An Encyclopedia of the History of Technology part 61 pot

PART THREE: TRANSPORT 582 The first compound locomotive was designed by the Frenchman Anatole Mallet and built in 1876; it was a 0–4–2 tank locomotive with two cylinders and ran on the Bayonne-Biarritz Railway. From this start various systems of compounding were developed by French, German, English and American engineers, the principal variations being in the number and layout of cylinders employed. Some systems were successful, some less so: compounding became a subject of controversy as long as steam locomotives were being developed in the Western world, opinions being divided about whether its inherent economy was not outweighed by the extra complication and expense in manufacture, maintenance and operation. Possibly the least successful but best publicized compounds were those designed for the London & North Western Railway by F.W.Webb from 1882 onwards. On many of these the two high pressure cylinders drove the front pair of driving wheels and the low pressure cylinder the rear pair, front and rear not being coupled together in the interest of free running. Valve gear for the low pressure cylinder was operated by a slip eccentric, with the ludicrous result, when the locomotive had backed on to a train, that if the front driving wheels slipped on starting, instead of moving the locomotive forward to set the slip eccentric, the rear wheels would revolve in reverse. Once these locomotives did get away, they could run well. Two-cylinder compounds based more closely on Mallet’s original ideas were more successful, and were built by August von Borries, locomotive superintendent of the Prussian State Railways, from 1880, and in England by T.W. Worsdell from 1884 for the Great Eastern Railway and subsequently for the North Eastern. A 4–4–0 locomotive of this type was eventually rebuilt with three cylinders, a single high-pressure cylinder inside and two low pressure ones outside, and became the prototype of similar locomotives built by S.W. Johnson for the Midland Railway from 1901 onwards which proved highly successful over many years. In the United States, Samuel Vauclain’s system of compounding used four cylinders, a pair of high and low pressure cylinders being positioned on each side of the locomotive with the piston rods of the cylinders in each pair connected to a common crosshead. In France, Alfred de Glehn and Gaston du Bousquet developed successful four-cylinder compounds, with the two high pressure cylinders driving one axle and the low pressure ones another. Mallet himself had meanwhile been developing his ideas in a divergent direction. In 1884 he patented a four-cylinder compound system in which the two high pressure cylinders drove one set of wheels at the rear of the locomotive and the low pressure another at the front: these wheels were carried on a separate set of frames, articulated to the locomotive’s main frames. Locomotives to this patent were first built by Decauville Aîné, a firm which since the middle of the previous decade had been developing light and portable railways of 40, 50 and 60cm gauge for agricultural and industrial use. In 1888, RAIL 583 Decauville demonstrated a 0–4–4–0 Mallet tank locomotive on a temporary 60cm gauge passenger line at Lâon, and followed this by a similar but more extensive line serving the Paris international exhibition of 1889 which used ten Mallets. Thenceforward the term Mallet came to be associated with articulation rather than compounding. The type became popular on narrow gauge railways on the continent of Europe, and was also used on main lines. The first Mallet in America was a 0–6–6–0 built to the standard gauge for the Baltimore & Ohio in 1904. In the USA increasing freight train loads had already led to construction of locomotives as large as 2–10–2s, and Mallet’s articulation principle, which had first been used on very small locomotives, was soon seized on in the USA as a means of building some extra-large ones. SPECIALIZED RAILWAYS By the early 1860s, traffic in London streets suffered much from congestion, and it was largely to help relieve it that the Metropolitan Railway was built from Paddington to Farringdon Street: the first underground railway, its tunnels were built beneath streets by ‘cut-and-cover’: that is, the course of the railway was excavated and subsequently covered over for the street to be reinstated. It was opened in 1863, worked by steam locomotives which, to minimize exhaust nuisance so far as possible, condensed their used steam, and in due course it was extended. By 1868 it had reached South Kensington, and the Metropolitan District Railway was opened from there to Westminster. Both railways were subsequently extended further. New York and other American cities solved similar problems by constructing elevated railways on continuous viaducts above the streets. New York had had horse-drawn passenger tramways