by Mike Simpson on Mon Jul 31, 2006 6:28 pm
Motions re change of measurement rules from SSAV (Originally proposed by Vic Measurer John Dixon)
Part 1 That the implied restriction on use of fittings that are not included in the building notes be removed. A note should be added to the building notes stating that any fittings can be used. It might be necessary to note that the positioning measurements of fittings are unchanged.
Part 2 That the measurement of 75mm minimum 150mm maximum from base of mast for boom vang attachment point [Measurement No. 108, Rule No. 6.1(h)#] should be deleted, allowing positioning of this fitting at any point above the base of the mast.
#NOTE: This rule is incorrectly identified as being Rule No.6.1(g) in some versions of the Construction & Fitting Out Notes.
Part 3 That the measurement defining the position of the vang fitting on the boom [Measurement No. 119, Rule No. 7.2(b)] be deleted, allowing this point to be anywhere on the boom. The location of the forward mainsheet block hanger to be controlled by a new Rule No. 7.3 to a measurement of 975mm (+/- 5mm) from the after face of the mast section. The free location of the vang attachment will be restricted by not being able to be any further aft of the forward mainsheet block hanger and also by the vang being able to clear the centreboard when it is raised.
And that the Secretary be directed to amend the Rules of Measurement and Construction and the Construction & Fitting Out Notes as required to properly reflect the results of the National Committee’s deliberations.
BACKGROUND
The following are some notes I made up in response to a request from National President Rob Jackson for some background information.
I understand the proposers believe the changes will simplify rigging of new boats without affecting relative performance of newer and older boats and can also be readily applied to older boats as and if maintenance or personal preference requires it.
Proposal 1. The opening up of allowable fittings is considered to be a reflection of what is substantially current practice on the part of measurers in that many specified fitting are at least difficult to find and, in many instances, they are simply no longer available. The Sabre can be rigged with inexpensive generally available fittings at little or no loss of performance than if the “crème de la crème” fittings had been selected and, in discussions with Phil Johnson, John Dixon and others, this view seems to be generally held by Sabre sailors of considerable experience.
Proposal 2. The deletion of the control on location of the vang attachment point at the bottom of the mast is proposed because no one can say why it was applied in the first place and it is felt that the ability to lower the location will increase the effectiveness of the vang for a given force on the tackle. Those who want to place the attachment in a higher location to increase mast bend relative to vang performance, however minimally, will still have that option.
Proposal 3. Some have said they would like the ability to place the attachment a little further forward than the present limit allows and that the deletion of the control on location of the vang attachment point on the boom would leave the after limit still pretty well constrained by the forward mainsheet block hanger location and by the possibility of fouling on a partly raised centreboard, it is thought there would be relatively small take-up of this option.
None of these proposals were seen as affecting relative performance of boats with or without the changes and are thus seen as compatible with the class philosophy of maintaining older boats’ relative performance.
DISCUSSION
I am expanding a bit on the above in response to Sue’s queries.
Disclaimer: These are my own thoughts and are not intended to influence State members conferring with their Committees nor members of State Committees or Delegates when they vote on the proposals.
My understanding is that the proposals will not allow you to use fittings that are a substantial change of type from the current style specified in the Building Notes. I’ll bow to the National Measurer’s interpretation on this, but I think a towel rail will still be required and the rest of the rig would only be varied slightly.
A couple of “for instances”:
(a) Willy’s quest to use T-ball fittings for attaching the vang to the boom would not be enabled by the change.
(b) The limit on the size of mainsheet pulleys would not change.
Re the “partly raised centreboard” this refers to the situation where, going downwind or coming into shore, you can lift your centreboard high enough to foul the vang tackle in a tack or gybe – this can be especially embarrassing when it happens without any input from you.
Now, let the flaming begin!
Regards
Mike Simpson