rig tension
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Thre are many threads on tuning on this site. That being said here are a few guide lines
https://northsails.com/sailing/resources/how-to-tune-your-rig
http://www.ballengerspars.com/mtguide5-97.html
https://theriggingco.com/2017/01/21/how-to-tune-a-sailboat-mast/
The
TUNING KEEL-STEPPED MASTHEAD RIGS
Once the mast is centered side to side, tighten both upper shroud turnbuckles evenly. Continue to tighten the uppers until they are both firm to the touch, or until the tension matches numbers provided by your tuning guide/rigger/sailmaker.
If the mast goes out of column, ease off tension until it is straight again. Be careful not to strip the turnbuckle threads. Do not overtighten.
Tighten all intermediates and lowers evenly on each side, sighting frequently up the aft side of the mast to make sure it remains straight.
This is the initial setting, with mast centered and straight, and all shrouds firm. When you tension the headstay/backstay, the mast should remain straight side to side.
UNDER SAIL
In moderate breeze, take the slack out of the upper on the leeward side (and count your turns so you can replicate the amount on the other tack). Tack, and then tighten the other upper the same amount.
Once the leeward uppers are tight, sight up the mast on each tack to check for side bend. If the middle sags to leeward, tighten the lowers. If the top appears to fall off to leeward, it could actually be the middle popping to windward; either loosen lowers or tighten uppers accordingly. Both over-tight lowers and loose uppers allow the tip to fall off, which creates a narrow angle of intersection between the uppers and the mast. Beware, as this can overload the shroud fittings and cause rig failure.
Proper tension will leave the leeward upper shrouds taut with 15 degrees of heel and a full crew on the rail. The uppers should be tighter than the lowers; they have more load and also stretch more because they are longer.
Check the rig periodically, particularly after sailing in heavy air. Look for stretch in the uppers and for over-tensioned lowers, which can overload the upper spreaders.
From this base setting, you will probably want to fine tune your rig for sailing conditions. Generally this would mean adding tension to the uppers in heavy air, and backing off a couple of turns in light air. Sometimes fine tuning is best done by tensioning/loosening the headstay instead.
MAST BEND AND HEADSTAY SAG
Working with the backstay and a combination of running backstay, baby stay, and/or vang, it is possible to control mast bend and headstay sag separately.
Backstay tension will bend the mast through compression as well as tighten the headstay. The mix depends on running backstay tension. If the runners are tight, they restrict mast bend, and the backstay impacts headstay sag. Looser runners allow more mast bend.
With a stiff mast, backstay tension translates primarily into headstay tension, controlling sag. A baby stay can then be used to add bend. The backstay contributes to bend as well, particularly once bend has been initiated by the baby stay.
Running backstays allow control of mast bend independent of headstay sag. A tight backstay will tighten the headstay and bend the mast. Tensioning the runners will straighten the mast.
https://northsails.com/sailing/resources/how-to-tune-your-rig
http://www.ballengerspars.com/mtguide5-97.html
https://theriggingco.com/2017/01/21/how-to-tune-a-sailboat-mast/
The
TUNING KEEL-STEPPED MASTHEAD RIGS
Once the mast is centered side to side, tighten both upper shroud turnbuckles evenly. Continue to tighten the uppers until they are both firm to the touch, or until the tension matches numbers provided by your tuning guide/rigger/sailmaker.
If the mast goes out of column, ease off tension until it is straight again. Be careful not to strip the turnbuckle threads. Do not overtighten.
Tighten all intermediates and lowers evenly on each side, sighting frequently up the aft side of the mast to make sure it remains straight.
This is the initial setting, with mast centered and straight, and all shrouds firm. When you tension the headstay/backstay, the mast should remain straight side to side.
UNDER SAIL
In moderate breeze, take the slack out of the upper on the leeward side (and count your turns so you can replicate the amount on the other tack). Tack, and then tighten the other upper the same amount.
Once the leeward uppers are tight, sight up the mast on each tack to check for side bend. If the middle sags to leeward, tighten the lowers. If the top appears to fall off to leeward, it could actually be the middle popping to windward; either loosen lowers or tighten uppers accordingly. Both over-tight lowers and loose uppers allow the tip to fall off, which creates a narrow angle of intersection between the uppers and the mast. Beware, as this can overload the shroud fittings and cause rig failure.
