Fractional Rig Tuning

Robspan · Apr 2, 2009

That looks like a great procedure.
When I raced my old boat, which was a masthead rig, I would tension the backstay, which would of course also tighten up the forestay. I was told by some of the hotshot racers that it was good for the boat to loosen the backstay after racing, to reduce the compression loads on the rigging and mast support. On a masthead rig, it's easy to detension.
But on fractional rigs, wouldn't you have to go through the same procedure in reverse to detension? For those who store their boats mast up, that looks like a lot of extra time.
Also, have you noticed any effect of the tensioning on the mast base or the attachment points of the stays?

walt · Apr 2, 2009

Rig tensioning is something Ive been thinking about - dont have anything to offer but another question on forestay tension.

On a mast head rig, looks like the back stay will primarilly tighten the forestay. But on fractional rig, tigtening the backstay will both tighten forestay and also bend the mast which makes the leach up high twist off.

So it would seem that the tension on the forestay with the fractional rig (like on the 26C and probably a lot of other Macs) would be more critical to get set "perfectly" since both forestay tension and main sail twist are affected by the backstay (vs. only forestay tension with the mast head rigging).

Ive kept my forestay fairly loose up till now since it makes trailer set up easier and generally tighten the backstay if the wind picks up since both of the effects mentioned above seem good in higher winds. But I would guess Im loosing some upwind performance relying on the backstay to tighten the forestay since Im also getting the loose leach on the main - which you probably dont want if your trying to point.

Also, for anyone who leaves the boat in a slip all summer with a tight forestay, do you loosen the forestay (with for example a Jonson lever) when your not using the boat? My mast already has a little permanent bend, I dont need any more and the boat is built light weight.

oreana123 · Apr 2, 2009

This for a fractional rig, a masthead rig is different...

If you have a straight mast with the above procedure, then the extra tension is only going to make the mast straighter. The triangle formed by the forestay, and the 2 upper sidestays are the primary supports of this rig. If you set up the standing rigging with neutral backstay (just taking up the slack with no backwards bend), and then sail to weather you will find that the backstay is looser than it was, due to the press of the sails. You cannot tighten the forestay on a fractional by tightning the backstay without bending the top of the mast aft, which will flatten the mainsail and depower it. You can sail to weather without the backstay on the boat.

As you can see, since the mast bends easily aft at the level of the hounds, getting a tighter forestay on a fractional will only be accomplished by the adjustment of the primary rigging ie: the tension of the forestay/upper sidestay triangle. Really, once the forestay is cut to a specific length, the only way to oppose it (and increase tension) is to tighten the upper sidestays. I suppose it is possible to tighten the primary wires tight enough to compress the mast into an "s" shape below the hounds, but so far I have not been able to do that with the diameter wire that I have. A straight aluminum extrusion such as our masts is very resistant to compressional loads.

Capt. Kermie · Apr 2, 2009

oreana1234 said:
In the interest of better performance, I offer the following guidelines. I freely admit that the following info is written with best upwind performance in mind, longevity of standing rig is not foremost of importance.

Why do some boats point better than others? This is a question that can be sometimes be answered by sail condition or deck equipment.

A question might be asked: how tight can you possibly make your standing rigging tension? An answer might be: as tight as you dare, taking into account the condition of your standing rigging, the conditions you sail in, the design of your chainplates and stem fitting, and the design of the compression post to transfer stress to the hull. In the case of a Mac D model, the daggerboard well is the compression post, and I think that the rig would fail before I drove the mast through the deck.

Next we will be dropping the mast, but not all the way, so rig your jib halyard to the bow rail, and tie off the bitter end to whatever you generally use, (cleat, etc) leaving an extra 12 inches of looseness in the line so it is not tight. We will be removing the forestay and the jib halyard will allow the rig to pivot back, allowing adjustment of the upper sidestays.

