'end-for-end' them.