Re-rigging single line reefing boom

[emandvee44]

We are not using the boat this year, mainly due delays caused by the virus and other commitments. I have identified some projects to undertake, one of which is to re-rig the reefing system. The reefing lines are in good shape, but are in my opinion too thick. They are all 14mm braid and the stoppers struggle to close on them, and there is the added friction due to their size. I am planning to replace with 12mm braid on braid. Selden have an operational diagram which gives a good idea of what is inside the boom.



I assume that I will have to remove the boom outer end fitting which is secured with star screws and pull the internal car out of the boom, at which point the old 1 & 2 reef lines can be removed (no.3 is a single line) It seems likely that some mice will be required to run the new lines. I can only guess as to the length of the lines so I will have to do the job in two stages; remove old lines, mouse. Measure (twice) and make up new lines and install.
Any comments /tips?
Thanks,
M.

 

[Norman_E]

That diagram shows that the luff line is attached to the traveller inside the boom. Not all single line systems are like that. When I had one (since replaced with twin lines to reduce friction) the travelling part consisted of two blocks back to back and both lines could be moused, removed, and replaced. If your system is as shown just mouse and replace the leach line. The luff line will be under tension equal to the halyard tension in the setup shown, whereas the leach line is under less and can be thinner. On my 45 foot boat all the reefing lines were 10mm in the single line system.

EDIT: My point is that you should not need to take the traveller out unless you are replacing the luff line, which I doubt you need to do, as all the friction and problems with clutches comes from the leach line.

 

[emandvee44]

That diagram shows that the luff line is attached to the traveller inside the boom. Not all single line systems are like that. When I had one (since replaced with twin lines to reduce friction) the travelling part consisted of two blocks back to back and both lines could be moused, removed, and replaced. If your system is as shown just mouse and replace the leach line. The luff line will be under tension equal to the halyard tension in the setup shown, whereas the leach line is under less and can be thinner. On my 45 foot boat all the reefing lines were 10mm in the single line system.

EDIT: My point is that you should not need to take the traveller out unless you are replacing the luff line, which I doubt you need to do, as all the friction and problems with clutches comes from the leach line.

Thanks - good point, time, effort and money-saving!
M.

 

[Catalina36]

You don't state the size of the boat but even 12mm is almost certainly too thick. 10mm is more than adequate in most cases.

 

[duncan99210]

If you’ve got a Seldon boom, the. 14mm is way too thick. I replaced my lines with 10mm rope, which is much more manageable from the friction point of view. It’s also more than strong enough to cope with the loads.
Replacing the lines.
For the first, second and third reefs, you’ll need to mouse the lines running to the back of the sail. It’s a simple job, just make sure the mousing connection is good. For the luff lines, you’re correct in assuming that you’ll need to remove the end fitting from the boom: that’s actually pretty simple. It’s a case of removing two screws and pulling the fitting out. The line from the car to the luff needs an eye splice on the end of it to attach it to the car inside the boom. I don’t think there’s enough room for a knot inside the boom, hence the splice. Again, the rope to the front of the boom needs mousing to replace it.
As to length, the luff ropes should be the length of the boom. The first and second reefs need to take account of the doubling inside the boom but the easiest way to check that is to measure the old lines. IIRC for my Bavaria 38, I bought 3 x 35m lengths. I ended up with enough line to do the job plus enough to make a 3 coloured rope mat from the leftovers.

 

[Norman_E]

You don't state the size of the boat but even 12mm is almost certainly too thick. 10mm is more than adequate in most cases.

True, but when I changed to twin line reefing I went for 12mm simply because the clutches on my boat grip best on 12mm and crucially its kinder on the hands when pulling in the reefs.

 

[TernVI]

On the other hand, it may be worth checking all the sheaves go round.
The sheaves inside the boom must be on the small side for such thick rope, which can cause a lot of friction.

 

[vyv_cox]

When I installed my single line reefing I removed the end fitting, old Kemp boom, which was pop-riveted. I replaced the rivets with Riv-nuts. My pennants were 12 mm braid-on-braid, which I replaced with 10 mm Dyneema, although I now realise that 8 mm would have been perfectly good, reducing friction even more. Check that clutches will take the new line size.

 

[cpedw]

I replaced the leech line with 8mm Dyneema and it works fine. The clutch holds well and I use a winch a lot so the small size is not a problem for my delicate hands. My case was simper as only reef 1 is single line. I left the luff line as is to save the bother of accessing inside the boom.
Now Vyv has posted so I feel I got it right!