|SJ23 Tech Tip F05, (Reissued 2011-08-25, B. Schimmel)|
|Most sailors will stay in protected water during lousy
weather stating that they don't have decent reefing on the mainsail.
This OK but
when you are out there you have to deal with whatever Mother nature hands
you. Being able to reef the mainsail quickly and easily is
sort of important when the weather turns nasty!
This is a time for acting, not thinking. The factory
reefing arrangement works OK but a crew has to go to the mast to set the first reef tack cringle on the
rams horn hook and then pull the clew line in. The trip to the
mast must be coordinated with the
helmsman. Reefing is usually easier with crew on board but I wouldn't count on
them if they novices. You can only watch anxious crew dance around on the coach roof
for so long, entertaining as they may be, before you have to do
something quick! Sailing in heavy weather
can humble a crew and sailing solo usually adds a
few twists that you may not have thought of. Staying within the safety
of the cockpit helps to avoid risks, which means the reefing lines must
be extended to the cockpit. This demands that the system be well
engineered and the process well thought through, unless
you enjoy entertaining as well! To determine which reefing system
you want on your boat you have to decide where you want to control the
lines lead to; cockpit, mid boom or mast.
Described here are two typical cockpit lead mainsail reefing systems that can be installed on an SJ23. There are variations of these that tend to be complicated but I prefer a simple and functional system. If you are unsure which one to choose, try using the system on a similar boat. That way you can experience the pros and cons before you spend your hard earned cash or perforate your boom with unnecessary holes. The biggest hurdle to overcome is not pulling in the reef, but releasing it. That is why some people opt to keep the free ends of the reefing lines on the boom. This system has the least internal resistance, is the cheapest to install but requires you to crawl to the mast to adjust the lines. I prefer to stay in the cockpit when I'm sailing solo which is why I lead the lines to the cockpit. Having used the single line system I can tell you that the dual line system works way better, which is why I mention it first.
DUAL LINE REEFING SYSTEM, (Separate Tack and Clew Lines) - The biggest advantage of a dual line system is that it has the least internal friction and the tack and clew lines can be controlled independently, making it easier to use than the single line system. The dual line system is depicted below, mainsail hoisted on the left and reefed on the right. For the sake of simplicity the lines for the second reef are not shown but they are shown in my drawing further below. The clew block (marked A on the boom) is positioned so the reef line intersects the strain (reefed sail) at about 450. If the position of the SJ23 boom on the mast is fixed then the tack eyelet should be positioned on the mast, about even with the bottom of the boom. This intersects the strain at about 600 (reefed sail) with most of the force being upward along the luff. The tack cringle will slide across the tack reef line when the boom swings, therefore it is OK to leave a bit of slack when the tack line is set. A perfectly packed, efficient sail isn't required for a reef since there is too much wind anyway. However, you should flatten it with foot tension as much as possible to reduce lift.
If you want the SJ23 boom to slide down the mast in heavy weather then the tack line fairleads must be installed on the boom instead of the mast. In this case you will have to mount the fairleads as far forward on the boom as possible. This configuration isn't that conducive to efficient reefing. I far prefer the fairleads to be mounted on the mast. Your choice.
The reef lines
(tack/clew) should be
colour coded so you pull the correct
line. The line lockers or
should be labelled so
you release the correct one. Of less significance is the colour
of the mid tie down lines. Don't use red line as it becomes black at night and therefore difficult
for most elderly gentlemen to see. Personally I like
the "hot" lime and green colours because I find them easy to see at night.
2011-10-21 Update - I am converting Panache from a single line reefing system to a dual line system using 1/4" polyester lines. There isn't much deck space to mount lots of lines so one has to careful with the design. As you can see at right and below I've doubled up the lines (prototype design) through each line locker and mast block to determine if my design can fit on the limited deck space and work effectively. (If you are contemplating this as a final design, remember that two lines through a locker must be the same diameter. In addition, two lines running through a common block or line locker have a tendency to twist and snag, so beware). The internal friction of the doubled up system was a bit high but acceptable. It worked OK the first time when I set and released two reefs in five minutes; quicker if I didn't have to explain it to the dock watchers! It worked well enough that I will now commit myself to the design. The system can only improve by adding individual blocks and line lockers.
For two reef points there should be an individual block and a line locker for each of the four lines. I will install two extra blocks at the mast base and a separate sheave for each line on the deck to minimize friction and eliminate the line twisting problem. Click here for a description of how the system works.
