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Old 05-09-2011, 06:11   #31
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Re: Manoeuvrability of Square Rigged Vessels ?

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Please forgive my intrusion on your forum, but I have a sail related question which I hope the experts on this forum will be able to answer.

I am interested in 18th and 19th Century naval history and a question has arisen about the relative manoeuvrability of modern day propeller driven ships and the various designs of square rigged warships used in the past.

It’s relatively easy to find a clear assessment of the factors that affect the manoeuvrability of prop driven vessels, and I have not had difficulty finding a formula for the calculation of things like turning circle radius based on hull length, weight, speed etc for modern day vessels.

However, I did do some sailing in my youth and my instinct is that the factors affecting the manoeuvrability of a sailing vessel are not the same as those affecting a prop-driven vessel.



For one thing sailing vessels are not pushed through the water, but pulled along, and like a horse and cart, I would have thought that turning has as much to do with the redirection of effort as pressure on the rudder.

So, the question is ‘What determines the manoeuvrability of a square-rigged sailing ship, and how would it differ from a prop-driven vessel?

Secondary, questions relate to the relative performance of a 3rd Rate Ship of the Line, to say a 5th or 6th Rate Frigate, and the importance of speed in the preparation to tack, rather than wear ship.

I am interested in any input from skippers or crew who have experience of sailing square rigged vessels, or links to any sites where this subject is discussed in more detail.
Hi Didz, here is a link to newsletter from Sydney Heritage Fleet, if you scroll through there's a description of going about with the "James Craig", I have never sailed on her but was the Shipwright charged with Her care for a couple of years http://www.shf.org.au/JCFullBy/FB%20May%202010.pdf hope this is some help to you. Regards from Jeff.
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Old 05-09-2011, 08:23   #32
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Re: Manoeuvrability of Square Rigged Vessels ?

I have no idea where this comes from, but a vague memory tells me that square rigged ships would take advantage of the wind shadows from other ships or islands to tack without losing progress to windward, but without such an advantage had to wear ship (jibe) to change direction. The idea of turning head to wind and coasting to gain a hundred yards or so would have entailed sail handling by a very large and skilled crew, something not normally found aboard all but the most exceptional vessels. Were it ever used to much advantage, the lore would be filled with such feats.

Powered vessels were a world changing breakthrough in maritime technology, and their enhanced maneuverability (with hazardous reputation and short range) were the primary reason that the first large scale commercial application of steam was in tugboats, (replacing small boats with a dozen oarsmen dragging anchor and chain a few hundred yards at a time) allowing vessels to enter and leave harbors with less restrictions placed by wind and tide.

As far as turning performance of early steam powered vessels; it is interesting to note that side-wheeler tugs were powered by independent engines that could be stopped and reversed with (then) amazing facility, providing the ability to turn in an extremely small radius.

Are you writing a book? I can imagine no case in which a square-rigged sailing vessel can turn inside a contemporary powered vessel, and that any turn will result in a significant reduction in the sailing vessel's speed.
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Old 07-09-2011, 03:36   #33
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Re: Manoeuvrability of Square-Rigged Vessels ?

Hi Dave,

Yeah! I think I understand that a powerboat (as opposed to a power driven vessel) has a somewhat different handling potential to say a super tanker, or cruise liner. I'm certianly not suggesting that a sailing ship can out perform the a powerboat or jetski etc.
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Old 07-09-2011, 04:42   #34
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Re: Manoeuvrability of Square-Rigged Vessels ?

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There are several videos of the Star of India you might find interesting, e.g.,
Yes...they were interesting, especially the second one, which makes it quite clear that the sails are playing a major, if not the major part, in turning the ship. Which was what I thought would be the case.

I was particularly impressed with the way that pressure was released from the foresails and applied to the mizzen sails when wearing. The aim being to pretty much slew the ship around by dragging the stern forward whilst losing way on the bow. Something akin to skidding a car around a bend I suspect.

What was a bit unfortunate was that the winds were so light when the video was shot (probably for safety reasons) that the vessel isn't leaving any wake to mark it's progress through the turn. So, it's impossible to judge from the video how tight those turns actually were.

