Question details:

Is it allowed to use servo for controlling the tension in the backstay?

Answer:

Relevant  Class Rules

Part 2
The rules of Part 2 are open class rules in which anything not specifically prohibited by the class rules is permitted.

C.9 EQUIPMENT
C.9.1 PROHIBITED
(a) Except where achieved by mechanical systems, automated control of rig and/or sails.

Answer

Servo may be a part of mechanical system used for controlling the tension of the backstay. It is allowed to use a servo controlled by the transmitter in the way that there is proportional or non proportional linear or rotational movement of the servo when actuated by the movement of a stick and/or a switch on the transmitter. In described way it is obvious that tensioning of the backstay is done by the competitor at his/her discretion. This is not automated control of rig prohibited by the class rule C.9.1(a).

However, using of servo to activate and deactivate an automatic tensioning system controlling the backstay is prohibited.

Question details:

Sailboat RC from Croatia (EU) as a manufacturer of IRSA radio sailing boats, its part and components has been warned about possible problems in the future with governments/customs regulations around the world dealing with the shipping of the parts made of lead.
According to the IRSA radio sailing Class Rules materials of keel and rudder shall not be of density higher than lead (11340 kg/m3 ).
Having in mind possible harmful consequences of using lead on the marine environment you are kindly asked to let us know whether the IRSA radio sailing boat bulb made of lead and coated with the long-lasting eco-friendly protective layer/coat is permitted.

Answer:

IRSA radio sailing boat bulb made of lead and coated with the long-lasting eco-friendly protective layer/coat is permitted according to the current Class Rules of all IRSA radio sailing boats.
So far, World Sailing (WS) as the world governing body for the sport of sailing has not issued any ban on the use of lead as ballast in the keels. IRSA as the worldwide radio sailing organization and an affiliated member of World Sailing (WS) will follow their possible future guidelines/rules aiming to reduce the harmful impact of lead or any other material used in boat construction which may danger the environment.

Question details:

Does a typical rc yacht balanced headsail boom meet the ERS definition of a boom?

Answer:

The ERS definition states:

F.1.4 (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 a sail may be set. Includes its rigging, fittings and any corrector weights, but not running rigging, running rigging blocks and/or any kicking strap/strut arrangement.

The question is raised because the attachment of a typical rc yacht balanced headsail spar to the hull is not at the very end but some distance, typically 10-20% of its length, from its fore end.

For a definitive answer this question would have to be answered by seeking an interpretation from the WS ERS Working Group. There are certain problems with the ERS definition(s) relating to spars which have been made known to the ERS WG and it may be that a defnitive answer would not be made. In the meantime the following discussion is offered.

Points to consider

1     Where it is important to identify the very end of a spar the ERS has such defintions e.g. the mast top point and the mast heel point. If it were necessary to require the very end of a boom spar to be attached to the mast or hull then we can assume a 'fore end point' would be defined. It has not been and so we should not take the ERS defintion of boom to mean that the very end of the spar is the critical point.

2     Experience shows that all practical main booms are attached to the mast using a fitting with the attachment point some distance from the very end. As these booms are not attached at the very end we should be able to assume that the very end is not intended as the required attachment point.

3    Spars can be considered to have two ends and a middle. If each of these regions is 1/3 of the total length then the attachment point of a typical rc yacht headsail boom is well within the end region.

Question details:

August 2018 changes to 2018 65 Class and Marblehead class rules. Why? And why have the Ten Rater and A Class rules not been changed?

Answer:

The 65, M, 10R and A class rules have certain restrictions and limitations relating to booms. In 2018 it became apparent that the ERS definition of a 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 its fittings - meant that the class rules did not work well for swing rigged boats.

The class rules for the 65 and Marblehead class rules have been changed by the IRSA EC - effective 1st August 2018 - acting to maintain the previous common understanding of the class rules. The A Class does not permit swing rigs so the class rules need no change. One DNM has provided a proposal to change the class rules in the 10R Class and so this will pass through the formal procedure for dealing with such proposals.

Please see the related Q&A - Does a typical rc yacht balanced headsail boom meet the ERS definition of a boom?

Question details:

When additional spar area is included in the certified rig area, what is the likely effect on measured waterline length and displacement?

Answer:

The table below shows the result of simple calculations using data for the hull form and additional spar area to determine the required change in waterline length and necessary change in displacement to achieve this. A working spreadhseet will be posted as soon as possible so that actual data can be used to make these estimates.

Question details:

Which spars of a Ten Rater swing rig can be excluded from the certified rig area?

Answer:

Relevant rules

Ten Rater Class Rules 2018 - Effective 1st November 2018

The relevant class rules are:

Section J – Rig Area

J.1         GENERAL

(a)     One spar, not being a mast spar, with a maximum spar cross section not exceeding 22 mm may be used to extend the tack and/or clew of each sail without being included in the certified rig area.

(b)     Where more than one spar qualifies under J.1 (a), the one with the smallest area, found using J.3 and/or J.4, shall be excluded in the certified rig area.

