A 4-masted barque, Part 2 - RC Groups
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Oct 24, 2007, 06:39 PM
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A 4-masted barque, Part 2


I am starting a new barque thread. After passing 100 posts in the first part, it is hard for me to go back and find particular postings. Part 1 covered building and debugging her. Part 2 will deal with, hopefully, interesting features of sailing her.
Part 1 here:
https://www.rcgroups.com/forums/showthread.php?t=743611
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Tea clippers were made for speed. They had hollow bows, and cut away sterns, thus fairing the lines and letting the water pass with less turbulence. If you look at a drawing of the lines of a tea clipper, it can be hard to tell the bow from the stern as each end practically mirrors the other. Sailing such a racehorse was an art, and Basil Lubbock described some elements of the art in his book, which I extract below:
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The handling of a Tea Clipper, extract from “The China Clippers” by Basil Lubbock (1950 reprint) pg 102-103.

<First, the danger of bearing away in a squall>
"The handling of a tea clipper was a ticklish business, and the captain who went into the tea races after being used to slower and less sensitive craft often found himself all at sea and made a bad mess of it at first.

A case in point was the dismasting of the Titania. In clipper ships it was bad practice to put your helm up <turn downwind > in a squall , though that Board of Trade only recognised that maneuver when one was passing the examiners.

Experienced tea-ship captains invariably gave strict orders to an officer, who had just come out of a non-clipper, never to keep away in a squall, but to luff and shake the squall out of her, though the officer had, of course, to be careful not to get his ship aback, and there was also the danger of splitting sails.

The danger of putting the helm up in a sensitive and heavily-sparred clipper was this. As the wind freed the ship gathered more way, and, her yards being more fore and aft owing to her long lower masts than those of other ships, the sails got the full weight of the squall abeam. If the ship was the least bit tender, or it was an extra heavy puff, she would per her rail under so far that the helm lost its power over her. Then, probably, the halyards would be let fly, but owing to the angle at which the ship was heeled, the yards would not come down, which meant that something had to go.

In Titania’s case, she encountered a fierce squall just north of the Cape Verds. Her captain, Bobby Deas, who had come from a wagon called the Reigate, ordered the helm to be put up. Even so, if he had been in time to get the ship off the wind before the weight of the squall struck her, all would have been well; but he was too late. The squall caught her her square on the beam. She went right over until her fairleads were in the water. The topsail yards stuck at the mast heads, and away went the foremast, jibboom, main topmast, and mizzen topgallant mast."

<Next, the danger of tacking in heavy seas>
"The Titania, Ariel, and Sir Lancelot were ships that required very careful handling and wanted knowing, but once a captain go the hang of them they would do anything for him but speak.

These three ships were very fine aft, with a counter like a yacht, which had a nasty habit in bad weather of dishing up the seas. This fineness aft also cause them to be troublesome boats to put about <put about - another term for tack> in a rough sea, as they fetched sternway so quickly, and of course, then took heavy water aboard aft. Thus it was customary to wear them around when there as a nasty sea running."

<Finally, sailing backwards by intention>
"No greater proof of the way these Steele <Robert Steele & Company, a clipper designer & builder in Greenock, Scotland, near Glasgow> clippers were cut away aft can be given than the story of how Captain England backed the Titania up the Shanghai River. In turning up the river he found that she stirred the mud up every time she came about and was very slow on stays <stays/staying – old terms for tacking>. So on one board, instead of staying, he threw everything aback, brought her stern up to the wind, and sailed her across backwards; and this he continued, making one tack bow first and the other stern first."
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The barque model is no tea clipper, but I have experienced these situations on the pond.

Bearing away in a squall is very hard to do w/o letting the main and mizzen square sails get taken aback (their yards must be squared up a bit to let the bow fall off). Thus, I usually luff if I can. Once the rail goes down, though, the barque’s rudder becomes useless, just like described above.

When tacking the barque in heavy air, she soon develops a stern board (sternway), even with a much more blunt stern than a tea clipper,. My counter is not cut away, though, so I don’t ship seas.

