Jib on A PD Racer? Gennikers or "Code 0"

[nickpullen]

Just wondering, has it been done? is it worth it? can it be done really simply? Will it give any performance increase? will it affect the position of the main?

I just think they look cool, and it gives you one more thing to think about while sailing, or your passanger...

[Boatmik]

Just wondering, has it been done?

Yes


is it worth it?

Depends on you.


can it be done really simply?

No ... the boat is too short so it has to be extended with a bowsprit. Plus you would have to design the new sails, spars, new mast position, bowsprit, more fittings and wires. It would add more rigging and derigging time, more building time, more sailmaking time.


Will it give any performance increase?

Almost certainly not - probably big performance downgrade and very certain manoeuvrability and handling downgrade


will it affect the position of the main?

Yes, the existing rigs balance around the existing mast and centreboard positions. Both will have to be changed.


I just think they look cool,

Can't argue with that. Might even be fun.


and it gives you one more thing to think about while sailing, or your passenger

This may be good ... maybe not!!

MIK

[b.o.a.t.]

The longer bit was suggestion of spinnaker or gennaker rather than a jib if a person is looking for extra strings to tweak, and more performance.

Question for MIK about the OZ PDR rules subset - Broad-seaming is verboten, but
what about V-darts in the corners , or 'gathering' as per the original polysail designs ?

cheers
AJ

(sorry, sorry, sorry AJ ... just abused my powers by accident and edited your post thinking i had quoted you in my own post. Readers be aware that this post by AJ was longer before I cut into it- MIK)

[Boatmik]

The dart method would not fit within the OZ PDR rules as it would be considered broadseaming.

Originally I did write it in that one dart would be allowed, but then realised that people could use more complex combinations of dart with edgerounding to move towards standard sailmaking procedures and making it a more complex exercise to balance the two methods to produce the fastest sail.

That dart method used by itself does result in a sail, but a very inferior one as it does not affect the shape of the sail at heights unaffected by the dart. So there is a bit of depth in the bottom and nowhere else and if the mast bends (or the jibstay sags then there is no allowance for that either.

It works a bit better for a four sided sail as there are two darts (creating draft at two different heights) and the sprit or gaff is likely to bend a bit less.

If spar bend or or the jibstay sag is taken into account then you have to cut the luffs (or heads) with the right curve .... so you may as well cut the curve a little bit deeper to create the camber you need at the different heights.

BTW ... I think it is a stunningly clever innovation at the same time, particularly for small sails mounted on relatively stiff spars - a great bit of thinking ... but it does have some technical limitations for boats that use spar bend to depower.

It is possible to make a kinda sorta OK sail with the dart method, but I have seen many more that are pretty bad.

As opposed to the edge shaped OZ sails which universally look pretty good ... the only dud I have seen was when one guy used cotton and the luff stretched to about a foot longer than the mast!!!

I would not have expected that either!!!

Best wishes
Michael

[b.o.a.t.]

I was actually thinking of darts or gathering to shape a spinnaker rather than a sparred sail.
How about cutting off about 200mm short of the top corner of a flat triangle & gathering it to a point with a single eyelet through the multiple layers to
form a rather crude radial-head spinnaker ? Nothing complex at all to breach the spirit of the rool about broad-seaming. :2tsup: No seams there at all to clash with the rools ! :2tsup: (Hey PAR, I think I'm getting the hang of this rule probing thing !! :U )

AJ

[m2c1Iw]

I was actually thinking of darts or gathering to shape a spinnaker rather than a sparred sail.
How about cutting off about 200mm short of the top corner of a flat triangle & gathering it to a point with a single eyelet through the multiple layers to
form a rather crude radial-head spinnaker ? Nothing complex at all to breach the spirit of the rool about broad-seaming. :2tsup: No seams there at all to clash with the rools ! :2tsup: (Hey PAR, I think I'm getting the hang of this rule probing thing !! :U )

AJ

AJ are you thinking retractable pole and launching tube as well:D

[Boatmik]

Hmmm ... OZ rules don't say anything about spinnakers.

So you would probably have to follow the existing sail rules of no shaped seams and polytarp. Darts would be a shaped seam, and remember that before spinnakers yachts used to hoist squaresails.

