Achievements in engineering during the last half century

Preface

MY endeavour in this book has been to describe briefly some of the principal engineering works carried out, at home and abroad, within the last fifty years, avoiding technical phraseology as far as possible, so that the descriptions may be perfectly intelligible to the general reader, and, at the same time, introducing various details and comparisons which may interest engineers as well. As the chief engineering triumphs have been accomplished in the last half century, there has been no lack of materials ; and some branches of engineering have necessarily been passed over, as indicated in the concluding remarks at the end of the book. I trust, however, that an adequate variety of engineering works of great magnitude, difficulty, and importance have been described, to justify the view that engineers, in directing the forces of nature to the use and convenience of man, are amongst the greatest benefactors of mankind.

Various details about several of the works described have been gleaned from papers in the Minutes of Proceedings of the Institution of Civil Engineers ; some particulars relating to the Hudson Tunne works have been obtained from 'Tunnelling under the Hudson iv Preface.

River,' by S. D. V. Barr ; about the Severn Tunnel from the late Mr T. A. Walker's book ; and about the Forth Bridge from Engineering ; and information about American bridges and works has been gathered from the Transactions of the American Society of Engineers.

I am indebted to Mr G. F. Deacon, the Liverpool engineer of the Vyrnwy works, for particulars about those works, for affording me an opportunity of inspecting them, and also for a photograph of the dam and lake from which the illustration in the book has been produced. The view of the Manchester Ship Canal works, at Eastham, is from a photograph given me by Mr Leader Williams, the engineer - in - chief of the canal ; the Tower Bridge illustration is from an engraving furnished me by Mr J. W. Barry, the engineer of the bridge ; and the Louviere Lift is from a photograph by Mr Lyonel Clark, of Messrs Clark & Standfield who carried out the work. The view of the Eddystone Lighthouse is reproduced, by permission, from an illustration accompanying Mr W. T. Douglass's paper on ' The New Eddystone Lighthouse,' in the Minutes of Proceedings of the Institution of Civil Engineers ; and the engraving on page 164, illustrating the blasting operations at Hell Gate, New York, is taken from the plate accompanying my paper on that subject in the same Minutes of Proceedings. Three of the sections^of American railways in the diagram on page 30, and the diagram of the switchbacks on the Oroya Railway, were obtained from ' The Economic Theory of the Location of Railways' by A. M. Wellington, a book containing a considerable amount of information on American railway practice.

The narne of Robert Stephenson, whose portrait ap-

Preface. v

pears on the frontispiece, will ever be associated with the development of railways ; and though his labours were terminated by his untimely death in 1859, before attaining the age of fifty-six, and thus are only identified with the earlier portion of the period covered by the book, he was the pioneer, in the Britannia Bridge, of the system of long span girder bridges, which has since received such a marvellous extension. In a book describing engineering works, I have deemed it preferable to devote the limited illustrations to the works of engineers of recent times, rather than 'to' portraits of living engineers, otherwise many honoured names should have found a place amongst its pages. Amongst the eminent engineers whose works have been recorded in the following pages may be mentioned Sir John Hawkshaw, the engineer-in-chief of the Severn Tunnel and of the Amsterdam Ship Canal ; Sir John Fowler and Sir Benjamin Baker, the engineers of the Forth Bridge, and the former the engineer of the Metropolitan Railway ; Sir James Brunlees and Sir Douglas Fox, the engineersin-chief of the Mersey Railway ; the late Captain Eads, engineer of the St Louis Bridge and of the Mississippi Delta works ; General Newton, engineer of the Hell Gate Improvement works ; Mr G. F. Lyster, the engineer-in-chief to the Mersey Docks and Harbour Board ; Sir John Coode, the engineer of Table Bay and Colombo harbours ; Sir Charles Hartley, engineer of the Danube Delta works ; Voisin Bey, the engineer-in-chief of the Suez Canal works ; the late Mr J. F. Bateman, the engineer of the Manchester Waterworks ; Mr Thomas Hawksley, the engineer-in-chief formerly of the Vyrnwy Reservoir works ; and Sir James Douglass, the engineer-in-chief of the new Eddystone Lighthouse.

vi Preface.