Proper tension will leave the leeward upper shrouds taut with 15 degrees of heel and a full crew on the rail. The uppers should be tighter than the lowers; they have more load and also stretch more because they are longer.
Check the rig periodically, particularly after sailing in heavy air. Look for stretch in the uppers and for over-tensioned lowers, which can overload the upper spreaders.
From this base setting, you will probably want to fine tune your rig for sailing conditions. Generally this would mean adding tension to the uppers in heavy air, and backing off a couple of turns in light air. Sometimes fine tuning is best done by tensioning/loosening the headstay instead.
MAST BEND AND HEADSTAY SAG
Working with the backstay and a combination of running backstay, baby stay, and/or vang, it is possible to control mast bend and headstay sag separately.
Backstay tension will bend the mast through compression as well as tighten the headstay. The mix depends on running backstay tension. If the runners are tight, they restrict mast bend, and the backstay impacts headstay sag. Looser runners allow more mast bend.
With a stiff mast, backstay tension translates primarily into headstay tension, controlling sag. A baby stay can then be used to add bend. The backstay contributes to bend as well, particularly once bend has been initiated by the baby stay.
Running backstays allow control of mast bend independent of headstay sag. A tight backstay will tighten the headstay and bend the mast. Tensioning the runners will straighten the mast.
Vangs were optional gear. Off the wind, the boom lifts without a vang and spills air from the mainsail. That costs sail area and may also contribute to rolling.
Rig one when you get around to it. All you need is a bail on the boom, a fitting on the mast base and maybe a three-part tackle.
Or spring for a rigid vang.
Before the modern era nobody used vangs. They put too much stress on the booms of the huge mainsails of the day. With our larger foretriangles and aluminum spars they became common and now nobody can live without them.
But we can. Just put a strap on the boom and secure a line to the toe rail or thereabouts. That temp rig also acts as a preventer.
Yeah, have to change it when you jibe. That might interrupt the crew watching TV down below.
Rig one when you get around to it. All you need is a bail on the boom, a fitting on the mast base and maybe a three-part tackle.
Or spring for a rigid vang.
Before the modern era nobody used vangs. They put too much stress on the booms of the huge mainsails of the day. With our larger foretriangles and aluminum spars they became common and now nobody can live without them.
But we can. Just put a strap on the boom and secure a line to the toe rail or thereabouts. That temp rig also acts as a preventer.
Yeah, have to change it when you jibe. That might interrupt the crew watching TV down below.
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p.gazibara
Member III
You could tune your rig based on the numbers, but it isn't that hard to tune it by sight and sail as well. The 27s should have fairly simple single spreader rigs, so not a huge amount of adjustment required. My double spreader express rig is very noodly so I could really see the little changes.
Step 1 - locate he masthead in the center of the vessel by tightening/loosening the cap shrouds with either a long tape hung from the masthead and measuring from the same point on either side of the boat, or by hanging a plumb bob on a calm day. (I had to do the latter because my e35 hand laid fiberglass isn't quite a mirror image.) Once centered, tighten the cap shrouds equally from then on.
Step 2 - with minimal backstay tension adjust forestry length to get correct mast rake. This should be determined from the spar builder/ rig designer. More rake typically leads to more weather helm, but you want some to give you good sail shape control. For my rig, rake is 1-2 degrees (approx 12" back from the gooseneck). You will need a plumb bob for this, but any weight in the end of a string will work, think weighted bucket.
step 3 - tension the lowers equally, sighting up the main track to make sure the mast stays in column (easier than is sounds)
step 4 -tension the other shrouds you may have to get correct mast pre-bend. Again, this figure comes from the rig designer, mine was 4". This is measured by tightening the lower shrouds evenly until the main halyard attached to the base of the mast shows the correct distance from the back of the mast. (A 4" gap for me)
step 5 - go sailing get the boat to about 20-25 degrees of heel and watch the mast. Is it staying in column? If not tighten the shroud that will keep enough tension to keep the mast in column (remember, what is done to one side must be done equally to the other)
thats it, once you have the mast staying in column you should've good. You should see a slight slackening of the leeward shrouds when pushing the boat, but not excessive.