(c)     A fitting shall be considered to be part of the spar when:

          (1)  it is faired into the spar; or

          (2)  it is bigger than is reasonably required for its purpose.

J.2         CERTIFIED RIG AREA

J.2.1       The certified rig area is the sum of the areas of the rig components of the largest rig, excluding the items listed in J.2.2,       

              where if the sum of the area of the components does not exceed 10% of the maximum permitted sail area, the area of each component shall be found as in J.3 and/or J.4, or otherwise

              where the area of each component shall be found as in K.3

J.2.2       (a)     spars as in J.1(a).

              (b)     fittings as in J.1(c)

              (c)     spreaders.

              (d)     rigging with a maximum cross section of less than 2 mm.

A.1.4 from the Ten Rater Class Rules

Spar                         

The main structural part(s) of the rig to, or from, which sails are attached and/or supported.

NB          The class rules use the defined term spar instead of the ERS defined term spar. A spar does not include the fittings and corrector weights. A spar does include fittings and corrector weights.

Discussion

CR J.2.1 makes it clear that the certified rig area is the sum of the area of the component parts excluding certain, specified, parts.

Excluded items include spars as in J.1(a). Specifically one spar, not being a mast spar, with a maximum spar cross section not exceeding 22 mm may be used to extend the tack and/or clew of each sail without being included in the certified rig area.

Note that there are several requirements for such spars to qualify for exclusion from the certified rig area. These requirements are:

• Not more than one per sail
• It shall not be a mast spar
• With a maximum spar cross section not exceeding 22 mm
• It shall extend the tack and/or clew of the sail.

Application

Form A

The most common form of swing rig comprises the following spars in addition to the mast spar:

Item 1   A spar cantilevered aft from the mast spar to which the main clew is set – this spar qualifies for exclusion.

Item 2   A spar cantilevered forward from the mast spar – this spar does not qualify for exclusion because it does not extend the tack or clew of a sail.

Item 3   A spar to which the headsail clew and tack is set – this spar qualifies for exclusion.

Of the above spars item 2 does not qualify for exclusion from the certified rig area. Items 1 and 3 qualify.

Form B

An alternative version of the swing rig comprises items 1 and 2 (as in Form A) and item 4.

Item 1   A spar cantilevered aft from the mast spar to which the main clew is set – this spar qualifies for exclusion.

Item 2   A spar cantilevered forward from the mast spar – this spar qualifies for exclusion.

Item 4   A near vertical spar attached at its upper end to the mast spar and at its lower end to the headsail clew – this spar qualifies for exclusion.

Of the above spars all items qualify for exclusion from the certified rig area. However, only one spar per sail may be excluded. Where more than one spar qualifies (for the headsail in this case) the one with the smallest area, found using J.3 and/or J.4, shall be excluded in the certified rig area.

Form C

An alternative version of the swing rig is similar to Form B but has a spar, item 3, connected to item 2 (fore end) and to item 4 (aft end).

Item 1   A spar cantilevered aft from the mast spar to which the main clew is set – this spar qualifies for exclusion.

Item 2   A spar cantilevered forward from the mast spar – this spar does not qualify for exclusion because it does not extend the tack or clew of a sail.

Item 3   A spar to which the headsail clew and tack is set – this spar qualifies for exclusion.

Item 4   A near vertical spar attached at its upper end to the mast spar and at its lower end to the aft end of a spar onto which the headsail is set – this spar does not qualify for exclusion because it does not extend the tack or clew of a sail.

Therefore the area of Items 2 and 4 shall be measured for area.

Other Forms

Apart from Forms A, B and C other arrangements of spars are possible. In each case the relevant rules shall be applied as above to determine which spars qualify or do not qualify for exclusion from the certified rig area.

End

Question details:

An owner has purchased a boat and wants to register change of ownership. The boat, K4172, was registered in May 1989.

Answer:

Discussion

At an event for Marblehead Class boats the current (2016, 2018 after 1^st April 2018) Class Rules apply.

Section B states:

For a boat to be eligible for racing, it shall comply with the rules in this section.
B.1 CLASS RULES AND CERTIFICATION
B.1.1 The boat shall:
(a) be in compliance with the class rules.
(b) have a valid certificate.
(c) have valid certification marks as required.

The boat shall comply with the class rules and have a valid certificate. However, 1988 class rule 2.6.2 indicates change of ownership invalidates the certificate. Therefore racing by the new owner under the original certificate, even if it exists, is not an option.

The boat has no valid certificate. In order to race a valid certificate is required. CR A.12.1 (b) applies – by application of A.9. A.9 describes the process for obtaining a new certificate.

Conclude

The boat shall be re-certified as per CR A.9.

The following points should be noted:
 
*The hull may comply with the class rules that applied at the time of its initial certification. This may be useful if any current class rule would prevent the hull from obtaining a certificate. On this basis the national letter in the hull may remain as K.

*The appendages shall comply with the current class rules.

*The rig shall comply with the current class rules.

*The sails shall comply with the current class rules or the class rules in force at the time of their initial certification. See 1988 CR 3.7.