Remember that the OZ rules have a frightening amount of retrospectivity available to quash "undesirable" trends that don't fit with the preamble, however sails like you describe don't require any or much modification to the standard PDR setup ... so if banned later they won't lead to the boat becoming useless! And you can still use the sail in any non OZ sanctioned events.

MIK

[m2c1Iw]

How about a gennaker lightest tarp material you can find sew in a luff cord say bout 30sq endless sheet Hmmmmm......say 400mm bow sprit would that give you enough slot?

[Boatmik]

30 sq ft?!?

And you call yourself an Australian!

Double it and add 10!

MIK

[m2c1Iw]

30 sq ft?!?

And you call yourself an Australian!

Double it and add 10!

MIK

:D waiting for that, but Mik du rools say no trap

Hmmm...... 70 eh .......spose 2 up with the lug rig I can feel a speed attempt looming

[Boatmik]

Howdy Mike,

Because you haven't sailed one of the wee beesties .. you don't know how hugely stable they are. With the standard sprit in the 25knots at Goolwa last year the boat was not pressed reaching (broad or beam)

Stopping the mast from breaking might be a problem with jibs and spinnakers or extra people!!!

BTW ... the speed records are not an OZ sanctioned event ... so you can do your worst and totally ignore the OZ rules.

MIK

[b.o.a.t.]

:D waiting for that, but Mik du rools say no trap

Hmmm...... 70 eh .......spose 2 up with the lug rig I can feel a speed attempt looming

You too huh ?
The lug mast looks strong enough to stand a bit of extra sail.
Reckon it could be done for the princely sum of about $50 all-up. :2tsup:
9kts ??? Bah !!

[b.o.a.t.]

AJ are you thinking retractable pole and launching tube as well:D

Have never used any of those new-fangled gizmos.
Was thinking long-ish broomstick with dog clips each end, & a 12' skiff style
#1 spinnaker in an attractive sky-blue... OzPDR screaming along with only
the last 2ft or so touching the water.

AJ

[m2c1Iw]

OzPDR screaming along with only
the last 2ft or so touching the water.

AJ

In those imortal words "Yeah Baby":rolleyes:

[m2c1Iw]

BTW ... the speed records are not an OZ sanctioned event ... so you can do your worst and totally ignore the OZ rules.

MIK

OK they are ignored, I had'nt given mods like this a thought.

Thanks Nick for spuring us on in the true Puddle Duck spirit.

I've got a good bit of oregon that will be just the thing for a bowsprit, yep I reckon a gennicker will be fun, mainsheet in teeth screaming along I can see it now:U

[nickpullen]

Whats a gennicker? Anyone got pics? I assume its similar to a Spinnacker.

Someone want to draw up an add on plan for the OZ PDR? Will the standard mast be up to the task?

[m2c1Iw]

Whats a gennicker? Anyone got pics? I assume its similar to a Spinnacker.

It's a cross between a genoa and a spinnaker made of lighter material than a normal headsail used when the heading is too shy or close hauled for a spinnaker. Sometimes called drifters when spinnaker material is used. The spinnaker on the 18' skiffs could be called a genniker as they are cut to work very shy rather than a traditional radial cut spinnaker for true downwind.




Someone want to draw up an add on plan for the OZ PDR? Will the standard mast be up to the task?

Over to Mik

[Boatmik]

Howdy Guys,

The OZ PDR was basically designed as a platform to play with. I have drawn up two rigs that are as efficient and simple as I know how to do. Also have done one retrofitted rig stolen from the Sunfish (which is a hugely popular class in the USA)

But that is it for the moment.

If you want to go for it ... its up to you.

Feel free to keep going in this thread and I am happy to contribute to make it work as well as possible ... but time for you guys to start doing a bit of sail designing I reckon!

Any tech stuff I can help you with .... just ask.

And note that I have changed the topic of this thread even.

Best wishes

Michael

[m2c1Iw]

OK I think Mik has pointed us in the right direction a Code O would be easier to make no seams and panels and probably work better than a genniker using tarp material.

I'm thinking on a lug rig as long as it is only used in light breezes the mast may take the loads when reaching.

