F.2.5 (Boom) Manufacturer

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The OD class rules (F.2.5) specify that the boom must be constructed by a licensed spar builder.

F.2.5 MANUFACTURER
(a) Masts, spreaders and booms shall only be constructed by builders licensed by ISAF.
(b) The extrusion dies shall be approved by ISAF

There are many questions with this rule related to the boom. What does the rule mean by “boom?” What does the rule mean by “builder?” If we start with the definition of a boom according to World Sailing’s Equipment Rules of Sailing (ERS):

F.1.3 Spar. The main structural part(s) of the rig, to, or from which sails are attached and/or supported. It includes its fittings and any corrector weights.

F.1.4 Spar Types.

(b) BOOM. A spar attached at one end to a mast spar or a hull and on which the clew of a sail is set and on which the tack and/or foot of the sail may be set. Includes its rigging, but not running rigging, running rigging blocks and/or any kicking strap/strut arrangement.

(iii) MAIN BOOM. A boom attached to a mainmast spar to support a mainsail.

So, a boom includes the main extrusion and the internal doubler sleeve, any riveted on bales and blocks, the outer limit mark, the end caps, the boom-side of the gooseneck and the gooseneck knuckle. It excludes items such as rigging for the outhaul, vang, mainsheet blocks, etc.

I can only assume that “Builder” encompasses all the companies and/or people who fabricate and assemble the boom. There are several organizations likely involved, from the company that makes the aluminum extrusions, the anodizer, the machinist(s), and finally the rigger(s) who perform some final machining and assembly.

Many Etchells booms are rigged by unlicensed (by ISAF/World Sailing) spar builders. While Etchells masts appear to be constructed only or mostly by licensed spar builders, booms seem to be constructed often by boat owners or by professional riggers. The World Sailing website for the Etchells class is many years out of date listing licensed spar builders. The IECA website is mostly silent about licensed spar builders. It is hard for owners to be compliant with these rules. In a related issue, even the apparently licensed spar builders do not provide much information to boat owners about what they are selling (e.g., fitting locations and key dimensions, configuration of sleeve, etc.).

The extrusion dies are also an interesting question. Who owns the boom extrusion dies used by Dwyer, Selden, Sparcraft, Rigrite/Kenyon? I understand that the Smidmore masts are made from extrusion dies owned by the Australian Etchells Association. I believe the Whale spars are in the same, or similar, situation. Are all these dies “approved” and are they periodically inspected for compliance with the specified dimensions? There should be an inspection report provided and published for (or by) the class.

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