Is the Hunter B+R rig safe to use with jib alone, without the topping lift and mainsheet for stability? On our 260 I would like to try jib alone in high winds .I have removed the topping lift in favor of a boom kicker.
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I began sailing my B&R rigged
H28.5 with only the genny up in high winds a few seasons ago and found that the boat handled wonderfully. It was easy to tack, and had very little weather helm. I cannot see any reason not to do this as I saw no evidence of mast pumping or undue stress anywhere on the rig. I would tend to believe, also, that with the shrouds aft of the mast, it may be safer to sail a B&R rigged boat on headsail alone than a conventionally rigged boat, IMHO.
H28.5 with only the genny up in high winds a few seasons ago and found that the boat handled wonderfully. It was easy to tack, and had very little weather helm. I cannot see any reason not to do this as I saw no evidence of mast pumping or undue stress anywhere on the rig. I would tend to believe, also, that with the shrouds aft of the mast, it may be safer to sail a B&R rigged boat on headsail alone than a conventionally rigged boat, IMHO.
I think what he is saying
Is that he feels that the topping lift, through the boom, through the mainsheet, becomes a "backstay" of sorts. Same for when the sail is up - you pull downon the sail and this pulls back on the mast. I think somebody needs to rig the boat up (with a topping lift) with the lift taught and the mainsheet slightly loose. Sail with only headsail, and see how much tension ends up on the mainsheet. btw - one of the big arguments about masthead rigs, is that they can sail on headsail alone much better than the fractional (supposedly). But I'm pretty certain that it is plenty safe to sail without a main if you have a backstay.
Is that he feels that the topping lift, through the boom, through the mainsheet, becomes a "backstay" of sorts. Same for when the sail is up - you pull downon the sail and this pulls back on the mast. I think somebody needs to rig the boat up (with a topping lift) with the lift taught and the mainsheet slightly loose. Sail with only headsail, and see how much tension ends up on the mainsheet. btw - one of the big arguments about masthead rigs, is that they can sail on headsail alone much better than the fractional (supposedly). But I'm pretty certain that it is plenty safe to sail without a main if you have a backstay.
Jib alone
Hal I've done it with no concerns about the rig. Remember that the mast moves aft when the forestay is released. The shrouds and bars prevent forward movement even without the topping lift and main sheet rigged. Also when the wind is aft, the main sheet is fully extended and the topping lift is slack so they are not acting to pull the mast aft. Under those conditions I am using flying a spinnaker as well, adding more forward pull on the mast. The problem is performance. The H260 won't point with jib alone. The first reduction I do as the wind stiffens is to roll the jib in some. I keep furling until I balance the rudder. I don't reef the mail until the conditions cause me to fully furl the jib. Once the mail is reefed, I add jib again.
Hal I've done it with no concerns about the rig. Remember that the mast moves aft when the forestay is released. The shrouds and bars prevent forward movement even without the topping lift and main sheet rigged. Also when the wind is aft, the main sheet is fully extended and the topping lift is slack so they are not acting to pull the mast aft. Under those conditions I am using flying a spinnaker as well, adding more forward pull on the mast. The problem is performance. The H260 won't point with jib alone. The first reduction I do as the wind stiffens is to roll the jib in some. I keep furling until I balance the rudder. I don't reef the mail until the conditions cause me to fully furl the jib. Once the mail is reefed, I add jib again.
masthead vs. fractional differences
Brian I may be wrong but suspect when you say masthead rigged boats "can sail on headsail alone much better than the fractional" that is true only because masthead rigged boats inherently have larger jibs. My take on this is that if the weather is bad enough such that someone would choose to use only a jib, the smaller, the better. As far as safe, if you consider the 3-point support design of the B&R rig, it should be as safe as a conventional backstayed rig. Not sure how appropriate but the typical analogy of a 3 legged stool compared with a 4 legged one is often quoted - if one leg breaks on either, it could ruin your day. My experience is the only real difference is it's not fun to sail DDW with a fractional rig but doing so on either type is bad form anyway...