Nevertheless, very useful, and hopefully now I have a YouTube 'tag' to work from I'll find it easier to find similar footage. I'm actually quite surprised those video's didn't come up in my earlier searches.

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Hi Didz, here is a link to newsletter from Sydney Heritage Fleet, if you scroll through there's a description of going about with the "James Craig"
Thanks.....Balance, momentum, timing and determination.
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Are you writing a book? I can imagine no case in which a square-rigged sailing vessel can turn inside a contemporary powered vessel, and that any turn will result in a significant reduction in the sailing vessel's speed.
Well to a certain extent that's the question being put. But I agree that it's difficult to generalize, particularly when it comes to power driven vessels as they vary significantly in size, weight, power and configuration.

The most powerful power driven vessel I've commanded was an Admiral's Barge, which was being used to ferry dignitaries from Greenwich Pier to HMS President on the River Thames.

That was basically a light weight wooden hull being driven by twin merlin diesel engines with four paired rudder panels. I was reliably informed that the engines were the same design as those used by WW2 Spitfire fighters, so it was like having two fighter aircraft under the bonnet. I soon discovered that by putting the helm hard over and throttling back on the outboard engine, whilst increasing the throttle on the inboard one I could virtually spin that barge like top. In fact, the only limitation was the desire not to jettison the saluting party off the bow into the Thames.

However, that was a very light weight hull, with a very powerful drive force and relatively large rudder surface. I'm trying to compare the performance of like for like, and I'm not so much interested in speed as maneouvring distances.

So, it's more like a comparison between say HMS Belfast and HMS Victory, than Victory versus say a Bowrider 240 Sport boat. Although even there we run into problems as I know for a fact that a modern frigates like the Type 26 & 27 are specifically designed to make very tight turns.

Whether the calcuation formula still remains reliable for such vessels is not certain. I would have thought that the laws of physic's would still hold firm and the turn radius would be predictable given the factors feed into the calculation. I'm just not sure that sailing vessels conform to the same rules.
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Old 07-09-2011, 07:26   #35
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I don't see the point of your question. There's simply no way a powered vessel could be out manoeuvred by a sailing vessel of comparable size. That's s given. First rate ships of the line were slow ponderous vessels typically operating with dubious stability characteristics , tacking was avoided wearing took a lot of sea room. An examination of contemporary accounts of the major battles under sail show the significant sea room and enormous time required to position vessels. This at a time of peak crew and knowledge.

The admiralty clearly saw this despite initial reluctance to abandon sail. ( though the rapid changeover to steam occurred for many reasons)

Also bear in mind one of the main reasons for the demise of sail was as the vessels scaled up, sufficient power could not be extracted from any reasonable sail configuration and manoeuvring such vessels in close quarters was almost impossible, thereby requiring tugs.

One could examine and compare the manoeuvring characteristics of different sailing vessels. But to compare them to power vessels is not very useful.

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Old 07-09-2011, 12:57   #36
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Re: Manoeuvrability of Square-Rigged Vessels ?

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I don't see the point of your question. There's simply no way a powered vessel could be out manoeuvred by a sailing vessel of comparable size. That's s given. First rate ships of the line were slow ponderous vessels typically operating with dubious stability characteristics , tacking was avoided wearing took a lot of sea room. An examination of contemporary accounts of the major battles under sail show the significant sea room and enormous time required to position vessels. This at a time of peak crew and knowledge.

The admiralty clearly saw this despite initial reluctance to abandon sail. ( though the rapid changeover to steam occurred for many reasons)

Also bear in mind one of the main reasons for the demise of sail was as the vessels scaled up, sufficient power could not be extracted from any reasonable sail configuration and manoeuvring such vessels in close quarters was almost impossible, thereby requiring tugs.

One could examine and compare the manoeuvring characteristics of different sailing vessels. But to compare them to power vessels is not very useful.

Dave
Well I think that is the point of my question, as many of the assumptions you are making don't actually fit with my understanding of how sailing vessels function.

So, the question really is whether you're assumptions are correct, or whether in fact ships such as HMS Victory were capable of making relatively rapid changes of direction by using the unique qualities that sailing vessels have and power vessels don't.