I recently did this this on my rig after I pulled if for an inspection and it was surprisingly easier than I expected.The best part is, it really got me in tune with my rig/sail trim. When I'm out these days I have a lot of fun playing with backstay /checkstay tension to get optimal sail shape. I can really tell a difference, i was able to get to 7.7~8 kts on a beam reach in 12ish kts of breeze. She really digs a hole and it's a lot of fun watching my aft corner sit a few inches above the waterline and the bow wave breaking way up front. When you get these boats going and maximize their waterline they really move (for a non-planing hull)
i would also also recommend a book called "Sail Power" really taught me a lot while I was doing all this.
i wrote up a whole blog post on this at sailingcinderella.com, but I might have yet to post it (finding the photos I took is quite a challenge and I have been doing Boat work instead of writing these days)
we are geared up for the Swiftsure Lightship Classic this weekend, gonna be a fun race on the old girl. My biggest challenge is starting in the right start. I seem to get dislexic and miss my start. Maybe I subconsciencely just like being the underdog...
-P
Step 1 - locate he masthead in the center of the vessel by tightening/loosening the cap shrouds with either a long tape hung from the masthead and measuring from the same point on either side of the boat, or by hanging a plumb bob on a calm day. (I had to do the latter because my e35 hand laid fiberglass isn't quite a mirror image.) Once centered, tighten the cap shrouds equally from then on.
Step 2 - with minimal backstay tension adjust forestry length to get correct mast rake. This should be determined from the spar builder/ rig designer. More rake typically leads to more weather helm, but you want some to give you good sail shape control. For my rig, rake is 1-2 degrees (approx 12" back from the gooseneck). You will need a plumb bob for this, but any weight in the end of a string will work, think weighted bucket.
step 3 - tension the lowers equally, sighting up the main track to make sure the mast stays in column (easier than is sounds)
step 4 -tension the other shrouds you may have to get correct mast pre-bend. Again, this figure comes from the rig designer, mine was 4". This is measured by tightening the lower shrouds evenly until the main halyard attached to the base of the mast shows the correct distance from the back of the mast. (A 4" gap for me)
step 5 - go sailing get the boat to about 20-25 degrees of heel and watch the mast. Is it staying in column? If not tighten the shroud that will keep enough tension to keep the mast in column (remember, what is done to one side must be done equally to the other)
thats it, once you have the mast staying in column you should've good. You should see a slight slackening of the leeward shrouds when pushing the boat, but not excessive.
I recently did this this on my rig after I pulled if for an inspection and it was surprisingly easier than I expected.The best part is, it really got me in tune with my rig/sail trim. When I'm out these days I have a lot of fun playing with backstay /checkstay tension to get optimal sail shape. I can really tell a difference, i was able to get to 7.7~8 kts on a beam reach in 12ish kts of breeze. She really digs a hole and it's a lot of fun watching my aft corner sit a few inches above the waterline and the bow wave breaking way up front. When you get these boats going and maximize their waterline they really move (for a non-planing hull)
i would also also recommend a book called "Sail Power" really taught me a lot while I was doing all this.
i wrote up a whole blog post on this at sailingcinderella.com, but I might have yet to post it (finding the photos I took is quite a challenge and I have been doing Boat work instead of writing these days)
we are geared up for the Swiftsure Lightship Classic this weekend, gonna be a fun race on the old girl. My biggest challenge is starting in the right start. I seem to get dislexic and miss my start. Maybe I subconsciencely just like being the underdog...
-P
Vang lore
Vang trivia -- I recall, with some foggy clarity, that most smaller boats in the late 60's and well into the 70's treated a vang as an extra. Some higher-end builders did put one on as standard equipment.
By the 80's, I recall parts vendors marketing attachment plates in various designs for the boom and mast, due to rising customer demand.
Anyone wanting to optimize sail shape would install a vang, if their boat did not have one. Discussions then focused on "how many parts" for the line and whether to lead it aft on the house top. And, whether to have the final part of the purchase double ended for ease of control from either side of the house top. That way someone already on the high side could adjust it without moving down and changing trim.
(While some would attribute all this foofaraw to "racing" it really was and always is about getting the last Nth of pointing ability and speed. Entering a race is just another way to spend some more-intensive time under sail!)
By the mid-80's, rod vangs were showing up, often augmented with hydraulics for quick rig adjustments to backstay and vang.
Aside: It is interesting to see technical advances move through the sailing food chain. We sold our prior '81 vintage boat in '93, and while it did have a soft vang and squeezer adjustable backstay, it used hank-on jibs and non-ST winches.