At this point one should first set the mast rake! You can do this by hanging a weight on the end of the mainsail halyard and let it dangle a few inches off the deck. On the 26M it is desireable to have minumum rake so I use the forestay to bring the mast forward enough so that there is only about 4 inches between the main halyard and maybe the gooseneck area of the mast or perhaps a bit closer to the base. Simultaneously, I snug up the side stays just enough to keep the mast somewhat perpendicular to the deck. The main purpose is to set rake at this point. Once you have the mast rake where you want it depending on the model you set the forestay adjustment more permanently by inserting a hairpin cotterpin through those little holes in the forestay turnbuckle threads. This creates a more permanent and accurate mast rake setting that will always remain the same each time you drop and raise the mast because the cotterpins will prevent any loosening or further tightening of the forestay.
Here is where we can put some real tension on the forestay. Loosen the forestay tbuckle, remove the forestay, let the mast roll back until the abovementioned halyard is holding up the mast. You can just as easily use the mast raising kit to hold the mast in place while adjusting the side chainplates. Each time you make a side chainplate adjustment you can use the mast raiser to bring the mast back up, then connect the permanently set forestay to see how the multihole sidestay adjusters line up. Each time you need to adjust them you disconnect the forestay and use the mast raise winch to let the tension off the shrouds so that you can make further adjustments to the side chainplates. Eventually through multiple attempts you will get the shrouds even, holding the mast staright and holding the right amount of tension on the forestay. It is the shrouds that exact the proper tension on the forestay, not the forestay itself which was used to set rake with.
Now it is possible to easily adjust those multi-hole sidestay adjusters. Find new tighter positions on the upper sidestay adjusters. Push the mast back up, crank down the forward stay turnbuckle, and see if the rig is getting tighter. Redo this until the upper sidestays and the forestay are tight enough for you. Walk away from the boat in front and on the sides and behind and sight the mast for eveness and straightness. Remember, the tighter you make the forestay, the better your boat will point. I don't think so! When you have reached the point that you think is the tightest you dare make the rig, sight up the mainsail slot and see if you are pulling the mast to pert or starboard. Drop forestay and adjust sidestays accordingly to center the mast side to side.
You can now put some real tension on the forestay by using the sidestays to pull the mast back and put some bend in it while excerting more tension on the forestay without having to adjust the forestay turnbuckle which has already been cotterpinned in place, not to be played with any further.
Getting the mast set better provides better sail shape and cuts back weatherhelm while preventing the boat from rounding up so much.
The forestay should only be used to set and keep the rake, the sidestays are what I use to put tension on it with while at the same time the sidestays also adjust the mast more perpendicular abeam and create some bend. You can now follow some of Oreana's instructions

Now tighten up the lower sidestays. You will be sighting along the mainsail slot in the mast for eveness side to side. Tighten the two lower sidestays until you have the desired tension, and the mast slot is straight.

If your mast is centered side to side, and straight when sighting up the mast slot, and your standing rigging is nice and tight, it is time to go sailing.

Mast Rake. I am not going to go into mast rake. I'd rather have a tight standing rigging, than worry about the small amount of mast rake available by adjusting the foestay turn buckle.

This is a good time to check for safety on all of the standing rigging. With this technique of standing rigging tuning, you will probably have to loosen the forestay turnbuckle all the way to assemble the rig, and you will probably choose to tighten the same tbuckle all the way to put maximum tension on.
Once the forestay is set for mast rake one should not have to loosen and tighten it for every launch, leave it alone it has already been set.
Now see if you can point any higher...John S

Not to sound too contradictive oreana but this is what I have discovered over time that works quite well on my 26M which has a rotating mast and no backstay. Mast rake makes a big difference and no rig tuning discussion is complete without it. Just my humble opinion.

oreana123 · Apr 2, 2009

Robspan

As far as extra wear on the rig is concerned, I have to say that my sailboat is hardly sailed, so the actual time that my rig is standing is woefully short. I have seen no adverse wear on any of my rigging, but I would sacrifice all the wires and replace them weekly, if I could point higher. The entire rig can be de-tensioned by loosening the foreward stay tbuckle, if it were so desired for storage with the mast up.

oreana123 · Apr 2, 2009

Capt Kermie

Thanks for the imput, I hope spring comes soon to you. The reason I avoided the dreaded mast rake setting is for the reason that I am tuning the boat for the tightest forestay tension. I believe that the rake on any boat is pretty much set by the length of the forestay, once it is cut and swaged. It almost seems like you agree to that much, since the technique you describe ends up with a fixed forestay length.

