HULL

• Hull minimum weight - 65lbs (27.2kg) painted/varnished with rudder fittings and all items required to make the buoyancy tanks watertight.

I did some quick calculations to show that it would be possible to build a PDR with a hullweight of 25lbs - just by using really thin ply with lots of small timber to support it. This adds a huge amount of labour to the building of the boat - so we didn't want that. The 65lbs should be easily achieved if people follow the plans and read the Appendix about "When not to use Epoxy" at their end.

• If a boat is underweight corrector weights may be fitted. Two kg may be bolted firmly to the structure of the boat in a place of the builder's choosing. The balance is to be bolted to the stern transom.

If the weight of the boat ends up lighter we still want it to sail with us - particularly if the builder hasn't tried to cheat the system.

But we want the sailing weight of the boats to be no lighter than the minimum.

So 2kg (4.41lbs) can be put in a place of the builders choice - probably the web on the back of the centrecase. But if the boat is grossly underweight - indicating the builder was TRYING to beat the system them the rest of the weight is attached to the back of the boat where it will slow the boat down significantly - a disincentive to building superlight boats.

• Hull minimum ply thickness - Bottom 6mm / 1/4in

• Sides/Decks/Interior minimum ply thickness - 4mm/ 5/32in

Restrictions on material thickness are the minimum we feel will give a durable boat. We initially built our boats completely out of 4mm. All was fine until Peter put his foot through the bottom of one. The 6mm ply is ideal.

Also our boats come out of 3 sheets of ply - and we wanted pressure on builders to stick to that. If they find ways to use 4 sheets then it will put the weight of the boat up.

• Hull Buoyancy Minimum - there are three normal configurations for buoyancy. They are listed here with the minimum buoyancy volumes. Boats must equal or exceed these volumes.

Safety! And also the tanks are important parts of the structure - they are a large part of what makes our boats so strong - so we want others to have them too.

• Maximum Beam at gunwales 1270mm / 4ft 2ins

This is simply to stop people adding wings to the boats to increase the leverage of the crew. They are ungainly, add expense and make the boats more fiddly.

SAILS

• No restrictions on size, configuration or number.

Yay!

• Reefing points may be fitted.

This allows the boat to be sailed in stronger winds or in lighter winds with a lighter crew - so if your nephew wants to learn to sail ... they can just head off.

• Only one sail and mast combination to be used in any one regatta. If damaged a replacement may be allowed by the regatta committee at their discretion

We haven't specified a maximum sail area - so people can go crazy with monster sails - after all they are so cheap. This rule will prevent them from using monster sails because there is a chance that the wind will come in strong and make their boat impossible to sail. It forces people to be sensible.

• No Battens or similar devices to be used.

Long battens make sails work better. Unfortunately good ones are also expensive and add a lot more complexity to the sailmaking. So they are not allowed under the OZ PDR rules.

• Sail Materials and Construction - Polytarp without seam shaping in the body of the sail.. The use of painted graphic on sails is encouraged.

Being a legalistic type (but in a nice way) - the first part is mine - it means that there are no special skills or special knowledge that can allow people to build a sail much better than anyone else's..

You simply have to get the curve of the luff approximately right when following our drawings.

Seam shaping (broadseaming) is a method of shaping every seam in a sail with a curved edge so that the depth of the sail can be controlled more accurately.

If you are a racing type and think it is too limiting - go out and drop a Laser sail from more than five years ago on the floor. It sits there flat and unwrinkled showing that it has no (or very little) broadseaming either.

Peter's addition regarding graphics on the sail is a great one. And a great Australian tradition. He gives information about types of paint and how to do it on this website.
 

SPARS

• Spars may be timber which may be solid, hollow or tapered. May be standard round extruded alloy section - no tapering allowed. The physical properties of the alloy must be less than or equal to 6061 alloy.

These materials are cheap and readily available. Tapered aluminium spars for the PDR would cost in the $A700 range - the cost of the whole boat.

No sail tracks allowed.

When I worked in a commercial Chandlery a couple of years ago there were three choices for a mast track to suit the PDR. One is cheapish (about $A5/metre) but way too heavy.

