HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Jun 28, 2009, 10:36 AM
Damp and Dizzy member
Brooks's Avatar
Bozeman, Montana, United States
Joined Aug 2003
3,381 Posts
Discussion
Topsail Schooner Bottle Boat

Topsail schooner based on Pride of Baltimore's sailplan. Plenty of wind while I was building, but naturally it died when it came time to test the vessel. So, we will have to see whether she will sail on another day. In the extremely light zephers, I managed one wear, but no tacks, nor progress to windward. This behaviour is typical of my other square-rigged vessels; they like and require wind to maneuver.

My thanks to Andy Trewin for devising an easy bottle boat design. I used an OceanSpray juice bottle (2 qt.) and a Skippy peanut butter plastic jar, (15 oz size). I used Marine Goop to attach fittings to the bottle. Sails are made of Tyvek. Masts and bowsprit are 5/32" dowel, yards and booms and gafts are 1/8" dowel.

My jar is not watertight, sacrificing a neat feature of Andy's design, unfortunately; I had to trim the bottom to get it to sit low enough in the hull to allow a decent-sized foresail. The rx is velcroed halfway up the side of the jar, so is protected somewhat from water sloshing in the hull. The OceanSpray bottle has corragated sides, so it's impossible to completely seal the jar to the hull with tape. I expect some water accumulation from boarding waves. If it proves a problem, I may add a new bottom to the Skippy jar.

The keel and rudder follow Andy's design, deep thin sections: keel 12", rudder 6" deep. Mine are made from lath, planed to an airfoil shape. The keel hangs from a aluminum L-section glued to the hull. The weight on the end is a small pill bottle filled with lead shot.

I am not sure this style of keel will prove sufficient for the schooner:
a) The ship rides high, only weighing about 1#, ie 1/4th of the hull's potential displacement. There is a lot of hull exposed to the wind, so windage losses may be severe, relative to the scale sail area. My brigantine is about the same size, with scale sails and a wood hull, and sails fine, so I am confident small square-riggers can be made to sail to windward. But the brigantine does not have the hull windage of this bottle boat.
b) My square-riggers sail slower than marconi rigs, so the narrow chord airfoil of the keel may not generate enough lift. I can easily add 1/8" plywood to the existing keel if necessary. For testing, I just made a keel-area addition out of a sliced up pop can. The center of effort, in a zepher, is about 1" forward of my calculated CE. I moved the keel forward, and you can see the hull is down by the head a bit (which helps balance the boat). As the wind picks up, perhaps the CE may move aft. Since the keel is is hung via a bolt and wingnut, it will be easy to slant it aft to move the CLR accordingly.

The rudder seems quite effective. It's my first deep, narrow-chord rudder, and I am pleased.

I don't have an on/off switch for the rx. The 4, AA battery pack must be disconnected after each voyage, thus the Skippy jar must be removed to gain access to the battery pack (velcroed to the ceiling near the transom. btw, ceiling in a ship's hull = floor for landlubbers :-). So, all my sheets and braces must be removable, thus the fishing swivels and bollard, and removable rudder tie rod. As an experimental craft, I left some make-it-easier-to operate details for later. The white cord on the rudder head is the foresail sheet - I need to add a cleat to the deck.

Link to Andy's pirate bottle boat:
http://www.rcgroups.com/forums/showthread.php?t=1058778
My Pamir:
http://www.rcgroups.com/forums/showthread.php?t=743611
Info on my brigantine:
http://www.rcgroups.com/forums/showthread.php?t=693988
Brooks is offline Find More Posts by Brooks
Last edited by Brooks; Jun 28, 2009 at 10:52 AM.
Reply With Quote
Sign up now
to remove ads between posts
Old Jun 28, 2009, 11:35 AM
Grumpa Tom
Kmot's Avatar
United States, CA, Los Angeles
Joined Sep 2003
22,905 Posts
Now that is really amazing!
Kmot is offline Find More Posts by Kmot
Reply With Quote
Old Jun 28, 2009, 11:49 AM
Registered User
Joined Jan 2007
565 Posts
super cool i ve allways wanted to experiment with bottle yachts but just have nt got a good knoledge of how to do it. yours looks awesome,
larryg is online now Find More Posts by larryg
Reply With Quote
Old Jun 28, 2009, 01:27 PM
Footy Pie-Rat
AndyTrewin's Avatar
Nr Bristol
Joined Nov 2007
85 Posts
Brooks, thank you for your compliments, however I think you should also be congratulated on your Schooner Bottle Boat. She looks great ~ well done

Like you my Bottle boats fom this design ride high and that was why I decided on my third bottle boat to foam the bottle and then cut it in half
and so you get 2 for 1 Footys ~ I called this design "BottleIT"

I cant remember if I posted photos on this website of it so will put some in this ~ I did enter two bottle footys in the Chris Dicks competition and have another couple to put in this years one.

