Making Balance Lugs faster 2013 – setting up sails, spars and rigging


The Overview

On other pages in this website you can see the simpler way we set up the lug rigs on our performance boats.  In general the boats are a reasonably close match for modern boats with modern rigs.  There is not a huge difference in performance between conventional boats and well set up balance lugs.

Goat Island Skiff going fast downwind with heavy load - Texas 200

The path to increased performance really has been a long process – about 120 years if you look at sailing canoes, which in many ways brought a lot of modern thinking and gear into existence in the late 1800s.

This was fundamental improvement in foils (centreboards, keels and rudders) and sail interaction with spars to automatically shed excess power in gusts and regain the power automatically after the gust passes.

Then to sail controls where the most significant stride has been in controlling sail twist.

Most of this was very well understood for modern rigs by  the mid to late ’70s and was achieved cheaply using timber, standard aluminium alloys and rope.

Since the 1970s there has been little innovation in boat setup or our thinking about the component design, but instead of an improvement in understanding the fundamentals most of what passes for “innovation” has been a shift to more expensive materials and items.

The first time the boom vang (or kicker) that controls sail twist was used in the International 14 class the boat that used it ran away with the race – we are talking about 5 or 10 percent increase in performance … not the half a percent from spending large amounts of money on carbon.

So point is .. that real innovation doesn’t cost much to apply and should be applicable to most types of sailing rig

The real advantage of modern rigs

The advantage is the opposite of what you see on recreational boat forums.  The discussion on any point goes around and around.  It might seem resolved and then it will reappear again.  Is a fresh painted surface less drag than a sanded bottom?

A great example are hydrofoil sailboats.  They have a long history from about 1915 with little improvement in speeds even up through to the 1980s with Russell Long’s speed record machine.  It could sail upwind and down, a beginner could tack and gybe it easily.  It was a high point.  But the real jump in development was when the Moths started using foils.  We saw the first boats struggling to take off in 8 or 9 knots of breeze, falling off the foils when tacking.  But quickly in the next seasons, the brilliant community of home boat developers found ways of making sure the Moths could become airborne in 7 knots of wind, then 6.  The current state of the art is if you can get the boat up then it will continue to foil in under 2 knots of wind – conditions most people (except for experienced sailors) would say “there’s no wind today”.

Monitor 1940 – 20+ knots, couldn’t tack – needed lots of wind to lift off – sails a few times with small improvements

monitor sailing hydrofoil

Icarus – mid 70s – speed range 23 to 28 knots – not able to sail efficiently in all directions, can’t tack efficiently – sails once a year for a week.

icarus hydroil cat

 

Moth – Mid 90s – full range performance in all directions – an 11ft boat that is faster than most catamarans around a racecourse, tack and gybe easily.

Moth foiling dinghy

Here is a graph of Moth Performance against other boats (which have changed performance little) over the years.  The recent steep part of the graph is because of the rapid hydrofoil development.

Graph of Moth yardstick handicap PYF over time compared to tornado FD 505

That’s the advantage of racing classes is that they have … racing.  And real improvements get tested by hundreds of thousands of boats every weekend.  They publish information (now on the net) but formerly in newsletters as the current champions would share their knowledge.  It is well known that if a group decides to share their knowledge effectively they can become a real force on the world stage.

The Goat Island Skiff group, in particular were aware of the tendency to lose information so we started to share information and also to make sure it was written down.  One of the resources is  the Lug Rig setup and tuning WIKI.  Another are the growing number of meetings of goat sailors, here at the Small Reach Regatta last year.

Lug rig tuning and setup - article at storerboats

We have recorded different spar weights for different construction and timbers and also the basic bend characteristics of the yard and boom.

This enabled us to identify a trend that people were making the yards somewhat stiffer and the booms very much so – particularly as they saw the advantage in a loose foot setup.

If information is recorded and shared trends like this start to appear.  And there is a ready menu of information for any builders who want to  be at the pointy end of development to make the lug rig faster, easier to handle, faster when reefed and maybe faster to rig as well.

In other words we have used the racer’s own trick as well as we can.  The internet means you don’t need a big number of boats in one location, though there are enough Goat Island Skiffs to meet in twos and threes reasonably regularly.

Previous Goat Island Skiff setup and basics of downhaul trim

If you want to improve the performance of your lug rig boat you have to wrap your head around the information on the goat island skiff setup page.  It is a wealth of tuning information that will make sure your sail looks good and works well.   A less good sail set up properly will always outperform the best sail if it is not set up properly.  It is attention to detail.  Most boats are set up with a number of deficiencies.  That page has the correct methods to rectify

Goat Island Skiff standard setup

Goat Island Skiff with standard rig from plans

The most important items are

1/ Non stretch halyard – usually Spectra is the best choice and using our standard method

2/ Powerful Downhaul

This DOESN”T mean you can ignore the other items and the halyard system shown on the page (from the Dixon Kemp Manual of Seamanship – 1850 something) is the only one worth considering for small boats.   Bolger had lots of nice words about the balance lug rig but had four criticisms.  This halyard system eliminates all four making it an excellent rig choice.