When we bought the Olson we found that, in a moment or two, we loved the rod vang and the hydraulic BS, and also the Harken furling that we immediately installed. Now, no one even questions these everyday sailing technologies.
Our '88 boat also came with all-ST winches, big ones. First reaction was: "why in Heck didn't we have those on the previous boat?!"
Hmmm. I was going somewhere with this.... Oh yeah, if you are keeping the E-27 for a while, do consider a rod vang. You will like it.
Regards,
Loren
Vang trivia -- I recall, with some foggy clarity, that most smaller boats in the late 60's and well into the 70's treated a vang as an extra. Some higher-end builders did put one on as standard equipment.
By the 80's, I recall parts vendors marketing attachment plates in various designs for the boom and mast, due to rising customer demand.
Anyone wanting to optimize sail shape would install a vang, if their boat did not have one. Discussions then focused on "how many parts" for the line and whether to lead it aft on the house top. And, whether to have the final part of the purchase double ended for ease of control from either side of the house top. That way someone already on the high side could adjust it without moving down and changing trim.
(While some would attribute all this foofaraw to "racing" it really was and always is about getting the last Nth of pointing ability and speed. Entering a race is just another way to spend some more-intensive time under sail!)
By the mid-80's, rod vangs were showing up, often augmented with hydraulics for quick rig adjustments to backstay and vang.
Aside: It is interesting to see technical advances move through the sailing food chain. We sold our prior '81 vintage boat in '93, and while it did have a soft vang and squeezer adjustable backstay, it used hank-on jibs and non-ST winches.
When we bought the Olson we found that, in a moment or two, we loved the rod vang and the hydraulic BS, and also the Harken furling that we immediately installed. Now, no one even questions these everyday sailing technologies.
Our '88 boat also came with all-ST winches, big ones. First reaction was: "why in Heck didn't we have those on the previous boat?!"
Hmmm. I was going somewhere with this.... Oh yeah, if you are keeping the E-27 for a while, do consider a rod vang. You will like it.
Regards,
Loren
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u079721
Contributing Partner
More Vang Points
It depends on the boat and the deck layout of course, but vangs often interfere with opening up main hatches. On my E38-200 I typically did not keep the vang rigged when I was cruising as I had to constantly remove it to be able to open the main hatch. You could of course reverse the main hatch so that it opened aft, which could then be opened even with the vang rigged. But then you wouldn't get a breeze in the cabin when anchored into the wind.
How does everyone else with a E38 handle the issue?
It depends on the boat and the deck layout of course, but vangs often interfere with opening up main hatches. On my E38-200 I typically did not keep the vang rigged when I was cruising as I had to constantly remove it to be able to open the main hatch. You could of course reverse the main hatch so that it opened aft, which could then be opened even with the vang rigged. But then you wouldn't get a breeze in the cabin when anchored into the wind.
How does everyone else with a E38 handle the issue?
Vang Talk
Vang interferes with Salon hatch.
As others have done, I reversed the salon hatch and installed a rigid vang on Discovery. When sitting in the slip I have interior fans to circulate air.
MJS
Vang interferes with Salon hatch.
As others have done, I reversed the salon hatch and installed a rigid vang on Discovery. When sitting in the slip I have interior fans to circulate air.
MJS
I reversed the hatch last time but not this time. I do have to close this one a little earlier going to windward if there's spray, as yesterday. But in heavy spray I found I had to close a reversed hatch anyhow.
On the 381 the factory Superhatch will open to the first "notch" with a soft vang. All in all, for me, it's a toss-up.
On the 381 the factory Superhatch will open to the first "notch" with a soft vang. All in all, for me, it's a toss-up.
woolamaloo
Member III
With the front facing hatch, I couldn't have any tension on the main sheet when the hatch is open. This would force me to put two lines on the boom to keep it from swinging back and forth through the cockpit. I'd tie one line to a stanchion base and the other to the traveler car. Adding the rigid vang (which I love), meant that I could only open the forward facing hatch about an inch - and I still couldn't tension the main sheet. Now that I've rotated my hatch, I can keep it wide open and I keep the low 30+ boom from sweeping through the cockpit by only tensioning the main sheet. Besides the 110V fans I have below while docked, I'm adding a couple 12V fans for anchored nights. I'm delighted with the eventual set of compromises. It's a definite improvement.