Brian I may be wrong but suspect when you say masthead rigged boats "can sail on headsail alone much better than the fractional" that is true only because masthead rigged boats inherently have larger jibs. My take on this is that if the weather is bad enough such that someone would choose to use only a jib, the smaller, the better. As far as safe, if you consider the 3-point support design of the B&R rig, it should be as safe as a conventional backstayed rig. Not sure how appropriate but the typical analogy of a 3 legged stool compared with a 4 legged one is often quoted - if one leg breaks on either, it could ruin your day. My experience is the only real difference is it's not fun to sail DDW with a fractional rig but doing so on either type is bad form anyway...
did it for two days straight
In my old h410 I ran downwind in a gale for two days with the jib furled approximately 50% and no main in 40-knot winds with 14-foot seas. Seldon furling mast. Never once saw the mast pump. (The boat, btw, pretty much stayed at hull speed for that entire run. We were en route from Monterey to Morro Bay, but the Coast Guard closed the harbor at Morro Bay because breakers were shoaling over the harbor bar. Had to keep going until Port San Luis with a crew that really hadn't slept in two nights. When we finally got to Port San Luis, you never saw three guys so happy to pick up a mooring ball.)
In my old h410 I ran downwind in a gale for two days with the jib furled approximately 50% and no main in 40-knot winds with 14-foot seas. Seldon furling mast. Never once saw the mast pump. (The boat, btw, pretty much stayed at hull speed for that entire run. We were en route from Monterey to Morro Bay, but the Coast Guard closed the harbor at Morro Bay because breakers were shoaling over the harbor bar. Had to keep going until Port San Luis with a crew that really hadn't slept in two nights. When we finally got to Port San Luis, you never saw three guys so happy to pick up a mooring ball.)
Tripod
Hal, When seen from above the B & R rig has the three stays radiating from the mast each at 120° to the others. Thus it is in perfect balance and, as other posts indicate, forms a tripod. This is a perfectly standard way of supporting any pole and is as strong as one wants to make it. The provisos being the strength of the wires and their fixings to the hull and it is equally strong in all directions. I believe the greatest loads come when the boat is knocked down athwartships. If the rig can withstand this then it should not see greater loads in the fore and aft direction unless the boat is pitchpoled. B & R say one can, and people regularly do, fly spinnakers on B & R rigs.
Hal, When seen from above the B & R rig has the three stays radiating from the mast each at 120° to the others. Thus it is in perfect balance and, as other posts indicate, forms a tripod. This is a perfectly standard way of supporting any pole and is as strong as one wants to make it. The provisos being the strength of the wires and their fixings to the hull and it is equally strong in all directions. I believe the greatest loads come when the boat is knocked down athwartships. If the rig can withstand this then it should not see greater loads in the fore and aft direction unless the boat is pitchpoled. B & R say one can, and people regularly do, fly spinnakers on B & R rigs.
Catamarans don't have backstays
The big cruising and racing catamarans have been sailing with both fractional and masthead jibs alone for years without a backstay without problems.
The big cruising and racing catamarans have been sailing with both fractional and masthead jibs alone for years without a backstay without problems.
Well, I'm on my fourth jib
and the original main (still in great shape) on my 1985 H34. I think that says (1) that the boat has been sailed a lot on jib alone, and (2) that I'm kind of lazy in less than 12 knots of wind.... I usually only raise the main for balance when the wind picks up or for a long sail where the best pointing is necessary.
and the original main (still in great shape) on my 1985 H34. I think that says (1) that the boat has been sailed a lot on jib alone, and (2) that I'm kind of lazy in less than 12 knots of wind.... I usually only raise the main for balance when the wind picks up or for a long sail where the best pointing is necessary.