*At world and continental championships the sail marks shall comply with the current RRS. The national letters shall be GBR.

*At other events the sail marks shall comply with the current RRS or the rules in force at the time of their initial certification. See 1988 CR 3.7 (f) to (h). Note that the use of national letters is not mandatory except at international events.

*If it is not clear when sails were certified they should be re-certified according to the current class rules.

Question details:

Can the spreadsheets for creating certificates and other spreadsheet based certification control forms be used on Apple computers?

Answer:

It seems they may not open and/or work correctly on Apple computers. IRSA does not have the resources to develop the same software to work correctly on Apple computers so, sadly, the options seem to be for official measurers and certification authorities to acquire the use of a pc or to use an emulator.

However, if you have been using IRSA certification material on Apple computers in the past, it is quite likely that you will be able to in the future.

Question details:

Why are the spreadsheets that create certificates (M, 10R & A Classes) openly available?

Answer:

Prior to 2016 there were two versions of the spreadsheet for each class.

In each case (M, 10R and A Class) the version available to the public (for use by official measurers, designers, sail makers and owners) allowed for data entry and calculation only and could not produce a certificate. The version made available to the IRSA DNMs only for use by their certification authority could produce a certificate. The idea was that it would be impossible forofficial measurers or others to have access to the certificate creation page.

In practice this did not work and the certificate creation versions were openly available. Recognising the way these things work in real life led the IRSA TC and EC to the conclusion that only one version of the spreadsheets is needed as it is the signature and official stamp on a certificate that authenticates it rather than the software from which it is produced.

Certification authorities are advised to take care to ensure that the method of signing and attaching their official stamp does not lend itself to illicit copying.

Each spreadsheet contains a (hidden) algorithm that finds a two digit code that is printed on each sheet of a certificate. The same code will be created each time the same data is entered. This is a simple precaution that confirms that the 'certificate' has been produced on the official IRSA version of the spreadsheet.

Question details:

Should the 2016 software should be used when ownership of a boat first certified to the previous class rule changes?

Answer:

No. The software for certification under the previous class rules should be used. Change of ownership causes the certificate to become invalid but it does not cause the boat to cease to comply with the class rules. A new certificate, to the previous class rules, shall be issued.

It is not possible to produce a certificate to the new class rules in the case of change of ownership because many measurements taken and used under the 2016 class rules are different to those used for the previous class rules.

A.12 HULL RE-CERTIFICATION

A.12.1 A hull may be issued with a new certificate, showing dates of re-certification and initial certification as applicable:

(a) when a certificate becomes invalid upon change of ownership

by application of the new owner to the certification authority in the country where the hull is to be registered. The application shall include the old certificate and re-certification fee if required. In the case of an imported hull the certification authority shall request the measurement form(s) from the previous certification authority and a new hull registration number shall be issued,.

In this case there is no requirement to apply the procedure in A.9 (which describes how a hull is certified). Use of the software for certification under the previous class rules should be used.

Question details:

Can a sail be used on more than one boat where each boat has different parent sail areas?

Answer:

Any sail can be checked against the certificate of any boat for compliance. If the sail is found compliant the measurer can mark the area of the parent sail on it. There is no limit to the number of boats that a reduced size sail can be used with, subject to it complying with the certificates of those boats.

Please see the realted Q&A

Why is the measured area of a parent sail required to be marked on smaller sails?

Question details:

Why is the measured area of a parent sail required to be marked on smaller sails?

Answer:

It is useful for race committees and competitor sailors to be re-assured that reduced size sails used by a competitor comply with his boat’s certificate. Prior to 2016 the class rules required reduced size sails to ‘fit inside’ the profile of the largest (measured) sails.

Although this was an apparently simple rule it was impossible for sails genuinely made to the same measured dimensions to comply with the rule if their luff curve (or leech length) differed from the largest (measured) sail. No marks identifying any sail with any boat were required.

The 2016 class rules require each sail to comply with the boat’s certificate. This is straightforward to establish using the sail measurement system and works for sails that are of maximum size but have a different luff curve. To show that reduced size sails have been checked against a boat’s certificate and have been found to comply, the measurer is required to add the area of the parent sail to reduced size sails.

Please see the realted Q&A

Can a sail be used on more than one boat where each boat has different parent sail areas?

Question details:

How large can the sail maker label be on sails? Or the manufacturer label on other items of equipment? The class rules do not restrict this?

Answer:

The relevant rules are contrained in the World Sailing Advertising Code, also known as Regulation 20.

Clause 20.7.1 states that the display of manufacturer's and sailmaker's marks is permitted at all times as detailed in Table 2 but not in areas that area reserved for Event Advertising. For radio controlled boats the area reserved for Event Advertising is 40% of the hull length on each side of the hull from the foremost point on the hull. No Event Advertising is permitted on the boom(s), backstay or sails.

20.7.2 tells us a manufacturer's mark may include the name, logo or other identification marks of the designer or manufacturer of the equipment.

