Technical Subcommittee

VC Technical:
Robert Grubisa , CRO
“vctechnical” at “iomclass.org”
Members: Brad Gibson, Marko Majic

Role and Functions of the Technical Sub-Committe (February 2010)

IOM Current Policy (February 2010)

Requesting Interpretations

The Executive, in consultation with the World Council, has developed an IOMICA policy on requests for interpretation of class rules.

  • IOMICA encourages discussion around the class rules
  • IOMICA encourages NCA/NCS officers to answer questions about the class rules at national level wherever possible
  • IOMICA encourages Owners to discuss the class rules with their NCA/NCS, in the open IOM Forum, and elsewhere, and encourages IOMICA and NCA/NCS officers to participate in such debate
  • IOMICA emphasises that while such discussion and debate should involve the exchange of informed opinion, any views expressed are neither official nor authoritative and do not represent IOMICA’s position
  • IOMICA encourages an NCA/NCS officer to request an official interpretation from the IOMICA Technical Sub-Committee via the VC Technical in all cases where an NCA/NCS officer feels this would be useful
  • In general, it is the NCA/NCS which is the source of official requests for interpretation
  • Official requests should be submitted to the IOMICA TSC with supporting documentation that provides diagrams, quotes relevant rules, and gives a summary of the issues
  • Where the IOMICA TSC becomes aware of a discussion about the class rules that, in its view, should be the subject of an interpretation, the TSC may make an official request on behalf of the class
  • All official requests for interpretation are announced by the VC Technical on the IOM class Web site so that all interested parties are clear whether an interpretation has been officially requested or not
  • Thereafter, requests for interpretation go to the ISAF-RSD.

Advice on new ideas

The Executive, in consultation with the World Council, has official advice on the class rules and new ideas.

If you are a commercial supplier to the IOM class:

  • Treat new ideas as if they are probably illegal.
  • Convince yourself that it is not so before marketing the equipment.
  • Consider asking the IOMICA Technical Sub-Committee for an interpretation.
  • If you sell equipment that is found to be illegal you may be obliged to correct, or replace, the equipment at your own expense.

The last item of advice derives from the consumer legislation that is in place in most countries, and is an implicit condition of trade otherwise. Something for sale must be fit for its purpose, and the manufacturer has liability if not a duty of care for it. It does not prevent any manufacturer agreeing with a customer that a particular item is “by special request of the customer” and is sold without representation or warranty of any kind. No problem in this case. The Technical SC and Measurement SC are in addition considering steps that might be taken to address the issue of manufacturers driving class development rather than the owners and the class association.

If you are an amateur builder:

  • If you come up with something you have not seen before, then assume that it is illegal until you are convinced otherwise.
  • Direct any questions to your national class association.
  • A certificate, or a certification mark, is NOT proof of the equipment being class legal. It is only proof that the equipment has passed such controls as are required by the class rules, and that the official measurer at the time of fundamental measurement did not find anything wrong with the equipment.
  • The owner always has the responsibility for the use of class-legal equipment, RRS 78.1 applies.

Current Requests for Class Rule changes

Request for  Class Rule changes  from  Roger Stollery, IOM NCA for GBR, technical secretary , concernig pigmentation in glass fibre. Download the pdf file

Request  for Class Rule changes  from Robert Grubiša, IOM ICA VC Chairman , concerning Mainsail Roach and Batten Control.

Background
Originally the intention was that IOM mainsail roach control should be achieved by regulating the
batten pocket positions and requiring the leech not to extend beyond straight lines between
pockets, between the upper pocket and the aft head point and the lower pocket and the clew
point. The same approach used by many ISAF classes.
A possibility for battens without batten pockets was however introduced and the “straight lines”
were then to interlink at “batten pocket points” found at the intersection of the leech and the
centreline of the batten pocket, or the batten when no pocket. This forced the leech to have a
“peak” at each “batten pocket point”. But when such a peak becomes “rounded” by tear and
wear the sail will become illegal as the leech will then project aft of the straight lines meeting at
the batten pocket point.
• A way to solve the problem is to create “zones” at battens, or batten pockets, where the
leech is not controlled by the straight lines. Similar to what is achieved when the straight
lines are taken “between the pockets” as described in the first paragraph.

Proposed Class Rules Amendments
Goals for the proposed amendments:

• To remove non ERS definitions if possible.
• To amend the current, and in practise impossible, leech requirements.
• To permit batten patches and to treat them equal to batten pockets.
• To permit mainsails without any battens/batten patches
• To simplify the current leech control rules if possible.
• To legalize currently used sails which do not comply with the current rules in regard to leech
shape at a batten pocket point and/or have batten patches.

Proposed amendments are included at the end of the document.

Comments on Batten Pockets and Battens without Pockets
There are currently a large numbers of mainsails with battens having one patch at its forward
end and another at its aft end. It is not likely that such patches would qualify as a batten pocket
and in any case only one would be permitted.
If batten patches are to be permitted, then it is difficult to see why the combined total
area of patches should be required to be less than what is permitted for a batten pocket.
And as a batten pocket may consist of any number and type of additional ply, why not allow the
same for batten patches? And in view of what is permitted for batten pockets, why not have the
same size restrictions for battens (stiffening) as for batten pockets?
26 December 2010
Prepared by Robert Grubiša, IOM ICA VC Chairman
(based on original proposal made by Jan Dejmo and comments received on informal
meeting with sailmakers and IOM ICA Exec representatives during European
Championship 2010 in France)

Download the unabridged pdf file.

Current requests for Class Rule Interpretations:

Relevant Technical Documents:

IOM Class Rules

Measurement Forms

Class Rule Interpretations

 

(The class rule changes proposed at the 2008 AGM were sent to ISAF for comments. IOMICA has now received a reply from ISAF)

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