Best wishes
AndyT
AndyTrewin is offline Find More Posts by AndyTrewin
Reply With Quote
Old Jun 28, 2009, 03:17 PM
Square-rigger
meatbomber's Avatar
Klatovy, Czech Republic
Joined Mar 2004
3,338 Posts
a footy sized Brig or Top`sls Schooner now THAT`s something
Just in the progress of building my first footy, so i`m going to watch this thread with argus eyes just likeyour other square rigger threads !

i have one of these lying around at home... that might be in for a conversion... the fuselage is stem to stern 34cm long and 8,5cm wide
meatbomber is offline Find More Posts by meatbomber
Reply With Quote
Old Jun 28, 2009, 03:50 PM
Footy Pie-Rat
AndyTrewin's Avatar
Nr Bristol
Joined Nov 2007
85 Posts
Hi Meatbomber ~ If you are going for a legal Footy, the easy way to do it would be to chop the stern and you need the the bowsprit less than 6.2mm to get through the slot ~ but it would be FUN to try
Good luck ~ let us know how you get on
Rgds
AndyT
AndyTrewin is offline Find More Posts by AndyTrewin
Reply With Quote
Old Jun 28, 2009, 03:52 PM
Registered User
Joined Jan 2007
565 Posts
if you could possible do a video of your schooner, it would be so oo sweet
larryg is online now Find More Posts by larryg
Reply With Quote
Old Jun 28, 2009, 04:01 PM
Footy Pie-Rat
AndyTrewin's Avatar
Nr Bristol
Joined Nov 2007
85 Posts
Brooks Sorry forgot to ask a couple of questions
1. What is marine goop? ~ is this something you make up your self ~ if so please can you tell us as PET is particularly hard to get anything to stick to it

2. just been having a look at your Pamir ~ love the use of buttons as bowsies!
Rgds
AndyT
AndyTrewin is offline Find More Posts by AndyTrewin
Reply With Quote
Old Jun 28, 2009, 05:03 PM
Footy Pie-Rat
AndyTrewin's Avatar
Nr Bristol
Joined Nov 2007
85 Posts
BottleIT Large Photos

Sorry should have added to a previous post ~ if you need larger photos of "BottleIT" please go to http://www.clevedonmodelboatclub.co.uk/footymenu.asp
or mail me

Rgds
AndyT
AndyTrewin is offline Find More Posts by AndyTrewin
Reply With Quote
Old Jun 28, 2009, 06:20 PM
Registered User
Joined Jan 2007
565 Posts
it would be cool to join two soda bottles togather for a longer hull and make a schooner that way....i may have to give that a go
larryg is online now Find More Posts by larryg
Reply With Quote
Old Jun 28, 2009, 07:41 PM
Damp and Dizzy member
Brooks's Avatar
Bozeman, Montana, United States
Joined Aug 2003
3,381 Posts
Some sailing

Two voyages this afternoon, one with wind about 5mph, another with 10mph. I made one tack at 5, but the ship did not handle well, nor would she work to windward. I decided to ballast her before returning for the 10 wind. The ballast helped.

Lowering the hull in the water would make it work for me (adding "keel"), instead of work against me (excess windage). I added 2 lbs of lead shot, in 2 pill bottles. With about 3 lbs. total weight, she rode at about her scale waterline. I could tack, about 1/3 of the time with the topsail struck, and wear at will (with or without topsail). This morning, I had to sail her down at the bow, contrary to the hull diagrams I've seen for Baltimore Clippers. But this afternoon, ballasting her to match the stern-down configuration of real vessels worked fine.

She is quite sensitive to helm and sheeting, more so than my bigger barque. So, it's learning to sail all over again :-). As with my previous experience with multi-masters, the sails have more control over course than the rudder. I like to control, separately, the sails fore of the CLR, and aft of the CLR. This maximizes my chance of making the vessel hold the course I want.