I notice you take exception with my described relationship between forestay tension and pointing ability. Would you care to expand upon that idea? Were you somehow trying to state that a loose forestay will outpoint a tight forestay?

My 26D has weather helm, enough to be safe. Any rake adjustment on my sailboat to control weather helm is made needless because I have an Idasailor rudder assembly, as well as an Idasailor daggerboard, which easily opposes the rudder stall that creates a round up. My tuning technique here is to tighten the forestay, without even a nod to minor rake adjustment, to point better. It is not for convenience, for long life of the standing rigging, or ease of assembly.

And by the way, I always lift my mast to stand the rig. Why would anyone want to put a long block and tackle, and a gin pole on a wimpy little mast like I have on my D is beyond me. I would be embarrassed. So you can see that we are poles apart on sailing, I have a D sailboat and you have another model boat altogether I have the ability to just pick the mast up, you need a gin pole. I want top performance from my sailboat---you have a motorsailer.

Robspan · Apr 2, 2009

My experience is that headstay tension, along with halyard tension and vertical sheet angle on the clew, are very important for upwind performance. But one thing that the 26C doesn't have is a good sheeting angle. The stays are out so far that the genny can't be sheeted in nearly as close as on other boats, resulting in an open slot. Oreana, how do you do upwind against other types of boats? Do you race against any J-24's or San Juans?
Btw, a gin pole and block and tackle make it a lot easier and safer when only one person, even if it's Hercules, is raising the mast.

ghickman07 · Apr 2, 2009

I've got an old mac V25. I just bought it and it has barely been used. I've got a standing rigging and did exactly what is mentioned above a week or two ago. Ive almost got the right tension I want. The upper shrouds are still loose and have been considering replacing those standing shrouds with some sweet turnbuckles.

High tension in strong winds is extremely important when racing. However, there is no point in breaking the rigging on your boat. Unfortunately the minute I put up my mast for the first time the mast post in the cabin fell through the floor (it did not punch through th keel). This retarded boat doesn't have the column sitting on the centerboard well like so many others do...

It seems pointless to take a chance with a Macgregor when racing... It's not a racing boat especially if you're a motor sailor. If you want to do this kind of tuning, buy a sweet J-30.

One cool thing about my mac 25 is the weight. If you have a mac 25 you are likely to do well with your handicap simply because of the relative weight difference between the other boats in your class. I have no idea how the 26's do, but the 26X (that is the motor sailing one right?) is not a true sailboat in my opinion.

I don't intend to go too tight... It's not worth it. I didn't buy a racer; I bought a mac. I can't complain about the price though

.

Capt. Kermie · Apr 2, 2009

oreana123 said:
Capt Kermie

Thanks for the imput, I hope spring comes soon to you. The reason I avoided the dreaded mast rake setting is for the reason that I am tuning the boat for the tightest forestay tension. I believe that the rake on any boat is pretty much set by the length of the forestay, once it is cut and swaged. It almost seems like you agree to that much, since the technique you describe ends up with a fixed forestay length.
Yes, I agree to a point about the fixed length but keep in mind the forestay turnbuckle can adjust the forestay length by about 2 inches when you unthread it in or out, how else do you tighten it

