CLASS RULES - B - THE MEASUREMENT RULES
1.0 General
1.1 The 505 ("the boat") is a one-design dinghy of 5.05 metres L.O.A. designed by John Westell and is an international dinghy class recognised by the International Yacht Racing Union ("IYRU").
1.2 The administering authority is the International 505 Class Yacht Racing Association ("the International Association") subject to its Constitution and subject to the rules of the IYRU.
1.3 These Rules and the other documents of the Class are published in French and English but should there be a difference between them, the English version shall prevail.
1.4 All boats shall be built, measured and-registered in accordance with these Rules. Should any conflict arise between the written Rules and the Measurement Diagrams which form part of the Rules then the written Rules shall prevail.
1.5 Any boat having a Measurement Certificate or any sail bearing a Measurement Stamp dated prior to the date of these Rules may be measured in accordance with the Rules prevailing at the date when the boat or sail was first measured unless these Rules state to the contrary or unless the boat or sail has been altered, modified or renewed after the date of any relevant change to these Rules. Any equipment which is altered, modified or renewed shall conform to the current Rules.
1.6 Neither the designer nor the International Association nor the IYRU nor any National Association accepts any legal responsibility in respect of these Rules or the designer's drawings or any claims arising from them.
2.0 Fees
2.1 The Constitution of the International Association provides for a subscription charge to all boat-owning members. National Associations may also charge subscriptions. The amount of the International subscription (which is collected by National Associations) shall be such sum as the International Association shall decide from time to time upon the recommendation of the International Executive Committee ("IEC").
2.2 Upon the application for a sail number and registration of a new boat the following fees shall be payable
2.2.1 The designer's royalty which is such sum as the International Association shall decide from time to time upon recommendations of the IEC not being less than ten pounds sterling.
2.2.2 The registration fee which is such sum as the International Association shall decide from time to time upon the recommendation of the IEC.
3.0 Registration
3.1 Sail numbers are issued by the International Secretary to National Associations upon receipt of payment of the designer's royalty and the registration fee.
3.2 An owner or his agent wishing to register a boat shall apply to his National Association for the issue of a sail number and a Measurement Form. The application shall be accompanied by payment of the designer's royalty and registration fee.
3.3 The registration of a boat as an International 505 Dinghy is completed upon satisfactory completion and return of the Measurement Form (through a National Association) and the issue of a Measurement Certificate by the International Secretary
3.4 No boat may race unless it has a valid Measurement Certificate and its owner and helmsman are members of the International Association.
4.0 Measurement
4.1 Boats and their equipment shall be measured only by measurers appointed by the IEC in consultation with the International Rules Committee ("IRC") or appointed by a National Association or appointed by a National Yachting Authority.
4.2 No owner may measure his own boat, sails or equipment, nor may a builder or sailmaker measure his own products.
4.3 Measurement shall be carried out using only the Documents supplied by the International Association, namely these Rules and the Measurement Form (including Instructions to Measurers) and the Official Templates.
4.4 In addition to the particulars required by the Measurement Form, the Measurer shall report on the Form anything which he considers to be a departure from the intended nature and design of the boat or to be against the general interest of the Class. In these circumstances the Measurement shall be sent to the IEC through the International Secretary. The IEC shall refer the matter to the IRC to decide whether or not a Measurement Certificate should be granted. The IRC is empowered to grant dispensation in exceptional cases. Such dispensation shall be recorded on the Measurement Form and the Measurement Certificate.
4.5 It shall be the owner's responsibility to ensure that the boat complies with these Rules at all times.
4.6 Remeasurement may be ordered by the International Association, the IRC or a National Association at any time.
4.7 New spars and sails shall be measured before use. Sails shall be signed and dated and where possible stamped by the measurer.
5.0 The Hull
5.1 Materials and methods of construction are not restricted except as provided by these Rules. The designer's drawings show a method of constructing in moulded plywood.
