Maneuverability of Square-Rigged Vessels ?

[HappySeagull]

Righton,MichaelC!or even a model would help.Cut your sails pretty flat.No salty piratical billowing please

See?... being aback is not always a mistake and a panic...it can be a brake and a maneuvering strategy too.

wearing is a B***er in close quarters (in any sail)because it takes sooo much room and as you noted,a big radius..a lot because the boat will just plain accelerate and GO faster the wrong way..even with sail reduced it's a huge waste of "hard-won" to windward .
So short hauls pointing not very high in modern terms(60degree is about it on a good day( 2 miles are sailed for one gained to windward but leeway and all can make it effectively worse) ... and then wearing at each end (before you hit the beach)is really hopeless.Long hauls are not so bad.

Just depending on what it is you must do...don't forget a ship carries her way a long way.You might imagine luffing round a BW into a smallish harbour on a pleasant day with some speed and then backing the fore tops'l to stop and drop anchor ...or stop alongside and board! Aharr!.

[HappySeagull]

I'm no expert box hauling...but the idea would seem to be to shoot ahead(carry way directly to windward and then as momentum is lost lose way almost to stop let the fore spin her to leeward (almost BACKING UP to windward)before you gather way again and wear round to the new tack...don't forget the shadowing effect of backed fores'ls on the sails "behind"... increasing the tendency of "lee helm"( the tendency for the bows to fall off to leeward ...the triangular sails on the forestays are also part of this picture if they are set ..see?with so many sails in a true ship(3 square rigged masts) the options are huge as to just WHICH sails will be set and how the ship is balanced because of their position and number.and Don't consider a Maneuvering ship to look like a postcard with all sails set.If you look at the 18th and 19th century paintings,you'll be miles ahead of youtube,I bet....trouble is,not many great painters were also seamen and once the ship was at sea,they started to make stuff up or even,didn't SEE what they were looking at.Oh,there are many exceptions..but you need to pick them out.For maneuvering,I guess you only need port scenes anyways.

[Didz]

Originally Posted by MichaelC

When you tack a square rigger, you don't just put the helm over and wait for the vessel to pass thru the wind, you back the foresails to catch the wind on the opposite side to drive the bow thru, much like we gaffers back our jibs to push the bow theur the eye of the wind.

Thats a technique I have used myself when racing ASC's, its particularly important in light winds or when the impetus into the maneouvre is less than one would have hoped. So, I can see why it would be almost standard practice for a square-rigger, especially if it was heavy in the water with guns and men.

The other thing I was wondering was whether the lack of a centre board made any difference in the handling. ASC's had a retractable centre board, and I only forgot to lower it once when trying to make a turn with disasterous results. I had ordered it raised to reduce drag during a long downwind run, and simply forgot to order it lowered when we got to the turn marker, nearly cost me the race.

Originally Posted by MichaelC

I had a square sail on my schooner [making her, when square sail was set, a mini brigantine]. I always backed the square when coming about, and she would spin on a dime when I did so. Obviously, with a screw driven vessel, you can turn her with more certainty than a sail driven vessel. In a shorter radius?

Thats really the gist of the issue, as far as I can tell many historians are assuming that square rigged vessels obey the same rules as modern day power driven vessels when turning. e.g. the longer the hull the larger the turnng circle, but that certainly doesn't match my experience with smaller sailing craft and I wondered if it was true of larger vessels.

@nv5l: No! I was generally searching for more obvious subjects like 'Square Rigged Ship' etc, but I'll have a look. I suspect if I find some then it will have the added advantage that when racing they will be looking to turn as efficiently as possible.

[cagney]

If you really want to know, try to get hold of Anthony "Tiger" Timbs, the former captain of the brigantine, later re rigged as a brig, "Eye of the wind".
Eye of the Wind - Wikipedia, the free encyclopedia.
He should know! He, among other things took "Eye" around he Cape Horn en route from NZ to Europe.

This is when I really wish I could go back in time, and ask my grand dad. He was a regular on the guano trade, Europe, Cape Horn and on to Antofagasta in Chile, and back. He did this as a captain, 7 - 8 times(from memory), beating east to west around Cape Horn.

I have no personal experience of square riggers at all. What I do have is a book in seamanship from 1914 with detailed description of how to tack, what to do when caught in "irons", and what to do if you just had to tack in an emergency, due to closeness of a danger, etc etc.

Try to get hold of a similar book! (don't ask me to quote from the book as I then have to dig into ancient terminology in two languages.)
My understanding is that the rudder just had an initial function as a part in starting the tack. Then it was all up to sail handling, as the ship more or less lost her way due to windage and the necessity to back wind the square sails on the fore mast when about 1 point from the eye of the wind. So the turning radii was bound to be less than for a steamer, if we are talking about normal maneuvering.

