SJ23 Tech Tip F17, (Updated 2023-03-28) Bob Schimmel, Norris Palmer.

Index

Step the Mast Using the Boom. (With Related Issues)
 INDEX - Step Mast (per SJ23 Manual), Step Mast (Block & Tackle), Related Issues.
The job of raising or lowering the mast is fraught with enough hassles and dangers to fill your boots!  I'm sure that everybody has a story or two to tell.  Since I don't need to add to my collection of stories, I built an A-Frame as a fool proof method of raising the mast.  See Tech Tip F18.

In the mean time, what follows is a reprint from the original San Juan 23 manual, STEPPING THE MAST, (with some additional warnings and good suggestions from several club members). 

INTRODUCTION: The SJ23 manual assumes the boat is fresh out of the factory and takes the owner through the assembly procedure of installing the rigging the first time.  Since there are no new SJ23s these days, I have eliminated the assembly instructions but you can read them online as Tech Tip H06.  Therefore, the following mast stepping procedure assumes that all standing rigging is correctly installed and securely attached to the mast.  However, before raising the mast, closely inspect all fittings for damage and ensure that every one of them is securely fastened and locked to the mast.  If a cotter pin looks mangled, replace it with a new one.  DON'T REUSE OLD COTTER PINS.  Use vinyl electrical or rigging tape over a sharp item.  And finally, fully understand the mast stepping procedure BEFORE the mast goes up (or down) and review your procedure with your helper before a turnbuckle is loosened.  Safety first. 

The black text in the description below is copied directly from the SJ23 manual.  The italicized blue text are my comments to add information or clarify Clark's 1970s "language".   I understand it, but many people today are confused with it!   Bob Schimmel.
 

STEP THE MAST (Instructions from the SJ23 Manual)

  1. Block the rear end of the trailer or keep it securely hitched to a vehicle so it can't tip.  Also, ensure you are on the shore side of any overhead electrical power lines or other overhead obstructions before stepping the mast. 
    (An alternative is to float the boat in flat water pointed into the wind so there is NO side force on the mast.  After having stepping the mast once on water, I now avoid it like the plague.  The risk of ripping the mast fitting loose with a rocking hull is too great unless temporary shrouds are used).

  2. Run all halyard shackle ends to the butt of the mast and secure them to eliminate clutter.

  3. Open the turnbuckles 3/4 of the travel. 
    (Ensure there is at least 1/2" of thread screwed in). 
    Tape the bottoms of the turnbuckles in the upright position. 
    (This is important to ensure the top half of the hinge operates freely to lay the turnbuckle on the deck.  Failing to tape the bottoms guarantees them  to jam, bend over and break.  Tape is cheap, use it).

  4. Close the companionway hatch (sliding hatch).  Walk the mast aft until you are able to match the mast step hinge to the deck plate.  Pin the mast in position with the mast resting on the rear support.  Insert a cotter pin on BOTH ends of the mast pin. 
    (Don't step on the sliding hatch if possible, especially if you are holding the mast.  It is barely strong enough to support a person, never mind the weight of the mast.  I would hate to see you drop through, with the mast in your arms).

  5. Connect the boom gooseneck to the short track on the forward bottom of the mast.    Tie the genoa sheets to the toe rail, in line with the shroud chain plates.  Run the free ends of the genoa sheets up through a couple of blocks attached to the casting at the top end (clew) of the boom.  Then run the sheets down to the deck through another block attached to a forward cleat. 
    (The forestay chain plate is much stronger than the bow "CLEAT" shown in the drawing). 
    Continue aft to a winch in the cockpit. 
    (    During the bottom 450 of the lift, the genoa sheets attached to the toe rail serve to add sideways stability to the mast provided the tension is equal on both sheets. Easier said than done.
    During the top 450 of the lift, there is less slop in the shrouds to limit sideways lean of the mast but the equal tension must be maintained to keep the mast centered. 
    Temporary shrouds attached to the mast are a positive way to control mast lean,  See Tech Tip F18).     

    Sketch illustrates the set up.
    NOTE 1: This sketch shows a single jib halyard attached between the mast head and the end of the boom.  It is prudent to back up the forestay with a halyard.  Two lines are stronger than one and less likely to break. 
    NOTE 2: - This sketch also shows a single sheet lead aft from the end of the boom to the winch in the cockpit.  It should show two sheets lead aft to the one winch as per step 5 above.  If you don't like wrapping two lines on one winch, send the other sheet to the vacant starboard winch and the two of you will have to crank in unison, keeping the boom centered over the deck.  Two winches reduces the effort and are good redundancy.

  6. Ensure the backstay and upper and lower shrouds are securely connected to their respective chain plates, with the turnbuckles taped in the upright position.  Ensure that all rigging is clear of any obstructions.

  7. Hoist the mast with the genoa sheets and winch.  Watch that the turnbuckles (toggles) or rigging doesn't foul.

  8. Once the mast is standing, hook up the forestay and tighten all the turnbuckles.  (Then lock them).   TOP 
     
STEP MAST THE MAST (Using Block & Tackle) - This is Norris & Karen Palmer's clever variation of the SJ23 technique listed in the SJ23 manual.  Suffice it to say the steadying side lines stay tight for the full arc of the mast and the mast stays centered by virtue of these lines being tied together at the bottom of the block & tackle.  What a clever idea.  Now this is using your kidneys!
 

