Nelson & His World

Does anyone have any examples of sailing speeds for vessels in Nelson’s time?

I know the Victory is said to have sailed at 8 to 9 knots in ideal conditions, and the maximum recorded speed was 11 knots. That isn’t much slower than a modern leisure yacht, despite its advantages of fibreglass and polypropylene. Not bad for a 3,500 ton floating gun platform! Of course the Victory had the advantage of a maximum sail area of 6,510 square yards (5,468 square metres) – a bigger area than a football pitch! A leisure yacht of a fifth or sixth the length of the Victory might only carry sail of 60 to 70 square metres (excluding spinnaker) – not much more than one hundredth of the Victory’s!

How much faster were frigates? 11 to 12 knots instead of the Victory’s 8 to 9 knots?

Tony,

One thought comes immediately to mind and that is the speed of the ships during the Battle of Trafalgar.

I know in one of my books there is a chart giving the speeds of several of the ships.

Unless my mind is playing tricks I am sure that Victory's average speed was something like 2 knots.

It really does give an interesting mental picture i.e. the great physical distance over which the battle was fought yet the ships lumbering along at barely walking pace.

MB

According to Robert Gardiner then "...by 1800 many British frigate classes were capable of 13 knots with a quartering wind,but perhaps more significantly, the number capable of 10 kts or more close hauled increased. French frigates were not noticeably faster, with one or two exceptions - and those were usually larger than the standard class".

Every ship from the late 18th century onwards, was required to complete a complicated 'sailing qualities' form on a regular basis, noting draught, height of gunports, speed etc. Looking at the results of these bears out Gardiners remarks,with most maximum speeds of frigates being around 12-13 knots.

Looking at the captured French frigates, the Imperieuse was said to very fast, able to achieve 13 knots under topsails alone. (but was also recorded as a 'heavy and deep roller, and very wet in any sort of seaway'). The Revolutionnaire was recorded running 129 miles in 9.5 hours, at an average of 13.5 knots

The smaller classes seem to have been good for 10-12 knots


The fastest I have seen was Newcastle (60 gun 4th rate - 1813) which claimed "14 knots with the wind 3 points on the quarter; rolls easy not very deep"

There is a very charming letter written by Nelson to Captain Keats, lumbering along in the 'Superb'. It is intended to reassure Keats that Nelson understands his difficulties with the ship. Nelson was notoriously impatient, so his comment that 'if we all went ten knots, I should not think it fast enough' maybe suggests that this speed is something only to be dreamed of in larger ships?


Victory, May 9th 1805

My Dear Keats,

I am fearful that you think the Superb does not go as fast as I could wish. However that may be, (for if we all went ten knots, I should not think it fast enough,) yet I would have you be assured that I know and feel the Superb does all which is possible for a ship to accomplish; and I desire that you will not fret upon the occasion.....'

With guns jettisoned and "pulling out all the stops" I believe that H.M.S. Pickle (schooner) averaged just 6.5 knots when bring news of Trafalgar back to England.

MB

Maximum speed of course depended on wind and wave and would only be achieved under certain circumstances I think - normally speed would be much slower

The Victory was accredited at the time, and since, as being one of the best sailers in the fleet and was partly the reason why Commander's in Chief valued her as a flagship.

However, there were other ships performed well too, and in Peter Goodwin's book 'Nelson's Ships' he gives, as an appendix, the various findings regarding the sailing abilities of the other ships Nelson served in. These observations were not usually made by Nelson at the time he served in them, but by another captain. I don't have my copy to refer to at the moment, but they provide a good example of the sailing abilities of each ship.

As one would expect most ships had a favourite point of sailing and would often perform slightly better on that point than another vessel, which was ostensibly of the same design and build. On another point of sailing the latter vessel may have the edge, so the speed of any ship was relative. I believe usually the best point of sailing for most ships was with the wind over the quarter, and became progressively worse as the wind drew ahead, even for the Victory, although still good. With the wind from ahead, ships often had to 'tack', which meant that the ship altered course through the wind (using the sails and rudder) until it blew from the opposite bow. Here again some ships performed better than others and were through the wind in no time at all, whilst others took a little longer to complete the manouver.

