[C320-list] Single Line Reefing

[Cliff Lee via C320-list]

After experiencing considerable resistance in adjusting our double line
reefing system, we discovered the lines were twisted inside the boom. We
were able to pull the aft block out through the end of the boom and untwist
the lines. Resistance vanished. I realize this is not necessarily the
issue at hand in this latest email thread, but it may be useful for anyone
experiencing issues with their reefing system.

Cliff Lee
Previous Comfort Zone Owner - 1995 Hull 268

[Jack Brennan via C320-list]

Even though I usually don't reef, I'm tempted to tinker with the boom sheaves and see what I can do.

Jack Brennan
Sonas, 1998 Catalina 320
Tierra Verde, Fl.

________________________________
From: C320-list <c320-lis...@lists.catalina320.com> on behalf of Cliff Lee via C320-list <c320...@lists.catalina320.com>
Sent: Tuesday, October 28, 2025 10:28 PM
To: c320...@lists.catalina320.com TtS <c320...@lists.catalina320.com>
Cc: Cliff Lee <rcliff...@gmail.com>
Subject: [C320-list] Single Line Reefing

[P.F. Ross via C320-list]

Jack and all,

I sail in similar conditions as Jack in SWFL and do use my single line
reefing occasionally, but I will try your jib and/or main alone schemes
next time I need to.

On this list over the years there has been much discussed about single line
reefing and I have tried a few different arrangements. However, I am most
satisfied with the setup I have now. I have posted a pic on my Owners
Gallery,
https://c320.org/mediagallery/media.php?f=0&sort=0&s=20251029161419405.
This is a marked up view on an image taken from the list that someone
posted probably decades ago. I believe the line routing is just as it was
when my boat was delivered in 1994.

My analysis of a friction free reefing system shows that tension T on the
cockpit reefing line would result in a force T downward at the tack cringle
and an angled force 2T downward and aft at the clew cringle. In reality,
there is friction and that is what most people seem to fight with this
system. The small sheaves in the front and rear of the boom (can't
remember exactly how small and I am not at the boat at the moment)
don't help, but not much we can do about those (but I haven't really
thought much about it). But what I call the "balancing block" inside the
middle of the boom has tiny sheaves and is a main friction source, IMHO.
So, I fashioned a balancing block with a couple of single blocks I bolted
together. I sized them (don't remember how big) so they would just fit
into the hole at the end of the boom. I also have a store-bought block
that I bought from Vela years ago (Seasure 29.60) but I have never
installed it since my homemade arrangement is still working.

Another modification I made to the original setup was to add a strap to the
outside of the boom so I could knot off the line coming down from the aft
cringle at somewhat of an angle, rather than coming straight down and
tying around the boom per original setup. This pulls the aft end of the
sail farther back as it is being reefed, more so than if this line came
straight down and tied off around the boom. This helped tremendously in
keeping the foot of the reefed mainsail tight.

I currently simply run the clew reefing line through its cringle, although
others would add a block here to reduce friction further. I have such a
block, just have not bothered to install it.

Some have suggested doing away with the balancing block entirely and I
tried that. I was not satisfied with the resulting reduced forces at both
tack and clew due to having all system friction combined in one line. The
balancing block ensures that whatever tension force T applied to the tack
cringle is the same as that applied to the clew cringle. And in the case
of the clew cringle, running the line though and back down to the boom
results in an angled 2T force there. This is all before friction, of
course, but now tack and clew line frictions stand on their own, rather
than being added together in the case of removing the balancing block.

Also sorry about my pic in owners gallery being rotated. Been a while
since I uploaded anything and I recall I could not figure out how to rotate
with the gallery. Furthermore, I couldn't even figure out how to delete
the image and try again. D'Oh! Maybe someone could help me with this.

Frank Ross
Beta Wave #206
Naples, FL

[Dave Hupe via C320-list]

Yes, there are small sheeves at the front of the boom, but the one at the rear (4 identical) is large (same as for the outhaul). 
Dave Hupe
1994 C320 #32

[Troy Dunn via C320-list]

All

The sheaves on my 1997 manufactured Charleston Spar are all the same size
front and back.

The Delrin sheaves are "self lubricating" until they aren’t. Oil based
lubricants are no bueno on these parts, but I suspect PTFE (aka dry lube)
is ok. On my 1998 hull…no amount of anything is going to restore these
dry, brittle sheaves. You can get replacement sheaves but they sure seem
expensive for what they are LOL.

Frank I looked at your setup, it appears to be substantially different than
the way I’m configured at the mast end but pretty much the same as yours at
the aft end of the boom. I don’t find I have any issues with the foot of
my main but, my outhaul has a 4:1 purchase inside the boom. I have a
loose footed main.

I have wondered about having those low friction rings (as opposed to
blocks) attached at the cringle. I think asking the line to go through
the cringle is another source of significant friction. (Probably the
biggest source if the sail is fighting you coming down which can happen
sometimes for no apparent reason.

I love reading about how everyone manages their sails, it gives a lot of
ideas of things to tinker with which is half the fun.

I’ve never been a fan of sailing headsail only. Maybe I’m overly
concerned about destroying the furler but I refuse to put a furling line on
a winch, so I’m always trying to think through the best way to get the
genoa in without flogging the sail. One of my favorite approaches is to go
deep downwind and block the Genoa with the main. Can’t do that if you
don’t have a main up LOL.

I also find that a reefed main and headsail just seems to balance the boat
better when conditions get into the +25 kts zone. We have jib car
adjusters and I have to say that this is definitely a game changer because
it eliminates leaving the cockpit completely for us .