through its streets since 1832, and Paris since 1855. The first street tramway in Britain was built in 1860 in Birkenhead by the American G.F.Train, and the first successful tramway in London was opened in 1870. Horse trams became a familiar part of the steet scene in many British cities; in the late 1870s steam trams came into use (generally, small, enclosed steam locomotives were used to haul tramcars), and from the 1880s cable haulage, which had first been applied to street tramways in 1873 in San Francisco, was also used in Britain. For climbing steep gradients, J.B.Fell patented a central-rail system in 1863. The additional rail, of double-headed cross-section, was laid on its side, and additional powered wheels positioned horizontally beneath the locomotive were pressed against either side of the central rail by a combination of levers and bevel wheels. The system worked satisfactorily over a gradient of 1 in 12 on a test line in Derbyshire, and was then installed on a temporary line over the Mont Cenis pass in the Alps, pending completion of the tunnel beneath. Its best-known application, however, was to the Rimutaka Incline in New Zealand, 4.8km (3 PART THREE: TRANSPORT 584 miles) of 1 in 15 on the line from Wellington to Masterton, where it lasted until an 8km (5 miles) diversionary tunnel was completed in 1955. The first mountain rack railway, the Mount Washington Cog Railway, was built by Sylvester Marsh in New Hampshire, USA; the first section was opened in 1868 and the summit of the mountain was reached the following year. Marsh had revived Blenkinsop’s early rack railway idea, but positioned his ladder-type rack centrally between the running rails to climb gradients as steep as 1 in 5. The Swiss engineer Niklaus Riggenbach had been working independently on a similar type of rack railway, and opened his first line up the Rigi mountain near Lucerne in 1871, reaching the top in 1873. Roman Abt, one of Riggenbach’s engineers, developed an improved type of rack in the early 1880s in which the rack teeth were machined in a steel bar; two bars were positioned side by side with the teeth of one bar staggered in relation to those of the other. The system was first used on a line in the Harz Mountains in Germany, opened in 1886. In this application, only parts of the line were rack-equipped, the remainder being easily enough graded to be worked by adhesion. Such rack-and-adhesion lines were built in mountainous areas elsewhere, both in the Alps, such as the Brunig line in Switzerland, and further afield, such as the Nilgiri line in India, and locomotives able to work by adhesion or rack were built for them. The Abt system became the most widely used rack system. The only rack railway in Britain, the Snowdon Mountain Railway, was completed in 1896 using this system and Swiss-built locomotives. Unusually, guard rails of inverted ‘L’-shape are positioned either side of the rack, the consequence of an accident on the opening day when a locomotive’s rack pinions mounted the rack so that it ran away, became derailed and fell over a precipice. Subsequently, if the pinions started to lift, grippers beneath the locomotive would make contact with the guard rails and prevent the pinions from becoming disengaged from the rack. The Pilatus Railway, opened near Lucerne in 1889, used the Locher rack system: a rack rail positioned horizontally has teeth both sides, and horizontal pinions mesh with it. This enabled the line to be built with a ruling gradient as steep as 1 in 2: it remains unique. Such sharp gradients have otherwise been the prerogative of funiculars, short railways independent of main systems, operated by cable haulage over gradients too steep for rack. Such lines were built in Britain as cliff railways from the 1870s onwards, and on the continent of Europe from the same period. EARLY ELECTRIFICATION Attempts were made to drive railway vehicles by electricity in the 1830s and in 1842, Robert Davidson successfully operated a battery-electric locomotive on RAIL 585 the Edinburgh & Glasgow Railway, hauling about six tonnes at 6.5kph (4mph). The first electric railway was operated by Werner von Siemens at an exhibition in Berlin in 1879. It was of metre gauge and a third rail between the running rails was used to supply electricity, generated by a dynamo at 150 volts, to a small four-wheeled electric locomotive hauling a passenger-carrying train. The railway was subsequently operated in Dusseldorf, Brussels and, in 1881, at the Crystal Palace in London. The same year Siemens started to operate a 2.5km (1 1/2 miles) electric railway on the outskirts of Berlin, on which passengers were carried in horse tramcars to which electric motors had been fitted. In 1883, Magnus Volk built his little electric railway along the sea front at Brighton, Sussex, which in modified form still runs, and the first section of the Giant’s Causeway electric tramway was