PDR, Lug vs. Spirit

nickpullen · #1 3rd Mar 2009, 01:12 PM

Good day fellas!

So Ive finished my PDR, and built it with the standard spirit rig, now it's all good and works, but im wondering what advantages the Lug may offer me.

In my pondering and reading, I have these:

Spirit PROs:
- Easy to rig.
- Only one spar to make.
Spirit CONs:
-Long mast (5m)
-no reefing
-Sail is very low to deck and hits wife on the head all the time!

Lug PROs:
-Reefing
-Shorter mast (3.xm)
-Looks nicer.
-It appears to have a but more head room under the sail?
Lug CONs:
-Harder to get the sail to set right.
-Uses 2 spars over spirits 1

Now, what are your thoughts on performance? Also, looking at the plans I think I may be able to cut down the Sprit mast to suit the Lug, it looks like is has the same taper, just have to beef up the new top end with a longer internal blocking... not sure about the spars, if they are reusable.

You can see the images below what I am on about under sail head room...

seajak · #2 3rd Mar 2009, 05:18 PM

Nick,

Another reason I was thinking of using the lug was so I could run the sheet up the boom and lead it to a block on the daggerboard case. I thought it might be easier two up for the crew to control the sheet if it wasn't passing over the skipper's legs.

cheers,
clay

koala · #3 3rd Mar 2009, 07:33 PM

Hey Nick

I thought that sprit sail hiting you is less of a problem than (the lug sail) boom hiting you

No reefing option for sprit sail is a concern for me too. As I haven't done any sailing yet I'm worried what would happen if the wind picks up heavily while I'm on the sea.

I'm almost done with my sprit sail. I was sewing yesterday but ran out of sticky tape

I quite like the triangular shape of the sprit sail, although the lug sail looks fine too.

Boatmik · #4 3rd Mar 2009, 11:15 PM

Quote:

Originally Posted by nickpullen

Good day fellas!

So Ive finished my PDR, and built it with the standard spirit rig, now it's all good and works, but im wondering what advantages the Lug may offer me.

In my pondering and reading, I have these:

Spirit PROs:
- Easy to rig.
- Only one spar to make.
Spirit CONs:
-Long mast (5m)
-no reefing
-Sail is very low to deck and hits wife on the head all the time!

Lug PROs:
-Reefing
-Shorter mast (3.xm)
-Looks nicer.
-It appears to have a but more head room under the sail?
Lug CONs:
-Harder to get the sail to set right.
-Uses 2 spars over spirits 1

Now, what are your thoughts on performance? Also, looking at the plans I think I may be able to cut down the Sprit mast to suit the Lug, it looks like is has the same taper, just have to beef up the new top end with a longer internal blocking... not sure about the spars, if they are reusable.

You can see the images below what I am on about under sail head room...

Howdy,
The spar tapers are the same for both rigs. So you could glue in the screws for the halyard attachment point on the sprit mast with epoxy at the right height for the lug and it all should work ok.

One of the advantages of the cheap sail making in the plan .. is you could make both and see what you prefer ... or even make different rigs from those two - much like the wider PDRacer world has experimented with.

As far as performance goes between lug and sprit ... I have no idea which will be the top performer. I thought the lug rig would lose a little bit so I did add a bit of extra sail in a guessed attempt to balance things up. Also by then I knew what a stable little boat the PDRacer is.

Generally for such experiments I would steer around jibs as they require stays to make the rig work well, but any option can be played with without affecting the relationship with the OZ rules.

Best wishes
Michael

Boatmik · #5 3rd Mar 2009, 11:22 PM

Quote:

Originally Posted by koala

Hey Nick

I thought that sprit sail hiting you is less of a problem than (the lug sail) boom hiting you

On a boat this size ... to be hit by either will be trivial. Ouch and keep on sailing. Maybe no ouch!

It is completely different to bigger, heavier boats with more rigid modern rigs.

MIK

nickpullen · #6 4th Mar 2009, 09:36 AM

Mik, thanks for that... Do you have a rigging guide for the Lug rig, the plan does not detail how the lines run and blocks and such...

Thanks.

Boatmik · #7 5th Mar 2009, 03:13 PM

Howdy Nick,

The setup of the boat hull is not too much different from the Sprit rig except the saddle on the deck that is behind the mast moves around to be to the side of the mast.

