Huzza! huzza! you know what that means.... I made up my mind to stop her at the edge of low water, and then examine and secure all that might discover itself. The tide rose to 15 feet 8 inches. She rose therefore easily over the rock, but was clear of it by only just five inches, which shows how near a squeak we had—it was a most anxious affair, but it is over. I marked 170 yards in the sand and on our warp, and at that extent I stopped her.... I have no doubt that to-morrow we shall see her free.
The following day they started for Liverpool. One hundred and twenty labourers were hired to work at the pumps, but only thirty-six came on board, and their services were unavailable, as they spent their time in discussing how much they were to be paid. Consequently, when the ship was taken in tow at 4 A.M. on the 28th there was 6 feet of water in the engine room and 5 feet in the fore hold, and she was making 16 inches an hour. Men from Her Majesty’s ships ‘Birkenhead’ and ‘Victory,’ which had been sent by the Admiralty to assist, were drafted on board, and the influx of water was reduced to four inches an hour. It was evident that Liverpool could not be attempted, so they made for Strangford Lough. A dense fog came on when they were off the entrance, and they pushed on to Belfast Lough, where the ship was grounded. During the night she was cleared of water, and the next day she started for Liverpool. The landsmen who had been hired the previous night to work the pumps were incapacitated by sea-sickness; and the ship was only kept afloat by the exertions of Captain Claxton and the dockyard hands who had been sent to assist in navigating her across. When she arrived at Liverpool she was placed over a gridiron, on which she sank when her pumps were stopped.
Notwithstanding the successful result of the efforts made for her rescue, the stranding of the ‘Great Britain’ in Dundrum Bay led to the ruin of the Company; and she was some time afterwards sold to Messrs. Gibbs, Bright, & Co., of Liverpool, by whom she was repaired, and fitted with auxiliary engines of 500 nominal horse-power. On a general survey being made, it was found that she had not suffered any alteration of form, nor was she at all strained. She was taken out of dock in October 1851, and since that time she has made regular voyages between Liverpool and Australia.
She is known as one of the fastest vessels on that line; and remains to testify to the ability and wisdom of those who, more than thirty years ago, were daring enough to build so large a ship of iron, and to fit her with the screw propeller.
| Dimensions of the ‘Great Britain’ Steam-Ship. | ||
| feet | inches | |
| Total length | 322 | 0 |
| The length of keel | 289 | 0 |
| Beam | 51 | 0 |
| Depth | 32 | 6 |
| Feet of water | 16 | 0 |
| Tonnage measurement | 3,443 | tons. |
| Displacement | 2,984 | " |
| Dimensions of original Engines, &c. | ||
| Number of cylinders | 4 | |
| Diameter of cylinders | 88 | inches |
| Length of stroke | 6 | feet |
| Weight of engines | 340 | tons |
| Weight of boilers | 200 | " |
| Water in boilers | 200 | " |
| Weight of screw-shaft | 38 | " |
| Diameter of screw | 15 | ft. 6 in. |
| Pitch of screw | 25 | ft. |
| Weight of screw | 4 | tons |
| Diameter of main drum | 18 | feet |
| Diameter of screw-shaft drum | 6 | " |
| Weight of coal | 1,200 | tons |
APPOINTMENT OF MR. BRUNEL TO CONDUCT EXPERIMENTS FOR THE ADMIRALTY WITH VARIOUS FORMS OF THE SCREW PROPELLER, APRIL 1841—TRIALS WITH THE ‘POLYPHEMUS’—OPPOSITION TO MR. BRUNEL’S EXPERIMENTS—TRIALS WITH THE ‘RATTLER,’ OCTOBER 1843-OCTOBER 1844.
SOON after Mr. Brunel had taken the bold step of recommending the adoption of the screw propeller in the ‘Great Britain,’ he was asked to send a copy of his report to the Admiralty. He did so; and in the course of a few months was invited to attend the Board on the subject of some experiments their Lordships proposed to make.
An interview took place on April 27, 1841; of which Mr. Brunel gives the following account:—
I attended the Board: Lord Minto stated that he wished a complete experiment to be made on the applicability of the screw to Government boats, and he proposed to place the conduct of the experiments in my hands as a professional man. I stated that I should have great pleasure in doing it, and should take great interest in it, provided they intended to make a good experiment and would place it entirely in my hands, without the intervention of any Government officers, but that I should communicate direct with the Lords, and of course with Sir E. Parry.[135] He said he proposed to build a vessel and engines on purpose, and that he particularly wished it to be left entirely in my hands, and took me apart to the window to impress this last condition on me.
Within a fortnight of his appointment, Mr. Brunel invited Messrs. Maudslay and Field and Messrs. Seaward to send him designs for the engines: they were to have been of 200-horse power, with a stroke of 4 feet. The engines were to make a smaller number of revolutions than the screw, the motion being communicated from the engine shaft to the screw shaft by drums and straps. This arrangement was adopted in preference to tooth-gearing, in order to facilitate the variation of the number of revolutions, in the experiments with different screws.