opened in Ireland. In the same year Leo Daft in the USA built an electric locomotive: current came from a central rail and this 8.9kW (12hp) locomotive, called Ampere, could haul ten tonnes. It had an electro-magnetic brake. Two years later Daft built an improved electric locomotive for the New York Elevated Railroad. From the mid-1880s electric street tramways were built in North American cities on which the cars collected current by trolley poles from overhead wires. The first electric tramway in Britain was opened in Blackpool in 1885: cars collected current from conductors in a conduit beneath the road surface. Overhead current collection was substituted later. The first electric underground railway was the City & South London Railway, a deep-level tube railway opened in 1890. Its sixteen locomotives each had two 37.3kW (50hp) motors with armatures mounted on the axles. Current at 500 volts DC was supplied from a conductor rail. The same system of electricity supply was used on the Liverpool Overhead Railway opened in 1893, the only elevated railway built in Britain. Here too were seen for the first time in Britain electric trains consisting of motor coaches and trailer cars, without separate locomotives, and electrically operated semaphore signals which returned automatically to danger as a train passed. In 1894–5 the Baltimore & Ohio Railroad electrified 11km (7 miles) of lines across the city of Baltimore, part overhead and part underground, at 675 volts DC with electricity drawn from a rigid overhead conductor. In 1899 the Burgdorf-Thun Railway in Switzerland was electrified using three-phase alternating current for the first time, at 750 volts, collected from double overhead wires, and in 1903 the 30.5km (19 miles) line from St Georges de Commiers to La Mure in France was electrified using direct current with a voltage as high as 2400: locomotives of 373kW (500hp) hauled trains weighing over 100 tonnes up gradients as steep as 1 in 38. The same year, on an 8km (5 mile) test line near Berlin electrified at 10,000 volts three-phase AC, speeds as fast as 209kph (130mph) were being reached. PART THREE: TRANSPORT 586 MONORAILS It was during the period before the First World War that monorails first caught public attention, although as early as 1824, H.R.Palmer had proposed a monorail in which divided vehicles would hang down either side of a single rail supported on trestles. An experimental horse-powered line was built, without lasting effect. About 1880, however, the French engineer C.F.M.T.Lartigue built about 190km (120 miles) of similar lines in North Africa along which wagons which hung down either side of the rail like panniers were hauled by horses or mules. The system was demonstrated in London in 1886, but with a steam locomotive designed by Mallet: it had a pair of vertical boilers and two grooved wheels. This led to construction of the 15km (9 miles) Lartigue monorail Listowel & Ballybunion Railway in Ireland, cheap to build, opened in 1888, steam worked, and successful in operation until 1924. The managing director of the Lartigue Railway Construction Company was F. B.Behr who developed a high-speed electrically powered monorail, demonstrated in Belgium at 132kph (82mph) in 1897. He promoted a company which was authorized in 1901 to build such a line between Liverpool and Manchester, upon which the cars were to travel at 175kph (109mph): but the Board of Trade was hesitant over their braking abilities and capital for construction could not be raised. It was at this period, however, that the Wuppertal Schwebebahn was built in Germany, an overhead monorail with electrically powered cars suspended from it. The first section was opened to traffic in 1901; the line eventually extended to some 13km (8 miles) and continues to operate successfully to the present day. In 1903, Louis Brennan patented a monorail system in which the cars would run on a single rail and use gyroscopes to maintain their stability; this was built and demonstrated in 1909 with a petrol-electric vehicle, but despite the attraction of cheap construction was never put into commercial use. There have been many subsequent proposals for monorails, some of which have been built. The Bennie monorail, in which a suspended car was driven by an airscrew, was demonstrated in the 1920s; the most notable of many systems proposed since the Second World War has been the Alweg system in which the track is a hollow concrete beam supported on concrete pylons; not strictly a monorail, for a narrow track on the top of the beam is used for the carrying wheels of the vehicles, while additional wheels bearing on the edges of the beam cater for side thrust. With the exception of the Wuppertal line, monorails and the like have seen little use in public service, and have always had greater success in exciting public imagination. THE PEAK YEARS In the period 1910–14, after eighty years of