I notice you take exception with my described relationship between forestay tension and pointing ability. Would you care to expand upon that idea? Were you somehow trying to state that a loose forestay will outpoint a tight forestay?
No, that is not what I imply at all. Mine is incredibly tight, so tight that I have to really crank the winch on the mast raising gin pole to pull the mast forward enough to pin the forestay and it takes two of us (4 hands) to get it pinned now that I have a snapfurler on it. It was not so difficult with the hank-ons but now with the furler it is more difficult and I have the turnbuckle cotter pinned so that the furler does not cause the turnbuckle to unthread when it spins.
It is the the tightness of the triangle I achieve that you described earlier that gives me improved pointing by reducing weather helm, since I do not round up so readily I can point higher, or so I believe.
My 26D has weather helm, enough to be safe. Any rake adjustment on my sailboat to control weather helm is made needless because I have an Idasailor rudder assembly, as well as an Idasailor daggerboard, which easily opposes the rudder stall that creates a round up. My tuning technique here is to tighten the forestay, without even a nod to minor rake adjustment, to point better. It is not for convenience, for long life of the standing rigging, or ease of assembly.
Perhaps you should experiment with some mast rake before you assume it would be needless, every little bit of adjustment adds to efficiency and may make the difference of an extra .25 or 1/4 knots, not a lot but a few of them together would add up.
And by the way, I always lift my mast to stand the rig. Why would anyone want to put a long block and tackle, and a gin pole on a wimpy little mast like I have on my D is beyond me. I would be embarrassed. So you can see that we are poles apart on sailing, I have a D sailboat and you have another model boat altogether (a 26M) I have the ability to just pick the mast up, you need a gin pole. I want top performance from my sailboat---you have a motorsailer.

You want top performance??? Perhaps a little mechanical advantage in the way of a gin pole may get your boat tuned just a tiny bit better and get you that extra bit of performance. The 26X mast raise system may work on a 26D model since it incorporates the use of your jib/genoa winches for raising the mast, all you need is some way of holding one end of the gin pole stationary at the mast base, and then use your jib halyard connected to the top side of the extended end of the gin pole and the block & tackle on the underside and then connected to a bow cleat. You then run the line from the blocks back to your winch and crank from there. You may surprise yourself once you get the mast just right. Trying to do it like hercules is just too awkward even if it is just a whimpy mast, you can get more accuracy with a mechanical advantage. If the mast is as whimpy as you say then it must be more suseptible to mast bend which would also add to your rig tuning. You need to find a mechanical method for cranking that mast good and hard if you want some rake in it, no way you can do that as hercules.

Capt. Kermie · Apr 2, 2009

ghickman07 said:
I've got an old mac V25. I just bought it and it has barely been used. I've got a standing rigging and did exactly what is mentioned above a week or two ago. Ive almost got the right tension I want. The upper shrouds are still loose and have been considering replacing those standing shrouds with some sweet turnbuckles.
Upper shrouds should be tight, tight enough to hold the forestay tight and produce mast bend, the lower shrouds hold the mast in place.
High tension in strong winds is extremely important when racing. Agreed!However, there is no point in breaking the rigging on your boat. Unfortunately the minute I put up my mast for the first time the mast post in the cabin fell through the floor (it did not punch through th keel). This retarded boat doesn't have the column sitting on the centerboard well like so many others do... Sorry to hear that!

It seems pointless to take a chance with a Macgregor when racing... It's not a racing boat especially if you're a motor sailor. If you want to do this kind of tuning, buy a sweet J-30.
Pointless??? How so? Think of them as a one class boat. We must have hundreds of them in the PNW, there are at least 30-40 Macgregors in the MYCBC club of the PNW and we hold an annual Regatta. For what it's worth the classics (26d & 26C) out perform the powersailers every race but the 26x & 26M boats give each other good competition and the races are fun. We have a big pot luck dinner afterwards!
One cool thing about my mac 25 is the weight. If you have a mac 25 you are likely to do well with your handicap simply because of the relative weight difference between the other boats in your class. I have no idea how the 26's do, but the 26X (that is the motor sailing one right?) is not a true sailboat in my opinion.

I don't intend to go too tight... It's not worth it. I didn't buy a racer; I bought a mac. I can't complain about the price though .

The 26X you say is not a true sailboat is in fact a sloop sailboat as is the 26M, both of which can sport a 50HP engine on the back, the 50Hp does not disqualify them as a sailboat, they are still a sloop styled sailboat, they just happen to be capable of higher HP outboard engine.