The designs ultimately sent to Mr. Brunel for his approval were those of Messrs. Maudslay and Messrs. Forrester. He reported to the Admiralty in favour of Messrs. Maudslay’s engines.
Before drawing up the detailed specifications, Mr. Brunel was desirous of procuring data for estimating the surface of the screw required to obtain the same resistance as that offered by the paddles of a ship similar to the new vessel. With this object he applied to the Admiralty for permission to make an accurate trial of the performances of the paddle steamer ‘Polyphemus’ at various speeds. This permission was granted; the trial, however, was fixed for such an early day that Mr. Brunel had barely time to make the preliminary arrangements, with the assistance of his friend Captain Claxton.
When Captain Claxton arrived at Southampton, the day before the trial, he found that there was no measured mile set out. He immediately hired men, got chains, staffs, and flags, and set out both a nautical mile and a statute mile. They made half a dozen runs each way with the ‘Polyphemus,’ noting carefully all particulars of speed, revolutions, &c.; and the results obtained were considered very satisfactory.
On October 1, Mr. Brunel received information from the Admiralty (now under the administration of the Earl of Haddington) that Messrs. Maudslay and Field’s tender was accepted. The engines were immediately put in hand, under Mr. Brunel’s supervision.
When they were approaching completion, he became anxious to learn something about the progress of the ship which was to have been built for them. Nowhere could she be found. The minutes were searched at the Admiralty, and it was ascertained that the ship was ordered, but that no ship had been laid down. This discovery, as might be supposed, excited considerable surprise. Mr. Brunel was sent for to the Admiralty to see Sir George Cockburn, the First Naval Lord. Almost the first words to him were: ‘Do you mean to suppose that we shall cut up Her Majesty’s ships after this fashion, sir?’—Sir George at the same time pointing to a model of the stern of an old-fashioned three-decker, in which large slices were taken off to give room for the screw, and the whole of the lower deck exposed to view, thus making the application of the screw look very ridiculous. On the model was written, ‘Mr. Brunel’s mode of applying the screw to Her Majesty’s ships.’ Mr. Brunel smiled, and denied its being his idea at all; he had never seen it before, and knew nothing about it. ‘Why, sir, you sent it to the Admiralty.’ This also Mr. Brunel denied having done. While an enquiry was being made as to where the model came from, Mr. Brunel employed himself in effacing the inscription with his knife. When the messenger returned, he reported that the model had come from the office of the Surveyor of the Navy. He was sent for, but did not appear. Mr. Brunel, to terminate this awkward interview, pleaded business, and bowed himself out.
Mr. Brunel often told this anecdote, and spoke of the adverse influence which had been exerted in some department of the Admiralty to prevent the successful issue of these experiments.
Soon afterwards Mr. Brunel was informed that the ‘Acheron’ would be prepared for the screw. He thereupon represented to their Lordships that the ‘Acheron’ could not, from her full after-body and other defects, be converted into such a ship as the Board had originally determined to construct for trying the screw; and, indeed, her unfitness was admitted by the authorities themselves.
To a letter on this subject, in which he stated that the attempt to apply the screw propeller to the ‘Acheron’ would not answer any of the objects which their Lordships had in view, Mr. Brunel received no reply, and for the next four months was kept quite in the dark as to what was going on. At length he made enquiries as to the cause of a treatment which, he said, he had never before experienced from any public body.
These enquiries proving fruitless, he at last wrote to the Admiralty, declining further interference, as it had appeared on investigation that the condition on which he had accepted his position from Lord Minto—namely, that he should have the entire superintendence of the experiments—had not been observed.
On the receipt of his resignation, Mr. Brunel was summoned to the Admiralty. He thus described his interview in a letter to a friend:—
Not a word was said about my complaint of the past, but they said they wished me to continue the experiments, and that my screw was to be tried first. I said that was not at all what would suit me; that I would, if they wished it, conduct an experiment as originally proposed; that I had no screw, that I was no competitor, but an arbitrator in whom the Admiralty had perfect confidence; that I was this or nothing. Then commenced a tedious fencing.... However, it ended in all parties being written to, and told that they were to follow my directions, and that I was to proceed to give such instructions as should enable a full experiment to be made of all screws generally. I then requested that this time I might have my instructions in writing.
In a few days Mr. Brunel received an official intimation that the ‘Rattler’ was to be adapted for the screw, under his directions.
The ‘Rattler’ was a vessel of 888 tons burden, 176 feet 6 inches between the perpendiculars, and 32 feet 8½ inches beam.[136] She had been commenced for a paddle-wheel steamer shortly before, and was of nearly the same tonnage and midship section as the ‘Polyphemus,’ but she had not the fine lines aft which were so important for the use of the screw.