20.7.3 tells us that a sailmaker's mark may include the name, logo or other identification marks of a sailmaker or of the sail cloth manufacturer or the pattern or model of the sail.

Table 2 – Manufacturer’s and Sailmaker’s Marks

Radio-controlled boat

Hull  - On each side of the hull, and may include the name or mark of the designer or builder - One mark to fit within a rectangle measuring 15% of hull length x 150mm                     

Spars and Equipment - On each side of spars and on each side of other equipment - One mark not exceeding 50mm length                    

Sails - On each side of sails and kites - One mark to fit within a 50mm diameter circle

Question details:

How is the area of the mast measured when the mast passes the deck at two points? This is relevant where the mast is supported in a mast gate, usually above the gooseneck and main boom, and the gooseneck andkicking strap is below the level of the foredeck.

Answer:

Class rule J.2 Measured Rig Area states:

"The measured rig area is the sum of the area of the components of the largest rig excluding (certain stated parts)."

The mast below the mast gate (the upper deck level) and above deck level is not one of the excluded parts so its area shall be included in the Measured Rig Area. Where the mast crosses the deck more than once the area is measured to the lowest point where the mast crosses the deck.

Section K.4 is referenced as the method for measuring the mast area and the diagram L.1 shows the lowest spar cross width, m0, taken at deck level.

No rules restrict the shape of the deck in the vicinity of the mast. It is for the owner to specify where the mast deck level shall be taken. If the measurer disagrees with the choice of that point he shall report his opinion in the comment box provided on the measurement form. The Certification Authority shall not issue a certificate and may ask for an interpretation on the specific case.

Question details:

Is the area of a fitting that has a faired section included in the measured rig area?

Answer:

CR J.1(c)  states:

Fittings faired into a spar and/or bigger than reasonably required for their purpose shall be considered to be part of the spar.

The class rule requires that a fitting that is faired into the spar (or bigger than reasonably required) shall be taken as part of the spar. The requirement is not met by a fitting that has a faired section. If the fitting is not faired into the adjacent spar then it is not faired in regardless of whether its section is a faired shape or not.

Builders and measurers should be aware that if a fitting is faired into the spar any hollows created in the profile of the spar are to be bridged for the purpose of measurement. CR K.4.2 (h) refers. The additional measured rig area may be far larger than the profile area of the fitting.

Question details:

Are rotating mast fittings included in the measured rig area? For example, mainsail head attachment fitting, backstay crane, shroud attachments,

Answer:

Mast fittings attached to the mast spar are component of the rig but are not spars according to the ERS definition F.1.1. They are not rigging, spreaders or corrector weights so the conclusion is that they are fittings. Whether they rotate or not with respect to the mast spar, providing fittings are not larger than necessary and are not faired into a spar (CR J.1 (b) ) there is no requirement to include their area in the measured rig area.

Question details:

Is the area of a mast stub (and any gooseneck mounted on it) included in the measured rig area?

Answer:

A combined stub mast item and gooseneck that supports the mast spar is a component of the rig but it is not a spar according to the ERS definition F.1.1. It is not rigging, spreaders or corrector weights so the conclusion is that the mast stub and the gooseneck are fittings. Providing fittings are not larger than necessary and are not faired into a spar (CR J.1 (b) ) there is no requirement to include their area in the measured rig area.

Question details:

Does the Certification Authority have to use an official stamp in the relevant place when issuing a certificate?

Answer:

There is no prescribed requirement for the size or style of ‘official stamp’. At an event the person inspecting the official stamp on a certificate has no means of knowing if it is the correct one or not. The important thing is that the issuing Certification Authority will recognise it at some future stage should the certificate be referred back to it for any reason.

Any size or style of official stamp will suffice providing the CA is happy that it can recognise it as authentic at a later stage.

Question details:

What has happened to the previous interpretations? There were many interpretations to the previous versions of the Marblehead, Ten Rater and A Class Rules. Where are they now?

Answer:

IRSA regulations restrict the life of an interpetation to two years - after that time any interpretation ceases to be valid. The reason for this is that it is expected that the class rules will be changed during the two year period to make the interpretation unnecessary.

Where the new class rules require equipment to comply with the current class rules, if the class rules incorporate the effect of the earlier interpretation(s), then clearly the intrerpretation(s) is no longer needed. This explains why some interpetations are no longer needed and have been removed.

Where the new class rules permit equipment to comply with earlier versions of the class rules (usually known as 'grandfathering') then the earlier interpretation, although expired, remains relevant and is retained for information. A few such interpretations are retained.

Many other interpretations that were issued in the period before 2014 have been revised and are presented here in the form of Q&As (see Q&A on the difference between an interpretation and a Q&A). Again, this explains why many earlier interpetations are no longer needed and have been removed.

Question details:

How are sails checked at an event (equipment inspection) for compliance with the certificate.

Answer:

At an event the equipment inspector (measurer) checks a sail by placing it on the measurement grid with the head point and tack point on the vertical grid line. The clew point is placed on the datum grid line.