In fairness we also have a stackpack, and we keep the slugs well lubed with
PTFE so when we pop the clutch on the halyard, our main is usually in the
bag (or mostly in the bag if the last couple of feet hang up) in about 3
seconds. We mess with getting the main sorted for the evening at dock or
at anchor. If that wasn’t the case, would I have a different attitude
about the headsail only thing? I might.

If anyone locates a reasonable source of those sheaves …that would nice.

Troy

Hull #514

[Jeff Smith via C320-list]

Troy’s point is worth emphasizing. The XP-44 that I race on had to replace
the furler after 3 months of use ($10K) because they took the furling line
to a winch, despite repeated reminders not to do so.

I also think 1 reef in the main and a reefed headsail work well in 20+
knots. It typically provides the same power/forward drive with more
control. Also, having a proper reefing system when your furling line snaps
in a small craft advisory and you don’t want to drop your Genoa is very
helpful. You all know how I know this…

I am going to think about carbon rings instead of the cringle.

Jeff
#121

[Mark Cole via C320-list]

Another option to consider is a smaller headsail and a reefed main. The previous owner of Fiddler’s Green raced the boat and left a lightly used #4 (90%) jib on the boat. About this time of the year, I swap out the 150 with the smaller headsail knowing winds will be stronger here in the Northwest during the winter. Below 15 knots, with the #4 and full main, I still get 5 kts or better. I’ll reef the main at about 15 knots, mainly to keep my wife or guests happy, and still do over 5 kts and keep pretty upright and have a very balanced helm. The #4 is a much heavier material so you don’t run the risk of blowing out the shape of a bigger sail, plus I don’t have to worry about rolling in that small sail. It can’t get much smaller…. An added bonus is that you get to use those little, short tracks on the top of the house. My wife’s mantra is “reef early, reef often”.

Mark
Fiddler’s Green, #8
A smooth sea never made a good sailor.

> On Oct 30, 2025, at 11:19 AM, Jeff Smith via C320-list <c320...@lists.catalina320.com> wrote:
>
> Troy’s point is worth emphasizing. The XP-44 that I race on had to replace

[John Brennan via C320-list]

I tinkered around with my boom a little today. Seems like a mess.

I loosened the outhaul line, which is spliced with steel cable at the boom end. Well, no matter how much I tried, I could not pull the cable end out from the boom. I can tighten it by wrapping the rope end at the mast around the winch and cranking it, but that's it.

Looking at my 320 manual, it appears that there is a block in the middle of the boom that handles one rope line from the mast and one rope/cable line from the aft end of the boom. The line from the aft end seems to be frozen.

The reefing line works, but it is very tight.

So I am at a loss as to how to remedy this. Part of me says the easiest solution is to install blocks on the outside of the boom and just say the hell with running lines inside the boom. It seems like a flawed system. Any better ideas?

[Troy Dunn via C320-list]

Jack

Despite having some very old (brittle and quite crumbly) sheaves, my system
still seems to work ok. Something odd must be going on inside the boom.
Maybe some lines got twisted in there or the block got tangled with the
reefing line.

Honestly modifying the boom with additional blocks seems like a lot of
money and work for not much gain.

I think removing the boom from the boat is actually not all that difficult
and I’m wondering if you might be able to remove it and just rework the
whole thing.

Another question. On hull 514 the sheaves come out of the boom quite
easily. It’s just a piece of steel axle that comes right out (as long as
the steel is "cocked" inside the slots, and if it is just make sure both
end are down all the way and the loosen the lines and it will slide right
out). So the question is if you remove those sheeves and look in from
the aft end with a good flashlight, can you see anything that looks
obviously off? For example IF your reefing line is on the starboard side
and crosses over to the port side and back to starboard side….or vice
versa….that would be a recipe for all sorts of bad things.

All I can think of at the moment.

Regards

Troy

[Jack Brennan via C320-list]

Hi Troy:

Those are good ideas. My approach on non-urgent problems such as this is to tinker when I have the time. Often, sooner or later, I have an ah-ha moment that leads me to a solution.

My reefing line is tight but not unmanageable, like some others who have participated in this thread. I might experiment with snaking a line through the boom for the outhaul, bypassing the blocks on the inside .If that's successful, I'll just cut the old lines. I suspect those blocks are more of a nuisance than a help at this point.

This is more of a personality problem than anything. It bugs me when something on my boat doesn't work, even if I don't use it much. As a practical matter, I never adjust the outhaul, so it's fine as it is. But damn, I should be able to adjust it. And I would like to know that I could reef the main if I had to, even if other strategies are usually more convenient for me.

Jack Brennan
Sonas, 1998 Catalina 320
Tierra Verde, Fl.



________________________________

From: C320-list <c320-lis...@lists.catalina320.com> on behalf of Troy Dunn via C320-list <c320...@lists.catalina320.com>
Sent: Friday, October 31, 2025 7:10 PM
To: C320...@catalina320.com <C320...@catalina320.com>
Cc: Troy Dunn <troutw...@gmail.com>
Subject: Re: [C320-list] Single Line Reefing

[wdoc1--- via C320-list]

When we purchased our boat in 2018, the single line reefing was inoperable because of a huge collection of bird nesting material inside the boom...sticks, grass and mud! Once removed, the system worked but still with a lot of friction. This improved after replacing the line with dyneema (w/ spliced poly cover on the bitter end) and a ronstan low-friction block at the luff until the line jammed in the shuttle block. I replaced the two flat surfaced/frozen sheeves on the shuttle block with properly grooved ones, and it works much better. I can share photos of the shuttle block if that's helpful. I also keep the boom opening covered with duct tape to keep birds out!
BillDiversion, 2000 C320Baltimore