She was not launched until April 13, 1843, just two years after Mr. Brunel’s first interview with Lord Minto; and she was then delivered to Messrs. Maudslay in the roughest possible state.
Except during the time that Mr. Brunel was prevented from attending to business by the half-sovereign accident, he was in constant communication with the dockyard authorities on matters relating to the construction of the ship, with Messrs. Maudslay as to the multiplying-gear and engines, and with Mr. F. P. Smith as to the forms of the various screws to be tried.
The engines and screw were fitted in the ship, after considerable delay; and, on October 24, 1843, Mr. Brunel reported on them in their completed state. On the 30th, the experiments were commenced.
More than twenty trials were made between that date and the following October, when the ‘Rattler’ went to sea, and Mr. Brunel could not of course any longer personally superintend the experiments; but, except on one or two occasions when his place was supplied by an assistant, all the trials that were made during the first year were conducted in his presence, and he transmitted the results from time to time to the Admiralty.[137]
The performance of the ‘Rattler’ was found to be satisfactory; and the position of the engines and screw being below the water line was so pre-eminent an advantage, that in 1845 the Lords of the Admiralty ordered more than twenty vessels to be fitted with the screw;[138] and since that time it has gradually superseded the paddlewheel for ships of war.
The services which Mr. Brunel rendered to the country during the whole of these proceedings were given entirely without pecuniary recompense, and in the face of opposition and discouragement; but he had the satisfaction of knowing that he had been mainly instrumental, not only in introducing the screw propeller into the mercantile navy, but also in securing its adoption in Her Majesty’s fleet.
INTRODUCTORY OBSERVATIONS—THE AUSTRALIAN STEAM NAVIGATION COMPANY—STATEMENT OF MR. BRUNEL’S PROJECT OF A LINE OF LARGE SHIPS (JUNE 10, 1852)—ADOPTION OF HIS PLANS BY THE EASTERN STEAM NAVIGATION COMPANY—EXTRACT FROM A LETTER DESCRIBING THE SCHEME (JULY 1, 1852)—LETTER TO J. SCOTT RUSSELL, ESQ., ON THE FORM AND DIMENSIONS OF THE GREAT SHIP (JULY 13, 1852)—REPORT ON MODE OF PROCEEDING (JULY 21, 1852)—REPORT ON ENQUIRIES RELATING TO THE DRAUGHT AND FORM OF THE VESSEL (OCTOBER 6, 1852)—REPORT ON THE PROCEEDINGS OF THE COMMITTEE APPOINTED TO CONSIDER MR. BRUNEL’S PLANS (MARCH 21, 1853)—TENDERS INVITED FOR THE SHIP AND ENGINES—REPORT ON TENDERS (MAY 18, 1853)—PREPARATION OF THE CONTRACTS AND SPECIFICATIONS—EXTRACTS FROM MR. BRUNEL’S MEMORANDA (A.D. 1852, 1853, 1854)—LETTER ON HIS POSITION AND DUTIES AS ENGINEER OF THE COMPANY (AUGUST 16, 1854)—LETTER ON AN ARTICLE IN A NEWSPAPER (NOVEMBER 16, 1854)—REPORT ON THE UNDERTAKING (FEBRUARY 5, 1855)—ARRANGEMENTS PROPOSED FOR OBTAINING ASTRONOMICAL OBSERVATIONS—LETTER TO G. B. AIRY, ESQ., ASTRONOMER ROYAL (OCTOBER 5, 1852)—APPOINTMENT OF MR. WILLIAM HARRISON TO THE COMMAND OF THE SHIP—MEMORANDUM ON THE MANAGEMENT OF THE GREAT SHIP (OCTOBER, 1855)—LETTER ON THE DUTIES OF THE CHIEF ENGINEER (MARCH 19, 1857)—SUSPENSION AND RESUMPTION OF THE WORKS.
MR. BRUNEL’S earlier labours in connection with the progress of Ocean Steam Navigation have been described in the chapters on the ‘Great Western’ and ‘Great Britain’ steam-ships.[139] The ‘Great Eastern’ is but the result of the application, under different circumstances, of the same principles which had guided him in his previous under-takings, the practical working out of the ‘idea which he had frequently entertained, that, to make long voyages economically and speedily by steam, required the vessels to be large enough to carry the coal for the entire voyage at least outwards; and, unless the facility for obtaining coal was very great at the out port, then for the return voyage also; and that vessels much larger than had been previously built could be navigated with great advantage from the mere effect of size.’[140]
In 1851, four years after the release of the ‘Great Britain’ from Dundrum Bay, Mr. Brunel became again connected with the construction of steam-ships. In that year he was consulted by the Directors of the Australian Mail Company upon the class of vessels which it would be advantageous for them to purchase, in order to carry out their contract for the conveyance of the mails to Australia. He advised them to have ships of from 5,000 to 6,000 tons burden, in order that they might only have to touch for coal at the Cape.