Some quick measuring and I'm thinking the following
1. Bowsprit 750mm 500 outboard and supported by 250 on the foredeck. Bout 40mm wide x 30mm high going out to 60 at the mounting points. Might laminate with a slight downward curve a la Gwen 12, cool. Mount using some alloy strap screwed to mast support cleats and bow transom. Maybe an alloy bracket screwed to bottom edge of the bow transom would hold a wire strop bracing the sprit. Tape the end to stop splitting and bolt a saddle for a pulley to run a tweaker attached to the tack for hoisting this would need a jam cleat and could be mounted on the side of the mast just above the deck.
2. The foot would be 2200 long so the clew would roughly be in line with the middle of the centre case when set. Endless sheet would run through pulleys attached by loops tied in the traveller just above the side deck. The mainsheet will need a swivelled jammer mounted on the back end of the Ccase might be a bit tight when tacking.
3. Luff length equals mast top to sprit end and some VB chord sewn in to control stretch although given the halyard is eased on these sails to get a good shape reaching, a chord may not be necessary.
Foot curve gradually increasing from tack to clew so clew lines up at about 40% up the luff. Perhaps 100mm of positive roach in the leech at the 75% point? I think the halyard could run through the mainsail eye and made fast on the main halyard cleat (save on fittings).

I will do a drawing and post soon. Thoughts so far?

Cheers
Mike

[nickpullen]

Sounds impressive. But, I did not understand 90% of what you said, I'm very novice!!! Drawings will help...
Thanks though...

[m2c1Iw]

Sounds impressive. But, I did not understand 90% of what you said, I'm very novice!!! Drawings will help...
Thanks though...

Hi Nick, may be a while before I post a drawing as I don't have access to a scanner at the moment.

I've been searching for some info on code 0 heres some sites explaining the concept.

http://www.ukhalsey.com/sails/CodeZero/
http://www.northsails.com/north_america/cruising_sails/G0QA.htm
http://en.wikipedia.org/wiki/Spinnaker

Mike

[b.o.a.t.]

Sounds impressive. But, I did not understand 90% of what you said, I'm very novice!!! Drawings will help...
Thanks though...

Me neither. Got bow-sprit, Gwen 12, sheets & halyard ok.
Tweaker ? I thought a tweaker's a person who thinks they can make their car go faster by adding spot-lights, roof-racks, GT stripes & etc.

I like the concept though.

Would you be able to get by with a straight luff, or would it need some concave to compensate for the wind blowing? The other thing is that I have doubts about polytarp's ability to be doused into a chute. Blimmin stuff seems to snag on nuffink at all at the slightest excuse. Totally unlike lightweight ripstop or whatever.

AJ

[m2c1Iw]

Me neither. Got bow-sprit, Gwen 12, sheets & halyard ok.
Tweaker ? I thought a tweaker's a person who thinks they can make their car go faster by adding spot-lights, roof-racks, GT stripes & etc.


Sorry actually called a tack line, allows the tack to be hauled back into cockpit. A tweaker is used to trim a spinnaker ie similiar:doh:




Would you be able to get by with a straight luff, or would it need some concave to compensate for the wind blowing?


Yep I think for tarp stuff the luff could be straight cut the round is induced by freeing the halyard slightly. The leech has positive roach to increase area and I'm guessing because of the cut the sail makers can eliminate flap for our purposes a straight leech would maybe work better. Need to see what Mik thinks.



The other thing is that I have doubts about polytarp's ability to be doused into a chute. Blimmin stuff seems to snag on nuffink at all at the slightest excuse. Totally unlike lightweight ripstop or whatever.

AJ

Hmmmm......I agree, need to find really light weight tarp stuff still a problem but I reckon you drop the halyard and just stuff it into the space in front of the front centre case brace then release the tack line and stuff the tack in after it.

Mike

[Boatmik]

Go for it guys! I am very impressed already!

MIK

[nickpullen]

MIK, Do you think the normal hollow 5m mast could handle this extra strain?

[Boatmik]

I think holding the mast up could be quite tricky once the wind got going. There is one trick that can be tried though .... and that is to have a figure of 8 knot in the halyard about a 8 inches from the spinnaker head. when hoisted the knot will jam against the halyard block. The halyard can then be belayed to a cleat on the windward quarter to help stay the mast.

Don't expect to gybe in a hurry though.