Having said that this is not really with any intention of proviing that sailing vessels are handier than powered vessels. Rather its more about establishing an alternative understanding of what determined the handling characteristic's of a sailing craft, and how they differed from those that affect a power driven vessel.

As far as the history of the steam powered warship is concerned I have to say that the navies decision to adopt steam power and abandon sail was a lot more involved than any issue about ship handling, and I suspect that one could easily get into one of those protracted debates about it similar to the ongoing one over the advantages of the musket over the longbow.

However, thats not really the focus of my question. I'm really much more interested in the way sailing ships handle and their potential performance, and the Star of India video is a tantalizing example of how the wind and sails can be used to achieve much more than a rudder on its own.
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Old 07-09-2011, 13:05   #37
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Read Dana's treatise, "The Seaman's Friend," which gives an excellent description of tacking and wearing, in all condition including heavy weather and confined spaces, e.g., using tide current to help swing the stern.

Google has it online, and you can read it for free. You can even skip to those chapters, if you want. As far as I know, it's the only description of it's kind ever written, at least in that much detail.
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Old 07-09-2011, 13:48   #38
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Re: Manoeuvrability of Square-Rigged Vessels ?

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Read Dana's treatise, "The Seaman's Friend," which gives an excellent description of tacking and wearing, in all condition including heavy weather and confined spaces, e.g., using tide current to help swing the stern.

Google has it online, and you can read it for free. You can even skip to those chapters, if you want. As far as I know, it's the only description of it's kind ever written, at least in that much detail.
Thanks, I have just been reading sections of it, and I've already discovered a few things that are pretty obvious when you read them, but which I had not considered until I did.

For example Dana's description of how the action of the wind on the sails affects the pivoting of the ships hull around its centre of rotation makes perfect logical sense but was something I had never considered.

The idea that filling the foresails alone, whilst emptying the mizzen, would naturally cause bow of the ship to swing downwind and the stern to swing to windward, even if the rudder were left fore and aft, is obvious once its pointed out, but not something I had thought of before, as every boat I've sailed has only had one mast so it's never been an option.

The reverse being equally true in that filling the mizzen sails whilst spilling the fore-sails will cause the bow to swing into the wind.

In the 'Star of India' video the master actually goes one better still, loosing the headsails to spill wind at the bow whilst backing the after sails to produce negative pressure on the hull. Presumably, that merely enhances the tendency to turn the ship into wind, even without the rudder being hard over.

These sort of techniques must have been standard practical seamanship procedures in Nelson's navy. The main information i am missing now is just how effective they were in turning the ship. As 'Goboatingnow' has just pointed out ships like the Victory were not racing yachts. They were heavy and unweildy, with high hulls and a lot of top hamper. So how effective were these maneouvres in turning them?
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Old 07-09-2011, 14:17   #39
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Re: Manoeuvrability of Square-Rigged Vessels ?

The transitionb from sail to power was never about maneuverability, or the ability to enter harbors unassisted. Power cargo vessels also need tugs for entering and departing. It has to do with size of vessel and size of harbor. The 19th century saw a steady increase in the cost of labor. This was driven largely by the increase in factories ashore, and the rise in population. It facilitated the shift from square rig to schooners for cargo carrying. But the schooners had barely gotten underway when the powered vessels allowed a trade of engine for masts, rigging and sails, plus fewer crewmen to operate the vessel. Double screw vessels are extremely maneuverable, single screw less so. Single screw vessels can 'tack' faster than square riggers in very light air. Above that it is questionable. Consistency, however, and overall maneuverability into the wind, is not. Cargo vessels did not carry external ballast, or even much of a keel. My 17' faering has a very thin external keel running 1 1/2" at the bow to 6" at the rudder, and she will tack, with a single sprits'l, even though that sail is polytarp and heavy. Most seamanship is exactly that. It depends on the knowledge and skill of the captain. As engines got better, however, their reliability and power increased geometrically, allowing feats under power that sailors could only dream of. But the noise ... and the stink .... I'll take my gaff rigged schooner and a big anchor ....
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Old 07-09-2011, 15:48   #40
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Re: Manoeuvrability of Square-Rigged Vessels ?