Thomas

[PjotrC]

Originally Posted by Dockhead

On the contrary, square rigged ships were a doddle to jibe, so changing tacks was often done by "wearing ship" -- heading off, coming all the way around through a jibe, then heading up on the other tack.

Another reason to gybe rather than tack is to avoid wear and tear on sails and rigging. Attached is a plot of a busy night we had during the Tall Ship Races 2009 in the Gulf of Finland, in a 6-7B easterly wind. The ship was a modern brig, STS Fryderyk Chopin.

A book to read on the subject is "Seamanship in the Age of Sail", by John Harland.

A nice simulator ("HMS Surprise") is available here:

HMS Surprise

Piotr

[MarkJ]

Originally Posted by PjotrC

Attached is a plot of a busy night we had during the Tall Ship Races 2009 in the Gulf of Finland, in a 6-7B easterly wind.

Piotr

That would send me crazy!
Can you imagine doing that for a few weeks?

Thanks for posting the plot, Piotr.

[Bruce626]

Mike Turner wrote: "The sailboat, when tacking (and to a lesser extent when gybing) will tend to slow and pivot around it's keel in making the turn, rather than executing the radial turn of the powerboat." ==> Based on what little I remember of large square rigged sailing ships of bygone days, I do not believe that they had keels that acted as external ballast. I think most of these ships were internally ballasted - the merchant ones anyway using stones or heavy bits of cargo to accomplish this. While there was likely a long keelson kind of timber down the center to protect the bottom and for structural purposes, I don't think these ships had anything to 'pivot' around. I don't know about the modern tall ships or your schooner. Perhaps just something to verify.

[MikeTurner]

Originally Posted by Bruce626

Based on what little I remember of large square rigged sailing ships of bygone days, I do not believe that they had keels that acted as external ballast. I think most of these ships were internally ballasted - the merchant ones anyway using stones or heavy bits of cargo to accomplish this. While there was likely a long keelson kind of timber down the center to protect the bottom and for structural purposes, I don't think these ships had anything to 'pivot' around. I don't know about the modern tall ships or your schooner. Perhaps just something to verify.

Bruce, you're correct that many of the old square riggers didn't have a "keel" in the modern sense of the word - certainly nothing like the fin keels modern sailboats have; and no external ballast. They would have the keelson you describe, and some had a "false keel" built below that. I've read that sometime in the 1700s the British Navy experimented with a lifting keel (what we'd call a centerboard I think), but I don't know much about it - O'Brien based one of the ships sailed by Jack Aubrey on this historical experiment.

Techincally, it's more correct to say that a sailboat pivots around a point that is based on the center of effort (CE) of the sailplan and center of lateral resistance (CLR) of the hull. Believe me, I'm no marine architect so perhaps someone else here can give a cogent explanation of this, I'm definitely at the outside edge of my limited knowledge of the physics of this. What I do know is that the CE can shift given the sail set, so the pivot point will vary given what sail is being carried as well as point of sail.

My schooner has a full box keel that encapsulates the majority of my ballast (I have some internal trim ballast) that is shallow draft (2'10"), and a centerboard that functions more like a fin and drops to a maximum of about 6'6". The centerboard isn't ballasted and carries only enough weight to give it negative bouyancy to drop. As it happens, though, we rarely lower the centerboard, mostly due to the shallow conditions we have throughout Mobile Bay. So I'm sailing as a shallow draft full keel boat, albeit one with a much sharper underwater profile than the old full-bodied square riggers.

As is discussed in other posts above, when tacking we first fall off the wind a bit to gain some momentum, and then after turning up backwind the jib in order to bring the boat through the wind - the backwinding helps with the pivoting action. In light winds we sometimes can't make this happen and so have to gybe rather than tack. So my full keel boat does pivot, not as you say around the keel, but rather around the CE/CLR.

I think my point earlier was that the OP was originally asking if a square rigger could turn in a lesser distance than a powerboat. I think the answer is "yes" in some conditions, given the tacking/pivoting action - the powerboat will turn in an arc around it's turning radius, more or less at a constant rate of speed; while the sailboat when tacking will fall off, turn up and through the wind, and fall off on the opposite tack, possibly inside the turning radius of the powerboat. But this doesn't take into account that generally the powerboat will complete its turn in less time than the sailboat will.

[Didz]

Wow! ok...well looks like I've triggerred a lively discussion anyway, and I've got quite a lot of useful input.

Here's a quick update on my quest for clarification:

YouTube video's: I took nv5l's suggestion and looked at lots of video's related to the tal ships race. Unfortunately, I didn't find any that were that helpful. Again lots of footage of tall ships in full sail on straight courses (I guess ships are more photogenic that way), plus lots of video's of attractive young girls hauling on ropes (again more photogenic I guess). But no aerial shots of ships performing serious changes of course.

