Class Rules

The rules for the Hurricane 5.9 SX are identical to the original Hurricane 5.9 rules, with the following amendments :

1. Introduction

a. The Hurricane 5.9 SX is a three-sail one-design catamaran that has been developed from the established Hurricane 5.9 one-design catamaran.

b. The majority of components of the Hurricane 5.9 SX rig are designed to be easily removeable so as to permit conversion to two-sail configuration if required.

c. Additions or alterations to the Hurricane 5.9 SX rig are not allowed unless explicitly permitted by these class rules.

2. Hurricane SX Sailplan

a. No alterations to the sailplan are permitted unless explicitly allowed by the class rules. Sails shall be as supplied by the manufacturer.

3. Hurricane SX Mainsail

a. The existing Hurricane 5.9 mainsail (Hyde one-design) shall be used with the SX rig and shall not be modified in any way unless explicitly permitted by these class rules. Battens shall be as supplied by the manufacturer.

b. The currently-supplied Fibrefoam (epoxy foam) battens or the earlier pattern Toyo (GRP) battens may be used in the mainsail. Battens may not be mixed.

4. Hurricane SX Jib

a. The Hurricane SX has a high-aspect jib that is rigged on the existing forestay and sheeted by means of a self-tacking track mounted on the main beam so as to facilitate the use of a spinnaker when sailing downwind. The area of the SX jib has been reduced significantly from that of the two-sail Hurricane 5.9 and has a sail area of 4.56 square metres. (VLJ measurement 5.6 metres, as referenced under the IYRU small catamaran handicap rating system (SCHRS)

b. The Hurricane SX jib shall be as supplied by the manufacturer (Hyde one-design) and shall bear a unique identification number that is allocated during production. It shall be attached to the forestay by means of a zip luff and rigged by means of single shackles to the existing 5.9 wire jib halyard arrangement and tack attachment plate respectively. The jib is fitted with an adjustable leech line, foot line and window as standard.

c. The jib luff tension shall be adjusted by means of a downhaul arrangement afforded by a single piece of rope (4mm polyester, max length 1.3 metres), the existing jib tack attachment fittings and the existing wire halyard. An additional block (max 20mm) may be added to the end of the wire halyard to reduce chafage. The means of attachment of the additional block is optional.

d. The jib track shall be as supplied (Ronstan, as supplied). The track shall be affixed to the main beam by means of four precision-made attachment pillars with clevis pins at their lower ends enabling attachment to mounting pads affixed to the front beam. The attachment pillars shall be as supplied and may not be modified in any way.

e. The jib track mounting pads shall be as supplied. A total of four machined aluminium alloy pads shall be affixed to the main beam with their centres positioned at 250mm and 535mm from the centreline datum and 100mm forward of the top of the rear edge of the main beam extrusion. The means of attachment to the main beam is optional. (Pop rivets are supplied as standard)

f. As an alternative to pop rivets, screws and threaded inserts (e.g. Rivnuts) are permitted as a means of attachment for all SX components that are attached to the main beam.

g. The jib track car shall be as supplied by the manufacturer and retained on the track by means of plastic end stops and machine screws.

h. The SX jib sheet is a two-stage cascade system comprised of a primary sheet which may be manually cleated to enable facile adjustment, coupled to a secondary arrangement that sheets the sail to the car on the self-tacking track. The length and diameter of all jib sheets is optional. (As supplied, the primary sheet measures 11 metres x 6mm diameter, the secondary sheet 2.25 metres length by 4mm diameter Dyneema)

i. The primary jib sheet shall pass through two swivel cleats mounted on main beam (Ronstan) and positioned such that the centre of the swivel bases measure 750mm from the outboard ends of the main beam extrusion. The primary sheet from each swivel cleat shall be routed through a double block (max 20mm diameter) attached to the spinnaker chute mounting hoop by means of one shackle and continue through one single block (max 20mm diameter) that is attached to one end of the secondary jib sheet.

j. The primary jib sheet may be led out to the shrouds. Rings or blocks shall be attached to the shroud chainplate adjusters. The “tail ends” of the sheet may be routed under the trampoline through the existing trampoline eyelets and joined so as to form a continuous system. Two turning blocks (max 30mm diameter) shall be affixed under the trampoline using existing attachment points to allow a routing system. Tensioning shall be achieved by the use of shockcord (4mm). An additional turning block (max 20mm diameter) shall be attached to the underside of the main beam for the purpose of the shockcord system.

k. The jib sheet purchase shall not be increased above that which is supplied. The secondary jib sheet shall be routed through jib sheeting blocks positioned as follows: One block with becket (max 20mm diameter) attached to the jib traveller car by means of one shackle. One block (max 20mm diameter) attached to the jib clew by means of one shackle. The tail end of the secondary sheet shall be fixed to the eye of the single block on the primary jib sheet.

l. One small camcleat with fairlead, as supplied, shall be mounted on the top of the main beam to control the jib car travel. The cleat shall be mounted on the starboard side of the main beam, with its inboard mounting screw positioned 60mm from the edge of the mast ball casting and 60mm forward of the top of the rear edge of the main beam extrusion. One single piece of cord shall be used to control jib car travel and may be routed through the hoop affixed to the inboard end of the spinnaker pole, or the spinnaker pole gooseneck with an optional shackle. The length and diameter of the cord is optional.