So, what I'm looking for now is some evidence....

a) That the Captain of the Victory and his contemporaries of the period would have used the same seamanship techniques to turn their ships as described by Dana and demonstrated by The Star of India.

and assuming that they did....

b) What was the result in terms of manoeuvrability for say a 3rd Rate Ship of the Line, and a 6th Rate Frigate. How tightly could they be turned, and how much windage would they lose in the process?
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Old 07-09-2011, 16:46   #41
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Re: Manoeuvrability of Square-Rigged Vessels ?

In an earlier post I mentioned the Sterling Hayden book. All this discussion has inspired me to go to the library and re-read it. If memory serves, he describes, in some detail, a manouver in tight quarters using the sails. As soon as I find it I'll post an excerpt. That said, I don't think anyone would argue that a square rigger could outmanouver a twin screw cruiser with a bow thruster, but I further think they weren't the wallowing slugs some here seem to think they were. I suspect the OPs intention was to find out just how manouverable they were, not to initiate a contest between apples and oranges.

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Old 07-09-2011, 17:21   #42
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In an earlier post I mentioned the Sterling Hayden book. All this discussion has inspired me to go to the library and re-read it. If memory serves, he describes, in some detail, a manouver in tight quarters using the sails. As soon as I find it I'll post an excerpt. That said, I don't think anyone would argue that a square rigger could outmanouver a twin screw cruiser with a bow thruster, but I further think they weren't the wallowing slugs some here seem to think they were. I suspect the OPs intention was to find out just how manouverable they were, not to initiate a contest between apples and oranges.

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Thanks for the reference, I didn't know about Heyden's story or book, but definitely plan to read it.. Thanks again...
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Old 07-09-2011, 17:25   #43
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Re: Manoeuvrability of Square-Rigged Vessels ?

Some of the finest explainations of sailing the square riggers of the 18th century were in the writings of Patrick O'Brien as MarkJ mentioned and the Forrester series of Horatio Hornblower. The actions of warping out of an anchorage, playing the offshore winds of various points of a lee shore, wearing ship in close quarters and strategies to engage the enemy of considerably larger and more lethal size are all described in some detail. These seamen, mates and captains were truly masters of the sea and their vessels. While works of fiction, the life aboard an English warship really comes alive and obviously considerable research has been undertaken by the authors. The maneuverability of the square riggers clearly was limited but the techniques described to overcome these deficiencies are very impressive. If you haven't already sources these series, I would encourage you to do so... Capt Phil
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Old 07-09-2011, 21:23   #44
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Re: Manoeuvrability of Square-Rigged Vessels ?

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Some of the finest explainations of sailing the square riggers of the 18th century were in the writings of Patrick O'Brien as MarkJ mentioned and the Forrester series of Horatio Hornblower.
Obriens work is technically suspect, Forresters work is better.

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The actions of warping out of an anchorage, playing the offshore winds of various points of a lee shore, wearing ship in close quarters and strategies to engage the enemy of considerably larger and more lethal size are all described in some detail.
Such techniques are still in use today by many modern sailors( with the exception of military ones) and relate more to the vagaraties of sail power, current and tide and the discipline inflicted by particular sail plans, then specifically related to any nimbleness.

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b) What was the result in terms of manoeuvrability for say a 3rd Rate Ship of the Line, and a 6th Rate Frigate. How tightly could they be turned, and how much windage would they lose in the process?
Questions on manoeuvrability like this are too general , what do you mean, rate of turn, sea room, speed of execution, total elapsed time etc.

What we do know, by contemporary account, by inspection, and by watching modern tall ships, is that smaller ships, particulary when fore and aft rigged , or partially so are more manoeuvrable, in the general sense of the word, a frigate was a faster ship taken over a broad range of sailing conditions then often bigger vessels with better waterline length, yet such vessels were often faster in a straight line. Equally we know that nimbleness was as much a function of crew expertise and motivation ( various historical accounts of comparisons between military and commercial vessels).