If this book should succeed in stimulating, and also to some extent in satisfying, the interest felt by most persons in large engineering works, and should lead to a due appreciation of the principles on which such works are designed, the methods by which they are carried out, and the difficulties experienced in their construction, and, moreover, if the book should establish the claim of these works to be classed amongst the ' events of our own time,' the objects aimed at will be accomplished.

L. F. VERNON-HARCOURT.

6 QUEEN ANNE'S GATE, WESTMINSTER, \Qth March 1891.

Contents

I. — THE LONDON METROPOLITAN RAILWAYS, AND THE

NEW YORK ELEVATED RAILWAY, ... I

II. — RAILWAYS ACROSS THE ALPS, THE ROCKY MOUN- TAINS, AND THE ANDES, . . .25 III. — NARROW GAUGE, FELL, RIGI, PILATUS, AND ABT

Chapter I. The London Metropolitan Railways, And The New York Elevated Railways

PROBABLY no better concise description of the most marked features of the present time could be given than the passage which occurs in the Book of Daniel, relating to the latter days, namely, ' many shall run to and fro, and knowledge shall be increased.' The development of railways, and the facilities thus afforded for locomotion, together with the extension of education and trade, have given a great impulse to traffic in large cities, and especially in London. With a rapid growth of population in the metropolis, and constantly increasing requirements, the traffic in the most important thoroughfares necessarily largely augments ; whilst little can be done to relieve the excessive traffic along the main streets, beyond a few new roads, constructed at enormous expense. Accordingly, schemes were naturally started, about the middle of this century, for enlarging and facilitating the means of communication, without encountering the delays and increasing the congestion of traffic in the principal thoroughfares.

2 Extension of Railways in London.

The growth of the metropolitan traffic, moreover, is not merely measured by the increase of population in the ever-extending area of London itself ; but the very large number of persons who now reside in the suburbs and neighbouring country districts, and come regularly into London for their day's work, have to be considered. It is of importance for this suburban population, and for travellers from a distance, that they should be able readily to get from the railway stations to their places of business, and from one terminus to another. Increased facilities of access have been provided by doubling the lines of way of all the principal railways running into London, and by extending the lines in some instances further into the heart of the metropolis ; such as the extension of the railways, terminating at Battersea, to Victoria Station in 1860; the extension of the South-Eastern Railway from London Bridge to Charing Cross and Cannon Street, constructed between 1860 and 1866 ; the London, Chatham, and Dover Railway extension, from Ludgate Hill to the Holborn Viaduct, about 1873; and the Great Eastern Railway extension, from Shoreditch to Liverpool Street, opened in 1875. Some idea of the great development of railways within the metropolis in the last thirty-five years may be gathered from the consideration that, vyhereas no railway bridge crossed the river Thames within the metropolitan area before 1860, there are now four railway bridges over the river below Chelsea, namely, at Pimlico, Charing Cross, Blackfriars, and Cannon Street, which have been all doubled in width since their erection. Moreover, trains now pass unseen through the world-famed Thames Tunnel, opposite the London Docks, completed in 1843, and purchased about

Commencement of Underground Railway. 3

twenty-five years later by the East London Railway Company to enable them to cross the river.

UNDERGROUND METROPOLITAN RAILWAYS.

As early as 1834, steam carnages were run along the Marylebone Road for conveying passengers between Paddington and Moorgate Street; and in 1837 the question of the improvement of railway communication in the metropolis was brought forward. The steam carriages could only carry a few persons ; and the tramways, laid down subsequently in various parts of London, whilst affording a comfortable means of locomotion, can only be placed along the less frequented wide thoroughfares, and, like ordinary omnibuses, tend more or less to impede the general traffic in the streets. In 1845, nineteen Bills were presented to Parliament for constructing railways in the metropolis, one of them consisting of a scheme for a general central station, an idea which has since been successfully carried out in some towns of more moderate size. At last, in 1854, an Act was obtained for constructing an underground railway from Paddington to Farringdon Street ; but, owing to difficulties in raising the necessary capital, the works were not begun till 1860. This first section of the Metropolitan Railway was opened early in 1863 ; the first portion of the District Railway between Kensington and Westminster was opened at the end of 1868, and extended to Mansion House Station in 1871 ; and, finally, the completion of the ' Inner Circle,' from Mansion House to Aldgate, was effected in 1884, The Underground Railway is termed the 'Inner Circle,' to distinguish it from the outer circle of railways with which it is in connection, going round by Addison

