Chapter IV: The Evolution of the Modern Racing Yacht (2)

It is fully twenty years ago that the late Mr. William Froude began to give to the world the results of his experiments on the resistance of planes of different lengths, coated with various substances and towed at varying speeds through the water. These experiments were conducted under the most favourable conditions, and with the nicest regard for accuracy, and practically confirmed Maquorn Rankine's deductions, although it was found that Rankine had somewhat overestimated the value attachable to surface friction, and had also overestimated the increase in frictional resistance, due to increased speed. Still the great fact remained that practically the entire resistance to a fairly formed body, moving through water at moderate speeds, is due to friction and to friction alone.

Rankine's reasoning, early in the sixties, had been too subtle for those fathers of shipbuilding at that date engaged in the art. Able, honest, practical men, most of them could have handled an adze, or maul, with the best of their workmen, and were more at home fairing a sheering batten, or directing a launch, than in analysing speed curves, or investigating strength calculations.

But one or two of the younger and brighter minds in the profession, more especially those who had the advantage of Rankine's direct tuition, felt that the old beliefs as to resistance presented such anomalous and unreconcilable results that they could not be founded on any true law of nature. John Inglis, jun., then a mere boy, instituted in Pointhouse Shipyard Rankine's method of estimating the resistance of ships, and for many years was alone in this mode of investigation.

Model of S.S. 'Merkara.'

SPEED IN FEET PER MINUTE RESISTANCE IN LBS.]

But with Froude's experiments all doubt on the matter vanished. It was no longer a question of 'condemned mathematics.' Froude had the happy knack of writing so that the proverbial schoolboy could understand him; and the schoolboy could see the value of resistance to motion through water weighed out as simply and accurately as a pound of currant bun. These experiments for the determination of the frictional resistance of water, published in 1874, were supplemented presently by experiments on models of actual ships, and also by towing a full-size ship, the 'Greyhound,' her resistance at various speeds being recorded by means of a dynamometer on board the 'Active,' the vessel towing her. The results of the experiments on model and ship were set out in a curve, when it was found, after the necessary corrections were made, that both curves were of precisely similar character. A basis of comparison between model and ship was thus established, the measure of this being set forth in what is known as Froude's law of comparison, which may thus be stated. The equivalent speed of a ship and the model it represents will vary as the square root of their lengths. Thus, in the case of a ship 100 feet long represented by a model 4 feet long, the equivalent speed of the ship would be five times that of the model, and at these equivalent speeds would present similar phenomena connected with resistance as the model does. This fact enormously increased the knowledge of investigators, and it was belief in it that gave the writer absolute confidence in carrying out the design of the 'Vanduara,' though he possessed experience in small boats only. Mr. Froude also split up the several elements of resistance to motion through the water into their component parts, assigning a value to each, and showing what was due to surface friction and eddy-making, and what to wave-making. Scott Russell had already argued for a given length of fore and after body for any given speed, and this was recognised by yacht-builders to some extent by their gradually lengthening out their vessels; but the disadvantages as well as the advantages of length could only be thoroughly realised on investigating Froude's experiments. An example is given of such an experiment in the diagram, which shows the resistance curve of a model of the 'Merkara,' built by Messrs. Denny Bros., at Dumbarton, where the several resistances are shown, each in its place. In this diagram the resistance due to surface friction is indicated by the dotted line, and the total resistance by the full line. Up to a speed of 250 feet per minute (for the model) the resistance is almost entirely due to skin friction, but after that the wave-making becomes more and more serious until at 370 feet per minute the wave-making takes more power than the surface friction.

While surface friction thus plays a very large part in the resistance of all vessels, and more especially in that of ocean-going steamers and ships, which from their large dimensions seldom attain serious wave-making speeds, yet undue importance may be placed upon friction, and, in the smaller yachts, especially, surface may be inordinately cut away. A notable example of this was the 'Thistle,' built in 1889 to compete for the America Cup; here the surface was so cut down that sufficient lateral plane was not left to hold her to windward, and although she sailed the water as fast as the American champion, the 'Volunteer,' she drifted bodily to leeward.