Lack of space on the Skippy lid dictated that I eschew my desires; the braces for the squaretopsail (fore of the CLR) are combined with the mainsail sheet (aft of CLR). The foresail is left sheeted for a beat, as are the inner, outer, and flying jibs. My brigantine was steerable with mainsheet, and this vessel proved likewise. The rudder helps, of course, provided I don't turn it too far. The setup allows, via standard servo travel, 45deg to either side. But that much rudder kills way, so the wear, in particular, requires the rudder to stay un-stalled, ie move it less than 45deg.
----------
The ship is under canvased, lacking sail-power, even in a good 10mph breeze. With all the ballast, including 1# on the end of the long keel, she is pretty stiff. So, little of the sail force is lost due to heel. She does move through the water nicely. However, the 3# gross weight makes it hard for the scale-sized sails to accelerate the hull, a necessary ability to get my barque to tack reliably. The lack of acceleration hurt my tacks this afternoon I am sure. I will get better performance with practice (skipper error is ever present :-). But at this point, I'd say the 2qt. juice bottle might be better adapted to a sandbagger style craft - sandbaggers were notoriously over-canvased, and this hull would benefit.
----------
I still can't work to windward. I struck the squaretopsail and tested performance under fore&aft sails alone. Course to windward improved, but she still did not gain enough ground to make it possible to sail out and back w/o my having to walk/wade to leeward of the starting position. She would point up, but made too much leeway to gain to windward. I think the keel is just too small for this slow-compared-to-a-Footy schooner. I'll replace it with a bigger one and see.
-----------
With more wind, and more hull speed, the CE moved aft. I had to move the keel aft to compensate, compared to this morning's zepher-drifter voyage. The pre-sailing, calculated CE position worked fine for the keel position.
------------
Andy, "Marine Goop" is a solvent-heavy glue product, probably similar to the glue you recommended. I find it in US hardware stores.
------------
Meatbomber, your hull (not fuselage, you flyer....*grin*), looks great. My juice bottle hull is about 26cm long (11cm wide, 9cm deep). I have a foretopgallant, just as your model, but have not sailed with it yet. The pair of squaresails on your mainmast was relatively common to US schooners of the 1800's; The photo I have of Pride of Baltimore, the Baltimore Clipper replica, does not show any squares on the mainmast.
-------
LarryG, Video will come when I learn to sail her :-)
Brooks is offline Find More Posts by Brooks
Last edited by Brooks; Jun 28, 2009 at 08:19 PM.
Reply With Quote
Old Jun 28, 2009, 08:56 PM
Sailing enthusiast
Sea Devil's Avatar
New Bedford, MA.
Joined May 2007
120 Posts
Excellent ! Looks like something I would do.
Sea Devil is offline Find More Posts by Sea Devil
Reply With Quote
Old Jun 29, 2009, 11:25 PM
Damp and Dizzy member
Brooks's Avatar
Bozeman, Montana, United States
Joined Aug 2003
3,381 Posts
Better performance today in rain and wind (10+mph). I could tack, with some restrictions, and wear. And, best of all, I could make good to windward under f&a sails only (did not set the squaretopsail).

The major changes since last voyage:
1. Replaced footy narrow chord keel with a large flat-plate keel, 19cm x 30cm deep. I removed the interior ballast of 1#. I decided to try to sail with more freeboard, ie less weight, and try to compensate for the exposed hull windage with more keel. This seemed to work today as there was much less leeway on a beat than last voyage. The new fin keel (actually an old fin for my barque) was centered on the CE. I may try moving the keel weight (1#) aft a bit to raise the bow. The longer keel made turns less zippy, as one might expect. In the barque, I can wag the stern around with my shallow, steering-oar-like rudder, compensating for a long keel. Bu the footy style deep rudder is less effective in sculling the stern around.

2. Recut the mainsail to remove excess material where it was binding on the boom and gaff. The stiff Tyvek mainsail was not flopping from side to side when I tacked, resulting in poor airfoil shape on one tack.
My brigantine's mainsail was cut from a plastic grocery sack, while the jibs and squaresails are Tyvek. The thin grocery plastic probably works better for fore&aft sails than stiff Tyvek. Tyvek stiffness is welcome for the square sails. And the extra strength of the Tyvek, compared to sack plastic, makes it suitable for jibs: I don't have to use stays but can simply depend on the jib luff to support the stress. But the more flexible plastic assumes an airfoil shape more readily than the Tyvek, so is a better choice for large f&a sails, I think.
-------
Tacking limitations
1. I have to sail through the tack. I can't just push the rudder over and snooze :-). The vessel does not develop enough speed on the beat to make tacking a ho-hum maneuver. I slack the mainsheet a bit, bear off to build speed, then tighten the mainsheet & start feeding in rudder. The effect of tightening the mainsheet is twofold - the tighter mainsail simply weathervanes the hull (it'd do that even if the mainsail was a flat board), and the tighter mainsail leech also sends the bow to windward.

