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Mast, Mast Rigging & Sails

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The original Improbable mast was a sturdy and (for the time) innovative aluminum mast using
aerodynamic rod rigging (quite rare). The sail plan was typical of the time, with a large foretriangle and
small mainsail, that was the norm for IOR rigs for many years. Although effective in a wide range of
conditions, this sort of rig requires many headsails and the ability to change them often. Not so great for shorthanding, although my dad did a nice job making it work by using it as a “cutter” rig utilizing the staysails.


Philosophy & Fate

Sometimes fate deals me a surprising hand of cards. When we brought Improbable
to James Betts Enterprises (JBE) she was slotted into a spot right in the front of the facility, just inside
the fence along 34 th Ave in Anacortes. The JBE crew got the old rig and rigging out of the boat and laid down nearby next to another mast lying just along the fence. It turned out to be an old carbon Farr 40 mast, which is a fractional rig, and which happens to have nearly identical foretriangle dimensions to the original Improbable rig. The overall height of the Farr 40 rig is taller, allowing a bigger mainsail. This was very attractive, as the bigger main would pretty much eliminate the need for overlapping headsails, making for a much better shorthanding configuration with fewer headsails, faster tacking, etc. Jim managed to acquire the mast & spreaders from another project, and offered it to me at a very reasonable price. The changeover will save over 100lbs in the rigging overall…


Many changes are involved in the rig reconfiguration. The spreaders are much longer, and are
swept aft more than the original, which provides better support and less mast compression. This
necessitates moving the chainplates for the shrouds to the outside of the hull, from the previous
inboard positions.

Plan — Headsails

Good quality used headsails from retired Farr 40’s are likely to be found at good prices. Also, as a former rigger, and avid single-handed sailor, I’m keen to find ways to optimize the F40 rig for ease of sail changes, etc. Ideally, I’d like to have free-luff furling headsails, which are slower to change yet much easier to handle when shorthanded.

Plan — Spinnakers & Gennakers

The Farr 40 has both fractional (roughly the same hoist as the original rig) and masthead spinnaker
halyards (yay!). The masthead kites will be a great option to have in light air and VMG running.

Plan — Mainsail

The taller mainsail will help eliminate the need for overlapping headsails. A bonus for shorthanded
sailing, and for faster tacking!

Challenges — Chainplates

The original aluminum headstay attachment structure was corroding, so had to remove it. We’ve found
a stainless-steel fitting off an old IOR racing boat that might work. Additional attachments will need to
devised for the headsail furling, etc. The design of the new outboard chainplates is TBD. We’ll need to
decide on metal (stainless steel or titanium, or aluminum?) or custom-made carbon. The latter,
although highly desirable, will likely be too much work and/or expense. We shall see…

Challenges — Headsails


As mentioned above, we may have a headstay fitting that will work. For the shrouds I’ve discussed
outboard chainplate ideas with Jim Betts, who has enlightened me to some great ideas, but we’re still
figuring it out. More to come….

Hopefully some good deals can be found for used Farr 40 headsails…which will be racing sails. For a
cruising set, finding used sails may be difficult so we may need to buy those new. Also, the flying-luff
furling headsails require torsionally stiff luff ropes, halyard locks, tensioners, etc. which are rather
expensive. Hopefully I can leverage my (very) old rigging connections to swing some deals…

Challenges — Spinnakers & Gennakers

Here again we’re hoping to find used Farr 40 kites, both fractional & masthead. So the main challenge here will just be $.

Unfortunately, the boom on the Farr 40 is too long to fit on Improbable without the risk of hitting the
backstay while jibing. So, we’ll almost certainly have to buy two new mainsails to fit the existing boom;
one for cruising and one for racing.

Challenges — Mainsail

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