4 Advantages of Underground Railway.

Road, Willesden, Chalk Farm, Broad Street, the Thames Tunnel, New Cross, and Clapham Junction, which latter railways both connect the outlying portions of the various lines converging to the metropolis and serve the suburbs encircling London. The Inner Circle, however, is not really circular in form, for it is an irregular oval,

5 miles long from east to west and i-f- miles wide from north to south ; and its shape suggests the idea that a railway cutting across the narrow central portion of the oval, say from Victoria, or Charing Cross stations, to Baker Street, Portland Road, or Gower Street stations, would be a distinct gain to the public, though probably not to the shareholders of the metropolitan railways. This shorter diameter, however, of the oval is traversed by omnibuses in connection with the railways.

The advantages of an underground railway in a city are that it does not occupy any of the surface area ; that it is hidden from view, and therefore presents no unsightliness or cause of discomfort in the neighbourhood of important buildings and main thoroughfares j1 that the purchase of land is avoided when it passes along under the line of a road, or in tunnel; and that it does not cause any interference with the roads and railways which it traverses in its underground course. On the other hand, such a railway necessitates the construction of an almost continuous covered way, resembling a succession of tunnels, through which trains have to run in the dark, and the ventilation of which is more or less imperfect. Buildings, also, have to be underpinned or pulled

1 Authority could certainly not have been obtained for the construction of a railway on a viaduct in front of Westminster Abbey, or along the Thames Embankment, in the line followed by the District Railway.

Construction of Underground Railway. 5

down along the line of the railway ; the diversion of the gas and water mains, intersected by the excavations, has to be effected ; and pumping has to be resorted to for keeping the low-lying works free from water during construction, and for draining the line after completion.

Persons travelling in the Underground Railway might very naturally imagine that the greater part of the railway had been made by tunnelling, just as high ridges are pierced by railways in tunnels, such as the Box, Merstham, Sydenham, and other well-known tunnels. The depth, however, selected for the railway, below the surface of the ground, was not sufficient for the adoption of this method of construction, except in two places, namely, between King's Cross and Farringdon Street, where a tunnel, 728 yards in length, was driven under Clerkenwell, and between High Street, Kensington, and Notting Hill Gate, where a tunnel was made under Campden Hill for a length of 421 yards. The rest of the covered way was constructed on what is termed the ' cut and cover ' principle ; for the ground was excavated from the top to the requisite depth, and the side walls, inverted arch at the bottom, and arch overhead were then built, and covered over at the top with earth again, thus forming a sort of continuous arched bridge under ground. Where the line runs along under the streets, the roadway had to be kept open for traffic, which was accomplished by forming a temporary road over the excavations, with planking laid upon cross beams of timber spanning the opening. In some cases, houses along the line of the railway were pulled down, and subsequently rebuilt over the arch of the covered way; in other cases, the houses were left standing, and were

6 Precautions taken in Excavations.

supported on a framework of main and cross iron girders inserted under the walls, the main girders resting upon the side walls of the railway. In some of these houses a timber floor alone intervenes between the railway and the kitchen ; whilst in others, small brick arches have been built between the girders, and support the floor. Considering the distinctly perceptible vibration which is felt even at some distance from the Underground Railway, houses standing directly over the covered way can hardly be regarded as very quiet and desirable residences, especially where a timber floor is supposed to afford an adequate safeguard against the rattle of the constantly passing trains. Nevertheless, habit has a marvellous influence in rendering people unconscious of frequently recurring sounds, so that noises which jar upon the nerves of a casual visitor pass unnoticed by the regular inmate, who is more than compensated for apparent discomfort by a reduced rent. The excavations were in every instance carried out in very short lengths, of about 4 to 6 feet, strongly strutted across with timber, and rapidly followed by the permanent brickwork of the retaining walls, so as to avoid the inevitable movement of the ground, and consequent damage to adjacent property by settlement, which results when any large excavation is made in the neighbourhood of buildings. Underpinning, which consists in carrying foundations down to a lower level by building underneath them into firm ground not liable to be disturbed by the excavations, has also to be effected with the greatest care, and in short pieces, so that the first portion may be rendered quite secure before the adjacent portions are dealt with ; and the operation necessarily involves excavating underneath a

