There has been a great discussion about hull lightness/strength.
Compared
to Australian racing dinghies our "lightweight" PD Racer is very
conservative at around 54lbs as a bare hull - no paint - no fittings.
We are setting a sensible weight for a durable trouble free boat
that can still be lifted by a couple of kids. We are finalising
the allowable minimum weight and it will be published on the RULES PAGE.
Within
the framework of the international rules you can build a boat as light
as you like. But for the OZ PD Racer we decided to have a
restriction to keep the boats really simple to build out of standard
materials.
So if you build one lighter than our rules allow you can race in Open PD Racer events and even compete internationally.
But what are the limits of wood technology - how light is POSSIBLE?
Also see the EPOXY and Boatbuilding FAQ
for more detailed info on building methods and materials that make the
OZ PD Racers possible - also good info there if you are actually
building any boat. As an example, the most radical class in Australia in terms of wooden structures was the International Moth.
Moths have now gone to a pointy ended hull, but for a long time they were a scow hullform as below.
The
Moth (example right) has no minimum hull weight requirement - so every
new boat made an attempt to improve the lightness of the structure.
The boats were almost all owner built and typical scantlings were Hull and internal web frames (except for cockpit) 0.7mm birch aircraft ply – which translates to about 1/32"
The cockpit had to be a bit thicker - they used 1.2mm (1/12") with 0.75oz fibreglass on the underside.
Hull weights were around the 32 to 35 lb mark for the highly stressed structure.
Boats were
of top rank competitiveness for about 2 to 3 years then would be sold
on to an intermediate level sailor who would use them for another 2 to
3 years. There were no visible wracking (wringing) deflections in
the hulls despite loads in the windward sidestay of around 1000lbs (wires used to break very occasionally!)
Now
they are all narrow skiff shaped hulls made of carbon/foam with
hullweights around the 15lb mark and have sprouted hydrofoils.
Because
of this rather Australian Tendancy to get away with whatever we can get
away with we are going to put a minimum hull weight restriction on
local boats. Lighweight timber structures are too well known
among the boating community and if there was complete freedom there
would be a flock of 10" thick puddleducks that weighed in around the 22
lb mark (they are 2/3 the length of moths, thus 2/3 the weight is not
unreasonable).
In fact the upper Moth pictured above becomes rather a
good prototype for the ultimate puddle duck racer - all proven
technology - the timber hull, the wings, the alloy mast - all quite
cheap - except for the sail.
Is the PD Racer a Planing boat?
And
no-one tell me that the PDR is a displacement boat and that will limit
the speed. My first boat was a Northbridge Junior - a 8ft version
of the Moth without the wings and similar bottom rocker to the
PDR. Me and a friend used to spend hours planing backward and
forward in front of the sailing club whenever the wind was up –
spray everywhere.
The
only reason the PDR have not planed is most of them have been built too
heavily and there has been an acceptance of the statement "they won't
plane".
(in
fact they do - the current PDR outright speed record and measured
performance under motor are well above the theoretical displacement
hull speed - see the planing video )
We did look at following the Moth scenario - to build the fastest boat possible - when we
started looking at building the puddle ducks, but decided our purpose is to
demonstrate to the racing mainstream here that you don't need to spend
much time or money to build a good little racing boat that is suitable
(AND FUN!!!) for a wide range of users.
The Death of Sailing in Australia
Sailing participation in Australia is in crisis.
All
the small local clubs that were in just about every bay or beach around
the coastline of Oz in the '60s and '70s with their fleets of mostly
self built boats have just about disappeared. On Sydney Harbour
alone there were approximately 50 clubs of various sizes - all very
active - mums, dads and kids. Now there are a third of that and
many clubs are struggling to get enough members.
What do you expect when a beginning boat for a couple of kids costs around $4,000-8,000 because of the technology involved?
The
really silly thing is that all the $5,000 boats go at much the same
speed for very even racing - which was also the case when they were
cheaper and simpler 40 years ago – the boats then had very even
racing. Even boats that were envisaged as being cheap training
classes have become involved in a foolish Arms Race.
We see the
PDRacer as a way of getting families back into sailing and we imagine
all sorts of little sailing clubs cropping up on beaches where a few
neighbours decide that it is a good thing to build a simple boat.
And the PDRacer is about as simple as you can get!!!
Cheap (and easy) to build and not too precious to be lent out to the local kids.
As
we will be in a position to do so we will be making local class rules
to retain the character and cheapness of the PDR or it will head the
way of all the other local classes.
So
there will be rules for weight, to restrict beam and restrict materials
- including a weight handicap system to favour polytarp/tyvek sails
with no more than one broadseam.
People will be able to have
sails like the Moth, but they will have to carry a significant amount
of ballast in the boat to compensate.
There has been a great discussion about hull lightness/strength.
The
Moth (example right) has no minimum hull weight requirement - so every
new boat made an attempt to improve the lightness of the structure.
Now
they are all narrow skiff shaped hulls made of carbon/foam with
hullweights around the 15lb mark and have sprouted hydrofoils.
The
only reason the PDR have not planed is most of them have been built too
heavily and there has been an acceptance of the statement "they won't
plane".
All
the small local clubs that were in just about every bay or beach around
the coastline of Oz in the '60s and '70s with their fleets of mostly
self built boats have just about disappeared. On Sydney Harbour
alone there were approximately 50 clubs of various sizes - all very
active - mums, dads and kids. Now there are a third of that and
many clubs are struggling to get enough members. 
Cheap (and easy) to build and not too precious to be lent out to the local kids.