A short history of Mr. Froude's discoveries in resistance was advisable before touching on 'Jullanar,' as this wonderful vessel, whether the result of intuition or of early and immediate appreciation of Froude's investigations, was a remarkable example of the modern theories regarding naval architecture.

The same year that 'Jullanar' was built, I designed my first racing yacht, the 5-ton 'Clotilde,' but whilst I had the advantage, through my friend Mr. John Inglis, jun., of specially early access to Professor Froude's investigations, I cut her away in a somewhat timid fashion, though sufficient for her at that time to be compared to a 'cart-wheel,' with the accompanying prediction that she might 'run on land, but would never sail in salt water.'

Meanwhile, with splendid audacity, and with no timid reverence for precedent, Mr. Bentall built the 'Jullanar.'

An Essex plough and agricultural implement maker, Mr. E. H. Bentall had but little training in naval architecture, but from boyhood had been fond of yachting and of yacht modelling. He fancied he could do something in the way of improving the form of the existing racing yacht. After cutting several half-models, he got one that pleased him, and on a piece of his own property adjoining the Blackwater river in Essex, the famous yawl, afterwards to be known as 'Jullanar,' was laid down.

_126 tons. Built by E. H. Bentall, Esq., 1875._]

Great length was taken in proportion to beam, as length means capacity for speed, and beam in those days was doubly taxed. Draft was untaxed, and was used boldly to obtain stability and weatherly qualities; but while such proportions would have been impossible with the ordinary form of forefoot and sternpost, as the boat would have been clogged up with wet surface, this was got over by cutting all deadwood clean away both forward and aft, in such daring fashion as was not attempted until 'Thistle' was built, years afterward and I should not have essayed such a form of profile in her had not 'Jullanar's' success given me a precedent. Add to these features the fact that every line in the vessel was easy and fair, and the only wonder is that the famous yawl was not even more phenomenally successful than she was.

Mr. Hunt, publisher of 'Hunt's Yachting Magazine,' has kindly supplied the following measurements of the 'Jullanar,' which were given to him by Mr. Bentall himself, when he would not let anyone else have them. Coming therefore from the fountain-head they are accurate, and should be preserved as a register of detail.

_'Jullanar'[3] 126 tons, yawl_

ft. in.
Length over all 110 6
Depth of hold 12 0
Length on load-line 99 0
Beam extreme, one sixth of load-line 16 10
" on water-line 16 5
" on deck 16 8
Depth after under load-line 13 6
" at forefoot load-line 1 6
" at midship 13 6
Height of freeboard aft 6 3
" " forward 7 9
" " midships 3 8
Height of freeboard bulwarks 2 0
Rake of sternpost, upright
Distance the greatest transverse section is abaft centre of
vessel at load-line 10 6

Distance of centre of gravity of displacement below water-line 3 4
Length of mainmast 75 0
" deck to hounds 53 0
" masthead 9 6
Diameter at deck 1 4
Length of main-topmast, fid to pin 38 6
" main-boom 56 6
Diameter centre of main-boom 1 0
Length of main-gaff 40 0
" bowsprit outboard 24 6
" gaff topsail-yards, No. 1 63 0
" " " No. 2 46 0
" " " No. 3 22 0
" mizzen-mast 51 6
" deck to hounds 36 0
" mizzen-boom 26 0
" mizzen-yard 35 0

[Footnote 3: _Vide_ 'Arabian Nights,' the 'Princess Jullanar of the Sea.']

To my mind the genius, daring, and originality of mind of Mr. Bentall were even more fully displayed in the design of the unsuccessful 'Evolution' than of the successful 'Jullanar.'