continuous development, railways were the foremost means of land transport. The only challenge to their RAIL 587 supremacy came from the electric tramways that were beginning to bite into the inner suburban traffic of large cities, and they were simply a specialized form of railway. Neither the motor road vehicle nor the aeroplane had yet made a serious impact. The developed western countries—Europe and the USA—had largely completed their main line networks, although construction of lesser lines continued. Elsewhere there were few parts of the world where railways were unknown, but long-distance lines were still being built and in some countries, notably China, the railway system was still in its infancy (see p. 577). The United States The railway network of the United States extended at this period to about 404,000 route kilometres (253,000 miles), owned by some 2500 companies of which about 1000 operated the system’s trains. There were about 60,000 locomotives. The USA was if anything somewhat overprovided with railways, and although fortunes had been made, that huge network had not been achieved without a great many company bankruptcies also. Approximately nine-tenths of the system was single track. Automatic couplings between wagons had been obligatory since 1893. Britain In Great Britain, there were about 33,800 route kilometres (21,000 miles) of railways; about half the system was double track, and services were by comparison frequent with many trains of moderate weight. Track was laid with bullhead rail weighing from 30 to more than 50kg/m (100lb/yd); most other countries used flat-bottom rail. The total included about 885km (550 miles) of light railways, some of standard gauge, some narrow, built under the provisions of the Light Railways Act 1896. This was a belated attempt to encourage improved rural transport by reducing both costs of promotion and standards of construction. It was largely ineffective, as comparable figures for some European countries, below, will indicate. Continental Europe France had a total of 50,700 route kilometres (31,500 miles) of railways of which about 38,600km (24,000 miles) were classified as d’intérêt général, the most reasonable interpretation of this term being main or trunk lines providing long-distance transport. Most of the system was operated by five big companies with concessions of limited duration from the state, the land on which the PART THREE: TRANSPORT 588 railways were built being considered public property. There were also nearly 11,300km (7000 miles) of railways d’intérêt local providing local transport within particular districts. Some 8500km (5300 miles) of these, and a small part of the railways d’intérêt général, were of narrow gauge—usually one metre, though 60cm was also used, largely at the instance of Decauville Aîné. In Germany, which then included Alsace-Lorraine, railways had been under the control of the imperial government since 1871, and were mostly owned by the individual German states. Main-line routes totalled about 60,000km (37,300 miles); there were a further 10,800km (6700 miles) or so of light railways, locally-owned and mostly of narrow gauge. Of smaller European countries, Belgium had a main-line system of nearly 4700km (2900 miles), mostly state-owned, with a further 3900km of light railways, mostly of one metre gauge and with some sections electrified. The Swiss railway system extended to 3500km (2172 miles) of standard gauge, mostly owned by the Swiss Federal Railways, and 1000km (644 miles) of metre gauge, mostly private. A total of 760 route kilometres (472 miles) was already electrified. This included most of the metre gauge lines, but it also included important main lines—the federal railways’ Simplon line with its 22.5km (14 mile) tunnel completed in 1907 and the company-owned Berne-Lötschberg- Simplon Railway opened to connect with it through the 14.5km (9 miles) Lötschberg Tunnel in 1913. This, the last of the great European main lines to be completed, was the final link in a chain of railways connecting France with Italy via Berne and avoiding the German-owned lines in Alsace-Lorraine. The Simplon and Lötschberg lines had been built for electric traction: the Simplon was electrified at 3000 volts 3-phase AC, but the Lötschberg line, following successful experiments elsewhere, was electrified at 15,000 volts single-phase AC. It had a ruling gradient of 1 in 37, up which 1864.25kW (2500hp) locomotives could haul trains weighing 310 tonnes. Further afield, imperial Russia, where the great railway-building period had been the last decade of the nineteenth century, had a network of some 70,800 route kilometres (44,000 miles) in use. The first trans-Siberian line had been completed in 1904. A traveller could leave London, Charing Cross at nine a.m. on a Monday and Ostend the same day, arriving in Moscow on the Wednesday and Vladivostock at 2.50 p.m. on the Friday of the