Lateen/spritsail rig

[Slow_boat]

I read an article in one of the mags a while back discussing various rigs and why bermudan is the most used at present and I thought to myself; what is wrong with lateen rig for cruising?

On the face of it, it's cheap and easy to make and repair because you need no fancy spars, rigging or sails, easy to handle and reef, has a low centre of gravity when the sails dropped, is efficient and has been in use for thousands of years until recently.

The same can be said for spritsail rig, so what is the downside and why is bermudan so universally used?

 

[Woodlouse]

Bermudans are efficient and easy to handle. No big bits of wood to send skywards. Simples.

 

[Slow_boat]

Not as easy as junk rig or freedom rig, which stress the hull far less but they didn't catch on.

 

[Tommyrot]

I've had a straight comparison between Bermudan, Lateen and Sprit rigs in a PDf file for some time. Surprising results, wish they'd tested the Junk rig as well....

Tried, but It's too big (1.1MB) for attaching here, but happy to forward it by email.

 

[highandry]

I don't know if modern lateen rigs have changed, but on the old Arab Dhows that used to run between Mogadishu and Aden, it seemed to take all hands and the ships cat to dip the yard when they went about on certain points of sail. Perhaps with lightweight spars it's different now?

 

[Slow_boat]

I seem to recall it was a bit like dipping a lug, easy enough if head to wind. A spritsail doesn't even need dipping!

 

[Ubergeekian]

The same can be said for spritsail rig, so what is the downside and why is bermudan so universally used?

C. A. Marchaj wrote a long (read: interminable) and detailed (read incomprehensible) series in one of the mags about the aerodynamics of various rigs some time ago. PBO, I think, though it may have been YM. His conclusion, as I recall, was that the crab claw rig beat everything else.

http://www.proafile.com/view/weblog/comments/rig_options_crab_claw/

However, that was on efficiency only. When you consider other aspects like controllability, sail handling and so on, bermudan seems to win. Mind you, I can't help feeling that modern racing rachts with little spar thingies at the top of their mainsails should be classified as gaffers - if only to shock the beard-and-sandals brigade.

Edit: I think the articles were PBO, September - December 1986.

 

[jimmyss]

I/we sailed a 20foot cot Sprit rigged for a number of years

they run before the wind like a bat out of hell..
simple to get ready


Do not not point up too well
When coming about unless you have plenty of way under you she will stop dead... this is because the sprit holds/pulls the top of the sail taut all the time, so it acts like a hauled in inverted jib..

 

[highandry]

I seem to recall it was a bit like dipping a lug, easy enough if head to wind. A spritsail doesn't even need dipping!

You're right there Slowboat, but the lateen spars seemed a good deal longer reaching well forward and right aft. They would let the halyard run, all grab the spar amid much jabbering and arm waving and drag it aft then haul it aloft on the new lee side. Mind you, they were big commercial Dhows and the spars were pretty hefty. With a modern carbon? spar it would be a lot easier. Good fun for me, a singlehander though!

Just as an addition. There's a couple of lateen rigged vessels that I see down here on the Algarve, a lovely looking rig I must admit.

 

[Tommyrot]

The lateen does look very pretty....

It's of little use comparing performance unless the same boat is used with different rigs, (even then a particular hull might suit one type of rig better than another) the article I've got does exactly that, the bermudan doesn't compare at all well with the lateen or sprit!

 

[TamarMike]

I seem to recall it was a bit like dipping a lug, easy enough if head to wind. A spritsail doesn't even need dipping!

From descriptions I have read about lateen sails dipping a Cornish style lugsail is simplicity itself, although I believe some small naval craft could make tacking lugsails quite complicated but I expect that was just to keep everyone's hands busy.

My current fibreglass yacht is of similar, possibly slightly less, displacement to the lugger I had previously with a considerably larger sail area (waterline length also similar although the yacht is 4' 6" longer on deck) yet I have been disappointed that speed and pointing ability are not much better except for going to windward in a choppy sea (the yachts mainsail is rather baggy and over 30 years old on the other hand the luggers sails were designed my myself with no pretensions to be a naval architect or rigger). Where the yacht is superior is in having only a fraction of the leeway of the lugger - due of course to fin keel compared with a wooden hull with internal ballast only. Tacking the dipping lug did take about 3 or 4 minutes each time but when she had been previously rigged standing lug with a jib sail handling and close quarters manoevering single handed were far far easier than with a bermudian rig.