Sailing backwards is easy to do in the barque, particularly when you don’t want to :-). Square riggers can go backwards almost as well as forwards, once the sails are all aback. If all 3 square masts are aback, the barque’s stern will seek the wind. But if they are all aback with M&M braced one way and the fore braced the other (say after a missed tack), the ship will run, backwards, for a long distance. She will ignore the rudder. In fact, I’m not sure how far you can go, as she seems pretty stable in reverse. I’ve seen John sail backwards 20 feet if he misses a tack (and done the same myself).

Part of the enjoyment in sailing a square-rigged model is connecting with the past. The barque allows me to partipate in a sort of rediscovery of historical seamanship.
Last edited by Brooks; Oct 24, 2007 at 06:57 PM.
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Oct 25, 2007, 06:38 PM
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Looped jib sheets


In a post in the part 1, I mentioned how my new cloth outer jib would not cross it's clew to the new leeward side after a tack. While putting the boat away, I discovered that the rescue bow line had wrapped around the jib sheets, forcing them to stay tight.

Today I made sure the sheets were free to run when the foresails were squared. This seemed to do the trick, as both outer and inner jibs would cross their clews. When the servo controlling the foresails is braced to the new tack, it loosens the jibsheets briefly. The slack provided apparently helps the 2 cloth jibs cross their clews over their neighbor's luff.

The Foretopmast Staysail (FTMS) sheet is a single line, leading from the clew thru a brass screw eye back to the servo.

The sheets for jibs forward of the FTMS have double sheets, a loop really. Their clews are free to ride on the loop. The loop is formed by knotting the line together aft of the screw eye.

All sheets are knotted to the same single line, which then goes to the servo. It took some fiddling to get the loops the right size; they have to be big enough to not foul their inner neighbor when the sheets are slacked for a reach.

The advantage of looped sheets is that they maximize the throw from the servo; one inch of servo arm travel yields one inch of jib sheet movement. They also allow overlapping jibs to assume the correct configuration after a tack, with all clews on the leeward side.

The disadvantage of looped sheets is that they don't give the jib as nice a shape as traditional double sheets, which constrain the clew. Since the clew on the loop can ride, it tends to bag the sail whenever the sheet is slacked off.
Last edited by Brooks; Oct 25, 2007 at 06:44 PM.
Oct 26, 2007, 07:03 PM
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hey
i enjoyed your posts some much i start building my own windjammer from the swcp
web site on square riggers,what is the one thing i should look into to make it a good sailer
thanks craig
Oct 26, 2007, 09:48 PM
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I am glad you are going to build a square-rigger, they are very beautiful and loads of fun. I can't think of any one thing that was of over-riding importance, though. The barque's development went through a series of incremental improvements, thus the 100+ posts :-). As time went on, I also wanted more and more from the craft - If I'd stopped at the free-sailer stage, per Boyle's design, the barque pretty much would have been complete at that point, in the sense that it sailed a self-correcting line on a beat in light-moderate winds. Most of the development revolved around making the ship maneuverable with RC.

I think a key source of information was Harland's book "Seamanship in the Age of Sail." Without it, I would not have known how to perform square-rigger maneuvers.

Maybe a key concept is that of adjusting the sails and keel location to get the CE and CLR to line up. They will both vary dramatically with a square-rigger, much more so than a fore&aft rig. Balance is going to be different for every sail configuration and every speed&heel angle. The beauty of RC is that it made it possible for me to adjust CE on the fly (thru differential bracing), and to use the rudder to help balance the CLR to the CE. Again, Harland's book helped me to understand these elements.

I forgot to say your scow looks nice :-)
Last edited by Brooks; Oct 26, 2007 at 10:05 PM.
Oct 27, 2007, 02:55 AM
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Key concepts from Boyle:

1. Do what you can to get more yard swing than traditional ships achieved. To work to windward, you need to be able to brace the yards more sharply than real ships:
a) discard shrouds since they limit yard swing.
b) place backstays so that the yards can swing 60 degrees off square.
c) suspend the yards in front of the mast (using screw eyes), rather than with traditional parrels.