Some of the Directors would not hear of so startling a proposition; but they nevertheless asked Mr. Brunel to become their Engineer; and he retained the post till February 1853. Two ships were built under his direction by Mr. J. Scott Russell—the ‘Victoria’ and the ‘Adelaide.’
It was, no doubt, his connection with the Australian Mail Company that led Mr. Brunel to work out into practical shape the idea of ‘a great ship’ for the Indian or Australian service, which had so long occupied his mind; and it appears that in the latter part of 1851 and the beginning of 1852 he devoted much time and thought to the subject. He collected facts relating to the trade with India and Australia which demonstrated the advantages to be gained by a rapid and direct communication for the conveyance of passengers and troops, as well as of merchandise. It was with these enlarged views that Mr. Brunel entered upon the construction of the ‘Great Eastern.’ He writes in February 1854, ‘In February and March 1852 I matured my ideas of the large ship with nearly all my present details, and in March I made my first sketch of one with paddles and screw. The size I then proposed was 600 × 70, and in June and July I determined on the mode of construction now adopted of cellular bottom; intending then to make the outer skin of wood for the sake of coppering.’
In the spring of 1852 he communicated the results at which he had arrived to Mr. John Scott Russell, Captain Claxton, and other scientific friends, and also to several Directors of the Eastern Steam Navigation Company.
This Company had been formed in January 1851 for the purpose of establishing an additional line of steam communication by the overland route, for the conveyance of mails, passengers, &c., between England, India, and China, with a branch to Australia. However, in March 1852 the Government determined to grant the contract for the whole service to the Peninsular and Oriental Company. The Directors of the Eastern Steam Company were therefore obliged to report to their shareholders that the object for which the Company had been incorporated could not be carried out.
At about this time Mr. Brunel’s scheme was brought before the Directors, and he submitted to them a detailed statement of his project.
After describing the size and capacities of the vessels then used on the route between England and the East, and the amount and cost of the coals they consumed, he continued:—
June 10, 1852.
The same amount of capital and the same expenditure in money for fuel now required for a line of ships of the present dimensions would build and work ships to carry in the year double the number of passengers, with far superior accommodation, and in about half the time, and two or three times the amount of cargo; the whole difference being produced simply by making the vessel large enough to carry its own coal, exactly as when the ‘Great Western’ was projected for the New York line, the passage had been considered an impossible one for steamboats, or, if possible, only at a total sacrifice of all return for the cost. Certainly, no steamboat then built could get across except by a chance fair weather passage, and then only by being completely filled with coals and leaving no room for passengers or cargo. Simply by building a ship of the size necessary to take the coal, over and above the accommodation required for a due number of passengers and a reasonable quantity of cargo, the passage was rendered perfectly easy and certain, and has since become a mere matter of course, and an ordinary and profitable trading voyage.
The increased size, instead of being a disadvantage, was found, as predicted by the projectors, to be a great benefit, and gave increased speed, even beyond that proportionate to the power; and this steamboat, built in 1836, is still as good as any of her size afloat.
Nothing more novel is proposed now, but again to build a vessel of the size required to carry her own coals for the voyage. The use of iron, which has since 1836 become common, removes all difficulty in the construction, and the experience of several years has proved, what was believed before by most unprejudiced persons, that size in a ship is an element of speed, and of strength, and of safety, and of great relative economy, instead of a disadvantage; and that it is limited only by the extent of demand for freight, and by the circumstances of the ports to be frequented.
A Committee was appointed to confer with Mr. Brunel and with Mr. Scott Russell, ‘who was fully acquainted with all Mr. Brunel’s plans, and had ably assisted him in maturing them.’[141]
The Committee reported to the Directors that they had met on the day after their appointment, when, Mr. Brunel being unavoidably absent, Mr. Russell had attended and entered into a very full explanation of Mr. Brunel’s plans, and that a long investigation of his proposition had taken place; that a few days later they had met again, when Mr. Brunel attended, and that after a further and most satisfactory investigation, they had come to an unanimous decision in favour of the scheme. This resolution was adopted, and Mr. Brunel was appointed Engineer to the Company.
The following extracts from his reports and correspondence carry on the narrative till the date of the next meeting of the shareholders (December 1, 1852), when the details of the project were laid before them:—
Extract from a Letter describing the Scheme.
July 1, 1852.