Books: I've not ordered any new books as yet although several of those mentioned look interesting. I was hoping to be able to glean the basic principles of the turning dynamic's without having to become an expert in seamanship. It is quite easy to find out how power driven vessels change course and the factors that affect it, but (not surprisingly perhaps) turning a sailing vessel seems a lot more complicated.

The 'HMS Surprise' programme linked by PjotrC looks promising, assuming that its an accurate model. Although I'm probably more interested in the factors that were taken into account when it was programmed that the actual programme itself, as if it is an accurate model then it must have been based on a thorough understanding of the performance of an 18th century frigate changing course, which is basically the question I was asking.

As far as Keels go, I've never seen a plan of an 18th Century warship with any sort of centre board system, but I'm assured that they deliberately carried heavy ballast close to their bottom boards to reduce their top-weight and given them stability. This was often rocks or stones, although I was watching a wreck analysis a few weeks ago where one vessel had used surplus cannon barrels stored along its keel as ballast. This strikes me as at odds with Hornblower and Bolitho's obsession with lightening their ships to imporve performance, but perhaps I'm being too simplistic.

I've even read some evidence of this ballast area being layered with sand and used as a graveyard for seamen who died on the voyage, instead of throwing them overboard. It appears some cultures felt it important to bury their dead rather than sink them in water. Doesn't sound very practical or hygienic though. But having said that Nelson's body was brought home for burial, rather than being tossed overboard like the rest after Trafalgar, though he was pickled in spirit for the journey to keep him fresh.

[Dockhead]

Originally Posted by PjotrC

Attached is a plot of a busy night we had during the Tall Ship Races 2009 in the Gulf of Finland, in a 6-7B easterly wind. The ship was a modern brig, STS Fryderyk Chopin.


Piotr

A little off topic:

We passed close by you in the middle of the English Channel at night in October, 2010 -- the Fryderyk Chopin was motoring West through the Channel and we were crossing Southampton to Cherbourg, sailing hard on a close reach. A beautiful sight in the moonlight your ship was. I think I have some photos somewhere.

[rgscpat]

Although old ships didn't have deep metal keels in the sense of modern sailing yachts, the re-creation of Juan Cabrillo's sixteenth century El Salvador by the San Diego Maritime Museum will be fitting a lead false keel below the keel. The keel has only recently been laid and pigs of lead are nearby. I don't know whether this is a modern innovation to improve safety or actually represents how Cabrillo's ship was built. On my blog (Desert Sea - New Mexico and Southwestern Sailing), I did put up a few pictures of the beginning of construction of the San Salvador. (I also put up some pictures of the museum's "Surprise" (ex Rose), which is a partial movie ship representation of a small, approximately 200-ton 12-pounder frigate of the late 18th century.

I'm guessing that burial at sea was more typical, for ships not near a port, and that burial in the hold might be unusual or exceptional or even accidental. Bodies would not be something to be left hanging around -- except for the occasional pirate as a warning.

Some of the smaller tall ships that represent armed vessels will have mock battles and duels upon occasion. Could these give you the footage of maneuver that you want?

[nv5l]

There are several videos of the Star of India you might find interesting, e.g.,

http://www.youtube.com/watch?v=CJ1XU...e_gdata_player

http://www.youtube.com/watch?v=BxCKG...e_gdata_player

[rgscpat]

( http://2.bp.blogspot.com/-udIXB_kcy8...%2Bdetails.jpg ) Details of attachment of sternpost to keel for San Salvador, showing room for lead false keel to be added later.



Stern framing with sternpost, keel, and template for mid-ships frame for recreation of San Salvador at Spanish Landing, San Diego, California, USA (formerly Alta California del Espa~na Nueva)

[Me-and-Boo]

Originally Posted by Didz

Wow! ok...well looks like I've triggerred a lively discussion anyway, and I've got quite a lot of useful input.

I've even read some evidence of this ballast area being layered with sand and used as a graveyard for seamen who died on the voyage, instead of throwing them overboard. It appears some cultures felt it important to bury their dead rather than sink them in water. Doesn't sound very practical or hygienic though. But having said that Nelson's body was brought home for burial, rather than being tossed overboard like the rest after Trafalgar, though he was pickled in spirit for the journey to keep him fresh.

Sand was used in the fighting ships as it is sort of used today in deck paint, to keep the decks non-slippery. During a battle there is a lot of blood, and blood is very slick stuff, so the sand was spread around to give better footing.

[goboatingnow]

I'm a fan of 18th and early 19th century naval history , but I think the notion that such vessels were more manoeuvrable then power vessels is quite ridiculous. A power vessel can simply spin on it's axis, gather and loose way on demand. Square riggers and even modern sailing vessels can use techniques to improve the response,but nothing near a powerboat. Powerboat perform arcing turns simply because it's easy on the crew and full speed can be maintained. But this is a user preference



Dave