In fact, when the boat is close enough to see the leech, I can adjust weather helm as desired simply by watching the curve of the leech as it responds to the joystick. It's fun to see this effect, something I had read about, but never actually noticed while sailing full size sloops. In general, this small schooner is much more sensitive to sheeting (and rudder and sail shape and basically everything) than larger models or even the real sailboats I have been on. Or, maybe more accurately, all vessels respond, but the bigger ones have enough inertia to hide the subtle effects that this light, maybe marginally powered, schooner model pushes right in your face *smiles*.

2. Pick a smooth part of the sea. Trying to tack in the biggest waves or chop is futile.

3. Only tack when the flying jib is not hungup on the windward side. On the real Pride of Baltimore, both the outer jib and the flying jib overlap their neighbors by a substantial amount. Due to the geometry of the inner and outer jibs of the real vessel, I was able to cut the model's outer jib so that it does not actually overlap, yet still retains the profile view of the real ship. For the flying jib, however, I could not make it look like the prototype w/o actually cutting it to overlap.
The stiff Tyvek will not swing to the new leeside when I change course, unfortunately. This has 3 bad effects: a) when the flying jib is stuck on the windward side it assumes a flat, non-aerodynamic shape, b) the flying jib bears on the luff of the outer jib, twisting that sail to a flat shape, c) the twist in the outer jib closes the slot between it and the inner jib, spoiling the smooth airflow over the inner jib. Bad news all around.... With the jibs acting only as drag devices, instead of airfoils, the ship sails slower and also has excess weather helm. Moral - if you are going to use multiple jibs, do what ever you can to make them behave properly, eg end up with all their clews on the leeward side for whatever course you pursue. I will try cutting a new flying jib out of bag-plastic, and make the overlap less.
---------
No photos due to the rain. btw, even though I don't seal the gap between the deck and the Skippy jar, I don't pick up much water in the hull. I emptied out about a teaspoon after an hour of sailing in large waves and large raindrops. Boy, you can't beat the ease of water removal with these bottle boats....just unscrew the bottle cap and dump it out :-)).
Brooks is offline Find More Posts by Brooks
Last edited by Brooks; Jun 29, 2009 at 11:30 PM.
Reply With Quote
Old Jun 30, 2009, 07:47 AM
**NOT GUILTY**
Capt.Crash's Avatar
Millbrook, Alabama
Joined Jun 2004
6,428 Posts
Awesome Brooks.

I saw a Footy like this somewhere...but this is over the top for sure!
Capt.Crash is offline Find More Posts by Capt.Crash
Reply With Quote
Old Jun 30, 2009, 08:36 AM
Damp and Dizzy member
Brooks's Avatar
Bozeman, Montana, United States
Joined Aug 2003
3,381 Posts
Capt.Crash, you are the topsail schooner expert. Have you ever worked to windward while flying your square topsails? I see paintings of topsail schooners doing so, but have always been suspicious of the artist's interpretation.

It seems implausible to me that one could get any real square sail, hampered in it's swing by the interference of yard and rigging, to match the trim of a fore&aft sail. My models' upper yards, without braces/shrouds/stays, will, under wind pressure, swing farther than real yards. So much so that I invented the jaw-jammers for the barque to control that swing. So, I guess it may be possible to beat with the squares set on the Baltimore, but I have not experimented enough yet with the setup to see for sure.

For modern sloops, you can get a spinnaker (sort of the modern analog to square sails) cut flatter than usual. It's effective on a beam reach or maybe even a little higher, but I have not seen anyone use one on a beat.

Pride of Baltimore II website:
http://www.intandem.com/NewPrideSite/Pridehome.html
Brooks is offline Find More Posts by Brooks
Last edited by Brooks; Jun 30, 2009 at 08:57 AM.
Reply With Quote
Reply


Thread Tools