Levels and Gradients of Railway. 7

short length of foundation, and supporting it temporarily by beams and props. This, and the avoidance of settlement, constitute some of the main difficulties in carrying out underground work through towns. A brick arch has been adopted for the top of the covered way, wherever the depth below the surface was sufficient, as being cheaper and more durable than iron girders ; but in places where the headway was inadequate, girders have been employed. The covered way supports a great many buildings erected since the construction of the line ; and extreme instances of the weights thus imposed are noticeable at Westminster and Blackfriars stations, where buildings 80 feet high are borne on girders spanning these stations. It is to be hoped that these girders may be successfully protected from corrosion ; for such a massive weight, resting on a girder, imperceptibly but gradually weakened by the oxidising influences to which it is exposed, would be liable in course of time to a serious catastrophe.

The importance of placing the numerous stations within easy access of the surface has led to the line being laid out, for the most part, in conformity with the surface slopes of the ground, just as in an ordinary railway, with ascending and descending gradients, but so as to keep always at a suitable depth below the surface. Owing to the greater elevation of the ground in the northern district, the level of the railway varies considerably at different parts, reaching about 80 feet above mean sea level at Edgware Road, on the Inner Circle ; rising to 167 feet at the Swiss Cottage, on the St John's Wood branch ; and falling, near Victoria Station, to 9 feet below mean sea level. The steepest gradient, of I in 70, occurs in. rising from beyond

8 Works connected with Inner Circle.

Gloucester Road, through the Campden Hill tunnel, to Netting Hill Gate ; and the next steepest, of I in 75, in rising from the valley of the old Westbourne stream to Paddington. The sharpest curves, of 10 chains (220 yards) radius on the Inner Circle, and 6f chains (147 yards) radius on the King's Cross branch, are of smaller radius than commonly employed, and in the latter case the smallest curve that has been adopted on a line of ordinary gauge ; but these curves were required to keep the railway within certain boundaries of property, and to form connections with existing lines, and the trains are never run at high speed over them. In consequence of the proximity to the surface at which the railway was formed, the excavations were mainly carried through the alluvial deposits of the Thames valley, and made ground, overlying the London clay which was reached towards the bottom of some of the excavations, and through which the Clerkenwell tunnel was driven.

One of the most interesting portions of the Inner Circle is where the Great Northern branch from King's Cross dips under the main line, in order to branch off on the opposite side to Snow Hill, so that the Underground Railway is actually burrowed under by another line ; and at one place passengers by the main line can see the crossing train almost vertically below them through the open girder work supporting the line on which they are travelling. Advantage was taken of the Thames Embankment Works to construct simultaneously the Underground Railway from Westminster to Blackfriars, through the land reclaimed by the Embankment; and a much-needed street improvement was effected, in conjunction with the construction of the last link of the Inner Circle between the Monument

Sewers carried across Railway. 9

and the Tower. The railway, on passing from under Cannon Street across King William Street, had to be carried directly under the granite statue of William IV., weighing 160 tons, which had to be most carefully underpinned previous to the carrying out of the excavations, and now rests on the top of the brick arch of the covered way, so that the trains run exactly underneath the statue. The intersected sewers were lowered for some distance on each side of the line, where practicable, and carried under the railway. In some instances, however, the sewers had to be taken over the railway, an example of which arrangement may be observed at Sloane Square Station, where the Ranelagh sewer is carried in a cast-iron tube, 9 feet in diameter, across the upper part of the station, being supported by girders on each side. The Fleet sewer and the Middle Level sewer have been similarly carried over the railway. The sewer running down the middle of Cannon Street, Eastcheap, and Great Tower Street had to be removed, and two new sewers had to be constructed, running outside the covered way on each side ; and the increased width consequently occupied by the works necessitated the underpinning of most of the houses along these streets. The provisions requisite for the temporary diversion of the sewers, and other pipes, during the progress of the works, naturally added considerably to the difficulties experienced in pushing forward the operations in the very limited space available.