5.2 Hull Shape
5.2.1 The hull shape shall conform to the designer's drawings and the offsets annexed within the tolerances specified by the Measurement Diagrams and these Rules.
5.2.2 Hull moulds shall be checked by reference to plugs, moulds and production hulls before general use and after any modifications. Any builder constructing a new mould shall inform the International Office certifying that it conforms to these Rules. The International Association may check moulds at any time.
5.2.3 Station 11 is defined as the plane at right angles to the base line shown in the measurement diagram and passing through the aftermost point of the hull, excluding rudder fittings. The after measurement point of the hull is the point on the centreline of the boat where the outer surface of the keel band would, if projected, intersect Station 11, neglecting any actual rounding of the keel band. Other measurement stations are planes parallel to Station 11 at the specified distance from it.
5.2.4 No part of the after edge of the hull shall be more than 7.5mm from Station 11. No part of the after end of the seat-tank shall be more than 20mm forward of the after edge of the hull. The design of the transom is free in other respects.
5.3 Keel Band
5.3.1 Along the centreline from stem to transom a flat keel-band shall project not less than 3mm and not more than 4.5mm from the surface of the hull and may be rounded to a radius of not more than 3mm. However at the sides of the centreboard slot the section may be 'half-round' instead of flat. Keel band widths shall be within the following limits:
Max (mm) Min (mm)
Transom 75 30
Station 9 75 65
Station 6 75 65
Station 3 35 25
Forward of Station 3 the keel band may be faired into the hull.
5.4 Foredeck
5.4.1 The after edge of the foredeck (which need not be straight between the centreline and the gunwale) shall lie within the tolerances set out in the Measurement Diagram. The after edge of the foredeck at any point along its length shall be at or above the "top of gunwale". The "top of gunwale' is defined as being a point 20mm inside the extreme edge of the hull regardless of construction.
5.4.2 Forward of the most forward position of the after edge of the foredeck the only apertures permitted are:
5.5 Forward Watertight Compartments and Seat-Tanks
5.5.1 The forward compartment and the seat-tanks shall be separate watertight compartments.
5.5.2 The watertight bulkhead and seat-tanks shall conform to the drawings within the tolerances specified in the Measurement Diagram.
5.5.3 The forward compartment may include one spinnaker chute only, the volume of which shall not exceed 20% of the total volume of the forward compartment, The construction of the spinnaker chute shall not impair the watertight integrity of the forward compartment.
5.5.4 The watertight diagonal bulkheads at the forward ends of the seat tanks shall lie at or forward of the after edge of the foredeck.
5.6 Centreboard Case and Thwarts
5.6.1 The internal dimensions of the centreboard case shall conform to the tolerances specified in the Measurement Diagram.
5.6.2 Athwart shall connect the top of the centreboard case to the inner faces of the seat-tanks. It shall not be more than 153mm wide and its after edge shall lie between 1375mm and 2591mm from Station 11.
5.6.3 Additional thwarts, bridge-decks and sheet horses may be fitted across the hull. The total width of all such additional thwarts etc, shall not exceed 150mm.
5.7 Not in use
5.8 Weight
5.8.1 Boats shall be weighed in dry conditions for measurement and certification after an uninterrupted period of two weeks not having touched water.
5.8.2 The weight of the hull only in dry condition shall not be less than 100kg. "Hull only" includes keel band, rudder fittings, chain plates, fairleads and any fixtures which are essential to the sailing of the boat and which are normally permanently bolted, glued or screwed in place. Fittings of exaggerated weight shall be excluded.
5.8.3 If the weight of the hull only is less than 100kg the difference to a maximum of 2kg shall be made up by metal ballast secured to the centreboard case and visible when viewed from a standing position next to the boat, half at the after end, half at the forward end, such ballast to be retained for the life of the boat or until the boat is reweighed in accordance with Rule B-5.8.2.
5.8.4 The sailing weight in dry condition shall not be less than 127.4kg. The sailing weight is the weight of the hull including metal ballast, the spars, standing and running rigging, centreboard, rudder and tiller, but excluding sails and battens.