The principle is, as I explained to you, a very simple one—that of building ships to carry their own coals, instead of incurring large expenses and great delay in coaling at numerous intermediate stations; and the result is a large vessel certainly, but one which, at the same cost of fuel as is now required for small ones, has, besides that room, for 4,000 or even 5,000 tons (measurement) of cargo, and as many passengers as offer. Thus the capital embarked in the one vessel is not so great in proportion to the tonnage space for cargo as the capital embarked in several smaller vessels carrying the same amount; while the current expenses are greatly less, and the speed, and economy of time by that speed and by avoiding tedious stoppages, greatly in favour of the large one. Practical men concur with me, not merely in the practicability of constructing the vessel, but in the great advantage as regards speed, seaworthiness, and safety resulting merely from the increased size; while all the mercantile men concur in the opinion that if goods can be carried direct in thirty to thirty-five days, the certainty of freight ensures a return far beyond all present proportion of return to cost.... On these points, of course, I quote only the opinions of the Directors. On the mechanical part I offer my own opinion, and may quote those of the first practical men of the day—Messrs. Maudslay, Messrs. Watt and Co., and J. Scott Russell, all of whom have assisted me in the project, and are prepared to join in it.
Letter to J. Scott Russell, Esq., on the Form and Dimensions of the Great Ship.
July 13, 1852.
The adoption of this plan being now determined upon, we must proceed to determine the details, and the first step unquestionably is the determination of the size and form of the ship. Now, in preparing the general design, I think the following conditions should be strictly complied with. If any of them appear to involve any great sacrifice in cost, or to involve any other peculiar difficulties, these difficulties can be considered afterwards; but the wisest and safest plan in striking out a new path is to go straight in the direction which we believe to be right, disregarding the small impediments which may appear to be in our way—to design everything in the first instance for the best possible results strictly according to the principles which theory, so far as it is supported by practice, teaches us, and without yielding in the least to any prejudices now existing unsupported by theory and practice, or any fear of the consequences; we can then afterwards weigh and balance deliberately the advantages of adhering to or giving up this or that particular part, or modifying dimensions, either from motives of economy, or as yielding to public opinion from motives of policy.
In determining the lines of the ship, for instance, I should adopt that which we have reason to believe the best possible without any concession, or any compromise or regard to any assumed difficulties of construction, or regard to assumed opinions; these difficulties will very likely vanish afterwards if disregarded in the first instance, as in the case of the continuous curve, in which my fresh ideas had the advantage even of your much greater knowledge, hampered by a little preconceived idea. With respect to the size, to arrive at it by constructive calculations from the fixed conditions that we can lay down is perhaps possible, but rather difficult, and I think we know sufficiently nearly now what the minimum size must be to work upon; that, and a trifling alteration afterwards in the scale, will suffice to bring it to the exact required capacity.
The positive conditions, then, are a maximum draught of water of 24 feet, when leaving the Hooghly with the coals for the voyage home; and the capacity must be at least 21,000 tons of displacement at this draught of 24 feet.
I think you will find that to effect this comfortably you must give a length of 650 feet at least, and an extreme breadth of 80 feet, but this beam of 80 feet requiring no fuller entrance than you would make with a beam of 70 feet, the 80 feet being obtained entirely by continuing a gentle curvature throughout the whole length, instead of having any parallel lines.
If the experiments upon the friction of surfaces turn out as I hope, and give us reason to expect a very much less resistance from a copper surface than that now created by painted iron, I suspect we may be led rather to increase our length and diminish the proportion of beam; but this is a very serious question, not entirely dependent on the consideration of the form of least resistance including friction, but also materially affected by the consideration of the advantages of the extreme steadiness of motion which length seems to give. It is a subject which must be well discussed and well considered, with the assistance of all those whose opinions and experience are likely to be of use to us. My own impressions, I confess, derived from considering the cases which we have, even after the striking result of the ‘Ocean Queen,’ are that positive length, independently of relative length, has much to do with it. When I see that the ‘Great Britain,’ although with a beam of about one-sixth of her length at the water line, and a midship section favourable to rolling, is nevertheless steady, I must conclude that positive length may compensate very greatly for a relatively wide beam. Now, we shall unquestionably have abundance of positive length. We must then be careful not to sacrifice much to keep a small beam, without being very sure that there are very great advantages; and, except for the assumed advantages of the long parallel or equal bearings, the form of least resistance, including friction, with a draught limited to 24 feet, and a required displacement of 21,000 tons, would, I apprehend, give us a beam nearer 90 feet than 70 feet. I should like to know exactly what the proportion would be without regard to the theory of the long narrow parallel forms; and then let us consider how much, if anything, should be sacrificed to attain the advantage assumed to be attained by relative length.
Let us therefore have at once the draft of a vessel of 21,000 tons displacement at the 24 feet water line, and of such form as will in your opinion give the greatest speed in smooth water, without seeking to make it narrow.
We must, of course, also bear in mind the comparative weakness of form caused by length, and the consequent increased thickness of material required, besides an actual increase of surface, involving a very considerably greater quantity and weight of material in the ship, which last consideration is very greatly in favour of breadth of beam; for I think you will find that the quantity of iron in two ships of 600 and 700 feet in length respectively, with the same displacement and the same ultimate strength to resist strains, will be fully in the ratio of their length.
