The life of Isambard Kingdom Brunel, Civil Engineer Part 11

'He was then a young man, but in the school of the Thames Tunnel he had acquired a close acquaintance with all kinds of masons' and carpenters' work, the strength and cost of materials, bridge building, and constructions under water, and with the working of the steam engine as it then stood. It happened not unfrequently that it was desirable to accept the tender of some contractor for railway work whose prices upon certain items were too high, and then it became the engineer's business to go into the details and convince the contractor of his error. On such occasions Brunel would go step by step through the stages of the work, and it was curious to see the surprise of the practical man as he found himself corrected in his own special business by the engineer.

Thus, I remember his proving to an eminent brickmaker who had tendered for the Chippenham contract that the bricks could be made much cheaper than he supposed. He knew accurately how much coal would burn so many bricks, what it would cost, what number of bricks could be turned out, what would be the cost of housing the men, what the cartage, and how many men it would require to complete the work in the specified time. The contractor was astonished; asked if Mr. Brunel had ever been in the brick trade, and finally took and made money by the contract at the proposed figure.

'In the case of the Maidenhead bridge, the contractor being alarmed at learning that the arch was the flattest known in brick, Brunel pointed out to him that the weight which he feared would crush the bricks, would be less than in a wall which he, the contractor, had recently built, and he convinced him by geometry, made easy by diagrams, that the bridge must stand. Knowledge of detail Brunel shared with the carpenter, builder, or contractor for earthwork, and he was their superior in the accuracy and rapidity with which he combined his knowledge, and arrived at correct conclusions as to the cost of the work and the time it would take to execute it.

'In talking to landowners and others whose opposition it was important to overcome, I have often been struck by your father's great powers of negotiation. The most absurd objections--and there were many such--were listened to with good humour, and he spared no pains in explaining the real facts, so that it sometimes happened that he converted opponents into supporters of the railway. In the course he took there was much skilful diplomacy, but there was no dishonesty, no humbug. He was very frank and perfectly sincere. His object was to impart his own convictions, and in that he often succeeded.

I never met his equal for sustained power of work. After a hard day spent in preparing and delivering evidence, and after a hasty dinner, he would attend consultations till a late hour; and then, secure against interruption, sit down to his papers, and draw specifications, write letters or reports, or make calculations all through the night. If at all pressed for time he slept in his armchair for two or three hours, and at early dawn he was ready for the work of the day. When he travelled he usually started about four or five in the morning, so as to reach his ground by daylight.

His travelling carriage, in which he often slept, was built from his own design, and was a marvel of skill and comfort. This power of work was no doubt aided by the abstemiousness of his habits and by his light and joyous temperament. One luxury, tobacco, he indulged in to excess, and probably to his injury. At all times, even in bed, a cigar was in his mouth; and wherever he was engaged, there, near at hand, was the enormous leather cigar-case so well known to his friends, and out of which he was quite as ready to supply their wants as his own.

His light and joyous disposition was very attractive. At no time was he stern, but when travelling or off work he was like a boy set free. There was no fun for which he was not ready. On the old Bath road, on a Wilts.h.i.+re chalk hill-side, is cut a large horse, the pride of the district, and only inferior in reputation to that of the famous Berks.h.i.+re vale. The people of the district, afraid to lose their coach traffic, were violently opposed to the Great Western Railway Bill. Talking over this one evening, some one suggested turning the horse into a locomotive. Brunel was much amused at the idea, and at once sketched off the horse from memory, roughly calculated its area, and arranged a plan for converting it into an engine. Ten picked men were to go down in two chaises, and by moonlight to peg and line out the new figure, and then cut away the turf, and with it cover up as much of the horse as might be left. From the tube was to issue a towering column of steam, and below was to be inserted in bold characters the offensive letters G. W. R. It was, of course, not intended to carry this joke into execution, but Brunel often alluded to it, and laughed over the sensation it would have created.

'He possessed a very fine temper, and was always ready to check differences between those about him, and to put a pleasant construction upon any apparent neglect or offence. His servants loved him, and he never forgot those who had stood by his father and himself in the old Tunnel days of trouble and anxiety.