5.8.5 Boats may be reweighed at any time by a Class Measurer providing that immediately prior to reweighing, the boat has not touched the water for a period of at least two weeks. The hull only weight, the sailing weight and the weight of any ballast shall be recorded on the certificate by the Measurer and returned by the Measurer to the International Office for recertification. The metal ballast referred to in Rule B-5.8.3 may only be removed or reduced at a reweighing commissioned by the owner under this paragraph and such reweighings may only take place at intervals greater than 12 months,
5.9 Sail Number
5.9.1 The sail number of the boat shall be clearly carved or impressed on the transom, spine, or aft end of the centreboard case in numbers of 18mm minimum height.
5.9.2 The IYRU levy plaque bearing the registered sail number shall be fixed on the transom, spine or aft end of the centreboard case.
6.0 Centreboard, Rudder and Tiller
6.1 One rudder and one centreboard only may be used at any one time. At all times when sailing, both sides of the centreboard and rudder shall have similar profiles. Leeboards, daggerboards, hydrofoils, trim tabs, fences and similar devices are prohibited.
6.2 The centreboard shall fit within the centreboard case not extending below the bottom of the hull when fully raised. The trailing edge may project above the centreboard case top when in the raised or partly raised position. No part of the leading edge which is more than 300mm from the tip and is capable of protruding below the hull shall be capable of being raised more than 200mm above the bottom of the hull.
6.3 The rudder shall be hung at the transom and no part of the rudder assembly shall pass through the skin of the hull. The tiller may be shipped through a port in the transom or over the top.
7.0 Spars
7.1 General
7.1.1 The object of these Rules is to maintain the sail plan of the Class to substantially the same design, whilst giving owners freedom to adjust the balance of the boat and to arrange the rigging as they wish.
7.1.2 A boat may not have facilities for setting more than one mainsail, one headsail and one spinnaker. No changes of sail are permitted during a race.
7.1.3 Except for fittings, spars shall be constructed solely either from aluminium alloy containing not less than 90% by weight of aluminium or from wood. Construction is otherwise unrestricted.
7.2 Mast
7.2.1 The mast may be stepped on the deck or into the hull. With the mast perpendicular to the base line, the after side at deck level shall not be less than 3048mm and not more than 3202mm forward of Station 11. The mast may be fixed or rotating. Excluding fittings, no dimension at right angles to the length may exceed 102mm.
7.2.2 When standing free with no sail set, the after edge of the mast from the top to a point 1000mm above the deck, shall be straight. The leading edge shall be a straight line or a fair continuous convex curve. Permanently bent masts are prohibited. A set, due to distortion, of up to 30mm between bands identified at B-7.2.3.2 and B-7.2.3.3 shall be permitted.
7.2.3 Bands of contrasting colour not less than 10mm wide shall be placed round the mast at the following three positions measured with the mast standing perpendicular to the baseline.
7.2.3.1 upper edge level with the top of the deck. Tolerance ± lmm (deck band)
7.2.3.2 upper edge 381mm above the deck band Minimum dimension
7.2.3.3 lower edge 6858mm above the deck band Maximum dimension
7.2.3.4 Extreme height of any spar 7011mm above the deck band Maximum dimension
7.2.4 The highest point of entry onto the block, sheave or fairlead for the spinnaker halyard shall not be more than 5105mm and not less than 5054mm above deck band. No rigidly fixed point for attachment of the block, sheave or fairlead may extend more than 35mm from the surface of the mast.
7.2.5 The highest point of entry onto the block, sheave or fairlead for the headsail halyard shall not be more than 4750mm and not less than 4648mm above deck band. A prolongation of the luff of the headsail when set shall cut the fore-side of the mast between these limits.
7.2.6 These measurements apply to masts whether fitted with mastjacks or otherwise. At all times when sailing, an extension of the upper surface of the deck shall intersect the mast at the upper edge of the deck band.
