Traditional Sailing Rigs and Performance - lug sails sprit sails

 Balance lugs, standing lugs and sprit rig sails - Tuning setup


Working toward efficient and well tuned lugsails spritsails and rigs.

Any reasonable level sailor can look at the pics right and see that this rig is doing most of the right  things.

The twist is controlled, the sheeting angles are relatively narrow (though never sheet the front sail of a boat in tighter than 10 degrees from the centreline) and the boat is moving along nicely in a light wind and a leftover chop.

This is what I mean when I say that properly set up traditional rigs can be effective ...
... a yawl or a ketch* that can sail round a racing course about equal with a Laser.

There are some wrinkles in the head of the mainsail (the "head" in a 4 sided sail is the edge tied along the upper spar - the top corner is the "peak") and they are a sign of me being lazy - but a few are OK when the wind is light and you are trying to power up the boat.

The other defect is the mizzen is too full.  Mizzens usually end up too full because sailmakers underestimate just how stiff such short yards, booms and gaffs are if they are designed to be strong enough.

The pictures above are of me sailing my first design - the BETH sailing canoe on Lake Burley Griffin in Canberra many years ago. BETH is the boat that helped me work out how to set up these types of sails properly - I already knew from my racing background what the aims were, but there are some specific things applicable to traditional rigs.

Which of the traditional rigs has good performance
The balance lug rig shown here is certainly one of the best candidates for a traditional rig that is capable of very good performance.  Any of the rigs that restrict sail twist as the sheet is eased are OK.  

I have used the balance lug on Beth as well as the Goat Island Skiff and the Drop-in canoe rig. A close relative of the balance lug is the lateen (or vice versa) - which the balance lug becomes when it is fully reefed.

Another is the sprit rig - which we used on the OZ PDRacers.

The PDR - the yellow boat right - is sailing is a good strong breeze.  Note how the twist is restricted and the mast is bending to depower the sail.   Because of the cut of the foot the sail looks like it is sheeted closer than it actually is - the tip of the boom is just outside the transom corner.

The pictures are all :old hat" for racing sailors but the mast on this boat cost $50 and the sail is made of polytarp and cost us $45.  When the boat is turned downwind as in the following picture the sail has little twist and is projected well to catch the wind.  This day I broke the sailing peak speed record for the class - raising it from 6.5mph to 9.2mph.

Another efficient rig is the lateen - which is a very close relative of the balance lug.  I've used the lateen for a number of canoes that have been fitted with my "drop in" outriggers.

Balance lug and sprit rigs will sail rings around a gaff rig unless the gaff rig has been set up with a modern boom vang.

Can Boomless Mainsails be "highly efficient"?
First - there are some good reasons to consider boomless sails, but if you want the boat to sail really well in all conditions then boomless is bad.  

Performance of such rigs can be OK and there is the argument of simplicity - for example a boomless sail on a rowing tender makes a lot of sense - fewer bits to set up for a boat that is not normally propelled by sails.  Cost can also be a good reason

But this section is to deal with those who say "boomless rigs are highly efficient".

Boomless lugs and boomless "leg of mutton" sails are inefficient crosswind and downwind because of excessive sail twist.  Any designer who says that they are "efficient" doesn't have enough sailing experience to make the call or is getting carried away with the promotional spirit of things.

The only exception to "boomless sucks" is in some fast multihulls which have a curved traveller track that keeps the sheet at the right angle all the time.   A multi with a straight traveller and no boom is pretty inefficient as well because the sheeting angle becomes silly as the sheet is eased and the sail twists excessively and the bottom of the sail becomes excessively flat until the limit of the traveller travel is reached then becomes excessively full as the sail is eased for  a broad reach or run.

A boomless rig has its place, but it is very hard to argue a performance advantage.

The reason that the boomed traditional rigs that I use have a lower performance than modern rigs is also because of this type of twist.  
BUT:-
  1. the difference between them and modern rigs is not huge because the twist is controlled.
  2. they are so much cheaper than a modern rigged boat that it is justifiable.
Why not talk about tuning modern rigs and their huge range of adjustability?
The modern bermudan rig generally relies on a boom vang to have the same effect - and that can cost quite a bit of money.  The traditional rigs on the other hand sacrifice something in fine adjustability and make up for it in simplicity and low cost.

Modern race boats go completely overboard with adjustable bits - between a quarter and a third of the $25,000 cost of a 505 (racing dinghy for 2 people) or a Lightweight Sharpie (racing dinghy for three people) is in fittings, ropes and wires - Ronstan, Harken and the rest.  This would be fine if it increased the performance by 25% but the reality is more like 5%.  But that is enough to win races.

Traditional rigs generally have a very low part of the cost involved in these parts - maybe about 5% of the all up cost - and the boat is already much cheaper anyhow.

In fact we built two OZ PDRacers for less than the cost of a shroud tension system on a 505 or Australian Sharpie in 2006.  $350 each.

And the tuning of modern rigs is well covered in other places.  I strongly recommend that traditional rig owners have a look at that information too - it covers the basics very well.

Back to traditional rigs
So you can get on the water cheaply and the boat can still go well - If both you and the designer have both done their jobs.

A large part of getting these rigs to work efficiently is down to the designer - he/she has to get the sail area right for the boat and position it correctly and also design the spars for the correct bending response as the wind strength fluctuates.  

There are few designers that actually do a good job of this part.  Iain Oughtred is one of the few who invariably gets it right with almost everything well positioned and specified.

If the designer understands this properly they can put much more sail area on the boat and still have it easy to sail in stronger winds.  Before we put together our OZ PDRacers with the flexible masts and matching sails the largest sensible sails in the fleet were around 65 square feet.  The OZ PDRs had 86sq ft when we first launched them and they were docile to handle and very quick.

Another area the designer is helpful is in setting up and choosing the rigging for the boat.  There is a big difference in the cost of blocks (pulleys) from Ronstan's basic range vs their deluxe.  In general if the right rope and the right fitting have been chosen by the designer and the correct placement and attachment specified there is no need to pay Ronstan or Harken the extra for ball bearing blocks.

The sailmaker is important too - a sailmaker who is interested in these types of sails makes a big difference too (though with the PDRacer we have included the plan to make sails for yourself at a fraction of the cost).

If the designer gets the rig right, the sailmaker was interested in the project and you get the details right then the boat will sail REALLY WELL - and perhaps more importantly - just be trouble free.

As far as the owner's responsibility - getting these rigs to work well is more a question of detail - just getting little things right - get them all right and the boat will GO!

Setting up and tuning lug rigs and lug sails - also Lateen sails and rigs
Here is a page for setting up most types of lug rigs and lugsails on small and medium sized boats.  Most of the advice for balance lugs will also work for Lateen sails.  
Setting up and tuning the Goat Island Skiff balance lugsail

Setting up and tuning sprit rigs and sprit sails
Here is a photoseries on Flickr about how to rig an OZ PDRacer.  Despite its humble appearance the OZ PDRacer is quite sophisticated with a hollow flexible mast (made of wooden floorboards) and a lightweight hull (29kg 65lbs).  Many of the methods will be familiar to good sailors of small boats - I've stolen them from all over the place through my sailing career.
Assembling the OZ PDRacer including setting up the sprit rig