following week. The British Empire In Canada, although the Canadian Pacific’s transcontinental line had been completed as long before as 1881, the railway network was still expanding fast: in 1912 there were 43,000 route kilometres (26,700 miles) in use and another 14,000km (8860 miles) under construction. India, which then also included what are now Pakistan, Bangladesh and Burma, had 27,000km (17,000 miles) RAIL 589 of 5ft 6in (1.67m) gauge, 22,000km (13,800 miles) of metre gauge and 4300km (2,700 miles) of 2ft 6in (76cm) and 2ft (61cm) gauges, to give a total of about 53,300km (33,500 miles). The broad and metre gauges formed separate but interwoven networks. Narrower gauges were used for feeder lines and for lines in mountainous regions such as the 2ft gauge Darjeeling Himalayan Railway. In Australia on the other hand, where some 27,000 route kilometres (17,000 miles) of railways were operated by the states or the Commonwealth government, gauge varied according to the choice made by each state. The principal gauges in use were 5ft 3in (1.60m), 4ft 8 1/2in (1.43m) and 3ft 6in. (1.06m). The mileage of 3ft 6in gauge exceeded the other two put together, but the 4ft 8 1/2in gauge had been chosen for the trans- Australian railway then under construction by the Commonwealth government: it would connect with the 3ft 6in gauge lines of Western Australia at one end and the 5ft 3 in gauge lines of South Australia at the other. It was opened in 1917. New Zealand had 4500km (2800 miles) of 3ft 6in gauge open; in South Africa there were about 13,600km (8500 miles) of 3ft 6in gauge and in Rhodesia a further 3800km (2350 miles), although the Cape-to-Cairo railway of Cecil Rhodes was and would remain a dream. South America Railways based on British practice, because they had been built by British capital, were common and extensive in South America. One such (with some mixture of American practice also) was the Central Railway of Peru, completed from Callao to Oroya in 1893 and subsequently extended. It gave access to the silver-mining area in the high Andes which in 1817 had attracted Richard Trevithick in search of the fortune that steam engines had failed to produce for him in England. Trevithick came with stationary mine-pumping engines, but proposed construction of railways also. That they were not built at the time is scarcely surprising: when the Central of Peru was eventually built its course, much of it climbing by successive zig-zags, took it over a summit no less than 4817.7m (15,806ft) above sea level. No other railway reached such an altitude. Early twentieth-century locomotives In the USA during the peak years, the high proportion of single track was associated, as both cause and effect, with the practice of running infrequent but heavy trains: compound Mallets as large as 2–8–8–2s were in use. Firing such large machines with coal was not easy: those of the Southern Pacific Railway burned oil. This had the added advantage that they could run cab-first, with the tender coupled behind the smokebox. In 1913 a triplex Mallet type PART THREE: TRANSPORT 590 locomotive was built for the Erie Railroad, with a third set of eight driving wheels beneath the tender, so that there were two high pressure and four low pressure cylinders. This locomotive proved able to haul a train weighing 16,300 tonnes at 24kph (15mph), the train being more than 2.5km (1 1/2 miles) long. Its main task, however, and the task of the others like it built in 1916, was to help freight trains up steep gradients. For fast passenger trains, the old 4–4–0 had evolved into the 4–4–2 ‘Atlantic’ type during the early 1890s: with this arrangement, the firebox could be much enlarged by making it wider than the frames and positioning it above the trailing wheels. Reverting to the six driving wheels of the 4–6–0 produced a 4–6–2 in which a large, wide firebox could be allied with a large long boiler: the remaining components of the locomotive then fitted into place with a symmetry that was to make the 4–6–2 ‘Pacific’ the classic express locomotive of the twentieth century. The first Pacifics were built by Baldwin in the USA in 1901 for the New Zealand Railways; from the following year the type was in service in America. In Britain, lighter and more frequent trains meant that locomotives were generally smaller than those in the USA. However, eight-coupled 0–8–0 locomotives were in use for heavy freight trains on main lines, and a few railways had started to operate 2–8–0s. The 4–4–2 had been introduced to Britain by H.A.Ivatt of the Great Northern Railway in 1898, with limited success until four years later he produced a large-boiler, wide-firebox version. The first 4–6–0s in Britain were goods locomotives built for the Highland Railway in 1894; the first for express passenger work were built by the North Eastern Railway in 1899–1900. Within a few years the heaviest British expresses were usually