7.3 Boom
7.3.1 The upper edge of the boom shall be straight when no sail is set. With the exception of fittings, no dimension of the boom measured at right angles to its length may exceed 102 mm. A set, due to distortion, of up to 25mm over the length of the boom shall be permitted.
7.3.2 With the boom attached to the mast in the normal way and lying fore and aft at right angles to the mast, the point where a prolongation of the line down the after-edge of the mast cuts the top of the boom shall be found; "the intersection point" ' A band of contrasting colour not less than 10mm wide shall be placed round the boom with its inner edge not more than 2858mm from the intersection point.
7.3.3 The overall length of boom from the intersection point (B-7.3.2) to outer end of boom shall not exceed 3308mm.
7.3.4 A prolongation of the top of the boom shall cut the mast at or above the band identified at B-7.2.3.2.
7.4 Spinnaker Pole
7.4.1 The overall length of the spinnaker pole shall not exceed 2516mm including pole fittings. When in use it shall be attached to a mast fitting protruding not more than 50mm from the surface of the mast.
8.0 Sails
8.1 General
8.1.1 Sails shall be made and measured in accordance with the International Yacht Union's Sail Measurement Instructions (third edition 1986), and comply with their requirements. In the event of conflict with these Class Rules, the Class Rules shall prevail.
8.1.2 Sails need not be made from woven fibre cloth material but shall otherwise comply with the requirements of the IYRU as to materials.
8.1.3 Stretching after measurement resulting in the maximum dimensions being exceeded is not permitted and continued conformity with Class Rules is the responsibility of the owner.
8.1.4 No sail shall have a hole or aperture other than the normal reefing and attachment points.
8.1.5 The following paragraphs of the International Yacht Racing Union's Sail Measurement Instructions shall not apply:-
Paragraphs 1.2,1.3,1.4 and 1.6.
8.2 Mainsail
8.2.1 The mainsail shall conform with the Class Rules and the measurement diagrams, except that a sail smaller in any dimension is allowed. No part of this sail shall be set above the lower edge of the band on the mast identified at B-7.2.3.3.
8.2.2 The luff and foot of the mainsail shall be secured to the mast and boom respectively substantially throughout their lengths.
8.2.3 The following dimensions, including bolt ropes where fitted, shall not be exceeded:
The half height width is the distance between points on the luff and leech found by folding the sail with the upper inner corner of the headboard first at the tack then at the clew. The three-quarter height width is the distance between the points on the luff and the leech found by folding the sail with the upper inner corner of the headboard first at the half-height of the luff, then at the half-height of the leech. The tack is the point where the luff and foot, if extended, would intersect, ignoring any round or hollow.
8.2.4 Not more than four battens may be used to support the leech. The outer ends shall be located within l02mm of marks dividing the leech into five (if four battens) or appropriate number of equal parts, except that no part of the top batten shall be placed higher than its mark. Measurement shall be taken round the curve of the leech, which extends from its junction with the foot rope to the upper, outer corner of the headboard. No batten or pocket shall exceed ll80mm in length.
8.2.5 The Class insignia to be displayed on the mainsail shall be in accordance with the shape and tolerances shown in the Measurement Diagram.
8.3 Headsail
8.3.1 The headsail shall conform with the official rules and diagrams, except that a sail smaller in any dimension is allowed. The head, tack and clew are the points where the sides, if extended, would intersect, ignoring any round or hollow in the foot or leech
8.3.2 The leech shall be a straight line or concave curve
8.3.3 The following dimensions shall not be exceeded:
8.3.4 Not more than three battens may be used in the leech of any headsail. The outer ends of the battens shall be located within 102mm of marks dividing the leech into four (if three battens) or the appropriate number of equal parts. Not more than one batten, part of which shall be within 50mm of the centre, is permitted in the foot. No batten or batten pocket may exceed 305mm in length and 51mm in width.
8.3.5 No part of the foot shall lie outside a measurement taken in the following way:
8.3.6 Sleeve luffs may be made to enclose the forestay but the width of such a sleeve shall be measured with the sail and shall not exceed 76mm.