2. Replace the traditional 3 section masts with a single pole mast. I made a 2 section mast since that was close to Boyle's recommendation, and also since that was how the Pamir was really rigged.
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I deviated from Boyle in using a deep fin keel. I accepted the departure from real ship design because it allowed me to use less Pb ballast (longer lever arm for righting). Also, by using a deep fin I could get a more efficient keel that would work to windward better. There is a lot of leeway with a square rig model since there is a lot more windage drag than in a fore&aft rig. I started with 2 keels, each 12" deep, one 7" wide and the other 14" wide. I was not sure which would work best. The results were that in strong winds, I needed the 14" width, while light winds were ok with the 7". The more surface area of the keel, the more water drag, so a small keel seemed important when winds were light. The more wind, the more windage, so the larger keel was required for the strong winds (if I wanted to beat to windward).

The new keel is 12" by 10" wide. It's probably a little small for heavy winds and a little big for light winds :-). I may ask John to make me a nice airfoil keel in the 14" size.

Because I was not sure where the CLR should be, I designed the ship so that I could (relatively) easily bolt the keel to a new position. I think that ability is important for any new model; you simply won't know for sure where the CE will be until you sail her. And since the CE changes, and the CLR too, experimentation in keel location will be necessary.

Most of your sailing time will be spent on a beat (if you want to stand in one place on shore and have your boat return to you). For example, a square rigger can only make good 1 or 2 points to windward (barque makes 1 point). Thus, on a 100 yard leg, you will only make 20-40 yards gain to windward. My pond is about 100x150 yd. To get to the far end, I'll need 7 legs if I can tack, more legs if I have to wear. The boat travels about 0.25 yard/sec on a beat and 0.5 yd/sec on a reach. So 700 yards beating will take about 45 minutes. The return reach will take 5 minutes. Needless to say, I set up my barque to do well on a beat :-). In actual practice, the wind here is not usually constant in speed or direction. By judicious tacking, I can sometimes make it to the end of the pond in 30 minutes. But I am always amazed at how quickly the barque sails back to the starting point on a reach....all that work gone in an instant *grin*. Square riggers are not made to perform to windward - Bligh finally gave up trying to sail E to W around the Horn, after 2 months of beating. He turned tail and rode the Westerlies to Australia and Tahiti and eventual mutiny.

If the wind is light and flukey, I may never make it to the end of the pond - as I've reported earlier, if the ship is offshore in a calm, it is hard for me to tell whether I've been headed, and thus need to tack before I lose ground. So, I have learned My patience level requires a minimum wind speed (or to always have the rescue tug available *grin*). Real ships suffered the same in light flukey airs. Many record setting runs were spoiled by light baffling winds a 100 miles from the destination. Clipper captains, by their log book entries, lived a stressful life.
Last edited by Brooks; Oct 27, 2007 at 03:33 AM.
Oct 27, 2007, 03:56 AM
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Sailors understood the value of bracing the yards more sharply to enable better progress to windward. Real ships could get their yards braced more sharply by manipulating the rigging: slacken parrels, pull in the leeward shrouds, cock the yard (windward arm down). Using RC to achieve the same would be complicated. Boyle's method allows sharp bracing w/o complication - let your desire for reality vs. ease be your guide :-).
Oct 27, 2007, 03:20 PM
Registered User
here are some pic of the boat .
I planned on going rc and one piece mast, limit rigging etc.
the only thing i handnt looked at was a deep keel ,i sail on a salt water
canal that isnt as wide as your pond so tacking is a must.
If i have to i will do the brooks tack as your mov shows
cant wait to try the boat out,its 38"x10" the other boat is my first scale
scratch scow (45x15) that sails like a barge, slow but its still fun.
Oct 27, 2007, 04:58 PM
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Craig you are a fast builder, your ship looks nice. I'm not sure if you wanted suggestions, but here are a couple. If this is all old hat to you, my apologies:

a. You will need to fasten the lower corners of each sail to the yard below it. These lines are the "sheets", and on my craft they are made of polyester carpet thead. I drilled a hole in each yard, similar to the ones you have already made, and tie the sheet to the yard via the hole. For the lowest sail, I added a yard near deck level. The sheets prevent the sail from streaming in the wind and flapping like a horizontal flag.