The two steadying lines that are attached to the top end of the boom go down to blocks at the toe rails, adjacent to the mast.  The lines are then directed forward to go through two more blocks at the bow, after which they are tied together to the bottom of the block & tackle as shown below.  Those short lengths of free line tied to the bottom of the block & tackle are long enough to keep the steadying lines tensioned and the boom centered as the mast is stepped. 

The top of the block & tackle with hoist line is attached to the top end of the boom.  The free end of this hoist line comes off the bottom block from where it goes aft to the primary winch in the cockpit as shown at right.  As the hoist line is pulled, the boom stays centered, raising the mast along the center line of the boat and protecting the tabernacle. 
 

  


 


FORESTAY - You may as well latch the forestay to the end of the boom so it doesn't clutter the deck.  When latched to the boom it also backs up the halyard and positions the turnbuckle where it is needed for fastening to the deck once the mast is standing.

WINCH - A 2 speed primary winch has a lot of mechanical advantage to lift the mast from horizontal, and more secure (safer) if it is self tailing.  Norris's clever technique is all the more incredible give that this is a MKII SJ23 with a 2' longer heavier mast than a MKI SJ23. 

LOADS - There is likely less load on each of these 4 blocks than on the 2 blocks shown in the SJ23 manual instructions above. 

This technique is definitely worth considering.
 
 

 

The person standing under the mast support isn't a bad idea.  Its a great safety idea when standing in the drop zone of the mast.  You just have to have the nerve to stay put under it when the stick drops.  Oh, and get your fingers out of the way!!  TOP 

 
NOTE: The issues listed below are not mentioned in the manual and should be taken into consideration to protect the rigging and hull against damage. 

TO STEP THE MAST ON LAND OR ON WATER - There are two fields of thought here.  If you step the mast on land, you have a solid platform to work from and you can retrieve a dropped item but you have to do a lot of ladder climbing.  If you step the mast on the water, the floating hull rocks as you move around, it is "difficult" to retrieve a dropped item but you can conveniently step from the dock to the boat.  One of the reasons why I once stepped the mast on the water is because I wanted to know what problems I would encounter.  There are many people who don't own a trailer and have to step the mast on water for maintenance.  Having said all this, I prefer the stability of the boat on the trailer and the ease of recovering a dropped tool.  I have reduced the number of times I climb the ladder or stumble along the deck by wearing a tool apron.

TAPE THE SHROUD TOGGLES - The toggles on the bottom of each shroud turnbuckle MUST stand up prior to (and during) mast stepping.  If a toggle lays sideways, (pointed to the toe rail or to the cabin), it will jam and the bottom of the turnbuckle will bend as the rigging is tightened.  Eventually the toggle will crack and break.  Check this out before the stick falls down!!!  To prevent this problem, wrap tape or line around the toggles to ensure they always stand up so the turnbuckles lay fore/aft.  If you want to get technical about this, a turnbuckle and a toggle are similar to a universal joint, which can flex only about 200 without binding. 

LOOSEN THE SHROUD TURNBUCKLES - The turnbuckles MUST be loosened about 3/8" prior to lowering the mast to prevent damaging the shrouds, the bulkheads or creating a deck leak at the chain plates.  This is because the foot casting on the mast protrudes slightly aft.  This protrusion raises the mast ever so slightly as the mast is stepped, stretching the rigging and/or pulling the chain plates up through the deck.  The shrouds can stretch only a teeny amount and have their limit.  The previous owner on my boat never released the turnbuckles and this neglect pulled the chain plates up, a little bit each year.  It took about 15 years to pull all the mounting bolts 3/8" up through the plywood bulkheads.  I should add that during this period, the cabin was damp due to poor ventilation.  This contributed to softening the plywood bulkheads which made this migration through the wood possible.  I have since dried the boat; Tech Tips B06 and C07, and repaired the bulkhead holes using the WEST system.  My rigging survived all this quite OK, but if you just can't seem to tighten your rigging properly due to having run out of thread, check the chain plates and bulkhead before the stick falls down!!!  Now you know why the chain plates leak water.  Seal them with Sikaflex.  This stuff is so tenacious it just doesn't let go. 

MINIMIZING MAST SIDE MOVEMENT - Side movement is probably the greatest contributor to creating water leaks at the hinged mast step.  The foot of the mast fits snug in the step and any sideways movement of the mast will torque the fitting off the deck to crack the deck seal.  It is the helper's job to control sideways movement.  If you use the boom or a spinnaker pole, as the manual suggests, either of the techniques shown here can keep the mast centered.  Failing that, your helper can nudge the boom sideways a bit to keep the mast centered over the hull.  This takes little effort and the person is in a safe place, outside the drop zone.  Alternatively you can use an A-frame as described in Tech Tip F18.  An A-frame is a good way to ensure the lift is dead center over the hull.  In addition to an A-frame you can use temporary shrouds to eliminate side swing.  The combination of using an A-frame with temporary shrouds can make stepping the mast a one-man job.  TOP 
 

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