The 'Evolution,' as her name implied, was the logical outcome of the then tonnage rule, and of the laws of resistance rediscovered, or at least popularised, by Froude. It seems self-evident now that with a belief in these laws only one type of boat could be the result; but Mr. Froude alone had the courage of his opinions, and built the extraordinary 10-tonner which, if it did nothing else, scared the authorities into changing the tonnage rule. 'Evolution' was by far the longest of the 10-tonners, her dimensions being 51 ft. × 6 ft. 6 in.--indeed about the same water-line length as the twenties. To get moderate wet surface the ends were cut away; but as 'Jullanar' already represented the utmost that could be done in that direction, while preserving a fair line of keel, this was cast aside in 'Evolution,' and the profile was that of a true 'fin' boat. More than this, it was found after a trial sail or two that she was very deficient in stability when the lead slab forming the keel was recast in the form of a bulb on the bottom of the plate, the completed design simply forming one of our modern bulb fin keels, but of course, owing to the 94 rule, with vastly less beam. 'Evolution' was not a success because of her insufficient stability, but with the meagre data in possession of the designer as to the stability of boats of this class, it would have been marvellous had the difficulty been overcome in a first trial. To those able to see the beauties in a design, it matters less whether the ultimate outcome has been successful or not, and while to 'the general' nothing succeeds like success, a few have a kindly sympathy and hearty admiration for those who have laboured, that _we_ may enjoy the increase. Many of the best and kindest thoughts and brightest ideas never reach fruition in this world, and so in the mechanical arts there is often more genius displayed in a failure than in a success, with this difference, that a mechanical idea seldom dies, but, 'blossoming in the dust' of one brain, is plucked and worn by another. 'Evolution' lay dead for fifteen years. She has had a striking resurrection on both sides of the Atlantic.

FT
L.W.L. 50.75'
D°. BEAM. 6.395'
EXTR. BEAM. 6.50
DRAUGHT 10.00

'Evolution,' October 12, 1880, 10 tons, Y.R.A. Designed by E. H. Bentall, Esq.]

In the autumn of 1886, as has been stated, the tonnage rule was changed to that of rating, the only taxed dimensions being length on water-line and sail-area. This change, though at once affecting dimensions, did not materially affect form, though even in the earlier boats designed under this rule more hollow was given to the sections, this being of course a necessity, as with the added beam abnormal displacement would otherwise have been the result. But displacement was not immediately cut down, and for a given length of load-water-line yachts had quite as much displacement as formerly; 'Thistle,' 120-rating, and 'Mohawk,' 40-rater, the only two large yachts built the first year for the new classification, both being wholesome big-bodied boats, with 130 and 58 tons displacement respectively. Overhang naturally increased somewhat, as it was apparent that this could be more usefully adopted with a shallow-bodied boat than with a narrow one, it being evident that the natural way of forming the stem and counter was to follow the general buttock lines of the fore and after body. This overhang on the fairly deep boats built up till 1890, so far from being objectionable, was a distinct advantage, as it gave a fine, easy, and at the same time lifting, bow in a sea, eased the bow riband lines when the boat lay down and was hard driven reaching, and carried the side fairly out aft in the long counter.

Profile of lines of 'Meteor' (late 'Thistle'). Designed by G. L. Watson, 1887.]

But beam was now steadily increasing, as untaxed dimensions are apt to do, while extreme draught also increased, and these two giving ample stability, displacement was more and more cut down. Length still had to be got somehow, but length ran up wet surface, and in the 'classes' for every foot of length a considerable amount of sail-area had to be given, making, as it were, a direct and indirect tax thereon. With an ordinary form of profile, the longer yachts would have been clogged up with wet surface; so profiles first imitated 'Jullanar' and then 'Evolution,' while displacement was cut down to a minimum, to give an easily driven form, and stability got in another way, by lengthening the righting lever of the ballast, by giving immense draft of water, and in the smaller classes concentrating this ballast in the form of a bulb, as in the altered 'Evolution.' With the shallow body, overhang has of course increased, the flat section carrying out naturally into overhangs forward and aft, which almost double the water-line length of the boat on deck. That such a type of boat sails fast for a given sail-area and water-line length is beyond dispute, but this exhausts almost all that can be said in its favour. For 1/2-raters, 1-raters, and 2-1/2-raters, the type is perhaps suitable enough, as these are only used as day boats, and extended cruising was never contemplated in them. But from 5-up to 40-rating the type is nothing like so good as that of the boats built prior to 1890. Expensive to build, expensive to handle, without head-room, or indeed room of any kind inside, they would thrash themselves to pieces in any sea but for the admirable manner in which they have been put together. A season, or at most two, sees the end of their success as racers; then they must be broken up, or sold for a mere song, as they are quite useless for cruising. So strongly was this felt by the various yacht-builders and designers, that in the autumn of 1891 they, in response to the invitation of the Yacht Racing Association, addressed a joint circular to that body, and, with I think exceptional abnegation of what looked to be their more immediate interests, pointed out the undesirability of the present type of yacht, in the following letter:--

