An update on RCB stay slides
3 Questions: Takao Otani asked three questions about RCB stay
slides:
1. will it be possible to fit on old boats with beveled deck? (the
new deck mold is changed to be able to fit either the "ball bearing
slide system" or the "C section track system" horizontally)
2. will the breaking load be different if the track is fixed on an
angle?
3. if different, will it be possible to have an up-grading kit
including wedge to fit "ball bearing slide system" horizontally
onto old type deck?
And the answers, from Frank Bethwaite and Marting Sly, are:
1. yes, it will be possible to fit the new system to the existing
deck profile on older boats, although no one has done it yet.
2. the breaking load is the same if the track is fitted on an
angle, like the existing track; the car is designed to work at
different angles.
3. there will be no need to alter any boats to retrofit the RCB
track. Frank advises that there is room for the RCB track on both
new and old decks, which will accommodate the 50mm ball "carriage"
plus the 70mm slider stop with the stays in the correct places
provided that the track is chamfered up for between 10 and 22mm to
fit the change of profile of the gunwale. If a different restraint
is used (e.g. a cleat, not the stop) there is ample room and no
chamfering is needed.
A cleat that works
Martin Sly has sent a photo of the latest cleat arrangement, to restrain the car without using a slider stop. Martin reports that both he and Chris Parkinson are using this arrangement, and it works well.
Trialling and approving RCB stay slides
In his "for
interest" comment, Frank Bethwaite has described the initiative
by the group in Melbourne that led to his decision to approve the
use of roller cars for the Tasar stay slides, and the testing that
led to his decision that a 19 mm Ronstan track (or the equivalent)
is required to ensure adequate working strength. These stay slides
are now being trialled in Melbourne and Sydney. At this point, the
method of restraint for the slide when it is pulled aft has not
been finalized, but those working on it are confident a neat and
efficient solution will be found.
The photos below show the stay car and track. The method of
restraint has not been finalized, but is likely to be a development
of the cleat arrangement shown on the right. The new cars and track
look good, and I think they will be a worthwhile improvement.
Frank has specified that the shroud attachment points should be
405 mm (16 in) aft of the mast pin when fully back, and 285 mm
(11.25 in) aft when fully forward. Graham Hanna has suggested a
tolerance of +/- 5 mm for these dimensions. As mentioned above, the
method of restraint is still to be determined.
I suggest that the class allow roller cars, with 19 mm track, to
be trialled until those trialling the system are satisfied that all
aspects, including the method of restraint, work well and are
operationally equivalent to the existing arrangement. At that time,
I will email the World Council and ask the members if they approve
the roller cars and 19 mm track as a change in the construction of
the Tasar, as supplied by the builder. This approval is required
under rule A.1.2 before the change can be made.
My hope is that the World Council can vote on this within the next
several months. However, if JTA, NATA or TAUK indicate that they
wish to trial the new arrangement before voting, the trial should
be long enough to allow that to happen.
If the World Council approve, Frank as designer can then ask ISAF
to approve this as a specification change (this is the process that
was used to introduce mylar sails). If the new arrangement is not
accepted as a specification change, it will be proposed as a rule
change, using the normal process of voting by region. In the
meantime, I suggest that each regional association allow Tasars
trialling the new arrangement to compete in Tasar events, including
National championships, with the roller cars and track.
Any and all feedback is welcome, either by emailing me, or posting
to the TasarSailors list or a Tasar forum. I will post any email I
receive on the website.
Richard Spencer Executive Secretary