B & R Is Supposedly Stronger
than the standard stay set-up. So the question reverts to: "Is it safe to fly the jib alone in high winds?" (Not: "Have I done it and survived without incident?") And I suppose that the answer is the same as it is for standard stays: The real issue is the removal of the forward thrust of the mainsail along the whole length of the mast. This is the same issue for a B&R rig as for any other. A fractional rig adds further issues. Doing this in high winds adds to the risk. My answer is that you will probably get away with it, since the rig is seriously over speced. But you have significantly increased the risk to your rig. David Lady Lillie
than the standard stay set-up. So the question reverts to: "Is it safe to fly the jib alone in high winds?" (Not: "Have I done it and survived without incident?") And I suppose that the answer is the same as it is for standard stays: The real issue is the removal of the forward thrust of the mainsail along the whole length of the mast. This is the same issue for a B&R rig as for any other. A fractional rig adds further issues. Doing this in high winds adds to the risk. My answer is that you will probably get away with it, since the rig is seriously over speced. But you have significantly increased the risk to your rig. David Lady Lillie
read more closely
The point here was not, "I did it and survived without incident," but rather, "I did it in severe conditions and never once saw the mast pump." There's a significant difference here. Many years ago Practical Sailor ran an article on mast failures resulting from jib-alone sailing. They found, if memory serves, that the failures were happening on boats with unswept spreaders where there was a single--rather than double--lower shroud. The masts would get out of column and fail. I offer no opinion whatsoever on whether the practice of jib-alone sailing is safe on a BnR rig. I simply don't want to assume the liability for such an opinion, especially given the fact that I'm not a professor of physics. That said, I can certainly tell you that I've sailed a BnR rig on a Seldon furling mast through a two-day gale downwind with jib alone at 50% and NEVER ONCE SAW THE MAST PUMP.
The point here was not, "I did it and survived without incident," but rather, "I did it in severe conditions and never once saw the mast pump." There's a significant difference here. Many years ago Practical Sailor ran an article on mast failures resulting from jib-alone sailing. They found, if memory serves, that the failures were happening on boats with unswept spreaders where there was a single--rather than double--lower shroud. The masts would get out of column and fail. I offer no opinion whatsoever on whether the practice of jib-alone sailing is safe on a BnR rig. I simply don't want to assume the liability for such an opinion, especially given the fact that I'm not a professor of physics. That said, I can certainly tell you that I've sailed a BnR rig on a Seldon furling mast through a two-day gale downwind with jib alone at 50% and NEVER ONCE SAW THE MAST PUMP.
Hunter's answer...
to the question, I posted a year or so ago and should be in the archives. The same q was discussed then. Allan
to the question, I posted a year or so ago and should be in the archives. The same q was discussed then. Allan
Allan's post from 5/19/03
for those who don't want to have to dig through the archives: Flying jib alone on BandR rig? There was a recent thread on the safety of flying a jib alone on a fractional BandR rig. It was an interesting question for me since I know a bit of physics and have a bit of blue water experience. Thus, I posed the question to Hunter and got a response from one of their engineers. Since others might also be interested, I post the essentials of the response below. The engineer said that the issue is whether the compression load, without the mainsail limiting it, creates too much forward bend in the mast. He said that the diagonal shrouds resist that compression bend whereas inline spreaders and shrouds do not. “If the mast is conservative as it is on our boats, it would take an unusual dynamic load to collapse a mast. A fitting would have to break. ... the boat would have to be well overpowered before you need to worry about that on our boats” Allan
for those who don't want to have to dig through the archives: Flying jib alone on BandR rig? There was a recent thread on the safety of flying a jib alone on a fractional BandR rig. It was an interesting question for me since I know a bit of physics and have a bit of blue water experience. Thus, I posed the question to Hunter and got a response from one of their engineers. Since others might also be interested, I post the essentials of the response below. The engineer said that the issue is whether the compression load, without the mainsail limiting it, creates too much forward bend in the mast. He said that the diagonal shrouds resist that compression bend whereas inline spreaders and shrouds do not. “If the mast is conservative as it is on our boats, it would take an unusual dynamic load to collapse a mast. A fitting would have to break. ... the boat would have to be well overpowered before you need to worry about that on our boats” Allan
it's a bad thing
When a mast pumps it flexes back and forth in the middle as the result of downward compression. The taller and more flexible the mast, the more likely it will pump once pressure on the masthead builds in stiff winds. When this happens, you can look at the masthead and actually see it pump up and down. Not only can this lead to metal fatigue, but the mast can flex so far out of column if it gets into a rhythm that it will ultimately fail. In the not-so-long-ago old days, the only way to keep a tall mast from pumping was to rig running backstays--called "runners"--that had to be switched during every tack. Then, somebody figured out that by sweeping the spreaders back the runners could be eliminated, which most of us, especially cruisers, would agree is a good thing even if it means a slight compromise in the ability to shape the sail.
