B&R Rig

[Franklin]

One day I was at a local sailor hangout and discussing the Regatta de Amigos race. One sailor who happens to teach ASA said "I own a Benny but I wouldn't take it on that race and a Hunter...without a backstay, I wouldn't even take that offshore". So that got me to thinking hard about the B&R rig.

When I walked home (my boat) I looked up at the mast and tried to figure out why they made it like that. It couldn't have been to get rid of the backstay so they can have a large roach as the first version of the B&R rig had a backstay. So why sweep back the spreaders? They always seem to get in the way on many angles of sail. I was puzzled but it started to come to me and I give credit to the few beers I had that night (beer always seems to get me thinking differently :dance.

I determined that night that they made it that way to give support to the middle of the mast as that's where most masts tend to break. The high tension put on the outside top shrouds pull back on the top but at the same time push forward at the two spreaders (my boat has double spreaders). Then the shorter mid shrouds pull back on the mast creating a stable mast in the middle.

So with the stablization of the middle of the mast and the small headsail (fractional rig), there isn't much risk of metal fatige in the middle of the masts that cause many masts to break. Why the small headsail helps? Because when sailing on just one sail in heavy winds, it doesn't create too much of a yank on the top of the mast. If it's a masthead rig and no main up, theory is that it will send a vibration down the mast to the unsupported middle of the mast. When I say unsupported, I mean forwards/backwards, not side to side.

So, there you have it. I thought I was sooo smart...or the beer was smart . Well, a few days ago I went to the Hunter site to look at the new boats because of the talk of the boat show. I ran across their explanation of why the B&R rig is stronger then a normal rig. They said something about the rig being supported by an equal pressure on the shrouds. So I got to thinking at lunch today about it. I guess that under a normal rig and on a reach, most of the pressure is on the windward shroud. Under a B&R rig, I believe all the pressure is equally distributed between the windward shroud and the forestay. That makes sense.

So, I open this topic up for discussion on the Ask All Sailors to get a wide range of opinions, not only on my drunken state theory, but also Hunter's claim. Fire away. What do you think? Do you think they are stronger? Do you think they are weaker?

Note: many rigs with backstays have mid shrouds that are angled a little forward and backwards so that helps but it doesn't seem to have much angle to it so I'm not sold on that helping much.

 

[sailaway78]

Makes sense to me

Franklin, I have always wondered about the B&R rig, with no backstay. Looks weak to me. But you do not hear horror stories about them coming down. I don't recall hearing of a single failure. And your deductions make sense to me.

 

[bffatcat]

No backstay

I dunno Im from the old school. I think of a boat without a backstay as fine
for coastal cruising. I would not want to sail it offshore. I would like a naval architect, someone in the know to explain to me how a mast without a backstay can have a rig as strong as a boat with one. I do not understand what the advantage of having a boat without a back stay would be.

 

[Les]

Franklin, I want to jump in this discussion early--I was an early adopter of the B&R rig back in the eighties. I had just bought a Hunter 40 and was commissioning it myself with the help of an engineering friend. I remember we laid the mast out on sawhorses and slowly attached shrouds and stays. Then the instructions said to tighten different diagonals until the mast had a certain bend in it. We actually tensioned the mast as it lay on the sawhorses. So when we put it on the boat, all we did was attach it to the hull and make sure the tension was equal all the way around. it was great.

But let me digress a moment. Before the B&R rigs, (I have had ten boats) we would put the mast INTO the boat fitting the bottom of the mast on the keel. Makes sense. Then we attached the shrouds and stays to the boat. But those boats had back stays AND backstay adjusters--you would bend the mast to deal with different wind conditions. The backstay adjuster was exciting especially if you had a hydraulic one--you could really bend the mast back. On my Ranger 32 race boat we actually would bring the ends of the boat up (out of the water) about two inches when using the back stay adjuster. It bent the mast but it also bent the boat. In essence we were loading up a bow and arrow--the arrow being the mast. AS I said, exciting times. But masts became smaller and more lightweight and in a sea way would begin to "pump" Hence, the beginning of "baby stays" to stop the pumping. I lost a mast in the Swiftsure because of this flexing. We also install running back stays to also stop this flexing and to assist the backstay.

So I was sold early on with the B&R rig. No pressure on the boat. But here is something else to consider--it is essentially a three legged stool. Very strong. I've talked to Brion Toss, a world class rigger and it said to me that if he were to go around the world in a boat, this would be the rig as it is inherently strong. A number of these rigs have gone around the world.

As for going "down Wind" I gave that up years ago, even when I was racing. I agree with those that say that "fast is fun." By heading up a few degree from dead down wind you pick up much more speed even with all types of spinnakers. I use to race a Hunter 35.5 with a bulb wing keep and we never went directly down wind but headed off on a broad reach. About halfway to the leward mark, we'd jib and reach off on the other tack. Most of the time we beat most of our class and a few others. It works. We won boat of the year in local racing one year do just that.

Now that I have a boat with in mast furling I'd wouldn't have anything else but a B&R rig. I agree with Brion--they are the strongest.