The real test of a reefing system is to release a reef. I was satisfied with the prototype system, despite the internal friction. The friction is why I had to use the winch handle to haul the mainsail up instead of hauling it up by hand.
At right is one method of turning the two extra lines on deck. Ignore that mess of loose lines at the base of the mast. They all straighten out and organize themselves when the mainsail is hoisted.
If I feel that the internal friction is still too much I may switch to slippery
Spectra line. The 1/8" Spectra has a working load of 2100 lbs, which
the requirements of an SJ23. The problem with Spectra is that the
dead ends must be spliced and stitched since it is too slippery to hold a
the live ends must be covered in polyester braid so the line lockers can
grip it. And finally, the thin Spectra line should turn over
narrow flat sheaves that match the line diameter since Spectra has a nasty
habit of developing a groove down the face of a curved sheave. This
is a marginal issue since the lines will
be loose for the majority of their lives.
Show at left is a rough sketch of how the first (lower) and second (upper) reefing lines should be installed on a SJ23 using the two line reefing system. The two lines per reef section are tack and clew. Each reef point is about two feet deep and parallels the boom. The second reef line is usually omitted from many reefing diagrams. For the sake of clarity I've shown both here. Somehow the gurus expect you to figure this out! Having said that, the lines on the port side of the sails are omitted since including them challenges the drawing ability of my software. However, it is shown in the Harken diagrams above. So there you go, guess I'm just as guilty.
CUNNINGHAM - This line is not shown because the drawing would become too cluttered. However, the cunningham cringle is shown, being the cringle just above the goose neck. There are several ways to pull this cringle down. You can run a line through this cringle similar to a tack reefing line described above. Alternatively you can slip a stainless tack hook (with line attached) in the cringle and pull the line down to tighten the luff. The purpose of this tension is to flatten the mainsail to match higher wind speeds. It is a useful technique for racing where tenths of a knot may allow you to win. In cruising I seldom bother with the Cunningham.
TACK LINE DEAD END - As mentioned above you have to determine if the tack lines on your boat are to be attached to the mast (shown on diagram) or to the boom. Regardless of which location, the dead end of a tack line is tied to a strap eye on one side, passes up through its respective cringle and down the opposite side through a fairlead and finally down to the turning block at the base of the mast if you want to terminate the line in the cockpit. Since the majority of the sail cloth is bundled on top of the boom it is important to keep the lines away from the cloth so they slide freely. This is why many people prefer to install the tack lines on the mast instead of the boom. I have transferred Panache's lines from the boom to the mast for the same reason.
CLEW LINE - The dead end of each clew line is tied to the pin of the turning block installed on the end of the boom. From there it goes under the boom and up to its respective clew cringle, then down through the same turning block on the boom. This balances the load on this turning block and creates a 2:1 mechanical advantage for pulling sail cloth. With the reefing line around the boom it also transfers the some of the load to the boom. Since there is limited space to install two turning blocks on the same side of the boom, the block for the second reef is usually installed on the opposite side. The clew line then goes forward to a turning block hung from the bottom of the boom at the goose neck. This greatly reduces the internal friction of the clew line since it can align with the direction of the pull to the deck block.
Hope this explains the rational behind the 2 line reefing system. The tack and clew lines terminate in their respective line locker installed on the cabin roof back at the cockpit.
Here are some extra tips you will find useful.
LINE REEFING SYSTEM, (One
for the tack and clew) - A
single reefing line is simpler to install but more difficult to
operate on a pocket cruiser due to lots of internal friction.
When a reef is set you end up with lots of line in the cockpit, which can be a nuisance
but doable if you stuff it in a bag.
The first reef should be a different colour than the second reef and the cam cleat
should be labelled to eliminate confusion when the
wind is increasing and the hull is heeling further. The problem with
this system is
internal friction through the cringles, blocks, and against the sail cloth
bundled on the boom. I have never been able to pull the reef line to
fully lower the sail to the boom. It always requires a trip to the mast to
fiddle with the lines or tuck cloth. Just the trip I'm trying to
The usual reefing procedure for a single line system is as follows:
There are many variations of these two systems. Some
sailors will dispense with leading the lines to the cockpit, preferring to
them on the front of the boom or on the mast. While this system
works very well, it necessitates going to the mast which may be difficult
if you sail solo. In this case you better have
a tiller tamer, auto helm or be very quick! Years ago I used this technique on
my previous boat but usually delayed the trip to the mast hoping that
the wind would subside. It almost never did!
NOTE: I borrowed the diagrams from a Harken Catalogue. Nice folk.