When a mast pumps it flexes back and forth in the middle as the result of downward compression. The taller and more flexible the mast, the more likely it will pump once pressure on the masthead builds in stiff winds. When this happens, you can look at the masthead and actually see it pump up and down. Not only can this lead to metal fatigue, but the mast can flex so far out of column if it gets into a rhythm that it will ultimately fail. In the not-so-long-ago old days, the only way to keep a tall mast from pumping was to rig running backstays--called "runners"--that had to be switched during every tack. Then, somebody figured out that by sweeping the spreaders back the runners could be eliminated, which most of us, especially cruisers, would agree is a good thing even if it means a slight compromise in the ability to shape the sail.
Thanks
Thanks. I was planning on jib only, downwind only. Things should be fine; I’ll just keep an eye on the mast for any unusual action.
Thanks. I was planning on jib only, downwind only. Things should be fine; I’ll just keep an eye on the mast for any unusual action.
Risk
Valid points, John. The experience you relate, and the Hunter engineer's comments about conservative design both fit my comments. But the Hunter engineer is also telling us that sailing without the mainsail limiting mast movement increases the risk. The question to ask is: Will unexpected high winds (see the article in Sailing this month about the boats anchored in Georgian Bay for an example) and rough seas create enough of " an unusual dynamic load to collapse a mast?" When you sail with jib alone, you are increasing the risk to your rig. I do it, but I know that I am sailing with higher risk, so I tend to do it on shorter legs, near to port. I have seen a nearby racing boat lose its mast, and it makes me cautious about thinking I can spot or anticipate the combination of conditions that will overload my rig. A combination of wind, waves, dynamic sail trim, and sub-optimal tuning of the rig brought his mast down when he never expected it. Running backstays prevent pumping of the mast by balancing the lateral (forward) stress of a fractional forestay that does not attach to the top of the mast at the same point as the other stays. Without running backstays, this forward stress pumps the mast while it is in compression from the tuned rig (about 2 tons of compression on our boat), and wind/wave conditions. I don't know how Hunter's use of the B&R principle balances this stress. David Lady Lillie
Valid points, John. The experience you relate, and the Hunter engineer's comments about conservative design both fit my comments. But the Hunter engineer is also telling us that sailing without the mainsail limiting mast movement increases the risk. The question to ask is: Will unexpected high winds (see the article in Sailing this month about the boats anchored in Georgian Bay for an example) and rough seas create enough of " an unusual dynamic load to collapse a mast?" When you sail with jib alone, you are increasing the risk to your rig. I do it, but I know that I am sailing with higher risk, so I tend to do it on shorter legs, near to port. I have seen a nearby racing boat lose its mast, and it makes me cautious about thinking I can spot or anticipate the combination of conditions that will overload my rig. A combination of wind, waves, dynamic sail trim, and sub-optimal tuning of the rig brought his mast down when he never expected it. Running backstays prevent pumping of the mast by balancing the lateral (forward) stress of a fractional forestay that does not attach to the top of the mast at the same point as the other stays. Without running backstays, this forward stress pumps the mast while it is in compression from the tuned rig (about 2 tons of compression on our boat), and wind/wave conditions. I don't know how Hunter's use of the B&R principle balances this stress. David Lady Lillie
December issue of Sailing
has the story on five boats anchored in Georgian Bay. I checked an illustration in their recent ad. Hunter's implementation of the B&R rig with a fractional forestay doesn't need running backstays because the back/side B&R upper stays attach to the mast at the same height as the forestay. The top of the mast which supports the top of the main is free-standing. David
has the story on five boats anchored in Georgian Bay. I checked an illustration in their recent ad. Hunter's implementation of the B&R rig with a fractional forestay doesn't need running backstays because the back/side B&R upper stays attach to the mast at the same height as the forestay. The top of the mast which supports the top of the main is free-standing. David
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