Capt. Kermie · Apr 2, 2009

Loos Guage

I forgot to ask previously, but does anyone use a Loos guage to tune the rigging with? I have one and I use it to get the shrouds tightened within specs so that they are neither too loose nor too tight. I don't worry too much about the tension on the forestay because every time I measure it, it is far more tensioned than the shrouds, goes to show just how tight my forestay is. The rigging should be tight, not so tight as to play music on the shrouds but damn tight. Also it is not just about tight rigging but also about mast rake and mast bend for optimum performance. The Macs are slow enough as it is, no sense making them worse with less than optimum tuning.

Blake · Apr 3, 2009

Apples and oranges

Capt. Kermie is talking about raising the mast with a roller furling jib attached. From his earlier posts, I believe Oreana uses a variety of hanked on head sails. This makes a big difference in the overall weight and general awkwardness of the procedure. Call me a sissy, but I will keep using my mast raising system, especially when lowering the mast to clear the bridge at Bridge Bay Marina!
Thanks for the great post guys. Rig tuning is some thing that I need to learn more about. I had hoped to be spending to day pulling the tarp off the boat and tuning the rig. Instead she sits under her tarp and 2" of new snow, with more falling and more predicted through Sat.:cussing: Spring

. Whoopee:dance:!

Jansen · Apr 3, 2009

Blake said:
Capt. Kermie is talking about raising the mast with a roller furling jib attached. From his earlier posts, I believe Oreana uses a variety of hanked on head sails. This makes a big difference in the overall weight and general awkwardness of the procedure. Call me a sissy, but I will keep using my mast raising system, especially when lowering the mast to clear the bridge at Bridge Bay Marina!
Thanks for the great post guys. Rig tuning is some thing that I need to learn more about. I had hoped to be spending to day pulling the tarp off the boat and tuning the rig. Instead she sits under her tarp and 2" of new snow, with more falling and more predicted through Sat.:cussing: Spring. Whoopee:dance:!

When you lower the mast for the bridge do you unhook the boom? What is your lowering procedure if you don't mind sharing?
Marvin

Blake · Apr 4, 2009

mast lowering

Yes Marvin, we do have to disconnect the the boom at the gooseneck, or else it will hit the cockpit and prevent further lowering of the mast. But now you've got me wondering if it would be possible to swing the boom off to either side while lowering the mast without disconnecting it. Our procedure has been to disconnect the boom and then lower the mast using the standard Mac mast raising system. We leave the gin pole, baby stays, blocks, etc., connected at all times, even when there are no bridges to duck. We lower it just far enough to clear the bridge and then raise it on the other side. I routinely raise and lower the mast single handed, but have only attempted ducking the bridge with the assistance of my charming wife Bridgett. Like Captain Aubrey, I am trying to come up with some clever word play concerning bridge and Bridgett(also known as Bridge for short), but like Aubrey so often does, I am drawing a blank. At any rate, I consider this a two person job, one to deal with the mast and one to steer.

beamreach · Apr 5, 2009

Re: mast lowering

Blake: We don't have any bridges to deal with down here, but what if you just raised the end of your boom with a topping lift, tied it off on a mast mounted cleat and lowered your mast enough to clear. Just a thought.

oreana123 · Apr 5, 2009

I started out discussing how to put the mast up, now we're talking mast down!

For what it is worth, I have a long mast crutch mounted on top of my rudder head. It allows me to lower the mast for a bridge, then easily reset mt rigging. This is the way I normally carry my mast. The best part is it allows me to put the pop top up, when the mast is secured this way.

I anticipate having to lower my mast this June when I start off on the Snake River at Hell's Point Park. There is a bridge between Lewiston and Clarkston, Idaho, that I'll have to get under, and then raise my mast.

Blake · Apr 5, 2009

Beamreach, I am pretty sure that we tried that. The gooseneck will only allow the boom to be pulled up so far, and that wasn't far enough.
This has been an interesting thread Oreana, even if it has strayed a little from the original topic. I hope to hear more about your Snake River cruise. I have always wondered what it is like to sail a river. Are you going point to point, or returning to Hell's Point Park?
In April, Bridgett and I will cruise for 7 days on Lake Powell. I hope to get some pictures posted when we are through.