'No doubt the exertions of those three years, though they laid the foundation, or rather built the fabric, of his reputation, also undermined his const.i.tution, and eventually shortened his life.

Everything for which he was responsible he insisted upon doing for himself. I doubt whether he ever signed a professional report that was not entirely of his own composition; and every structure upon the Great Western, from the smallest culvert up to the Brent viaduct and Maidenhead bridge, was entirely, in all its details, from his own designs.'

In the press of work and the altered circ.u.mstances under which he superintended the construction of his later railways, many changes inevitably followed. The open britzska gave place to a close travelling carriage, which in its turn became useless; and no time was left for fun or practical jokes; but the same energy of mind and the same kindliness of heart remained uninfluenced by increasing occupations or advancing years.

CHAPTER V.

_THE BROAD GAUGE._

ORIGIN OF THE ORDINARY GAUGE OF RAILWAYS--ADOPTION BY MR. BRUNEL OF THE BROAD GAUGE ON THE GREAT WESTERN RAILWAY--REASONS FOR ITS ADOPTION--THE PERMANENT WAY--REPORTS OF MR. NICHOLAS WOOD AND MR.

JOHN HAWKSHAW, 1838--EXTRACT FROM REPORT OF DIRECTORS OF GREAT WESTERN RAILWAY COMPANY (DECEMBER 20, 1838)--EXTENSION OF THE BROAD GAUGE SYSTEM--BREAK OF GAUGE--ROYAL COMMISSION ON THE GAUGE OF RAILWAYS, 1845--LETTER OF MR. BRUNEL ON THE BROAD GAUGE (AUGUST 6, 1845)--GAUGE ACT OF 1846--THE MIXED GAUGE--REPORT OF RAILWAY COMMISSIONERS, 1847--NORTHERN EXTENSIONS OF THE GREAT WESTERN RAILWAY--ADVANTAGES OF THE BROAD GAUGE--PARTIAL ABANDONMENT OF THE BROAD GAUGE.

The railways designed by Mr. Brunel were, with a few exceptions, distinguished from those in all other parts of England by a peculiarity in the width between the two rails forming each line of way, or in what is called the _gauge_. In most railways, the distance between the internal edges of the rails is 4 feet 8 inches, being what is termed the _narrow gauge_; on Mr. Brunel's railways, it was seven feet, or what is termed the _broad gauge_.

The gauge of the earlier railways, which were but a modification of the old wooden tramway, was made that of the tram plates which they superseded; and this had been originally fixed to suit the distance between the wheels of the country carts in the north of England.

When Mr. George Stephenson introduced the locomotive engine, the gauge of the lines in the Northumberland district had been already fixed. In laying out the Stockton and Darlington line (1821-1825) he saw no reason to depart from the gauge he had previously adopted; and, indeed, some of the waggons to be used on this line were brought from the Northumberland collieries. In this way the first important railway in England was made with the gauge of 4 feet 8 inches; not from a deliberate choice of this width on the ground of any peculiar advantages, but from the mere fact of its already being established elsewhere.

In the construction of the Manchester and Liverpool Railway, in 1826, the same gauge was adopted as on the Stockton and Darlington; this course was also followed by the Grand Junction and the London and Birmingham Railways, and thus the 4 feet 8 inches gauge became established in that part of the country.

Long experience appears to have determined the general type of wheeled vehicles: the wheels being of somewhat large size, and the body placed between them, so as to come down close upon the axle-tree.

This type, which gives obvious advantages in a mechanical point of view, appears to have been adhered to in all railway vehicles used before the opening of the Liverpool and Manchester Railway; these, however, were chiefly coal-waggons. But on the Liverpool and Manchester Railway it was soon perceived that the great increase of carrying power which the railway afforded must be met by a corresponding increase of s.p.a.ce in the rolling stock, as it was necessary to accommodate light bulky goods and pa.s.senger traffic. The available width between the wheels was limited to about 4 feet 6 inches, and to carry in this width any large amount of cotton goods, or of pa.s.sengers, would have required a train of an inordinate length. To meet this difficulty a new form of vehicle was designed; the wheels were made small, and the body was raised and widened out, projecting on either side over the tops of the wheels.