Report to the Directors on Mode of Proceeding.
July 21, 1852.
Since the adoption by the general meeting of the plan recommended by the Directors, I have been engaged very constantly in maturing the details of that plan, and considering the course which it would be necessary to follow in order to carry them out in the surest, safest, and most efficient manner.
The steps which are about to be taken are unquestionably in the right direction, but they are considerable ones, and must be taken with deliberation and certainty, and without leaving anything doubtful; and, when determined upon, they must be followed up with decision.
Although you will probably determine upon constructing not less than two vessels in the first instance, yet they must both be proceeded with at once, and must in fact be exact duplicates of each other. The success of the two, therefore, depends upon that of each; there can be no average struck in such a case, but the two ships must be designed and executed on such principles and with such perfection that no doubt can exist of the result.
By well considering all that has been done, by selecting all that has been most successful, and by a judicious application of such results to the peculiar circumstances of our case, all this certainly can, I think, be assured, but it can be assured only by proceeding with the caution and the decision which the circumstances demand.
In the first place, as to the designing of the whole, the principle being determined upon, much may be ascertained by mere calculation, but for these calculations data are required, which nothing but experience can furnish. I have, therefore, availed myself of the assistance of those most competent to afford the required information. I have called in to my assistance the gentlemen whom I had already named to you as best able to give strength to our position by the value of their opinions, and best able to execute the various parts of the work with that experience and perfection which are essential to our success.
With respect to the form and construction of the vessel itself, nobody can, in my opinion, bring more scientific and practical knowledge to bear than Mr. Scott Russell. As to the proportion of power to be adopted, the form and construction of the engines, screw, and paddles, besides Mr. Scott Russell, I have had the benefit of the deliberate consideration and advice of Mr. Field, of the firm of Maudslay and Field, and of Mr. Blake, of the firm of Watt and Co. I have written also to my friend Mr. F. P. Smith, to whom the public are indebted for the success of the screw, for his advice on the subject. With such assistance I think we may rely upon the certainty of being able to design and to execute all that is best in the mechanical and ship-building department. In the naval department I have had the opportunity also of consulting two gentlemen, Captain Claxton and Captain Robert Ford, who possess special knowledge and experience on the subject. I have had several conferences with all these gentlemen, I have explained fully my views, and, with their assistance, settled preliminarily some of the principal points of detail. What I should propose to the Directors now is, that with that assistance I should proceed to prepare in detail the design of the ship, and the exact dimensions and form of the engines; that, in the meantime, I should obtain information upon certain points which will govern you as to the mode of contracting for the construction of the ships, and also that I should be authorised to adopt some means of determining one or two most important points which must govern some of the principal dimensions.[142]
Report to the Directors on Enquiries relating to the Draught and Form of the Vessel.
October 6, 1852.
Since the date of my last letter to you, recommending that certain enquiries and investigations should be set on foot to determine several points which would materially influence the plans I should have to submit to you, many circumstances have occurred to delay these investigations. Not having sent any competent person expressly to Calcutta to ascertain with certainty the draught of water that might be adopted, I have endeavoured to obtain as much information as possible upon this point from persons capable of affording it, who might be in England.
Several very competent men, captains of long experience in that particular navigation, and even local pilots of the first standing, happened to be within reach, and I have had personal communication with these gentlemen. Notwithstanding, however, these fortunate opportunities of obtaining information from the best existing authorities, we are left in pretty nearly the same state of doubt as to the maximum depth as we should be by a mere inspection of the charts, the opinion of very competent men varying so much as to fix this maximum as low as 21 and as high as 23½ and even 24 feet. They all concur, however, in fixing Diamond Harbour as the point in the Hooghly which may easily be reached, but beyond which it would be almost impossible to go.
A question as to the extent of swell which in so large a ship might be given to the sides, increasing the capacity without materially increasing the resistance, involved one of the experiments to which I referred in my former letter; these experiments have been made, and the result, such as it was, of the enquiries before referred to as to the navigation of the Hooghly, led me to direct the preparation of draughts of three different models of ships, and upon further consideration of these three, and under the circumstances, I have come to the conclusion of recommending one which will have the following dimensions:—namely, 670 feet in length, 85 feet beam, and a deep water draught of 30 feet.
Such a vessel would be able to carry her own coal for the voyage home out of the Hooghly with about 23 feet draught; but if between now and the period when the exact arrangement must be determined, it is found expedient not to attempt so great a draught in the Hooghly, the same vessel will, by coaling at Trincomalee on the return voyage, be exactly adapted to work out of the Hooghly with a good cargo of goods and coals for Trincomalee with only 20 to 21 feet draught.