There were of course other factors to take into account, such as the strength of the wind, the sea state and the amount of sail set. Very important too was the fact that the ship's captain had to get to know the vagaries of his command and how to get the best out of her. This included having the right amount of sail set in any conditions and the ship trimmed properly to her waterline. Most ships probably sailed best when slightly more trimmed by the stern. As a voyage progressed, the stores and sometimes the guns were moved around to keep the optimum trim. Other ploys could be adapted too, and in light winds buckets of water were sometimes hoisted aloft to dowse the sails. This was so that the weave of the cloth would tighten up and so hold more wind. C.S. Forrester wrote a good account of this in his book about the War of 1812 with America, where two frigates (one British, one American) are opposing each other and employing this tactic.

Tony

All newly built ships were taken on trials as soon as rigged. Officers in charge had to fill out a proforma. I have copies of three. They are "Bellona" (74) 1783 which says, in relation to speed

"Question. How does she behave close hauled and how many knots does she run
in a topgallant gale
in a topsail gale
under reefed topsails
under courses?"
"Answer. 9 knts with smooth water.
8 to 8 and a half knts.
7 and 6 knts
Depends on the wind. The most knts she runs before the wind is 10 - 12 knts."

"Minden" (74) 1810, where the answers are
5 - 7 knts according to the swell
Much the same
no entry
With the wind one point, free on the beam will go 7 -8 knts. Her best sailing is with the wind abaft the beam when she will go at 8 -9 knts.

The third is the frigate "Doris" 1822. The answers here are slightly different ie
Under single reefed topsails - 9 knts 4 fathoms
Under double reefed topsails - 9 knts
Large under all sail possible - 12 knts
Before the wind - 10 knts 6 fathoms"

Don't ask me to account for the differences between "Bellona" and "Minden"! The former, although older, was pretty fast. The problems of keeping a fleet together are clear.

Brian

PhiloNauticus!

Just one quibble - "Imperieuse" was not French but was the captured Spanish ship "Medea", taken in the famous, or infamous, incident when 4 frigates under Graham Moore attacked a squadron of equal size returning from S America carrying $4m and precipitated war in 1804.

We don't want French shipbuilders to get all the credit for fast ships do we?

Brian

Thank you everyone, for all the great information you have provided. I phrased the question vaguely as there would be so much variation with weather and sea conditions.

Yes indeed - Mansfield in the Minotaur, last but one in the weather column, took 3 hours to reach the battle after the Royal Sovereign first engaged – Imagine the frustration!. But that was also the time it took Dumanoir to return with the van squadron, after some of his ships had to use boats to pull their bows round, so the Minotaur and Spartiate took on five enemy ships fresh to the battle.

PhiloNauticus, the ‘Sailing Qualities’ reports seem to be volumes ADM 95/23 onwards at the NA. Each volume seems to cover a range of years. Do you happen to know whether the reports are in any particular sequence within each volume – date, or ship’s name? (Just wondering whether it would be possible to request a copying estimate for particular ships, or whether to leave it until the next visit.)

That seems a very impressive average speed for a small vessel over a number of days with foul weather conditions some of the time, and then becalmed one day as they neared England – they resorted to the sweeps for several hours.

PhiloN, your quotes from Robert Gardiner prompted me to stop being so lazy, and get his ‘Frigates of the Napoleonic Wars’ down off the bookshelf. That includes several pages of analysis from the ‘Sailing Qualities’ reports, and suggests the benchmark for performance was the 40-gun Endymion (1795), with 14.4 knots recorded sailing large, albeit reduced to 18-pounders. With 24-pounders, she still reached 13.6 knots, and was capable of 11 knots close-hauled. Gardiner does point out the limitations of the data on speeds quoted in the reports, both from the point of view of captains quoting peak speeds, and perhaps exaggerated speeds, and also the inaccuracies of estimating speed from a log-line measurement with a sand-glass. But more importantly he points out that the measurement of speed in knots for dead-reckoning navigation was deliberately exaggerated otherwise there was the danger of underestimating the distance travelled, which could be disastrous if you made landfall in the dark when you weren’t expecting it! This was done by significantly shortening the distance between the knots on the log-line, so that speed was exaggerated. A recorded speed of 13 knots is equivalent to a speed of 11.5 knots by modern calculation. This does help explain why speeds sound so impressive.