Les

 

[Don S/V ILLusion]

The following is an excerpt from the discussion of B&R rigs taken from the Resources tab here on this web site. Anyone interested may find the entire discussion useful, particularly if you are wondering how to tune such a rig. If you ever sailed a boat with runners, you'll appreciate the comments:


"The performance-minded skipper will benefit from the inherent aerodynamic efficiency and quick tacking ability of the B & R rig due to the smaller mast section and swept back spreader arrangement. The cruising sailor, who often sails with minimum crew, will enjoy the feeling of safety and comfort of not having to worry about constantly moving about the boat and undoing various parts of the rigging.
B & R rigging systems are on boats the world over. World cruisers and racers, OSTAR boats, 2 ton, 1 ton, 1/2 ton, 1/4 ton boats and multihulls. Wherever one finds sailors who want performance and reliability.
The basic difference between a B & R rig and a conventional rig lies in the B & R's use of swept back spreaders and diagonals. The swept back spreaders eliminate the running backstays. The diagonals perform the same function as inner forestays"

 

[RichH]

Structurally the B&R rig is the same as a standard backstay rig. The B&B simply sweeps the spreaders aft to take over the structural job of the backstay.

The functional difference is substantial in that due to strain elasticity of all materials it is impossible on a B&R to easily adjust the important forestay tension/function (for pointing ability and to match the luff shape of the headsail) ... you can adjust such tension but it then become a VERY complex thing to do while 'underway'.
Hunter probably correctly realizes that on most sailboats in this 'category' as such rigging adjustments needed for 'precise or performance sailing' is hardly/never needed by those who tend to buy their products.

 

[Franklin]

Structurally the B&R rig is the same as a standard backstay rig. quote]

don't think I would agree with that, but I will agree that Hunter owners are not the type to be adjusting rigs while underway.

Let me see if I get it right, you tighten the backstay to tighten the forestay when pointing, but loosen the backstay when broadreaching to loosen the forestay and tighten the main, right?

If so, then I bet Hunter is thinking that they'll just keep the forestay tight at all times and when broadreaching and the sailor wants performance, they'll throw up a A-spin. Just a guess but that's a little off topic as it has nothing to do with stability and strength of the mast.

 

[Grizz]

'86 vintage B&R?

Wow, and here I sit with a 1986 model Hunter that has a backstay with an adjuster, which we do both upwind and off the wind. Off the wind is a bit of a pain due to the swept spreaders, 'cuz you've got to be careful with how far you ease the main, but upwind the spreaders permit pointing angles not possible with perpendicular spreaders. Not that this turns the h28.5 into a sled (far from it) but it helps us point a bit higher than comparable boats.

Tuning the mast after this spring's mast-step has proven to be a bit of a bugger, but I think we got it close last week...just in time to put her to bed for the winter! Oh well, we'll note the marks and be ready for next year.

 

[RichH]

Grizz --

I'll bet the farm that the design team at Hunter had a meeting which went like this ... our boats are not for performance sailing, we can put up a cheaper lighter weight mast and get rid of the backstay that 1. our targeted customers probably wouldnd have any idea how to tension and 2. then we can increase the roach area of the mainsail to get the max. of such fractional design.

This is not a 'bad' method nor am I "hunter bashing" nor the B&R rig in any way, as many modern boats (maybe correctly) are tending to go back to fractional rigs. Its not such a bad idea when you are targeting buyers of lower cost, pure 'coastal cruisers', etc. ... the close to or already 'retired' set that principally uses the boat solely as 'recreational'.

Hunter markets to 'weekend kroozers' not those who are interested in 'performance' or long distance passagemaking.

 

[Grizz]

No bet...

...even if you don't have a farm! Agree, 'cuz the design alterations from the late 80's to today, ie the Hunter Arch conducive to Bimini, no backstay, galley & cruiser comforts, support your contention. Don't believe the meeting was as succinct, but close.

 

[Franklin]

RichH

How do you explain the early models that had the backstay with the swept back spreaders?

 

[Steve Dion]

I just returned from a trip up the coast of California (about 400 miles) on a 1997 H'376. We sailed/moto sailed all the way. We only deployed the jib for the majority of the trip. We were in moderate seas 6-7' seas every 6-8 sec. It was no cake walk, but the boat and rig held up without any problems.

As someone mentioned, I have not heard of any failures because of the lack of a back stay.

 

[Steve Dion]

Re: RichH

Franklin:

If you look at the older models they had a narrower angle and the spreaders were shorter than the newer rigs without a backstay.

 

[kloudie1]

Basically, a structure if done right, be as strong as the designer decides it to be.. The backstay can be designed in or out of a rig as the designer decides to take advantage of a strong point or design around a disadvantage for his purpose.. The only disadvantage of the B&R in my opinion is that it has to be kept in tune more than a conventional rig, which is more tolerant of mal-tuning! Check out this boat:http://www.youtube.com/watch?v=x9Mvu57FP3c It has NO stays and yet is OK to use in blue water!