When the Metropolitan Railway was first designed, it was intended that the traffic should be worked by smokeless, hot-water locomotives, not burning fuel, as it was supposed that the trains would be small, and that locomotives from other lines would not travel over io Deficient Ventilation on Inner Circle.

it to any important extent. Accordingly, no attention was paid to the subject of ventilation in the first section of the Metropolitan Railway ; and the Baker Street, Portland Road, and Gower Street stations were built entirely underground. When, however, on the opening of the line, heavy locomotives of the ordinary type were adopted, the glass had to be removed from the side openings at these stations, and openings made in portions of the covered way, to afford an outlet for the smoke from the engines ; and even now at times the relief thereby afforded is very imperfect at the stations above mentioned. These defects in ventilation have been avoided in the more recently constructed portions of the line, by placing the stations in uncovered places where possible, with access to the open air at each end, and with occasional openings between the stations. Where, as at Cannon Street and Mark Lane stations, access to the open air above the stations was impracticable, large openings for ventilation have been provided at the side ; and fans for producing artificial ventilation have been set up along this section of the line. In spite of all the precautions taken and improvements adopted, the atmosphere at some of the stations is still considerably vitiated on damp, oppressive days by the offensive smoke from the locomotives ; and the removal of this nuisance, by the adoption of some other form of motive power not open to this objection, such as electricity, would unquestionably add to the popularity of the Underground Railway. If the Inner Circle formed a separate system, without suburban branches, and without connections with other lines, there ought to be no difficulty in introducing a smokeless motive

Smokeless System of Traction needed. 1 1

power ; but the matter is complicated by the variety of the connections, and the distances to which some of the branches extend. Some trains merely traverse a portion of the Inner Circle on their way from one place to another, as for instance from Richmond to New Cross, and from Woolwich to Finsbury Park ; whilst trains run from the metropolitan railways to Edgeware, Enfield, Hatfield, Hendon, Brentford, Ealing, Hounslow, Wimbledon, Willesden, the Crystal Palace, and Chesham. Any special system of traction could not therefore be easily applied to such varied routes, on some of which the trains are drawn by locomotives belonging to different companies. Even, however, if a smokeless system was only adopted for the Inner Circle trains, and those passing also over the loop round by Addison Road, the line would be relieved from the smoke of over eighteen trains per hour throughout the day, or about one in every three minutes, which would greatly reduce the vitiation of the air throughout the covered portions of the line.

The extensions of the Metropolitan Railway have far exceeded the anticipations of its early promoters, who contemplated merely a sort of improved and accelerated underground omnibus, or tramcar service ; whereas the railway is now in communication with most of the metropolitan lines, and luggage trains may be seen passing over it late in the evening. The public mind, also, is occasionally somewhat startled by hearing of the proposed extension of the/ Underground Railway' to Aylesbury, and even to Oxford, which is considered an unwarranted departure from its mole-like character. The Inner Circle alone, which constitutes the real underground railway, has a length of only 13^ miles; whereas the Metropolitan

1 2 Railways connected with Inner Circle.

Railway has nearly 20 miles of line open, and the Metropolitan District Railway, owned by a separate company, has 13 miles open, making a total, with the city link jointly owned by the two companies, of 34^- miles. The extensions of the Metropolitan to Chesham, and of the Metropolitan District to Hounslow, Richmond, and Wimbledon, have indeed made these lines cease to be exclusively metropolitan, whilst extending their capabilities and advantages. The Inner Circle, however, will always remain the special feature of these railways, on account both of the novelty of the design, and the special difficulties involved in its construction. It has also satisfactorily achieved one of the main objects kept in view by the legislature during its development, namely, the connection of the termini of the various lines entering London ; for it is in direct communication with the Great Western, the Great Northern, the Midland, and the Chatham and Dover railways near their termini ; with the East London Railway, through Whitechapel, and thence with the Great Eastern, Brighton, and South-Eastern railways. The Inner Circle is also in fairly direct communication with Cannon Street Station, on the South-Eastern, through Snow Hill, Holborn Viaduct, and Blackfriars Bridge, and is connected somewhat circuitously with the North-Western and North London railways through Willesden ; with Victoria, by Battersea ; and with the South- Western by a similar route. Moreover, Praed Street Station adjoins Paddington, Gower Street Station is near Euston, King's Cross Station is close to both St Pancras and the Great Northern terminus, and Bishopgate Station adjoins Broad Street and Liverpool Street stations ; whilst Cannon Street, Charing Cross, and Victoria stations, on the Inner Circle, are