Brian, thanks for your figures for 74-gun ships, which are very useful comparisons.

Kester, I will post again on wetting the sails...

Kester, for an account of wetting the sails to increase speed, we need look no further than Parsons’ account of Nelson’s chase of Le Généreux in the Foudroyant, where Berry tries almost every trick in the book to gain some speed:
‘Get the engine to work on the sails’ refers to wetting the sails by hosing them with a pressure pump / water engine / fire engine. This is interesting (to some of us!) as a pressure pump or fire engine was not commonly found onboard ships at that time. Did the Foudroyant have one, or was Parsons applying his knowledge of later practice to his earlier memories?

Putting shot in the hammocks (on the windward side) would have reduced the heel of the ship, making the sails more efficient. Slackening the stays and giving the masts some play was presumably to reduce the risk of damage to the masts by a gust of wind when carrying a lot of sail, or by violent pitching of the ship at speed. I’m guessing that hanging butts of water in the stays was to maintain some tension while providing some spring in the stays? Would that be right? Or were the butts of water to use for wetting the sails? But if the sails were sprayed from an engine on deck, this would not have been needed. Emptying the water and pumping the ship would be to lighten her.

The reason that wetting the sails worked was not understood at the time. It did tighten up the weave of the cloth, but the very small amount of air that passed through the weave of the canvas would have made virtually no difference to the performance of the sails. I would imagine that any gain in performance thus achieved would have been lost by the extra weight of wet sails. The reason that wetting the sails worked was that the canvas shrunk as the weave tightened, and the sails therefore tightened up and became flatter. Flatter sails are more efficient (provided they are not too flat!), but the reason was not understood at the time, and indeed many explanations that you see today are also flawed. The action of the wind on a sail is sometimes explained by treating the wind as purely a force applied in its direction of travel. If the sail is at an angle to the wind, then the force can be resolved into two components, one useful component perpendicular to the sail and one parallel to it which is not useful. The sail itself then acts on the mast and the useful component of the wind’s force can further be resolved into a forward component and a sideways (leeway) component. According to this explanation, the perfect sail would be completely flat, so that the whole sail can be set at the optimum angle for the maximum forward component of force. If the sail is curved, then different parts of the sail are at different angles to the wind, and only one part of the sail can be at the optimum angle. However this cannot explain the degree of efficiency of sails when sailing into the wind. For a ship sailing close-hauled 6 points off the wind, the useful forward component of the force on the sail would be very roughly a third of that for a ship sailing with the wind on the quarter. If this was the full explanation, then instead of a frigate sailing 10 or 11 knots close-hauled and 13 knots with the wind on the quarter, I would guess it would perhaps sail at only 4 to 6 knots close-hauled.

The reason for the seemingly almost magical efficiency of close-hauled sails is that aerodynamics allows the wind to produce a force on a surface that is sideways (perpendicular) to the wind’s direction. This is easy to prove by holding the edge of a piece of paper and blowing horizontally across the top surface. The back edge of the paper will curl up and lift into the air, showing that there is a force acting vertically upwards even though you are blowing horizontally. This is also the force that keeps an aeroplane in the air when it is flying horizontally. The propeller or jet can act horizontally and does not have to be angled up or down, the wing can be completely level, but there is still a force generated which acts vertically upwards on the wing which counteracts the downwards gravitational force.