Langham Hotel, London: October 6, 1892.

We (C. P. Clayton, William Fife, jun., Charles Nicholson,
Arthur E. Payne, H. W. Ridsdale, Joseph Soper, and G. L.
Watson) have met for the consideration of the questions put
before us in the circular of the Council of the Yacht Racing
Association, dated September 27, 1892.

We have considered that, besides the saving in time to the
Council and to ourselves, it would be more satisfactory for
many reasons to have such a preliminary meeting for
interchange of ideas on the important issues raised in this
circular, and we trust that this course of action will be
approved of by the Council. We may state that we are
practically unanimous in the opinions hereinafter expressed,
the only exception being on the one point of taxing
overhang, Mr. Ridsdale feeling that he could not go with the
majority in this.

We would, then, most respectfully submit to your Council
that as designers of racing yachts we have no desire
whatever to interfere with the present rating rule. It has
the merit of being the existing rule, and is a perfectly
fair one for racing yachts together by, as indeed is any
rule whatsoever, so far as designers are concerned, provided
its conditions are clearly stated beforehand. But as naval
architects, and, if we may be permitted to say so, as
trustees for the yachting public, we think it our duty to
point out any deteriorating tendency in a rule. We cannot
help fearing that the present length and sail-area rule has
such a tendency, and is leading, if it has not already led,
to an unwholesome type of boat.

We take it that the general yachting public require in a
yacht: That she shall be safe in all conditions of wind and
weather; that she shall combine the maximum of room on deck
and below with the minimum of prime cost; and that she shall
be driven as fast as may be with the least expenditure of
labour--i.e. that she shall have a moderate and workable
sail-area. Therefore, as but few men can afford to build for
racing, and for racing only, and as the racer of to-day is
the cruiser of a few years hence, any rating rule should by
its limitations encourage such a wholesome type of vessel.

On the above assumptions we have based our advice, and it is
for your Council, as representing the general body of
yachtsmen, to determine whether these assumptions are
correct or not.

We are all agreed, then, that the present length and
sail-area rule is a most admirable one for the
classification and regulation of time allowance of racing
yachts. But we are also of opinion that the tendency of
this rule is such as to induce a vessel of so large
dimensions, relative to displacement and internal capacity
(i.e. the useful living room on board the ship), that it is
advisable to so alter or modify this rule that a type of
vessel having more body may be evolved.

We suggest that length and sail-area (as being the leading
elements in speed) should be preserved in some form, but
modified so as to make it the interest of builders to
produce a bigger-bodied boat.

The direct method of doing this would be to introduce
displacement or register tonnage in some way as a divisor in
the formula, but we foresee so many difficulties in the
practical working of this that we are not prepared to advise
it.

By taxing breadth and draft or, alternatively, girth, and by
reducing the tax on sail, we think this result may be
arrived at indirectly. As to the precise value that each
element should take in such a formula, we, at this stage,
are not prepared to venture an opinion.

The above on the general principles of the rule.

But we also feel that the details of measurement, &c.,
require revision.

