IOM Class Rules change proposal-battens, pockets, leech, etc

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Robert Grubisa
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Location: CRO 16
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IOM Class Rules change proposal-battens, pockets, leech, etc

Post by Robert Grubisa » 14 Jul 2011, 17:23

Hi all

As promised, please find link on PDF file with IOM Class Rules change proposal here: http://www.iomclass.org/

I hope that text is self-explanatory. Let me know if some additional info is needed. Input from IOM community including sailmakers, measurers and others are expected. Idea is to propose mentioned class rule change as IOM ICA Exec proposal on next AGM including some your comments, if needed.

Note that main aim of the the proposal to accommodate almost all exisitng sails in new edition of the class rules and to avoid measurement problems in the future. There is no reason for any additional costs for sailmakers due to the proposed text.

Please inform others about this proposal, specially sailmakers in your area.
Robert Grubisa

Hiljoball
Posts: 270
Joined: 06 Jan 2006, 00:47
Sail number: CAN 307
Design: V8
Location: CAN

Re: IOM Class Rules change proposal-battens, pockets, leech,

Post by Hiljoball » 14 Jul 2011, 23:43

Having read the proposal, it looks very complex. Is there a simpler way? For example,


Both flutter patches and battern pocket patches are defined as secondary reinforcements in the ERS Section G6.2

Flutter patches look like reinforcement at the leach end of the battern.
Battern pocket patches are shown at the inboard end of batterns.

Under the IOM class rules in Section G, flutter patches are listed with max dimension of 50mm. What is wrong with allowing the flutter patch to be wrapped around the leach of the sail, as long as it lies within the dimensions of the sail?

Then simply add “Battern pocket patch” with (say) max 15mm under G3 and G4 Secondary reinforcement.



Under G.3 Mainsail and G4 headsail

Secondary reinforcement:
from nearest sail corner measurement point ......................... ..... 125 mm
for flutter patches ................................................................... ....... 50 mm
at luff fittings, luff slides and/or luff openings ........................ ....... 20 mm
add battern pocket patch …. 15 mm


John
John Ball
CRYA #895
IOM CAN 307 V8
In my private capacity

Hiljoball
Posts: 270
Joined: 06 Jan 2006, 00:47
Sail number: CAN 307
Design: V8
Location: CAN

Re: IOM Class Rules change proposal-battens, pockets, leech,

Post by Hiljoball » 17 Jul 2011, 18:12

One of the reports I read, mentioned Sails Etc sails at the Worlds with reference to the batten reinforcement and flutter patch issue.

Yesterday, I got access to a set of Sails Etc A rig. They have both the spreader patch and the flutter patch. I am hard pressed to see how the patch causes a measurement problem as the leach is almost a straight line. It is a very obtuse angle. This is a quibble over fractions of a mm....and to me, way inside measurement error.

I suggest that as simpler approach than the proposed template would be to add a line to the sail dimensions list in G.3.3 and G.4.3 such as

Flutter patch batten pocket point overhang max 2mm.

This would allow the flutter patch corners (at the fold over the leach) to lay outside of the straight lines to the measurement point, yet ensure that they are not excessive in any way.


Secondary reinforcement:
from nearest sail corner measurement point ......................... ..... 125 mm
for flutter patches ................................................................... ....... 50 mm
Flutter patch batten pocket point overhang .............. ....... .......... ....2mm
at luff fittings, luff slides and/or luff openings ........................ ....... 20 mm


John
John Ball
CRYA #895
IOM CAN 307 V8
In my private capacity

Dave Alston
Posts: 30
Joined: 24 Jun 2011, 12:54
Sail number: GBR3096
Club: Market Bosworth
Design: Fatboy
Location: Rugby - UK

Re: IOM Class Rules change proposal-battens, pockets, leech,

Post by Dave Alston » 20 Jul 2011, 20:23

Robert,

I must confess to being most impressed with your proposal and the effort you have gone to certainly shines through. It does take a brave man to delete words rather that to add words and you are to be commended upon this.

However I must also agree in part , and most reluctantly, with John Ball’s comments.

One is not certain if your intention was to allow no battens at all, which is what your amendment creates.

However if this was your intention, it is quite unnecessary as the batten is presently not defined in terms of stiffness or material and could simply be a piece of tape representing a batten afixed to the sail.

The premise that a sail is non-compliant with the class rules if the leech between the battens does not meet in a point or is straight is TOTALLY untrue. Again a case where clear ENGLISH sentence has not been understood by a minority.

The rule states ‘The leech shall not extend AFT of straight lines between:

This does NOT imply that the sail has to be cut in a straight line at all, it simply restricts the leech to be inside or forward of the theoretical line between the points defined.

But keeping the objective of the rule amendment in mind ‘To allow Batten Pocket Patches’

The simple addition of

Batten Pocket Patches……………………………………………….. 20mm

Would bottom that out. But please delete all that reference to the Baten Pocket , it is redundant

But the issue of cringle in the luff remains. What do you say you adress this at the same time?


One I have worked out how to attach a file I will do a sketch and suggested amendments. Oh how do you do attach a file help me?????

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