b. Your braces, to control yard swing, will have a better mechanical advantage if they don't lead to a tie-off on the centerline of the ship. On a real ship, the course braces were led to the rail on each side of the ship; higher yard braces were led to the centerline, however. My barque's RC'ed course braces lead to the servo arm, which is extends 1" past either side of the centerline. On my free-sailing brigantine, the non-RC'ed course braces lead to the rail, just like a real ship; I adjust them by hand when the craft comes ashore. My barque's upper topsail braces lead from the servo arm to a pair of screweyes on deck, then to a pair of beads aloft (used as turning blocks), then forward to the upper topsail yard. The beads are tied to the mast behind, at about the same height as the uppertopsail yards. Their tie line extends through the gap in the sails about 1-2 inches in front of that mast.

c. The line you have strung between all the yards is similar to "Lifts" on a real ship. It will help control over-swing of the yards to some extent (that function is assummed by the sheets on my craft). Your lifts will hamper the removal of yards and their sails when the wind picks up, though. On my barque, I untie the sheets and can then lift off the yard. You'll have to untie your sheets and also unreave your lift, which can be done, just adds a step.

d. For your fin keel, I'd suggest one about a foot deep and with a width a little less than the distance between your foremast and mizzenmast. I think my ship sails better with the 14" wide keel, than with the 7" one. For the weight on the bottom, try the minimum amount that will right your craft if it is laid over in the water. Any less, and the craft will not be self-righting, a fatal flaw unless you have a rescue boat, and an irritant at any time. Once sails touch the water in a knock-down, surface tension will try to hold them there. More weight can be added to stiffen the ship in a strong breeze, if you have enough buoyancy to support the extra weight. The stiffer the ship, the more strain on the rigging, however; the ship can't heel as easily to shed wind stress, which must then be absorbed by the rigging.

e. Your rudder will need to be bigger than scale size, as Hoghappy and others have stated.

f. Jibs set on a bowsprit, triangular staysails set between the masts, and a spanker set on the mizzen mast are useful sails to balance the rig. You'll likely find yourself experimenting with various configurations to achieve the balance you desire.

g. For your first few cruises, don't plan on being able to sail to windward. That is, have a plan to retrieve your ship if it ends up stuck on the lee shore (like the other side of the canal *smiles*). Making good to windward requires skill with the rudder, practice tacking, and correct balance of CLR and CE. As a sailor already with your scow, you will have an advantage over a beginner :-).
Last edited by Brooks; Oct 27, 2007 at 05:17 PM.
Oct 28, 2007, 11:25 AM
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Scale speed


I've commented here before that the Syren, my 1/25th scale brig from SC&H, really "flies" in even a moderate breeze. Per Brooks idea, I mounted a GPS unit and sailed yesterday. Winds were variable in speed and direction, but at times consistent W and NW.
I won't post a clip of the GPS track because it's hilarious - even the backing shows!
But I did get good speed data. Max speed was 2.8mph, avg moving speed 1.0mph, and avg overall speed 0.9mph. Overall distance was 1.77 miles.
Brooks reports a spedd of 0.25 to 0.5 yds/sec (about 0.5 to 1mph). The brig GPS indicated speed works out to a 1/25th scale 70MPH! No wonder it looks so fast and can be heard slicing thru the water. Even the avg speed (25 smph) is double (???) the max prototype speed.
Anyway, twas a very good day of sailing. Need to get out and sail more. Yesterday, between maneuvering the kayak and taking pics, the sailing really suffered. Pics will be on the brig thread later today.
Brooks - how long and how heavy is the Pamir? What scale?
Oct 28, 2007, 03:14 PM
Registered User
Getting info on rc square rigs is hard to find so i take what i can get i put the boat together i 3 days but its a ply bulkhead with planks from an old pine redwood?/?/?.
etc. not sure what wood it is,ripped on my table saw nailed then epoxy in and out no
cloth on the deck or sides. the bottom got bonddo and 6oz cloth.
the line on the sails just are holding things in place, i will get rid of them later,i got the lines on the fore sails sewn on. the sails are taking longer to do than the boat.
i mocked up the keel in the line drawing this gives that 6-7" keel you said above,the wieght of the boyle boat was 18lb, 6lb ballast, my boat is 9lb right now plus its 2" longer, i can get 6lb of beebees in a full 3" fasle keel which follows the lines but will it work. i might have to try just for fun.
I was resewing the main and moving the mast on the scow today to windy to sail.
are there any square rig boats being sold other than toys or $600 kits?
i got a nirvavana and then the scow just to see if i could sail and scratch build.
my first sail boat was a 16' boat from free plans that was fun but sailing a real boat is
hard work rc is lots more fun.
i can build but the math ce.clr.etc bluried eyed reading!!!
thanks craig
Oct 28, 2007, 03:29 PM
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Barque model dimensions: hull LxWxD 36 x 5 1/2 x 4 1/2 inches ; Depth given w/o islands, for total depth w/islands add 3/4". Length overall with bowsprit 42"