I have been in communication with the eminent engine builders whose names I have mentioned on a former occasion, and with Mr. F. P. Smith, the inventor of the screw propeller. Some trials and investigations are still in progress to determine the relative advantages of a copper and iron bottom, on which question may depend the arrangements which may be requisite to provide for docking or rather laying up for cleaning, and when these points are determined I shall be prepared to lay before you a complete design of ship and engines for your consideration.
Efforts were made to induce the public to assist in carrying out the project. In February 1853, the Chairman (the late Mr. Henry Thomas Hope) and several of his colleagues formed themselves into a committee for the purpose of communicating with Mr. Brunel on the subject of his plans, and reporting to the Board thereon.
The results of this conference were embodied in the following report which Mr. Brunel addressed to the Directors:—
Report on the Proceedings of the Committee.
March 21, 1853.
To enable the Committee to arrive at a correct conclusion on this difficult question, I had gone through rather lengthy calculations of the minimum dimensions and the comparative estimated cost of the ships which would in each case answer the purpose under the several different circumstances which might be assumed; and the results of these calculations were laid before the Committee, and the relative advantages and disadvantages of each assumed case discussed....[143]
After much discussion, and comparing the probable receipts with the estimated expenditure, and allowing fully for interest of capital embarked, I think it appeared to the Committee that as a mere mercantile transaction, and with reference only to the Australian trade, the larger vessel would be the most economical, showing not merely the means of securing the largest return, but involving an actual diminution of annual expenditure....
The Committee were unanimously of opinion that the largest size of the first class would be the best, and would in every way answer the objects of the Company.
The dimensions arrived at by calculation for this ship would be in round numbers, 670 feet long, 80 feet beam.
This sized vessel would combine most of the advantages which we seek to obtain. It would carry coal to Diamond Harbour and back to Trincomalee; it would afford room for about 800 separate cabins larger than those now fitted up in packet ships, with large saloons, capable of accommodating 1,000 or 1,500 first and second-class passengers; and would carry 3,000 tons weight of cargo, without making any allowance for that increase of speed proportionate to the mere increase of size of which we see every day fresh proofs; the average speed of the ship, with the proposed power of engine and calculated consumption of coal, would be 14 knots at the average, making the passage out in 34½ days, say 36; but with that increased speed which has been shown to take place with increased dimensions, we may speculate upon the voyage being performed in 30 days.
This same vessel, fitted up for the Australian voyage, and loaded deeper, would carry coals to Australia and back, would take out 3,000 passengers easily, and a small amount of cargo only, but could bring back any amount that could be conveniently collected, or if provision were made for taking in 3,000 or 4,000 tons of coal in Australia, that additional amount of cargo might be taken in the passage out. The passage out to Port Philip should be made easily in 36 days, and home by Cape Horn in the same time.
The Committee having come to the conclusion that this class of vessel would best fulfil the several conditions which the circumstances imposed, I have been engaged in determining the several details consequent upon this selection of size, and have put in hand drawings of the ship, which will enable me to arrive more correctly at the cost, and will enable us to obtain tenders for the construction. These details involve a great deal of study and consideration, and the making of the drawings alone requires some considerable time, so that I do not think much advance can be made under three weeks from the present date, but I will endeavour to expedite the work as much as possible.
Mr. Brunel was authorized to continue his communications with engine-makers and ship-builders, and to invite tenders.
After very detailed and careful calculations of the smallest capacity that would secure the attainment of the objects sought for, the dimensions of the vessel and the power of the engines were finally determined; tenders were received from Mr. Scott Russell, Messrs. Watt and Co., and Messrs. Humphrys and Co. for both sets of engines, and from Mr. Russell for the construction of the hull of the ship and for placing her afloat.
A meeting of the Directors was held on May 18, when Mr. Brunel submitted the various tenders he had received. The Board agreed to adopt his recommendations, and to accept the tenders of Mr. Scott Russell for the ship and paddle engines, and that of Messrs. James Watt and Co. for the screw engines.
The following report, which Mr. Brunel placed before the Directors, gives a detailed account of the steps he had taken to procure the tenders, and the grounds on which he had formed his judgment of them:—
Report on Tenders.[144]
May 18, 1853.
According to your instructions, I applied to the several parties with whom I had previously been in communication on the subject of the engines and ship, for tenders for their supply. As regards the engines, I drew up a short specification, defining generally what was required, and leaving the parties to make their own designs and propose to me the form of engine they would adopt.
With respect to the ship, where no such variation could be permitted, I have had very detailed drawings and specifications prepared.
Copies of the specifications are annexed.
In defining the power of the engines and boilers, I have, in conformity with my own views and of those of several of the Directors, who have expressed themselves strongly on the subject, required a very full amount of power, without naming the nominal horse-power, which is a very vague mode of defining anything but the cost which by custom is made dependent upon that nominal power; but I have defined dimensions of parts and surface of boilers which will ensure the means of exerting a very large amount of power.