The admiralty never developed "standardised" manoeuvrability tests because its virtually impossible to do so, comparisons are therefore , of necessity general and anecdotal. A first rate ship of the line was primarily a gun carrying platform first as such vessels were developed to act out the "line of battle " type of action. manoeuvrability was less important then sheer fire power.

Later as captains such as Nelson and others developed more open styles of combat, there was a move away from such ponderous vessels, towards frigates and smaller ships of line types, Developed to a zenith by the early US frigates, very large by royal navy standards for frigates, but designed as single ship hunter/killers rather then as part of a large offensive force.

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Old 08-09-2011, 03:38   #45
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Re: Manoeuvrability of Square-Rigged Vessels ?

@rgspat: Point taken, although I do live in that part of England which happens to be farthest from the sea. Nevertheless a trip to a Nautical Museum might be worthwhile provided I can find one that has practical knowledge of seamanship in the 18th Century.

From past experience I find that practical knowledge often has more value than historical research, and there have been a number of occasions in the past where re-enactors have provided vital clues to how things were really done historically which were never recorded in enough detail for historians to discover.

Square-rigged ship handling seems to be another area where seamen of the period never thought it necessary to record how they did things, to them it was obvious and so one can study a ships log and note the course changes and details of it’s movement in battle, but rarely will you find any information on how those movements were achieved. It was considered too obvious and mundane to record and so isn’t available to the historian.

Consequently, I’ve run into brick walls before where historians will tell me ‘Well they did this and then they did that?, and I say ‘How?’ and you just get a blank stare.’

@Dick Pluta: I can see I’m going to have to make a trip to the library.

@Capt Phil: I've read all of the Hornblower and Bolitho series and certain there are incidents in those books that suggest the author was assuming quite a nippy response from his fictional vessels in the stories.

Unfortunately, fictional books and films aren’t necessarily a solid source of historical fact, as we all know from films like Master and Commander and Waterloo. So, I can’t really rely on the exploits of Horatio Hornblower as a source of valid information, just inspiration.

@goboatingnow:
Quote:
Questions on manoeuvrability like this are too general , what do you mean, rate of turn, sea room, speed of execution, total elapsed time etc.
I see what you mean, and it’s clear from the responses on this thread and the evidence I’ve seen and read so far that this sort of information is not normally considered important when dealing with the practicalities of sail handling.

Let me try and be a bit more specific.


The above diagram is copied from an article on the Nautica website discussing the manoeuvrability of power driven vessels.

It’s supported by a formula which accurately calculates the dimensions that are marked most importantly the ‘Steady Turn Radius’ and ‘Tactical Diameter’.

This formula is considered to be true for all power driven vessels regardless their size or configuration. Thus it is possible to calculate and predict the performance of any power driven vessel performing a steady turn. So, for example it would be possible using this formula to calculate the steady turn rate of the USS Monitor, or CSS Merrimac even without any physical testing.

What prompted my initial question was the absence of anything similar to predict the performance of a square rigged sailing vessel, and thus the absence of any way of calculating the historic manoeuvring capability of ships like HMS Victory.

So what I’m looking for is some set of basic rules of physic’s or examples of actual performance which apply to modern sailing vessels and can then be assumed to have applied to historic one’s.

So, for example Blue Stocking mentioned that in his experience the Charles W Morgan needed 30 ships lengths to complete a change of course.

So, assuming that this was a course change of 90 degree’s and given that Charles W Morgan is 113’ in length, this would suggest a turn radius of 1,130 yards and a tactical diameter of one and quarter miles.

In other words if the master of the Charles W Morgan decided to wear ship and return along the same course he would lose 1.28 miles of sea room in doing so and end up sailing back along the same route but 1.28 miles downwind of his previous position.

Now if that was a shown to be a consistent measurement of performance for all sailing vessels then by taking the length of the hull of the HMS Victory (226’) we can calculate that it would have a steady turn which was twice that of the Charles W Morgan and would lose over two and a half miles of sea room in performing a change of course.

However, both those figures ignore things like box-hauling, and tacking, and given that few seamen of any period like losing ground to leeward the question arises how much they can save by using their seamanship skills.
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