The two lighter alternatives are wonderful bits of technology, but are around $A25/metre. So to put on the PDR you would have to buy a 6metre length (the minimum). Good-bye $A150.

Are you starting to understand why modern boats are so expensive?

FITTINGS AND MECHANICAL ADVANTAGE

Again from my days in the boat shop a very significant part of a modern boat's cost are all the cool bits that make every part of the sails adjustable. Unfortunately it adds a thousand dollars to the cost - in senior dinghies like NS14s, Cherubs, Sharpies, Fireballs it adds several thousand dollars as well as creating an organisational problem of making it all work.

Let me run through the system required to adjust the sidestays of a lightweight sharpie or 505 when it is sailing. This is to show how one of the most expensive things you can add to a boat is mechanical advantage.

Don't worry about the jargon - just think of your wallet. We have a total of $A759. Three decades ago these same boats didn't use these systems at all and the sailing was still great.

(prices are in Australian Dollars, current 2006)

1 ball bearing triple block (ie pulley) each side - $90 = $180

1 ball bearing triple block with becket $95 = $190

Two single ball bearing blocks $25 = $50

Double ball bearing block with becket $45

Single side mount block = $25

Two single blocks $25 = $50

Two carbon cam cleats $42 = $84

Spectra or Dynex rope to make it all work = $55

Miscellaneous screws, bolts, tangs, washers saddles = $80

The silly thing is most of the simple boats for beginners have gone (or are going) the same way.

Be reassured - our PDRs use a total of 3 blocks.

• No Ball Bearing Blocks (Pulleys) allowed

Ball bearing blocks are twice or three times the cost and are not as strong as the plain sheave equivalents. Because they are not as strong they tend to be heavier.

It keeps our 3 blocks down to a cost of $A38 for the boat. If we allowed ball bearing blocks it would be closer to $A90.

• No ratchet blocks with a manual switch

Ratchet blocks are not needed with our standard PDRs - the load on the mainsheet is very light. But if you want or need to add a ratchet block (it takes the pressure off the rope so it is easier to hold) one with a switch will cost you 2 or three times more.

• No mechanical advantage greater than 3:1 for sail adjustments that go to a quick releasing cleat

We might toughen this rule later with limitations on what you can adjust while sailing - everything else will have to be tied off. But for the moment it is to prevent the situation with the expensive fittings above. Mechanical Advantage is the most expensive thing you can add to your boat.

• Boom vang (if fitted may exceed 3:1 but may not involve more than 3 sheaves or exceed 4:1)and may only have one cleat. The cleat must be fitted within 200 mm of the mast.

This is for boats that use a conventional boom rather than a sprit boom. A simple cascade system would only cost around $A40 to put on the boat.

• Leaning aids - No clothing or equipment is to be used to help hold the boat upright while sailing apart from simple conventional toestraps used in the conventional way.

This prevents trapezes or other methods of holding the boat upright. They add some equipment cost but also result in the boat construction having to be more sophisticated to deal with the loads. The use of the word clothing eliminates the hiking pants used by Laser and other sailors which have sail battens and other stiffeners to allow the body to be moved more outboard for more righting moment - they can cost a very large part of the cost of building a whole OZ PDR (our original boats cost us $350 each).

SAFETY EQUIPMENT - MANDATORY

• Any boat racing without the specified safety equipment will be disqualified from all races of the series in which the omission is noticed.

This is simply a big penalty if people don't take the responsibility of having the right safety equipment aboard. If you don't have it - your results are scrubbed completely.

RACING

• If the course is shortened by sound or visual signal all competitors may use their paddles at their option. Finish is as per the race instructions.

Generally classes have rules telling people what a paddle has to be like so that they will be able to paddle to shore if there are problems. By including the speed a good paddle can provide part of the racing we expect the PDRs to have the best paddles of any sailing boat in the business!

• Sailors not having fun will be disqualified.

OPTIONAL EQUIPMENT

• The use of waterbombs, squirt guns, water pistols and the like while racing is not prohibited, however it is considered poor form to target committee officials in a start boat prior to the race, and such action could almost certainly result in disqualification, or even toilet cleaning duties at the end of the regatta.

Well the optional equipment is of course entirely optional, as are the penalties, but theyare included to reinforce the spirit of the rules.

 

Michael Storer