Oops, this is getting ridiculously long-winded, but I’m nearly there! Sails (including square sails) also act as aerofoils, and deflect the wind towards the stern of the ship. But counter-intuitively it is the air flow around the outside of the curve on the leeward side of the sail that is most important. This air flow actually accelerates as it follows the round the curve outside the sail and is also deflected towards the stern. Bernoulli’s principle tells us that the pressure is lower in faster flowing air, and therefore the pressure differential between the windward and leeward surfaces of the sail create the forward force. An equally good explanation is provided by Newton’s laws by taking into account the deflection of the airflow. However, although both Bernoulli’s principle and Newton’s laws were known, nobody had yet identified that this was the explanation, and the concept of an aerofoil was unknown.

But why wet the sails to make them flatter, when a curved sail acts as an aerofoil? The answer is that the sails were too curved. Too much of a curve separates the airflows, creates turbulence, and reduces the efficiency of an aerofoil. Although a flat board can still act as an aerofoil (the airflow creates its own curve), the best shape is a flatter curve than was usually present in sails at that time.

What intrigues me is how naval architects and seamen made such effective use of forces that they didn’t understand. But if it works, do it!

However it does seem strange to me how little comment there seems to have been about the surprising efficiency of close-hauled sails at that time.

Tony!

No one has given you an authoritive answer to your question about the organization of ADM 95/-, so I will (dangerously) try to extrapolate from a single example.

Adm95 runs from 23 to 62 and covers 1755 to 1838 (ie 40 numbers and 83 years) so there is no neat correlation between piece and years. When I looked up 'Doris' ten years ago, it was in (according to my notes) ADM 95/50 folio 79. Since 'D' is high in the alphabet and the 1821 survey was dated 31 March, a correlation between folio number and either of these factors seems remote. Its easy to find the report on a particular ship if you know the date, but there seems to be little logic to the arrangement.

Looks like you will have to go back to find the report on 'Minotaur'.

Brian

Tony,

Many thanks, I think, for your full explanation!

Yes, I am sure you are right and today we are generally much more aware of the scientific principles involved with the making and performance of sails. This, I suspect, has come about about through the development of aircraft and also very likely the scientific developments made in the striving to produce the ultimate racing yacht for such events as the America's Cup.

In Nelson's time and later, such technical considerations were largely unknown. Seamen were more concerned if something was practical and thus various techniques were worked out by trial and error, until a workable idea was arrived at. When it had been, they may only have known that it worked but had no real explanation as to why it did so.

I came across this reference to the escape of the USS Constitution from an enemy (i.e. British) squadron, and which I was referring to earlier. You'll have to scroll down to near the bottom of the page for the reference:

http://www.history.navy.mil/docs/war1812/const4.htm

Isaac Hull mentions the use of the 'engine' for playing water on the sails, and I have heard that it was generally hoisted into the tops, on any ship, for this purpose. This would make more sense and perhaps the water butts suspended from the stays were to provide the water.

Thanks Brian, for your info on ADM 95. There are a few ships I would be interested in, so it may take a while.

Thanks for the link and extra information on the Constitution, Kester.

The other reason for having water in the tops when in action was of course to extinguish fires, or to wet sails and rigging to prevent fire. In 1796 Samuel Bentham proposed the use of forcing pumps as a fire engines in the tops, and was particularly keen that they should be used for other purposes to ensure they were kept in good working condition. One of the uses he proposed was for wetting sails to improve their efficiency, and he believed this worked both by closing the weave and also by making the sails flatter:
His proposals were in response to the Admiralty asking him for his opinion on "a proposal of Mr. Taylor's respecting a forcing pump”, but as far as I am aware, there was no widespread adoption of the idea for another fifteen years or so, when another pump was proposed.

Moving a little out of our time, I came across a note by Frank Scott in the Mariner's Mirror of a story that a clipper once logged 'Sixteen knots and a Chinaman' when the Chinese crewman who nipped the log-line at high speed was whipped over the taffrail and lost overboard.

Moving back to Nelson's navy, can anyone tell me how many intermediate fathoms were actually marked on the log-line between knots? Every fathom, every second fathom, just half knots, or none?