The earliest description of this form of waggon is contained in the second edition of Wood's 'Practical Treatise on Railroads,' published in 1832, about two years after the opening of the Liverpool and Manchester Railway. In Plate III., Mr. Wood shows a truck with a raised platform overhanging the wheels, and adapted for carrying loose boxes of coals; adding, in the description:

Although the drawing shows only the form of boxes used for the conveyance of coals, yet it will readily occur that the form can be varied to suit the carriage of any kind of articles; the framework or body of the carriage being raised above the wheels, the breadth can be extended to any width which the distance between the railways [i.e. between the up and down lines of road] will admit (p. 75).

Such was the state of matters when, in the year 1833, Mr. Brunel was appointed Engineer of the Great Western Railway. With the view of leaving the question of gauge open for future consideration, he procured the omission in the Great Western Act of a clause defining it. He came to the conclusion that it would be desirable to adopt a wider gauge, and he recommended this measure to the Directors in a report dated October 1835.[47]

In October 1836 a Royal Commission, consisting of Mr. Drummond, Under-Secretary for Ireland, Mr. R. Griffith, Colonel (now Field-Marshal) Sir John Burgoyne, R.E., and Professor Barlow, of Woolwich, was appointed to report on the establishment of railways in Ireland. They considered carefully the question of gauge, and their arguments in favour of an increase in the gauge were afterwards stated by Mr. Brunel to be identical with his own.

They drew attention to the advantage of large wheels, the use of which would be facilitated by a wider gauge; and they thought it a matter of importance to be able to place the bodies of the carriages between the wheels, instead of over them.

It was the width of the carriages, and not the distance between the rails, that determined the general dimensions, and therefore the cost, of the works of a railway. Mr. Brunel saw many advantages to be gained by an increase in the gauge, even while retaining the existing dimensions of carriages; and he thought it unwise at the commencement of a work of such magnitude as the Great Western Railway to retain a limit the inconvenience of which had already become apparent.

He says, in his evidence before the Gauge Commission:

Looking to the speed which I contemplated would be adopted on railways, and the ma.s.ses to be moved, it seemed to me that the whole machine was too small for the work to be done, and that it required that the parts should be on a scale more commensurate with the ma.s.s and the velocity to be attained. (Q. 3924.)

The width between the rails being the fundamental dimension of 'the whole machine,' on which its entire development must depend, Mr. Brunel proposed to begin by the enlargement of this dimension, and recommended that on the Great Western Railway the gauge should be seven feet. He considered that the whole of the parts of the railway and of its rolling stock would be susceptible of continual, though gradual improvement, and that it was highly advisable to remove, in the outset, a great obstacle in the way of this progress.

He did not in the first instance propose any important change in the details as consequent on the wider gauge; and in regard to one of the princ.i.p.al points, the diameter of the wheels, he said:--

I am not by any means prepared at present to recommend any particular size of wheel, or even any great increase of the present dimensions. I believe they will be materially increased; but my great object would be in every possible way to render each part capable of improvement, and to remove what appears an obstacle to any great progress in such a very important point as the diameter of the wheels, upon which the resistance, which governs the cost of transport and the speed that may be obtained, so materially depends. (Report in Appendix I. p. 532.)

Mr. Brunel also looked forward to the advantages which a wider gauge would give for the construction of the locomotive engines. Difficulties had been already experienced from the limited width between the wheels, which cramped the machinery, rendering it difficult of access for repairs; it also limited the size of the boiler and fire-box, on which the power depended. For this reason Mr. Brunel considered that a wider gauge would present great advantages, as it would allow the locomotives to be constructed of greater power, and with their machinery arranged in a more advantageous manner. He also thought that the greater width of base for the carriages would give increased steadiness and smoothness of motion, with greater safety, particularly at high speeds, and that there would be the advantage of being able to use larger wheels for the carriages. Moreover, he had in view the possibility which the broad gauge would give of adopting wheels of a still larger diameter without raising the centre of gravity, the body of the carriage being placed between them, as in the original type of common road vehicles.