5. Hurricane SX Spinnaker

a. The Hurricane SX spinnaker shall be as supplied by the manufacturer (Hyde, one-design) and shall measure no more than 21 square metres in area. (Measured in accordance with IYRU SCHRS). The spinnaker shall be fitted as standard with three retrieval patches, with a hard eye and webbing strop at each patch, and an adjustable leech line and foot line.

b. The spinnaker sheet length and diameter is optional and shall not be reduced below 15.5 metres in length by 8mm diameter, as supplied. The spinnaker sheet shall not be tapered. The means of attachment to the spinnaker is optional.

c. Spinnaker sheeting blocks shall be fitted to Hurricane 5.9 jib sliders (HK84) in the extruded aluminium track at the inboard edge of each deck. The type of spinnaker sheeting blocks is optional subject to a maximum diameter of 70 mm (HK82). The means of attachment between the spinnaker sheeting blocks and sliders is optional.

d. The ratchet blocks (HK82) previously used for the Hurricane 5.9 (non-SX) jib may be used as spinnaker blocks.

e. Additional fixings (such as pop rivets) may be added to reinforce the attachment of the extruded aluminium track to the inboard edge of each hull.

f. Spinnaker sheet turning blocks shall be attached to the upper rear track in the main beam extrusion by means of the sliding attachment keys supplied by the manufacturer. The means of attaching the spinnaker sheet turning blocks to the keys is optional. The sliding attachment keys may be locked in place if required, with the means of locking optional. The spinnaker sheet turning blocks may be fitted with positioning springs to prevent capsize of the block. The design of the block is optional subject to a maximum diameter of 70 mm (HK82).

g. One Spinlock cleat shall be centrally-positioned on the upper face of the main beam, the centerline of the cleat to be positioned at a distance of 150mm from the centreline datum. The cleat may be fitted with wedges, as supplied, to facilitate use.

h. One turning block (max 20mm diameter) to allow routing of the spinnaker halyard shall be mounted on the upper face of the main beam by means of a hoop that is fastened to the beam. The forward end of the hoop shall be positioned 890mm from the extremity of the main beam extrusion and 75mm forward of the top of the rear edge of the main beam extrusion. The block may be fitted with a positioning spring so as to prevent capsize of the block.

i. The size of the spinnaker halyard shall not be reduced below a minimum diameter of 5mm and length of 23.25 metres (as supplied). Tapered halyards are disallowed.

j. Two single blocks (max 30mm diameter) shall be mounted on the trampoline in order to provide an effective routing for the spinnaker halyard. The blocks shall be affixed to the trampoline by means of a short length of cord (length and diameter optional) and shall be positioned using the additional reinforced eyelets as shown in Figure 1. The blocks may be fitted with springs so as to prevent capsizing of the blocks.

k. One single turning block (max 20mm diameter) shall be mounted in front of the rear beam by means of short length of cord or webbing strap attached to the upper face of the trampoline for the purpose of routing the spinnaker halyard shockcord.

l. One single block (max 20mm diameter) shall be mounted on shockcord for the purpose of tensioning the continuous spinnaker halyard. The block may be fitted with a swivel to prevent twisting. The exact routing of the shockcord is optional and may make use of the existing 5.9 trampoline eyelets and attachment points. No additional eyelets may be added to the trampoline.

m. The spinnaker tack outhaul shall be connected to the spinnaker halyard by means of back-to-back single blocks. (Max diameter 30mm.) The length and diameter of the spinnaker tack outhaul shall not be reduced below 5.2 metres in length by 5mm diameter (Dyneema, as supplied).

6. Mast fittings

a. A stainless steel hoop shall be rivetted to the front of the mast, the centre of which shall be 1340mm from the bottom of the stainless steel hounds fitting on the mast.

b. Two holes shall be drilled in both edges of the mainsail track for the purpose of attaching a rope strop. The holes shall be positioned 15mm from the aft edge of the mast track and nominally 15mm apart. The diameter of the holes is nominally 6mm. The uppermost hole shall be centred 7740mm from the bottom edge of the mast extrusion.

c. One single block with swivel (max 30mm diameter) shall be attached to the front of the mast by means of one shackle and the rope strop (4mm diameter) attached to the holes in the mainsail track. The height of the block shall be adjusted by means of a further rope (between the shackle and the stainless steel hoop on the mast) to ensure that the bearing surface of the block measures not more than 7709mm from the bottom of the mast.