The following dimensions are then compared with the certificate values:

• luff perpendicular
• cross widths at 200 mm intervals up the sail
• height of the sail above the uppermost grid line that the sail cuts
• heights from the datum grid line to the sail foot

This process is described in detail in CR Section K. Sails with values that are the same or less than on the certificate are compliant.

If the sail is a reduced height sail it is likely that it will not have heights from the datum grid line to the sail foot that are compliant with this procedure. However Section C contains rules that apply at and event and Section C.8.1 (b) tells us that sails may be moved vertically when carrying out equipment inspection.

Answer:

It is inevitable that a new set of class rules may have a rule which is thought to be in error or in need of amendment. Suggest a rule change to your DNM. If it agrees, or if you are the DNM, send it to the TC Chairman for further discussion. Please read carefully our regulations and Q&A to avoid unnecessary work before you send any suggestions to the TC. Proposals for rule changes should be based on meaningful technical evidence and not on loud repetitions.  

Question details:

Under what rules are sails certified for a 10R certified before 1st July 2016?

Answer:

Section C 8.1 (c) of the class rules tells us that for hulls and sails certified before 1st July 2016 the profile of each alternative sail shall fit within the profile of the sails recorded on the certificate. These class rules continue to apply to a hull and sails certified before 1st July 2016.

New sails fall under Section G 1.1 which tells us that sails shall comply with the class rules relating to the certificate, or with the 2016 class rules. For a hull certified before 1st July 2016 the previous class rules continue to apply.

Question details:

Use of boats with certificates issued by sources other than IRSA affiliated bodies?

Answer:

No.

The IRSA international classes are distinct from classes using the same name but which are not administered (ultimately) by IRSA. For example the Naviga administered One Metre, Marblehead and Ten Rater classes are different classes and the certificates issued under those rules are not valid for IRSA events (world or continental championships) or events normally organised by IRSA affiliated bodies. The same is true for the Marblehead class administered by the American Model Yachting Association which uses class rules different to the international class rules.

The owner of a boat in one of those classes can obtain a certificate for the international class after having his boat measured to the IRSA class rule. To do this he should find an official measurer (please see the Equipment Rules of Sailing) and then contact his certification authority (normally the body in his country that administer rc sailing and is affiliated to IRSA). If he is a member of a body affiliated to his World Sailing Member National Authority (the body responsible for the administration of SAILING in his country) he will then be eligible to take part in events for the international class.

Question details:

A Ten Rater has its largest sails measured for the purpose of establishing its rating. Those sail sizes are entered on the measurement form and are recorded on the certificate. The same is true for an A Class boat and for a Marblehead (usually the largest of A rig, of B rig and of C rig). Is it necessary to have smaller sails measured and certified?

Answer:

Yes.

The smaller sails are measured to ensure they are indeed smaller and that they meet the other requirements and restrictions. Then they are certified (usually by the measurer signing the sails) to show that this porocess has bene completed satisfactorily.

Question details:

Does an alternative sail have to fit within the profile of the 'largest' measured sail?

Answer:

No. Under the 2002 class rules it is required that 'alternative' sails shall fall within the profile of the sails recorded on the certificate. The 2016 class rules do not require this.

Sail makers will be aware that sails are 3D objects and small changes to the inbuilt shape at the seams will have an effect on the profile of the sail. Although apparently simple in its requirements, the 2002 class rule creates several problems. Unless the sailmaker knows the leech length of a sail he is replacing he is unable to make a sail of the same profile (even if it is a purely 2D object). Even 1 mm more, or 1 mm less, leech length or luff curve results in the profile of the replacement sail not matching the original. It is not smart to have a class rule that does not allow the owner to replace his equipment and easily meet the class rules. Further, unless the sails measured and recorded on the certificate are retained by the owner when he has replacement sails they, and the other 'alternative' sails cannot be checked according to the class rules.

The 2016 class rules no longer require alternative sails to fall within the profile of the sails recorded on the certificate but treat the issue in a slightly different way that solves the problems mentioned above and gives other benefits. How?

The way in which the 'largest' sail is placed on the measurement grid has been revised marginally - the head and tack are placed on a line perpendicular to the transverse grid lines with the clew placed on a grid line. At and above the clew the cross widths are taken as usual (but at 200 mm intervals instead). Below the clew the depths are taken at 50 mm intervals. The dimensions are recorded on the certificate.

'Alternative' sails are checked by placing them on the grid in the same way and checking that their dimensions (measured in the same way) are equal to or less than the certificate dimensions.

There is no requirement for these 'alternative' sails to fall within the profile of the 'largest'. This introduces freedom to have sails made with different luff curves (or fullness/camber for example) but which comply with the certificate. Any width added at the luff needs to be removed at the leech. Provided the cross widths measured at all grid lines remain less than or equal to the certifiate values, the sail complies. See the diagram above.

The sail maker has all the information he needs to make sails that comply with the class rules as extended by the boat's certificate without asking for more. At equipment inspection there need be no difficulty in establishing a sail's compliance under the 2016 class rules.

This freedom exists for boats with certificates to the 2016 class rules only. Boats measured to the 2002 class rules and any new sails made for them shall continue to comply with those class rules. 