8.3.7 An extension of the headsail luff when set shall cut the centreline of the deck between the stemhead and a point 400mm abaft the stemhead.
8.3.8 There shall be a transparent panel in the lower part of the headsail of a minimum size of 0.15sqm to ensure visibility to leeward for the crew.
8.4 Spinnaker
8.4.1 The spinnaker shall be a symmetrical three cornered sail in accordance with the Class Rules and Measurements Diagrams except that a sail smaller in any dimension except half width is allowed.
8.4.2 The following dimensions shall not be exceeded:
8.4.3 The width at half the height of the luff shall not be less than 85% of the greatest width wherever found when measured in the following way:
8.4.4 IYRR Appendix B3 paragraph 1.3(c) is replaced by the following Class Rule: The numbers only shall be symmetrically placed on the forward side of the spinnaker totally below an arc whose centre is the head of the spinnaker, and whose radius is 40% of the mean length of the two leeches and totally above an arc of 60 % of that dimension.
9.0 Materials
9.1 Except where prescribed by these rules, either directly or by inference, there are no restrictions on the use of any materials in construction.
9.2 The use of particular materials may be prohibited or limited:
9.2.1 On the proposal of at least two National Associations and passed by a two-thirds majority of those attending the International Annual General Meeting and entitled to vote on changes on these rules as prescribed by the International Constitution.
and
9.2.2 if such proposal is approved by the International Rules Committee and the IYRU.
9.3 Such prohibition or limitation will continue either
9.3.1 for such period from the 1st January next following as may be prescribed being not less than 1 year nor more than 3 years when it shall lapse unless renewed by the procedure in Rule B-9.2.1
or
9.3.2 until a permanent change is made to these Rules in accordance with the International Constitution either to incorporate such a prohibition or limitation or to make another provision which is inconsistent with it.
9.4 The prohibition or limitation may be expressed to apply to all spars, sails, fittings and equipment belonging to a boat when the prohibition or limitation comes into force. Such prohibition or limitation shall not apply to hulls completed before it comes into force.
10.0 Buoyancy
10.1 Owing to the large amount of tank space, it is not practicable to test each boat by complete immersion of the watertight compartments. The measurer shall inspect the compartments carefully and satisfy himself that they are tight.
10.2 The owner shall maintain the integrity of the watertight compartments in an efficient condition and the Measurement Certificate will automatically become invalid should he fail to do so.
11.0 Equipment
11.1 Devices which indicate remotely or transmit or correlate data about wind direction, wind speed, boat speed or location shall be prohibited.
11.2 No anchor and chain or rope is required.
12.0 Crew and Weight of Clothing and Equipment
12.1 The crew shall consist of two people.
12.2 Only one person may be suspended outboard from spars or rigging. No device attached to the hull and projecting outboard beyond the line of the gunwale may be used.
12.3 The total weight of clothing and equipment worn or carried by a competitor whilst racing shall not exceed 1 1 kilograms when weighed by method 1 in Rule B-1 2.4 or 15 kilograms when weighed by method 2 in Rule B-1 2.4. Compliance by either method is acceptable. Weight jackets may be worn in accordance with IYRR
12.4 When required to check the weight of clothing and equipment the competitor may elect for method 1 or 2.
The competitor shall be totally immersed in water up to the chin for not less than two minutes in the clothing and carrying the equipment with which he competed in the race, with all weight pockets and water containers filled. He then shall stand out of the water and drain for one minute at the end of which period he shall be weighed immediately with all the clothing and equipment. He then shall remove all the clothing and equipment and be weighed. The difference is the clothing and equipment weight, which shall not exceed 11 kilograms.
All clothing and equipment worn or carried by the competitor shall be thoroughly soaked by submerging in water for five minutes and then hung or placed on a rack which permits free draining and allowed to drain for one minute at the end of which period the weight shall immediately be recorded, in accordance with IYRR Appendix 10 - Weighing of Wet Clothing