The GIS rigging will give you a decent rundown on setting up the ropes on the rig.

http://www.storerboatplans.com/GIS/GISRigging.html

arbordg · #8 9th Mar 2009, 04:21 PM

[quote
The GIS rigging will give you a decent rundown on setting up the ropes on the rig.

http://www.storerboatplans.com/GIS/GISRigging.html[/quote]

I put the balanced lug rig on mine, and it performs beautifully. At the 2008 world championship there was a sampling of nearly every sort of rig. In spite of several handicaps - having never sailed a PDR before, never having this boat in the water before, sailcloth a notch too heavy for the size, and lack of general sailing expertise - Shredder, in light air, with her large lug rig, went from a very delayed start to finish in fourth place.

I have since sailed Shredder in a variety of conditions, including some quite strong winds (see foto below - taken when I've just passed into the wind shadow of a nearby headland, after some exhilarating sailing). Did beautifully - other than breaking my experimental leeboard.

nickpullen · #9 11th Mar 2009, 08:33 PM

When hooking up the main sheet to the lug rig, can it be attached the exactly the same as the spirit? ie, a block at the end of the boom and then one on the traveler... I see in the pictures above its setup with a block midway along the boom, and then on the GIS there is a forward block near the dagerboard case... Im confused.. What effect does this have?

Cheers..

m2c1Iw · #10 11th Mar 2009, 08:45 PM

Quote:

Originally Posted by nickpullen

When hooking up the main sheet to the lug rig, can it be attached the exactly the same as the spirit? ie, a block at the end of the boom and then one on the traveler... I see in the pictures above its setup with a block midway along the boom, and then on the GIS there is a forward block near the dagerboard case... Im confused.. What effect does this have?

Cheers..

I'll have a go at this Nick. The GIS has a block forward for convenience that is a ratchet block mounted low down and forward of the helm works better. I was thinking of doing the same thing but having now sailed the duck it is a little cramped to run the mainsheet in this fashion. I may still give it a go when I fit up the Code 0.
For the lug I attached a block on the boom about 250mm from the end then to the block with becket on the traveler only. In fact I currently have it the other way around with the becket at the boom but found this a bit cumbersome.

Hope that makes sense.

Mike

Boatmik · #11 12th Mar 2009, 01:13 AM

Well, after sailing alongside Mike's sexy black PDRacer which has a lug rig and my pink sprit rig boat it is an irresistable conclusion that the lug is faster and higher winded.

The lug is 89sq ft.
The Sprit is 82 sq ft.

The wind was about 8 knots or less ... so quite light. But whichever way I pointed the lug seemed to be faster. It was not a systematic test ... but the blakc boat was hard to keep up with.

It might be too early for an overall conclusion but that seems to be the case so far.

I did go in a race against some other boats and managed to do well upwind in those same conditions against longer boats, particularly upwind - lots of sail and the nice foils. The short length and thus slower "hull speed" seemed to be a real limitation downwind - good and easy progress in that direction - but not enough of it!

Look forward to trying more to see how they compare in a bit more wind.

I may get some pics shortly through Duckflat when they arrive of both PDRs on the water at one time.

Best wishes
MIK

m2c1Iw · #12 12th Mar 2009, 01:47 PM

Mik,
Apologies for shooting off the other day but my host was on a timetable.

Nick,
Monday was launch day for "A Ducks Transom" down at Goolwa during the Wooden Boat Festival and it performed way above my expectations, having the designer present was a bonus and I would have liked the time to do some tweaking with Mik's guidance.
I will post some pics in the build thread when I get them off my photographer.
Twas a great little sail the weather was perfect for the first time out as Mik said a gentle breeze and yes the Lug is definately quicker on all points but wait until I get the Code 0 going man it will blow your sock off

Looking forward to some decent sailing time.

Cheers
Mike

Boatmik · #13 12th Mar 2009, 03:06 PM

Looks like some more testing in rougher weather is needed. If you are still faster I will be extending the mast of the sprit rig!

Also using Rob Badenoch's method of getting rid of some of the wrinkles in the top of the sprit rig. The lug just looks fantastic!!!

If all else fails .. I will have to convert to the balance lug too.

MIK