Question details:

At what point, on change of ownership, does the certificate become invalid?

Answer:

The certificate becomes invalid upon a change of ownership. The change of ownership is the important criterion – not the signing of the certificate by the new owner – not the issue of the new certificate in the new owner’s name.

However, while the concept of ownership is normally well understood between any two people it may be that the law of the land becomes relevant in particular cases and this may vary depending on the contract involved and where the ‘transaction’ takes place.

The view is that IRSA class rules are not intended to, nor do they, shed any light on ownership or when it changes hands.

Question details:

What is the difference between a Q&A and a Class Rules Interpretation?

Answer:

An interpretation is requested when it is not clear (to a designer, builder, measurer, class association or certification authority) how a class rule shall be interpreted. When an interpretation is issued it should be kept in mind that the interpretation is valid until the class rules are changed or for two years maximum only. The purpose of this last rule is that two years gives sufficient time to consider if the effect of the interpretation is a) desirable or b) undesirable. Depending on the decision or choice (a or b, by the IRSA TC or the class depending on whether there is an independent class organisation or not) the class rules can be revised accordingly.

Thus, when drafting any interpretation, it should be kept in mind how the class rules should/could be revised to make the original interpretation request redundant.

It follows that, if no revised class rule can be written, there is no need to issue an interpretation. Where no interpretation is required, but only an explanation of the effect of the class rules, it follows that it would be appropriate to deal with the original request by issuing a Q&A to be published on the IRSA website and elsewhere as appropriate.

This is the guiding principle used by the IRSA Technical Committee when considering any question about the class rules whether it is a formal request for an interpretation or not.

Answer:

The ERS is a document maintained by the ISAF which is a revised on the same 4 year cycle as the Racing Rules of Sailing. The current version may be found on the ISAF website and there are several versions in translation listed there too.

http://www.sailing.org/documents/isaf-equipment-rules.php

Question details:

Section C of the class rules requires the hull registration number to be displayed legibly on the external surface of the hull with a minimum height of 20 mm.

Answer:

Yes. Providing the hull registration number digits are of minimum height 20 mm, are clearly legible, are easily visible, are painted, engraved, bonded in or moulded in, and are on a non-removable part of the hull then both rules are satisfied by a single set of numbers.

However, it is often more convenient and attractive to use vinyl numbers on the deck to satisfy the Section C rule and some more convenient method on an inside area to satisfy the Section D rule.

Bear in mind the purpose of the rules: the Section C rule is for the benefit of the race committee and other competiors at an event to help identify a boat when it does not have it's rig in place; the Section D rule is to permanently and uniquely identify a boat so that it may be grandfathered, if needed, at a later date. In 50+ year's time the number will also add value and interest to any boat that has survived that long.

Question details:

Why are boat weights and lengths not required to be checked at certification control (measurement)?

Answer:

It used to be normal for class rules to require all equipment to be checked for compliance with the class rules. It was also normal for the certificate or class rules to state that alterations would invalidate the certificate. Yet it was commonplace for owners to make alterations to their boat/equipment without returning to the measurer to have it re-checked. This made it tedious for scrupulous owners to enjoy the freedom to develop their boats in the same way that less scrupulous owners did.

Clearly, when a boat competes at an event it is important that it complies with the class rules in all aspects. However at certification control (measurement) it makes no sense to check the overall length or draught of a boat because those dimensions necessarily depend on the weight of the boat and its flotation which are in turn affected by the weight and placement of removable items (rudder, fin, ballast, rc equipment). By removing those checks from certification control a tank and accurate scales are not required before a certificate can be issued. Only at an event when those items are in place need, and can, those dimensions be checked. If a tank and accurate scales are available at certification control measurers are encouraged to monitor those checks if owners wish. But owners need to be made aware of their continuing responsibilities after the certificate has been issued.

The freedom granted to the owners to alter equipment is balanced by their responsibility to ensure that their boat complies with the class rules when competing at an event. It follows that equipment inspection at an event (always difficult when flotation has to be checked) is the only way to monitor correct compliance with the class rules. At an event a tank can be used to check all the boats, far more efficient than at each boat's certification control. 

Should a boat be found not to comply with the weight and dimensional limits the responsibility lies clearly and solely with the owner for failing to ensure compliance. Altering the boat and failing to take steps to ensure continued compliance with the class rules might be taken as a breach of RRS 69 by a jury.

Question details:

Why is the waterline length not required to be checked at certification control (measurement)?

Answer:

Prior to the 1994 version of the class rules it was required to determine the waterline endings, measure the length between them and use that figure to determine the rating. The waterline endings were not marked with limit marks and no data was recorded that might determine those points. According to the certificate any alterations to the boat that affected the rating would invalidate the certificate.

However it was commonplace for owners to alter the fittings, mast position, spars, sails, on board rc equipment etc and not repeat the measurement process. Note that even a weight reduction would alter the rating thus rendering the certificate invalid.