being hauled by 4–4–2s or 4–6–0s. The only 4–6–2 so far built in Britain, by the Great Western Railway in 1908, had been a failure. The Great Western, however, was going through a period of rejuvenation which had commenced after the conversion of the last broad gauge lines in 1892. Locomotive superintendent G.J.Churchward was steadily improving locomotive design and experimenting to that end. In 1903–5 he obtained three De Glehn compound Atlantics from France for comparative trials with his own locomotives. He eventually adopted neither compounding nor Atlantics, but from the details of their design much was learnt and the four-cylinder simple (i.e., non-compound) 4–6–0 became the standard GWR express locomotive. Continental railways employed locomotives which, though not as large as those of the USA, were generally larger than those in use in Britain. Belgium, France, Germany, for instance, all had Pacifics in service, and the Northern Railway of France was trying the 4–6–4 wheel arrangement. It was from Germany that there came perhaps the most important development in locomotive design since the multi-tubular boiler: the superheater. There had been many attempts to design superheaters for locomotive boilers, and none was particularly satisfactory until the Prussian engineer Wilhelm Schmidt designed the firetube RAIL 591 type, in which steam en route from boiler to cylinders is passed through U-tubes or elements which are themselves housed within large diameter fire-tubes within the boiler barrel. This brings the steam close to the hottest gases leaving the firebox. Superheaters of this type were first used on the Belgian State Railways, and introduced to Great Britain in 1906 on two goods locomotives built by the Lancashire & Yorkshire Railway. In 1908, D.E.Marsh equipped his new 4–4–2 tank locomotives, designed to haul London, Brighton & South Coast Railway expresses, with Schmidt superheaters and these, in comparative trials with London & North Western 4–4–0s, showed marked economy in coal and water consumption. In 1910 the LNWR introduced its own superheated express locomotives and superheating quickly became standard practice worldwide. In 1909, Beyer Peacock of Manchester used the patent of inventor H.W. Garratt for the first time when they built two articulated locomotives for a 2ft (61 cm) gauge line in Tasmania. In the Beyer Garratt design the boiler supplies steam to two separate engine units, between which it is supported on pivots. One of the engine units carries the water tank, the other the coal supply. The next Beyer Garratt locomotive was built in 1911 for the 2ft gauge Darjeeling Himalayan Railway. Like the Mallet, the Beyer Garratt started small, but was eventually to be built in very large sizes. The breakthrough was to come in 1921 when a 2–6–0+0–6–2 Garratt was built for South African Railways: hauling the same load as a heavier Mallet, it proved faster and more economical. It also rode much better. Beyer Garratts were subsequently widely used (except in North America where Mallets were preferred) and especially in Africa. Electrification Several railways had been experimenting with petrol-electric railcars from about 1906 onwards. These self-propelled passenger vehicles used electric transmission to overcome the internal combustion engine’s inflexibility. Railways which tried them included the London, Brighton & South Coast, the Delaware & Hudson, the Victorian Railways in Australia (see Figure 11.3) and the New Zealand Railways. The first, experimental, diesel-engined locomotive, of 746kW (1000hp), was built for the Prussian State Railways in 1912. Its mechanical transmission was inadequate for the task it had to perform, but the following year the first diesel railcar, with electric transmission, went into service in Sweden. By 1912 there were numerous electrified railways in operation. The principal reasons for electrification included ease of ventilating long tunnels, low cost of hydro-electric power in some countries, high power for steeply graded lines and good acceleration for lines with dense suburban traffic and suffering, perhaps, from electric tramway competition. Electrified lines now also included 116km (72 miles) of the New York, New Haven & Hartford Railroad, a 117.5km (73 mile) section of the Prussian State Railways and . On many of these the two high pressure cylinders drove the front pair of driving wheels and the low pressure cylinder the rear pair, front and rear not being coupled together in the interest of. Germany, for instance, all had Pacifics in service, and the Northern Railway of France was trying the 4–6–4 wheel arrangement. It was from Germany that there came perhaps the most important development. narrow track on the top of the beam is used for the carrying wheels of the vehicles, while additional wheels bearing on the edges of the beam cater for side thrust. With the exception of the Wuppertal