Weight with new fin keel: 15 lbs.
new fin keel alone: 6 1/4 lbs, of which 4.4 lbs. is the ballast pipe.

Built via Bread and butter layers, bottom to top: 3/8" plywood, 2 1/8" pink foam, 3/4" white pine, 1 1/4" fir, plus islands of 3/4" white pine. To reduce weight, 3 holds were jigsaw cut out of the fir layer. The piece of fir I had was fairly heavy. Draft of hull while sailing is about 2-2 1/2 ", plus another 14" for the keel.

Scale approximately 1:100. Yes, scale speeds would be very slow (and boring *grin*).
Oct 28, 2007, 03:45 PM
Registered User
total darft should be around 9-10" with a fasle keel.
the boats bigger cause i copyed from pic on comp. it didnt want to blow up to the right dem.
the hull set down in the water if i can find the right ballast
Oct 28, 2007, 03:57 PM
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Craig - The Center of Effort (CE) and Center of Lateral Resistance (CLR) can be computed, but I don't bother. Initially, I just bolted the keel on at the center of the hull, then adjusted it fore & aft to get the ship to balance right wrt the wind. I like a little weather helm while beating, so that's one reason I moved the small keel forwards from the center spot. (The big keel needed no forward movement). Make your keel easy to move, and then set it wherever the ship tells you to, no eyestrain needed :-).

The CE of a square-rigger is totally adjustable: set no sails on the fore, and the ship will point into the wind; the CE of this sail configuration moves way aft of the CLR, so the ship weathervanes. Set no sails on the mizzen, and she will point downwind; the CE is now forward of the CLR, so naturally she moves accordingly. So, I set the sails I want to see, and then move the keel to give me the balance I desire. Interestingly, when I measured the CLR at the 1/4 chord point (same as for a wing) for both the 7" and the 14" long keels, once I was happy with the way each sailed, and penciled their locations onto the hull, they both came out within 1/2 inch of each other. This tells me that the sails I like to see (which are based on the historic sail configurations used) yield a CE that is pretty invariant, whether I set sails for light airs or set sails for heavy winds.

My ship sails more realistically, I think, with the 14" wide keel. The course is steadier, with less scallopy motion. But it's an aesthetic thing. I also think the ship works to windward better in a strong wind with the wider keel. The ship is a little less maneuverable with the 14" keel (but seems perfectly happy to tack and wear with the new 10" keel). Make a couple different sized keels and see which one you like best. As you said, there is little info on square-rig models, so you are probably going to be doing some experimenting. My ballast pipe is just tied on to the keel plate with heavy string, so is easy to move to another keel. Not the most streamlined attachment method, but it's convenient.