_On the hull._--The overhang, at least forward, should be
taxed, as it may be carried to such an extent as to be a
source of danger, but it need not be taxed excessively or to
extinction.

The L.W.L. should be marked forward and aft.

Should girth or draft be used in the formula in centreboard
vessels, some proportion of the drop of board should be
added, and a limit should be placed on the weight of the
board.

In the smaller classes, at least, the crews should be
limited.

_On the sails._--The perpendicular of fore triangle should
be measured from top of deck to where the line of luff of
sail would cut mast.

That the question of limiting the relative area of mainsail
to total sail in the various classes be considered.

Mr. Alexander Richardson, of Liverpool, was unable to be present at this meeting, but this note has been submitted to him, and receives his endorsation:--

The Council of the Yacht Racing Association, however, took
the view that what the yacht-owning public want in a racing
yacht is speed, and speed at any price, and on the
yacht-builders clearly understanding this they withdrew
their objections as having been made under a
misunderstanding, but asked to be tied down to some extent,
in a letter dated November 8, and in the following words:--

'Our opinions, as expressed in that letter of October 6,
practically remain unaltered; but so far as we are able to
interpret the wishes of yacht-owners, as stated in the
public prints, and more especially as expressed by your
chairman and the majority of your committee, we now take it
that speed, and speed before other good qualities, is what
is to be aimed at.

'We consequently withdraw any suggestions made in that
letter, as having been made under a misapprehension as to
your requirements.

'But while it may be determined to retain a length and
sail-area rule, either in its present or in some slightly
altered form, we would most respectfully suggest that, at
least in the classes above 5-rating (if, indeed, a lower
line should not be drawn), the tendency toward abnormal and
un-shipshape form should be curbed in some way. The main
direction in which we would propose such limitation in form
would be in the outline of longitudinal section, and we
would suggest that this should be bounded by a fair line,
concave, or at least not convex, toward the water-line. That
the sternpost should show, say, a quarter of an inch above
the water-line aft, and the rudder be hung thereon. That
overhang forward and aft should be restricted, as also the
extreme forward position of mast; but as we deem it
undesirable to absolutely prohibit any form, we would simply
propose to tax such variations from this normal one so
heavily as to make their adoption unprofitable.'

The Yacht Racing Association, however, thought it undesirable to limit form in any way, and beyond the adoption of the proposed method of measuring the fore triangle, and marking the L.W.L., the rule remained unaltered.

1893 therefore saw new boats in the classes, fast, it is true, in fresh breezes, but undesirable from anything but a racing point of view. In the unclassed vessels above 40-rating things were not quite so bad, as with a practically unlimited sail-area a fair amount of body was required to carry it. Besides, men who did not mind spending two or three thousand on a 'machine' hesitated before putting down ten or twelve. In America, however, where money is spent like water when the national honour is at stake, 85-foot machines were built on the off chance of their being successes; but it is gratifying alike to American and British yachtsmen that the Cup should have been defended by such a wholesome type of vessel as 'Vigilant' undoubtedly is.

In a short chapter showing the evolution of the modern racing yacht, many links in the chain of descent must be left unnoticed. I have had to leave almost undescribed Dan Hatcher's wonderful fleet, beginning in 'Glance' and 'Muriel,' and culminating, perhaps, in 'Norman'; Nicholson's famous schooners and yawls ('Florinda' was a standing miracle for years); Michael Ratsey's equally fine ships; Richardson's grand cutters and Clayton's clever 'length classers'; the work accomplished, and still being accomplished, by the famous William Fifes, besides many others whose labours are more fully recorded in other parts of these volumes. But I think no one of all that band who have loved and worked for the sport of yacht racing cares for the type of ship which has been evolved by their own ingenuity and the present Y.R.A. rule, and I am convinced that they would thankfully welcome any legislation which should protect the yachting public against the present extravagant, costly, and by no means seaworthy type of boat.

60 tons (1797), to Australia. Three keels, 1798, 1800-1-2.]

[Footnote 4: The first ship to discover that Tasmania was an island.]