Temporary sidestays going from about 3/4 up the mast to the back of the foredeck might stop the whole thing from disappearing over the bow in a gust.

MIK

[b.o.a.t.]

If one were to increase the the lug mast diameter from 62mm to say, 70mm,
(still in 12mm thick staves) I'm guessing that it would add significant stiffness
& strength - probably more than the 10% dimensional increase. With a
*little* extra beef around the partner & step, it might be possible to avoid
the complications of stays & etc altogether. Would be a smaller maximum
size sail than a leg o' mutton masthead rig, but one that can still be carried
when the wind picks up a bit.

[Boatmik]

Howdy AJ,

I think the additional staying makes better sense than extra mast diameter.

Extra diameter is with you forever so will be slowing the boat on all points.

Whereas stays add negligible weight and can be left off completely if desired too.

A couple of low stretch ropes would be all that is required for the sprit rig.

Lug is a bit more tricky as the yard and boom end will want to catch the stays sometimes (which is why I think lug rigs with stayed masts (ie lug rigs with jibs) a bit strange. But can be done.

MIK

[b.o.a.t.]

Howdy AJ,

Lug is a bit more tricky as the yard and boom end will want to catch the stays sometimes (which is why I think lug rigs with stayed masts (ie lug rigs with jibs) a bit strange. But can be done.

MIK

The yard end is the one I was thinking of regarding stays.
And snagging the foresail too. Jib / reacher #2 on Teal was somewhat abbreviated
based on experiences with jib #1... Gennaker would probably need a gathering/furling
line from luff to leach at yard height to pull it clear of yard when tacking / gybing /
swimming.

Readings on adding stays to free-standing flexible masts suggest not great idea.
Divert stresses from strong tension in mast to weaker compression.
(The vector diagrammes made sense that way, anyway.) So stronger, stiffer mast
made sense in that context.

cheers
AJ

[keyhavenpotter]

This thread very promising. Should be some great pictures, if you can keep the hulls in the water that is! Best ever sailing I have had was blasting across the Solent under Gennaker in force 5 winds. Great stuff.

I would guess a PDR, with a big rig, will plane very early, say 10 to 15 knots of breeze. Once on the plane the wind will go so far ahead with a fullish sail you will have to keep bearing away to keep the apparent wind correct, so a fairly flat gennaker might be good.

When it's made, stick it on the Goat!

Brian

[m2c1Iw]

The yard end is the one I was thinking of regarding stays.
And snagging the foresail too. Jib / reacher #2 on Teal was somewhat abbreviated
based on experiences with jib #1... Gennaker would probably need a gathering/furling
line from luff to leach at yard height to pull it clear of yard when tacking / gybing /
swimming.

While a code 0 is designed to work close hauled 45deg in effect I think on the PD reaching in lightish wind single handed will be when it is used with no tacking. A gybe should be OK and not foul the yard.



Readings on adding stays to free-standing flexible masts suggest not great idea.
Divert stresses from strong tension in mast to weaker compression.
(The vector diagrammes made sense that way, anyway.) So stronger, stiffer mast
made sense in that context.

cheers
AJ

I was thinking some strap chainplates could be fitted by drilling slots between the gunwhale and ply in line with the baulkhead and screwed to the cleats to fit wire side stays. The working angle given the hull width and bulkhead position seems to be OK but I think it's too much messing around. I figure it is more likely our intrepid sailer will capsize before breaking the unstayed mast.
So unstayed it will remain if a broken mast results just have to build it stronger:rolleyes:

Mike

[m2c1Iw]

What do you think would this (http://cgi.ebay.com.au/Skiff-Spinaker-asymmetric_W0QQitemZ230294207472QQihZ013QQcategoryZ102817QQssPageNameZWDVWQQrdZ1QQcmdZViewItem) be too big on the PDR:D

Mike

[Boatmik]

Howdy Mike,

I think temporary stays for a record run ... or a stirring photo ... would be fine. Maybe could go on the cockpit front bulkhead in the corners against the hull side.

Or you could give it a burl and see what happens to the mast bend!!!

With the lug rig option making the mast stiffer is not that deleterious to performance as it would be for the sprit rig - would ruin the mast sail combo gust response thingy.

MIK