My ship rides high with the ballast pipe weight I am using - she is at about the draft of the real Pamir sailing in ballast, w/o a cargo. I like the high ride because it keeps the decks and their exposed servos dry. The loaded 4-masted barques would ship lots of water on deck in the passage from Australia to the Horn. Their 3 island design was chosen specifically to reduce slosh of shipped water, and thus reduce the chance of losing crewmen overboard. Generally, steel-hulled ships were loaded deeper than wooden hulled ones. When Irving Johnson showed his film of a trip on a 4-masted steel hull barque, the sea captains in the audience came up afterwards and said they'd never seen a deck swept so deeply; they told him a wooden hulled vessel would have never survived the passage. One can read numerous accounts of wooden-hulled clippers whose decks were swept in storms and hurricanes, but they were notable events, not every watch occurrences like on the steel-hulled barques.
Last edited by Brooks; Oct 28, 2007 at 04:16 PM.
Oct 28, 2007, 05:44 PM
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Courses and shrouds


Thoughts on Setting a Course with Shrouds.

Boyle leaves off shrouds. They interfere with the swing of the yards, reducing the allowable bracing angle. That in turn reduces the ability of the square-rigged model to work to windward. This problem was also present on real ships, but they could manipulate their rigging to reduce it. Manipulating RC rigging in a like manner would be complicated.

The problem is most severe with the courses since the shrouds of the lower mast run to the edge of the hull (unlike upper mast shrouds, which run only to the edge of the tops). In a real ship, the shrouds would interfere with the course, except that the foot of the course is not bent to a yard. On the contrary, the foot of a real ship's course is free to assume an arc shape. This arc allows the foot of the sail to avoid contact with the shrouds even if the course's yard is braced sharply for a beat (actually, the course can rub on the leading shroud, but it's not a big problem for a real ship).

The problem for modelers is that a realistic, free-footed course requires 4 lines to handle the tacks&clews. RCing those 4 lines can be done, but it's complicated. To simplify the handling of the model's course, Boyle uses a Bentinck yard, a small diameter yard that spans the foot of the course. The tacks and clews are thus constrained, and can be handled much more simply; they can be left to their own devices, actually...swing the main course yard, and the main course Bentinck yard will follow.

The Bentinck yard would be practically frozen in the square position with the lower mast shrouds in their normal position. Boyle's solution is to discard the shrouds, and move the backstays (which would also restrict the Bentinck yard) inwards, closer to the centerline of the vessel.

I have given some thought to how one might modify the Bentinck yard so as to retain it's advantage of simple RC course handling, yet still rig the model with shrouds. It appears that if the straight yard were replaced by one with a broad "M" shape, we might get the best of both worlds. The yard's M shape would be designed to provide clearance at the shroud/yard intersection. To keep the M from drooping, it would be necessary to run support lines from the "peaks" of the M up to the main yard, but this seems feasible. This proposed method would probably not work with Tyvek sails as they might be too stiff to assume the necessary arc in the foot of the course. As you can see from the photo, the arc assumed by the sail is pretty big.

Some elements of the design:

1. Moving the pivot point of the Bentinck yard forward, away from the mast, reduces the size of the M needed. In fact, if you moved the pivot point forward to 1.7x the 1/2 beam, the Bentinck yard could remain straight. However, the farther you move the Bentinck's pivot point away from the above yard's pivot point, the more distortion you induce in the sail shape.

2. Moving shrouds aft of their scale position would also help. Move them far enough aft, and they turn into Boyle's backstays :-).

3. Movement of each item will be constrained by the surrounding masts and their rigging.

4. The shorter the depth of the course, the less arc needed. The Pamir photo shows that the foot of the fore course actually flies quite a ways above deck. Cutting the course foot in an arc upwards when constructing it would also yield more clearance from the shroud (since the foot would intersect the shrouds farther up from the deck, where they start to narrow inwards on their way to the top).

6. I don't know if the model's sail could absorb the large arc needed. Clearly, real sails can.
Oct 28, 2007, 06:51 PM
Registered User
the wind dropped to 10 so out to try thescow after i moved the mast and cut down
the main from the scale drawing wow she sails good now,i guess i had to use the
rudder to much and it slowed and caused more healing you know when you get it right.
if you had the lower sails with a controls put around the shrouds and inside like the jib
you might be able to have the shrouds like a real ship but this doesnt help with the yard swing. esay ,forget outer placed shrouds or just have fake ones that the yards
could moved when tacked


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