In 1994 the requirement to add limit marks was introduced and it became permitted for the first time to alter the boat without the certificate becoming invalid. 

The purposes of this change:

• to permit owners to freely modify their boats (which they did anyway) but for the first time within the class rules
• with suitable equipment the measurer (certification measurer or equipment inspector at an event) can easily dry measure between the marks to establish the rated waterline length
• with a tank, or any piece of calm water, the owner/measurer/sailor can float the boat and establish that the waterline endings are inside the limit marks without the need to precisely determine the waterline ending positions
• there is the possibility that other sailors can judge whether a boat is floating to its marks or not

The new freedom granted to the owners was balanced by their new responsibility to ensure that their boat complies with the class rules and certificate when competing at an event. It follows that equipment inspection at an event (always difficult when flotation has to be checked) is the only way to monitor correct compliance with the class rules. But there is nothing new about this - it has always been so.

Should a boat be found to float with the waterline endings beyond the limit marks at an event the responsibility lies clearly and solely with the owner for failing to ensure it floats correctly. Altering the boat and failing to take steps to ensure continued compliance with the class rules might be taken as a breach of RRS 69 by a jury.

The 2016 CR have followed the same logic but have introduced some further safeguards. Boat weight is determined at certification control and is recorded on the certificate. At an event the boat may not weigh more than 0.05 kg more than this figure. The waterline limit marks shall be long enough to be visible when afloat.

Question details:

When a boat with a reverse sloping transom (retrousee transom) has a waterline limit mark placed at the waterline, but where the transom/stern of the boat extends beyond the limit mark under the water, what is the correct treatment under the class rules?

Answer:

The class rule C.4.1 (c) requires that no part of the underwater hull extends beyond the waterline limit marks.

C.4.1 (c)   submerged parts of the hull shall not extend beyond the inboard edges of the waterline limit marks.

In the case described a part of the underwater hull does extend beyond the waterline limit mark (which is correctly placed). The boat does not comply with C.4.1 (c) and therefore is not eligible to compete in competition.

The owner needs to find some way to place the limit mark so that the boat complies with the class rules.

Question details:

Where the deck is irregularly shaped near the mast, where is the correct place for the deck limit mark?

Answer:

The IOM class rules do not seek to restrict the shape of the deck near the mast. It would be complex to do so and the point to which rig height is measured is taken to be relatively non-critical.

A deck limit mark shall be displayed on the hull centreplane near to the mast position. The mark shall be a minimum of 5 mm in diameter.

It is for the owner to decide where to place the mark.

Once the mark is placed the measurer can carry out his measurements.

Equipment inspectors (event measurers) carrying out pre-race checks may wish to make the deck limit mark 'permanent' by signing over the top.

Question details:

A recent ruling for the IOM class says the certification authority for the hull is the DNM of the country where the owner is resident.  Does this apply to the M, 10R, and A Classes too?

Answer:

Yes.

The IOM, Marblehead, Ten Rater and A Class class rules indicate the certification measurement forms (measurement forms) are sent to the certification authority in the country where the hull is to be registered. This seems to give the owner some choice over where his hull is to be registered.  However, ERS C.3.1 defines the certification authority as 'the MNA of the owner'. Where the term certification authority is used it shall be understood to be the certification authority in the country where the owner is resident or in the country of which the owner is a national. This is normally the DNM (Delegated National Member for radio sailing) in the country.

Question details:

Who issues a certificate for Marblehehad and 10R classes?

Answer:

The certification authority issues the certificate. As of 1st July 2016 all the IRSA classes have the same administrative section. It is A.9 that indicates it is the certification authority that issues a certificate.

The term 'certification authority' is defined in the ERS as:

For the hull: the ISAF, the MNA of the owner or their delegates.

For other items: the ISAF, the MNA of the country where the certification shall take place, or their delegates.

The members of IRSA are the bodies to which the administration of RC sailing has been delegated (if not the MNA of the country itself) and which are known as the DNMs. So, for the hull it is the IRSA DNM of the owner.

For other items it will usually be the same but it could be the MNA or delegate of MNA in another country where the emasurement took place. This would apply where, for example, sails were certified in house by a sailmaker who had been delegated the authority to do that.

See also the related Q&A concerning who is the certification authority, or DNM, for an owner.

Question details:

1. Is a spar that is attached to the hull and extending from the mast and along the foredeck a part of the rig for measurement purposes and should it be included in the certified rig area?
2. Is a spar that is attached to the mast of a swing rig and extending forward to support a spar to which the tack and/or clew of a headsail is attached to be included in the certified rig area?

Answer:

1. If the item is part of the rig (if it is removed when the rig is removed from the hull, then it is a part of the rig rather than a part of the hull) then it shall comply with the class rules for the rig.

       The relevant class rule is J.1 (a):

One spar, not being a mast spar, with a spar cross section not exceeding 22 mm is permitted to extend the tack and/or clew of each sail without being included in the certified rig area.

The spar described does not extend the tack and/or clew of a headsail so its area shall be included in the certified rig area.