The Downhaul on a balance lug is responsible for tensioning the both the luff and leach (front and back edges of the sail) . Leach tension controls the twist of the sail.  Before Bermudan rigs started to be scientifically developed in the second decade of the 1900s the lug rig was the predominant small boat racing rig – because it has twist control.

Basically the history of major performance improvements in sailing have been about the control of twist.  The nice thing about the balance lug is that it controls twist without any extra gear.  The downhaul does need to be powerful.

We are typically using pulley systems or pulleys backed up with a truckers hitch to give these mechanical advantages.  A rough guideline

Downhaul for balance lug rig - tuning and setup article on storerboatplans

1/ Beth sailing canoe – 67 square feet mainsail – 2:1 pulley system backed up with a truckers hitch – maybe about 5:1 after accounting for frictional losses

2/ OzRacer – a very stable boat can carry 89 sq ft.  Similar to BETH

3/ Goat Island Skiff – 105 square feet – 6:1 or 8:1 using pulleys.  This is much less than the 12 to 1 or 16 to 1 used in the boom vangs (kicker) in conventional boats.  More about that later.

We have found that the downhaul needs to be adjusted for changes in wind strength and boat speed.

1/ Light winds – boat is not moving reliably –  the downhaul can be slackish – this allows the sail to twist which helps the boat accelerate and accommodates for the wind shear effect from the combination of apparent wind and the wind gradient (wind is stronger higher up because it is further away from the ground).  The point where you start to put in significant tension is when the boat is moving reliably.

2/ Light and moderate winds where boatspeed is consistent – downhaul should be very firm. 

3/ When the boat is overpowered in the lulls be BRUTAL with the downhaul.  It must be brutally tight.

So that’s where we were about 4 years ago.

And then along came Brian Pearson.

The Lesson of the Lymington Scow

Brian rolled up on my forum because he could see we were being serious about improving the efficiency and performance of the balance lug rig – a kindred spirit.  He races (among other things) in the Lymington Scow class which is rigged with a Balance lug mainsail.  Some boats are raced singlehanded with mainsail only and others are sloop rigged.

It is an excellent low cost class and provides very tight racing because the speed differences between boats are restricted by length.

Lymington Scow

I was completely unaware of them but when Brian mentioned they were built by John Claridge (several times world champion as well as builder and designer in the ultra competitive Moth class)

John Claridge in the Moth Class - builder and designer.  Current builder of Lymington Scows

Remember what I said about boats improving fast when there is regular racing … well … the scow has been a racing class since 1905.  And Brian has been one of the sailors with runs on the board.

They have learned a thing or two.

Remember I said that modern boats have powerful boom vangs/kickers?

Well, the Lymington Scows do too.

They have a setup that was quickly fitted to this Goat Island Skiff

twin vang setup on balance lug rig

The  sailors that used it found it effective and powerful.  It also allowed some interesting (some would say strange options) of moving the boom backwards and forwards relative to the mast for steering balance upwind (a couple of degrees of weather helm in the tiller please) and on a run downwind the sail could be centred with more equal areas either side of the mast

Sail forward in downwind position

Bruce GIS vang sail well forward

Sail back in upwind position

Bruce DSCF0415

I was lucky enough to go sailing on Bruce’s (woodeneye on my forum) Goat one the central Coast of NSW.  Powerful, but I didn’t like the expense of two vang systems and also I thought it was too finicky for average sailors.  If you wanted to reduce the tension in the after vang you had to take up some of the slack in the forward vang.  Also it was easy to lose where the boom should actually be because it is all floating around – to confusing except for the experts and frustrating for some would be experts (me).

The Lymington scow avoids some of this complication as the boom is carried with the forward end adjacent the mast – see the photo of a section of their fleet up the page.

It was also getting away from the simplicity of the Goat Island Skiff.  The boat in standard form has a total of 5 or 6 blocks (pulleys) and it is a fast boat without all the stuff.  So was there a way to get the same effect with something like the original gear?

The original gear can do this … at the Small reach regatta and more complex gear doesn’t change this much.

Enter the Vanghaul and Bleater (it is a GOAT) – a gentleperson’s approach to Balance Lug efficiency

So the criteria have changed or become better defined.