As regards the ship, I have not spared strength of materials, and have required the best workmanship.
The result of this application for designs and tenders is, upon the whole, very satisfactory, although two of the parties from whom I had hoped to have received proposals have not been able to send any....
Mr. Blake, of the firm of Watt and Co., and Mr. J. S. Russell and Mr. Humphrys, have, as I had before reported, devoted much attention to the subject: from these gentlemen I have received distinct well-considered designs of the screw and paddle-engines.
I have been in frequent communication with these gentlemen, and have seen their plans while in progress, and have made my suggestions upon them, and assisted more or less in maturing them, and at all events in preventing the adoption of any principle or arrangement that I should afterwards object to. Notwithstanding this, the three designs, particularly for the screw engines, are totally dissimilar, and I am placed in the difficulty of having to choose between three totally different plans, each designed by skilful and experienced men, and each possessing many known and acknowledged advantages.
I should also observe that, although I have known the general arrangement which each would adopt, I did not receive the plans or the tenders which I now forward until last evening, and that of Mr. Humphrys as late as 10 o’clock this morning, and that I have not therefore had time to draw up any very detailed report upon them.
The following are, however, the principal considerations which influence me in the selection which I am disposed to recommend.
It must be borne in mind that the screw engines will be the largest engines that have yet been made. The principal part of the propelling power of the ship will be thrown upon the screw; and upon these engines therefore will mainly depend the performance of the ship, and particularly upon their constant never-failing working, probably for thirty or forty days and nights, must depend the certainty of the ship’s performance.[145] Under all these circumstances, the compactness and stiffness of framing, the greatest possible simplicity of construction, and the fewest possible number of parts, and, finally, the absence of any novelty, however promising, that can introduce any unforeseen difficulties, are conditions which would outweigh in my mind many advantages that might, and I think would, be attained by several arrangements which have been suggested.
All the designs now submitted comply with these conditions to a very considerable extent ... but the extreme simplicity of Mr. Blake’s engine leads me to prefer it.
As regards the paddle engine, I unhesitatingly give the preference to that proposed by Mr. Russell. I believe it to be as simple an arrangement as can be adopted for engines with such a slow motion and so long a stroke as these must have, and the single crank in the centre I consider a great advantage....
As regards a contract for the ship, I have found it more difficult to proceed in the ordinary course. The conditions which we must ensure of quality of workmanship and execution, under close inspection and within reach of one’s own supervision, are not easily attained; and, though as a matter of course readily promised and undertaken by all ship-builders, they are rarely secured. It is essential also that the ship should be built where the engines can be readily fixed on board before launching, and in a yard which can be devoted to the purposes of the ship, and whence the launching can be effected with the engines and boilers on board.
All these are conditions not easily secured. I have been in communication with one or two parties, and the result is a tender from Mr. J. Scott Russell, which I enclose, and which has in fact been framed upon my calculations. Owing to the recent rise in iron it is somewhat, but not materially, above the amount at which I had originally estimated the vessels; but the tender, founded upon the supposition of two such vessels being ultimately ordered, is as nearly as may be the same as my original estimate, and upon the whole I consider the tenders both for engines and ships very satisfactory and confirming fully our previous calculations.
These tenders do not include, in the case of the engines, either the screw itself or the paddle wheels, nor, in the case of the vessel, the cabin fittings, masts, and rigging, boats, or stores. I should estimate these roughly at 50,000l. more,—at least such an allowance ought to be ample; but these details will require a great deal of consideration, and could not be included in the original contracts; while at the same time they can mostly be better and more economically supplied by competition or by arrangement with the special makers of the respective articles....
During the next six months Mr. Brunel was engaged in preparing the formal contracts and specifications. These documents were settled with much care, and after frequent communications with the contractors, who consented to the insertion of clauses which gave the full control and supervision over every part of the work to the Engineer, with very large powers of interpretation. They required, however, that, should Mr. Brunel cease to act as Engineer, any disputed point should be settled by arbitration, and not by his successor.
Besides the delay occasioned by the magnitude and novelty of the undertaking, there were other difficulties which helped to postpone the commencement of the works. The Directors were unable, under their charter, to enter into any contracts until a certain amount of their capital was actually paid up; and, as several shareholders had retired when the change of plans was determined upon, it was no easy work to get the shares taken. That this was eventually accomplished was due mainly to the exertions of Mr. Brunel and Mr. Charles Geach, one of the Directors.[146] ‘Could I have foreseen,’ Mr. Brunel writes, ‘the work I have had to go through, I would never have entered upon it; but I never flinch when I have once begun, and do it we will.’
Several times they nearly broke down, but at length the contracts were signed, and on the same day, December 22, Mr. Brunel gave the formal notice to the contractors to proceed with the works. ‘After two years’ exertions (he wrote), ‘we are set going, the contracts entered into, and the work commenced.’