www.svbeatrix.com — The website of the Sailing Vessel Beatrix, Kelly-Peterson 44 #276 (1980).

 

Reefing Problems Noted
  1. Big belly in the reefing band (see panoramic photo below).
  2. Tendency for the sail to be sucked down into the slot in the boom, very bad if this happens. (Photo 4)
  3. To see if moving the dead-end aft made a difference I used a snatch block on the end of the boom (Photos 5 and 6). This pulled the reef band much flatter, but as it turns out if I pull the cringle aft, the slot and pulley are a good 50mm forward of the "clew" of the first reef.
  4. I realized that I needed to move the attachment point much farther aft and the cheek block at least 1" aft of the straight line distance from the luff to the leech at the reefing band.
  5. Later I found out this was an oversight when our new sails were made.. When we moved from the original three reef points to two "deep and deeper" reefing points (almost a 1.25 and a 2.5 reef) this caused the reefing cringles to move forward; this made it impossible to put in a decent flat reef. I was inexperienced enough to not notice this problem at first.

 

 


Original Reefing Setup
  1. Reefing line was on a padeye with a ring hitch port side of boom.
  2. Reefing line ran through the cringle and back down to a slot in the boom.
  3. Slot and padeye were at the same distance from gooseneck.
  4. There was a cheek block inside the boom which led the reef line to an exit near the boom-mounted winch.
  5. Chafing was a problem due to misplaced cheek blocks and exit blocks.

 


New Reefing Setup
The major change was to install a double exit block at the end of the boom. The original boom setup on the KP44 had a single exit block for a topping lift. When we installed a boom gallows and rigid vang, the topping lift was not used anymore. The double exit block replaced the single block. The reefing lines (first and second) run from an external padeye on the boom, up and through the reef cringle at the leech, and then aft to the double turning block. From there the lines run internally towards the mast and exit through the original exit plates. Note that Beatrix is now flying the main loose-footed (which makes it very easy to tie off the reef ties). If chafing at the cringle remains a problem, then a turning block on the sail is an option, but I doubt it will be an issue.

 

 

New Reefing — Controlling the Reefing Lines
Another problem with reefing has always been the boom-mounted reefing winch. This was always hard to use because of the jumpy motion of the boom in a seaway and the necessity to lean out past the protection of the mast pulpits. To solve that we simply removed the winch from the boom and used a couple of Schaefer flip-flop blocks which we had on board to maintain fair leads on the reefing lines. Installation of two XLS Spinlock line clutches made controlling the reef lines very easy. Other boats have mounted the reefing winch below the boom and used blocks to redirect the lines. I like using the halyard winch for reefing because it is safe and easy to grind on either tack.

The method for reefing is to release the main halyard line clutch, lower the mainsail to the reef point, engage the clutch, and clip on the reefing shackle. Leave the halyard loose, take up on the appropriate reef line with the line clutches closed. The lazy reef line needs to be brought in by hand as the working line is tightened. We have placed a whipping around the line at exactly the right point so when it exits the line clutch, the outer reef line is at the correct tension. Finally, take up the halyard to remove the slack. Don't put too much force on it.

 

 

Notes on Choosing the Correct Reefing Line
  • Type: double-braid or high-tech?
  • Strength: at 5:1 breaking-load-to-working-load ratio the following figures imply around 16,000 pound breaking load.
  • With the above load figures this implies a 7/16" or 1/2" high-mod line such as Validator II or Warpspeed
  • I chose to use 3/8" (10mm) Validator II with a BL of 11,000 pounds. This has a 100% vectran core with polyester cover.
  • Starzinger and Evans say that reef lines should be moderate stretch (3 out of 5) and low weight (4 out of 5) 

    "Reef lines tend to be shorter and lower than the halyards so are a little less sensitive to stretch and weight, but is prone to chafe from the many sharp turns and experiences a lot of flogging. They typically use line at one notch down in sophistication/cost from that used for the halyards"

    As I think about the line loading problem I am wondering about the load calculations.  I calculated Main Sheet Loadings (below) when choosing winches based on the formula on the Harken website. Carol Hasse of Port Townsend Sails supplied different numbers.

    Another approach is to ask "how many pounds can I apply to a line with my winches"?.   Based on my arm strength and winch sizes (40 on the halyard winch) the most I can reasonably crank into a line with a 10" handle is 30 pounds * 10" / 12" *  power factor.  This works out to be 25X the Winch Power Factor.   For the 40 winch that is 1000 pounds.  On the mainsheet I have a 5:1 advantage but on the reefing line I only have a 2:1 advantage with lots of friction.  So although Hasse has calculated a maximum load with gusts of around 3400 pounds, all I can crank in with the winch is 1600 pounds.  The load on the mainsheet might be 3400 pounds, but it's unlikely that the load on the reefing line will be so great except in very strong gusts.  It's true that without the sail slugs the load has to be divided between the luff and the reef cringle.  It might have been prudent to upsize to 7/16" Validator II (with a BL of 15,200); but if we are sailing in wind gusts over 50 knots it is probably time to put up the trysail.

    Maybe there is some practical experience here that dictates reef line size and quality.  At this time my biggest problem seems to be chafe and I think a lot of that comes from the misplaced dead-end and cheek block positions. So far, with the new reefing system, chafe has not been a problem.

     

     

    REEFING LINE LOADS FROM HASSE & CO.

    REEF
    POINT

    Sail Area
    (sq. ft.)

    WIND
    (knots)

    LOAD
    (lbs)

    LOAD
    (kg)

    Wind Gust
    (knots)

    Clew Line BL
    (lbs)

    Full Main

    331

    0-18

    2282

    1035

    40

    11410

    1st Reef

    225

    18-35

    3325

    1508

    55

    16625

    2nd Reef

    167

    25-50*

    3527

    1600

    70

    17635

    * trysail up at 50 knots

    Data provided by Hasse & Company, Port Townsend, WA (USA)

     

    CALCULATED MAIN SHEET LOADINGS USING HARKEN FORMULA
    Sail Area as % of Main Load (lbs.) for Apparent Wind (Knots)
    5 10 15 20 25 30 35 40 45 50 55 60
     Mainsail  100%        68      272      611   1,086   1,697   2,444   3,326   4,344    5,498    6,788    8,213    9,774
     Mainsail 1st Reef  75%        44      176      397      705   1,102   1,587   2,160   2,822    3,571    4,409    5,335    6,349
     Mainsail 2nd Reef  50%        24        96      217      385      602      867   1,180   1,542    1,951    2,409    2,915    3,469
     Storm Trysail / Third Reef  28%     10.1     40.2     90.5   160.8   251.3   361.8   492.5      643       814    1,005    1,216    1,447
    Main Sheet Load (lbs) = E**2 * P**2 * 0.00431 * V**2 /(sqrt(P**2 + E**2) * (E - X))
    Formula Source from Harken
    This formula is not so well accepted as the Genoa Sheet Loadings formula.


     

    Also see: Beatrix Running Rigging Diagrams


     
    Last modified: August 24 2014 02:37