Click on image above to get a LARGE VIEW of the sketch

 

 

Main and Mizzen Spreaders, Far East Mariner Ketch, 31’ & 32’, Based on Murre, M31, Hull 150, January 2006

 

Spreader drawings were traced full size, except for length, onto 19” x 24” onion paper.  All measurements are included on drawing.  Measurements noted on one spreader but not the other indicates same for both.

 

Spreader Material: Whatever suits your purpose.  For lightness, Sitka Spruce (used by Far East) or clear Doug Fir.  In Sensible Cruising Designs, L. Francis Herreshoff recommends “Ash, Oak, or hard Mahogany”.  Ross Norgrove in Cruising Rigs and Rigging professes to having used Teak for spreaders, this to insure against dry rot “never mind the weight aloft.” 

 

Spreader Overall Lengths

Main = 38 ¾”

Mizzen = 32 ¾”

 

Thickness  

1 7/16” for both spreaders along entire length.

 

Widths

As you’ll see from the drawing, the maximum width of the main spreader is 3 3/8”, and it holds this width for at least 2/3rds of the spreader.  At five inches from the outboard tip, the width has tapered to 2 3/8”, and within a half inch of the tip, the width has diminished to its minimum width of 1 5/8”.  The same pattern applies to the mizzen.

 

A = Spreader Washers, make 8 total, one top and one bottom of each spreader.  Washers are 1/16" thick SS plates that are squared at bottom and rounded heavily toward the mast end.  Precise shape is unimportant.  Each washer is fastened with four ½” #8 screws.  The spreader pins (through-bolts which attach spreader to mast) are 5/16” x 2” SS, same for all four needed.  Be sure to use a nylon lock nut or score the bolts when in place.  These are swinging spreaders, man!  See Norgrove’s Cruising Rigs and Rigging, P. 120 for benefits of this design.

Main washer dimensions = 2”x 2” plate.

Mizzen washer dimensions = 1 ¾” x 1 ¾” plate.

 

B = These curved lines and profiles attempt to describe the fore and aft wing effect on each spreader.  The bevel angle is 20* for both main and mizzen, and so appears steeper on the narrower mizzen spreader.  The leading edge of both spreaders is not overly rounded.  Do not let the aft edge radius dip below 3/8”, nice and blunt—don’t sacrifice a strong wing just to make it pretty.

 

C = Stay Guard, make 4.  These guards protect the spreader wood from the chaffing of the upper shroud that fits into the notch at the end of the spreader.  These guards are 1/16” SS.  You’ll have to shape them to fit.  They are held in place by #10 round head machine screws with nylon lock nuts.

 

D = Seizing Holes.  There are two tiny holes, just big enough for seizing wire, drilled a couple inches from the outboard end of each spreader.  When rigging the boat, seizing wire is threaded through these holes and around the upper shroud in neat figure eights.  Wrapping the seizing wire tightly helps keep one spreader from drooping (as mine has for the past two years).  Except for the boot that goes over, seizing wire is all that binds spreader to shroud.  Wrapping the holes in tape insures against water intrusion.