The broad gauge was also considered by Mr. Brunel in prominent connection with the peculiarly favourable circ.u.mstances of the Great Western line, in regard to its gradients and curves. He thought that 'it would not have been embracing all the benefits derivable from the gradients of the Great Western Railway, unless a more extended gauge was adopted.' In the first place, it was evident that a diminution of the frictional resistance would present the greatest advantage where the gradients were flat. In regard to curves, the wider gauge was at that time considered by him to be more advantageously applied where the curves were of large radius than where they were sharp.[48] On the Great Western Railway both gradients and curves were remarkably good; with the exception of two inclines of 1 in 100, on which auxiliary power was proposed to be used, there was no gradient between London and Bristol steeper than 1 in 660, the greater part of the line being nearly level, and except between Bath and Bristol there was no curve sharper than about one mile radius.

For these reasons Mr. Brunel thought that unusually high speed might easily be attained for pa.s.sengers, and great tractive power for goods.

He said:--

I shall not attempt to argue with those who consider any increase of speed unnecessary. The public will always prefer that conveyance which is the most perfect, and speed, within reasonable limits, is a material ingredient in perfection in travelling. (Report in Appendix I. p. 532.)

In deciding that the distance between the rails should be seven feet, Mr. Brunel seems to have been guided by the principle that the wheels should be put sufficiently far apart to admit of an ordinary carriage body being placed between them.[49]

Mr. Brunel did not antic.i.p.ate that the difference between the gauge he proposed and that of other railways would lead to any important inconvenience. The views he held on this subject were expressed fully by him in a report of December 13, 1838. He says, speaking of the difficulty of communication between the Great Western and other railways:--

This is undoubtedly an inconvenience; it amounts to a prohibition to almost any railway running northwards from London, as they must all more or less depend for their supply upon other lines or districts where railways already exist, and with which they must hope to be connected. In such cases there is no alternative.

The Great Western Railway, however, broke ground in an entirely new district, in which railways were unknown. At present it commands this district, and has already sent forth branches which embrace nearly all that can belong to it; and it will be the fault of the company if it does not effectually and permanently secure to itself the whole trade of this portion of England, with that of South Wales and the south of Ireland; not by a forced monopoly, which could never long resist the wants of the public, but by such attention to these wants as shall render any compet.i.tion unnecessary and hopeless. Such is the position of the Great Western Railway. It could have no connection with any other of the main lines, and the princ.i.p.al branches likely to be made were well considered, and almost formed part of the original plan; nor can these be dependent upon any other existing lines for the traffic which they will bring to the main trunk.

Mr. Brunel was not singular in holding the opinion that it would be desirable to allot a given district to one railway, which might conveniently serve it by means of a trunk line and branches of a special gauge. In the Eastern Counties line, designed in 1836, by Mr.

Braithwaite, and opened in 1839, a gauge of 5 feet was adopted; and Mr.

Robert Stephenson, as engineer of another line, the Northern and Eastern Railway, branching out from the Eastern Counties to the northward, adopted the same gauge. It was not till the Northern and Eastern line was extended, some years afterwards, that the rails of the whole system were altered to the narrow gauge.

Mr. Brunel's recommendation was adopted by the Directors of the Great Western Railway; and, in their report of August 25, 1836, after observing that the generally level character of the line would greatly facilitate the attainment of a higher speed of travelling, they pointed out the advantages of the broad gauge, and stated that engines had been ordered specially adapted to the nature of the line, which would be capable of attaining with facility a rate of from thirty-five to forty miles per hour.

The line was opened between Paddington and Maidenhead on June 4, 1838, and the performance of the engines was considered satisfactory, trains of eighty tons and upwards being drawn at speeds of from thirty-eight to forty miles per hour.