1/ We want to control twist better

2/ It can’t be more complicated than the standard system

3/ It can’t be much more expensive than the standard system

One of the other changes of the previous year or two contributed.  Many builders had decided to change over to a loose footed mainsail and get rid of the lacing along the foot.  This is very good for sail power, but the result is that the existing downhaul and the square lashing used to hold the boom against the mast can easily slip forward or back if not fully tensioned.

The double vang photos above show a loose footed sail … no lacing along the boom so you can adjust the sail depth more easily.

The other change that had led to was experimentation in the boom stiffness and dimensions as the standard boom in the plans only works with a laced foot – this is a snapshot – you can see the complete data on the WIKI

Boom bend data from Goat Island Skiff WIKI.

In a couple of days discussion on the Goat Island Skiff forum we worked out a new combination.

One of the sailors was having a small problem when rigging – the boom would swing forward and get caught under the gunwale.  The original square lashing wasn’t cutting it – particularly when a loose foot arrangement was used on the boom.  The square lashing …

Goat Island Skiff boom to mast connection that has been replace by the bleater - article on lug rig advances Storerboats

So he had tied a rope to the front end of the boom and then to the mast.  We decided to call it a bleeater … well, they are Goats.  I’ve seen it set up that way before.  The middle one is a direct corollary of the halyard system we use but not adjustable.

This illustration below shows the original square lashing compared with the bleeter (bleater)

better rigging for balance lug rigs - article on storerboats

 

The “strong version” holds the boom to the mast with much more force and can cause binding on square masts.  The Moderate version still has the tension vector pulling the boom up close to the mast providing the boom is always pulled forward.

So here we introduce the vanghaul – a mixture of boom vang /kickerand downhaul which works nicely in conjunction with the bleeter.

The really exciting thing to me is it is EXACTLY the same setup as the original but with the rope and downhaul redeployed.  A really nice solution.  Not everyone likes it though – if the bleeter tends to bind and restricts the boom from rotating around the mast you will have to use the moderate version.  Some still don’t like it, some really like it.

So to explain the development.

First a powerful downhaul

Starting point for the new arrangement were loose footed mainsails on stiffer booms making it difficult to prevent the boom slipping forward.

Information from Brian Pearson changed our thinking.

Finally using the same parts we engineered a more workable solution for the majority of sailors.

Then the comparison of the original, the two vang and the bleeter/vanghaul system in this diagram

bleeter and vanghaul - useful setup tips for lug rigs on small boats - article on storerboat plans

Top section is the system in the plan and the general lug setup for all the storerboats.  It is simple and effective.

Mid section is the two vang system from the .  Boy racers will still really like this system with it’s infinite adjustment and ability to throw the rig around relative to the mast.  It allows the widest range of options but at the risk of some complication, a little extra expense and also a need for the knowhow to feel what the boat is doing and to put the sail in the place you want.

The bottom illustration is the Bleeter  (green) with Vanghaul (purple).  One important note is that the power of the vanging is proportional to the distance between the tack of the sail (forward bottom corner) and the vanghaul.  So the comparison with the conventional rig is shown to the right.  The distances should be about the same from the tack of the sail … not the mast as we were tempted to think.  If you have the vanghaul too far back from the  mast you lose luff tension in the sail, very bad for pointing upwind.  So for Goat sized boats we have found the vanghaul should be attached to the boom about 4 or maybe 6 inches (100 to 150mm) behind the mast as a starting point.

Sailing is the final test for the correct position of course.

Like I said, not everyone likes it, but some certainly do.  And it uses the existing gear and means that you have a good excuse to update a puny downhaul.

Links

Setup

Goat Island Skiff setup page – the primer  for lug rig setups

The Goat Island Skiff and OzRacer WIKI for recording information about components and setups beyond the basic

Videos of the Goat Island Skiff and OzRacers in Action

All the performance articles on Storerboats website

 

Results

BETH sailing canoe in regular weekly fleet racing

Goat Island Skiff in regular weekly racing

Faster and safer downwind with lugsails and other non stayed rigs

 

Plans

Goat Island Skiff Plans information

OzRacer Mk2 plans – single person slightly race oriented

OzRacer RV plans – family cruiser slightly race oriented

 

Subscribe to be informed of new information – once a week email at most on weeks I publish articles.  No email on weeks with no articles.  No spam ever


 


3 thoughts on “Making Balance Lugs faster 2013 – setting up sails, spars and rigging

  1. […] we have the “Bleater” arrangement (see GIS woodenboat forums) we are now going to move the downhaul aft on the boom so it has more of […]

  2. […] than the first two static test prototypes.  This will alow the downhaul or alternative “vanghaul” to be tensioned much higher to reduce sail twist without overbending the yard along the top […]

Leave a Reply