 

[Woodlouse]

My current fibreglass yacht is of similar, possibly slightly less, displacement to the lugger I had previously with a considerably larger sail area (waterline length also similar although the yacht is 4' 6" longer on deck) yet I have been disappointed that speed and pointing ability are not much better except for going to windward in a choppy sea (the yachts mainsail is rather baggy and over 30 years old on the other hand the luggers sails were designed my myself with no pretensions to be a naval architect or rigger). Where the yacht is superior is in having only a fraction of the leeway of the lugger - due of course to fin keel compared with a wooden hull with internal ballast only. Tacking the dipping lug did take about 3 or 4 minutes each time but when she had been previously rigged standing lug with a jib sail handling and close quarters manoevering single handed were far far easier than with a bermudian rig.

Get a new mainsail and your upwind performance will be revolutionised.

 

[TamarMike]

Get a new mainsail and your upwind performance will be revolutionised.

PM sent to Father Xmas

As regards sail handling the power of a lugsail can be smoothly adjusted using the halyard to dip the yard, and the sail can be raised and lowered on any point of sailing if the wind isn't too strong. The lug mizzen sheeted to a long outrigger when sheeted tightly in immediately weathercocks the boat bringing her to a standstill, both above attributes very useful when anchoring in a confined space or picking up a mooring (or, no doubt, lobster & crab pots when she was a working boat).

Spritsails can be partially or fully brailed up against the mast, on small boats making them the sail equivalent of an outboard.

When needing to reduce sail area the usual practise with dipping lugs was simply to change to smaller sails shifting the mizzen forrard (although reefing a loose footed sail is also easy it can then no longer be tacked without releasing the tack fom the bow).

Loose footed gaff sails could also be scandalised using brailing lines but with a boom slacking the peak halyard has the same effect. The equivalent on a bermudian rig is lifting the boom to spill wind with the topping lift.

I think one of the main advantages of Bermudian rig is the stiffness which can be achieved with the tensioned standing rigging while tall narrow sails of all types tend to achieve a better shape when it matters going to windward, particularly taking advantage of the modern fabrics and stitching design (unlike my baggy 30 yr old mainsail as Woodlouse pointed out).

 

[Tommyrot]

I've uploaded the file I've been droning on about for anyone interested, you'll have to click on "Free download" and wait a few seconds, sorry.....


Fastest rig.pdf - 1.2 Mb

 

[westernman]

The report says gaff is faster than bermudan too.

So why did all the big racing yachts in the 1920's change over from gaff to bermudan?

 

[Cornishman]

The report says gaff is faster than bermudan too.

So why did all the big racing yachts in the 1920's change over from gaff to bermudan?

The rig was developed in Bermuda where the winds are lighter in the sailing season than they are here, but it was already a well known fact that the wind is stronger the higher you can set a sail. The triangular sail does away with the need for a topsail which requires skilled hands to set it, particularly if it is yard headed and with a jackyard extending its foot beyond the peak of the gaff. With an unskilled crew we would often take ages to set the main topsail in Hoshi. A single pole mast, called a Marconi in the US because of its similarity to the early radio masts, is lighter and takes the sail to greater heights so increasing the luff length without becoming top heavy. This is important when going to windward.
Skilled paid hands were becoming scarce in the 1920s as many were from the fishing fleet which was rapidly being converted to steam power and later diesel, so the sailing skills began to disappear.

 

[Slow_boat]

The report says gaff is faster than bermudan too.

So why did all the big racing yachts in the 1920's change over from gaff to bermudan?

As I understand it, it is because races are on a three leg course favouring upwind performance. Races are won or lost on the upwind leg.

 

[Twister_Ken]

Any rig putting a big heavy stick at the top of the mast is inevitably going to increase the polar moments of roll and pitch, so the boat will bob about more, destroying speed and upsetting those with delicate digestions.

Carbon fibre would be good though.

 

[Slow_boat]

But quicker downwind.

How about lateen rig with a bipod mast? It would save rigging stresses on the hull and give a lot of deck space..

 

[TamarMike]

Any rig putting a big heavy stick at the top of the mast is inevitably going to increase the polar moments of roll and pitch, so the boat will bob about more, destroying speed and upsetting those with delicate digestions.

Carbon fibre would be good though.

In theory weight aloft should have a damping effect on rolling leading to a slower (but in extremis more dangerous) roll - HOWEVER in practise a yard aloft will not necessarily swing in tune with the mast if waves are rolling the boat but the wind is light so the set of the sail is continuously disturbed, not a problem off the wind but losing drive going to windward (maybe someone can advise if a topsail helps steady the rig). In contrast the low down boom of a bermudian rig is subject to less disturbance as well as being securely held in position by the sheet and vang.

Another problem with applying those traditional rigs without a boom to yachts is that the sheets have to go where they have to go to get the correct lead to the clew - no question of coachroof v bridge v sterndeck travellers! This can lead to the choice between a horse or traveller in the most inconvenient part of the cockpit or having seperate port and starboard sheets.