  2. Same answer as Q1 – see 1. above.

Revised on 11.11.2018. to be in accordance with Ten Rater Class Rules - Effective 1st November 2018

Question details:

1. Would a hull with an open central section of the aft overhang (fig 1), extending from the transom forward to a short distance aft of the aft waterline ending, comply with the class rules?
2. Does the presence of a deck across the top of and joining the twin overhangs (fig 2) make any difference?
3. Does the width of the open section (fig 3) make any difference?
4. Does leaving the twin overhangs un-decked (i.e. each is no more than just the thin skin of the primary hull moulding) (fig 5) make any difference?

Answer:

1. No. The open section is a hollow in the surface of the hull (see definition of hollow below). Since hollows in the external surface of the hull are prohibited less than 40mm above the datum waterplane and more than 15 mm from the centreplane, the proposed feature clearly falls outside the rule D 2.4(b) and the hull does not comply with the class rules.
   Hollow is undefined in CR, ERS and RRS. The Oxford English Dictionary definition of the noun ‘hollow’ is: “a hole or depression in something”.
2. No. The presence of a deck does not change the presence of hollows in the external surface of the hull to be tested under D 2.4 (b).
3. Yes. D 2.4(b) (3) makes an exception for hollows within 15mm of the centreplane which are permitted. The reason for this exception is to permit the hollows that are formed by the presence of the keel and rudder where they join, or are faired into, the hull. If the hollows are entirely within this region they are permitted.
4. No. In this arrangement the upper surface of the overhangs are “inset transom and upper surface of deck” and thereby, any concavity in that upper surface is not prohibited by D2.4(b) 5).
   The absence of a deck or any other structure apart from the hull shell does not change the presence of hollows in the external surface of the hull to be tested under D 2.4 (b).

The 2002 CR have the same effect.

Question details:

For the purpose of initial certification control (measurement), is it possible to take the largest cross widths of two or more sails and use these to create dimensions for a ‘virtual’ sail that is recorded on the certificate?

Answer:

For boats certified to the 2002 CR, no. The Ten Rater class rules I.2 and J.2 refer to the measured rig area and measured sail area of the largest rig. It follows that the largest rig and sails to be used shall be presented to the measurer and be certified.

The Ten Rater class rule does not require that the largest rig and sails be used at any event. However, alternative sails are mentioned in Section C and in order to certify those sails the measurer shall check that they fall within the profile of the largest sails (the dimensions of which are recorded on the certificate). This check cannot be made unless those largest sails are present.

For boats certified to the 2016 CR, yes. The concepts of measuring the largest suit of sails and alternative sails having to fit within the profile of those sails no longer apply. It is possible that the dimensions of 'virtual' sails could be placed on the measurement form and sails checked against those dimensions for compliance.

Question details:

Under the 2002 CR and where a hull design has plumb (vertical) ends and the waterline endings extend to the extreme ends of the hull, may the waterline limit marks be placed around the bow and/or on the transom?

Answer:

No. The class rules require the waterline limit marks to be placed on the undersurface of the hull.

A waterline limit mark placed around the bow some distance up from the LWL is not on the undersurface of the hull although it may be across the centreplane of the hull. Similarly with the waterline limit mark placed on the transom. These waterline limit marks would not comply with Class Rule D.2.1.

It is suggested you add a short extension(s) to the hull, where appropriate, that may carry the required waterline limit mark(s) that are on the underside of the hull as in the diagram below.

The 2016 CR contain different wording and this issue is effectively resolved.

Question details:

Is it necessary to float a Ten Rater at the time of certification control (measurement) to establish the correct placement of the waterline limit marks?

Answer:

No. The true waterline length is not a measurement that is required at certification control (measurement) or at any other time unless the purpose of the measurement is to determine compliance with the certificate (equipment inspection).

What is required is placement of the waterline limit marks and measurement of the distance between them. Class rule C.4.1 shall be complied with when the boat is racing and, providing the boat complies fully with the class rules when racing, no rule is broken if the boat has not been floated at the time of initial certification control.

The requirement in the 2002 CR to have the waterline endings no more than 30 mm inboard of those limit marks no longer applies.

Question details:

What sail identification marks shall be displayed when a hull holds a certificate in more than one class.

Answer:

When a boat races it shall carry the appropriate sail identification marks for that class. Providing they do not affect the legibility of the marks, alternative class insignia may remain on the sails.

Answer:

No. C.6.3 prevents the movement, articulation, retraction or extension of hull appendages (including the ballast). Additionally RRS 51, which is not excluded by Appendix E of the RRS, states that movable ballast ‘for the purpose of changing trim or stability’ is not allowed.

1994 CR 4.1.1 prevents movement of the ballast fore and aft and canting keels per se are not prohibited. However, when a race is un using the RRS and RRS 51 is not cancelled the effect is the same.

The same logic applies to the other classes too.

Question details:

Can a boat with a certificate in one class also hold a valid certificate in another class?

Answer:

There is no rule in any of the International One Metre, Marblehead, Ten Rater or A Class class rules which prevents a boat from having a valid certificate for another class.