Accommodation afforded by Inner Circle. 1 3

very near to the respective termini of the same names. Waterloo Station alone is at a little distance from the Inner Circle, owing to its situation on the opposite side of the Thames ; but even in this case, Westminster Bridge and Charing Cross stations are as close to Waterloo as circumstances permit.

Considering the scattered positions of the various termini of the railways entering London, and the difficulties inseparable from the construction of a railway right across London, it must be acknowledged that the Inner Circle, though the result of several successive extensions, has been remarkably well laid out, as a whole, for accommodating the various lines ; while, at the same time, it gives quick and easy communication between distant parts of the metropolis, and even between one suburb and another on opposite sides of London. The Great Western, Midland, and Great Northern railways have specially profited by the Underground Railway, for they are indebted to it for their access to the city, and the consequent development of the suburban traffic along their lines. Moreover, though the final link in the city, which completed the circuit of the Inner Circle, has not hitherto brought the traffic anticipated from the trains being able to run round continuously in both directions, owing probably to the considerable elongation of the narrow end of the oval eastwards, this link, with the Whitechapel extension, has placed the populous East End and the eastern suburbs in direct communication with the Inner Circle and its numerous branches.

The rapid succession of trains on the Inner Circle required for serving the Addison Road loop, and the numerous branches, in addition to the Circle trains running at intervals of ten minutes each way through-

1 4 Block System for Safety of Traffic.

out the day, has been only rendered possible of accomplishment by the introduction of the block system and the employment of continuous brakes. The block system insures, by a carefully arranged system of signalling, that, if the engine-driver pays proper attention to the signals exhibited, no two trains on the same line shall be in the same block, or interval between two adjacent signal cabins, at the same time. Each signalman is instructed not to lower his signal, and by the most recent electrical contrivance he is prevented from lowering his signal, for the passage of a train, till the signalman in the next cabin in advance informs him, by telegraph, of the passage of the train in front past that cabin, and consequently that the interval between the two cabins is empty. The occurrence of accidents is accordingly prevented, if the signals are obeyed, by interposing an interval of space between each train and the next. There are signal boxes at every station ; and intermediate cabins are sometimes placed between the stations where the interval is rather greater, or the traffic very large, notwithstanding the small distance between the stations along the Inner Circle. The number of blocks, indeed, into which a railway can be divided is only limited by the necessity of making the shortest block longer than the longest train ; but whilst a greater number of blocks within a certain distance increases the number of trains which can be admitted to that section of a railway at the same time, it reduces the speed of the trains, owing to the frequency of the signal boxes at which the engine-driver must be prepared to pull up if necessary. The accommodation, however, of a number of trains is of more importance on the metropolitan railways than great speed ; and the

Value of Continuous Brakes. 1 5

continuous brake enables the train to be pulled up within a very short distance, on approaching a signal set at danger. Tiie continuous brake puts a brake on the wheels of every carriage of a train simultaneously, instead of the brake being only applied to the engine and the guard's van, as in former days; and thus, by increasing the frictional area and applied weight, a train entering a station at a good speed can be brought to rest by the time the engine has reached the further end of the station. This rapid stoppage of the train, combined with the quick starting again of the engines, reduces the time occupied at stations to a minimum ; so that the average period of transit between the stations, including stoppages, on the Inner Circle is only about 2| minutes. Accordingly, the continuous brake, besides ensuring a greater immunity from accidents, facilitates rapidity of transit. Iron rails wore rapidly under the much increased friction, due to the augmented brake power, entailing frequent repairs and costly renewals. The introduction, however, of heavy steel rails, at a moderate cost, has greatly increased the durability of the rails, and reduced the expenses of maintenance. The success, therefore, and safe working of the numerous trains running on the Inner Circle are due to a combination of a variety of improvements ; and the only important amelioration which appears needful is an improved ventilation of the covered way.