7. Spinnaker Pole and Chute

a. The spinnaker pole shall be a tubular aluminium alloy extrusion, as supplied by the manufacturer, measuring 38 mm diameter, 3.6 metres in length. Ends shall be plugged.

b. One single block shall be mounted at the forward end of the spinnaker pole (e.g Ronstan 30mm diameter) for the purpose of outhauling the spinnaker tack. The block may be fitted with a spring to prevent capsizing of the block. The hoop may also be used to securely locate the inboard ends of the spinnaker pole mounting stays.

c. The inboard end of the spinnaker pole shall be fixed to main beam by means of an articulated tiller extension fitting fitted on the centreline datum on the front edge of the main beam. Previously-supplied fittings for the “Sport Rig” may be used as an alternative.

d. The Hurricane SX Spinnaker chute shall be as supplied by the manufacturer and of standard design. The chute shall be attached to the inboard end of spinnaker pole by means of two stainless steel threaded fastenings. The chute shall also be tied to aluminium pole along its length.

e. The chute/pole assembly shall be suspended on the lower end of the forestay by means of a threaded eye and one shackle that shall be affixed to the attachment hoop moulded into the top of the chute.

f. A minimum of four (1×19, 2.5mm) wire stays for securing the spinnaker pole and chute assembly shall be attached to the bridle wire tangs. (Two to be attached to the inboard edge of each hull.) The wire stays may not be shortened. If required, optional shackles, rings or cords may be used to facilitate attachment of the wire stays at each tang.

g. The lower forestay bridle wires shall be attached to the tangs by means of stainless steel shackles, pin diameter 6mm. A longer upper forestay strop is available from the manufacturer to replace the (old-pattern 5.9) item and may be substituted if required to set an appropriate mast rake.

8. Miscellaneous

a. All sails may be fitted with optional airflow indicators (tell-tales) as required.

9. Permitted Upgrades

As the availability of parts has changed over the years, the class has evolved wherever practical and cost-effective, rather than continue maintaining outdated and inefficient systems. Below are several modifications introduced in response to cost and supply challenges:

Mainsheet System:

The existing 7:1 Harken system has served the class well for over 30 years. Production of these blocks has been discontinued. Modern catamaran designs use more modern systems from a range of suppliers, so a decision has been made to adopt the 9:1 purchase system, providing smoother, more efficient sheeting with smaller sheaves and reduced weight compared to the original setup.

The recommended maximum purchase allowable has been set at 9:1, with no restriction on manufacturer or layout.

A previous rule change allowing owners flexibility in how the mainsheet is attached to the boom remains in place. Approved methods include rope or webbing strops and quick-release shackles. The requirement for a stainless steel attachment strap has been removed.

Downhaul System

The upgrade to a 16:1 downhaul system was approved and adopted several years ago. A standard kit using Harken hardware is available from AW Sailboats. The Rules and Tech sub-committee specified only a maximum purchase of 16:1, without defining an exact configuration.

Variations to the system (including additional clamcleats on the mast for coarse adjustment) are permitted. However, users should be aware of the increased risk of rope failure and avoid excessive downhaul tension, which can cause serious mainsail damage.

Mast Rotation

With a wide range of mast rotation systems used within the class, it has been decided to leave the fit-out of the new boom section to individual preference.

The mast rotation rule continues to allow a maximum purchase of 5:1, with equipment remaining optional. A variety of systems have evolved over the years, including direct boom-to-spanner cleat setups, flip-flop cleats mounted on the rear of the mast, and systems routed through the trampoline to cleats on the deck and into the end of the main beam. Each offers its own advantages in practicality and cost, and all of the above are used successfully by teams at the front of the fleet.

Outhaul Systems

The current internal outhaul system uses a 4:1 purchase, which remains the maximum permitted, with equipment and system layout left open to individual preference. The general trend has moved towards a simpler 2:1 setup, as the outhaul largely self-adjusts with downhaul tension and usually only requires occasional adjustment, typically between races. This allows sailors to choose a system that best suits their needs and budget.

Boom Tube Section

The original rectangular boom section has been out of stock for several years, and sourcing new extrusion from manufacturers is no longer economically viable.

After reviewing modern catamaran class designs, a tubular section was selected as the most appropriate replacement. A 2-inch diameter tube was chosen to accommodate the loads generated by the standard pinhead sail sheeting position.

2-inch aluminium anodised tube is also widely available, often found in boat parks as old Laser / ILCA top-mast sections. A custom inboard boom-end fitting is available from AW Sailboats, and is used to interface with the existing gooseneck arm, allowing a 2.5m Laser / ILCA section to be used as the boom.

Footstraps

Class rules permit up to two webbing-reinforced footstraps per hull. The Rules & Tech sub-committee has agreed that these foot loops may be positioned either on the trampoline or along the deck edge.

As long as they are constructed from webbing-reinforced material, the design and configuration are left to individual preference.

Tiller Extension

The existing FX6 tiller extension has been a long standing tried and tested friend of the class, however with the manufacturer no longer trading, the Rules & Tech sub-committee are working to look at available alternatives. If you are in need of a new tiller extension, contact AW Sailboats for the latest update.

Removal of Disused Fittings

The original SX kit was designed to enable a quick and efficient conversion back to two-sail mode. However, due to the success of the SX rig, it is now clear that only a small number of sailors regularly carry out this conversion.

The Rules & Tech sub-committee has therefore agreed that, when sailing in SX rig mode, there is no requirement to retain barber-hauler fittings or shroud adjuster plate-mounted jib cleats. Removal of the crew reaching line system is also permitted to allow footstraps to be fitted to the transom.

Page updated

Google Sites

Report abuse