Fullscreen HTML5Med Res (??MB)HTML4

STEAM LOCOS COME OF AGE THE EVOLUTION OF ELECTRIC RAILWAYS By the turn of the century, steam locomotives were the supreme mode of land-based transport. But there were already a number of places where electric locos were more suitable. By BRYAN MAHER The first underground city railway began operating in London in 1863, initially using steam locomotives. Yes, doubting reader, they really were steam operated. Smoke abatement measures included ventilation shafts at strategic points along the tunnels and a unique locomotive design whereby the exhaust smoke and steam was piped back into the side watertanks. But passengers still coughed and spluttered. The solution was the introduction of some electric locomotives in 68 SILICON CHIP 1890, leading ultimately to the use of electric multiple unit sets. A live third rail laid beside or between the running rails provided direct current supply to an insulated sliding brass shoe attached underneath the train. Voltages up to 750 volts were used and the return current passed back via the wheels and the running rails. The second happening destined to eventually change the face of railroading was the invention in 1897 of an internal combustion engine using compression ignition of fuel. This engine was the brain child of Germany's Herr Doktor Rudolph Diesel. Intended initially for aircraft propulsion, the failure of the diesel engine in this application lead to its use in shipping. Railway applications of the diesel engine were slow in coming though, with Sweden taking the honours for the first dieselelectric locomotive in 1913. We'll talk more about that later in this series. Electric traction develops The London Underground was not the first foray into electric propulsion for trains. The world's first electric railway carrying farepaying passengers ran in Berlin, Germany in 1879. True - it only carried twenty passengers sitting atop three flat trucks running on a narrow rail gauge (less than 500mm). This was the first use of the voltage supply on a 'live' third rail One of the world's first articulated Mallet type locos. Delivered to the Santa Fe Railroad in 1909, it weighed close to 300 tonnes in working trim and had a tractive effort of 108,300 lbs, greater than anything ever built for Australia or England. (Santa Fe photo). system. Installed at the Berlin Exhibition by Siemens-Halske, its top speed of 13km per hour was impressive, at least to the frightened passengers. In the following year, Thomas Edison opened to the public his small electric railway at Menlo Park, New Jersey USA. By 1881 a 2.5km electric tramway was operating in Berlin and Lichterfelde, Germany, while in the USA Edison commissioned the first steam driven electric power station at Perl Street, New York City the following year. Frank Sprague operated an electric railway system at St. Joseph, Missouri USA in 1887, and a larger system, The Union Passenger Railroad, at Richmond Virginia immediately followed. Tunnels again The greatly respected Baltimoreand-Ohio Railroad chose to electrify a section of their main line in 1895 because of the problems associated with steam locomotives in the 2.4 kilometre tunnel at Howard Street, Baltimore. This, the first main line electrification in America, used low voltage direct current on an overhead trolley wire (using the catenary suspension system) from 1895 until 1901 when a third rail system was substituted. In New York, Boston and Chicago, the city fathers inflicted upon their citizens the dreaded "EL", the Electric Elevated Street railroad systems, to celebrate the turn of the century. To date all systems had used direct current, of 500, 600 or 750 volts, collected from the live third rail. Difficulties with commutators, used for carrying currents into the motor armatures, placed a practical limit on the direct current voltage at around 1500 volts. Some systems, however, placed two motors in series and used 3000 volts. Massive generators were installed at four to 10 kilometre intervals along the tracks. These connected to either a live third rail beside or between the running rails, or alternatively to a catenary Wire strung high above the roof of the train. These designs are used to this day in many parts of the world. The live third rail method was adopted by the United States for elevated and underground tracks, and also by the London Underground which spread vertically and horizontally and eventually grew into the world's largest electric suburban railway system. It uses a 750 volt direct current supply. Italian pioneering Italy, always a nation to 'do it their own way', brought into use in 1900 the world's first Three Phase Alternating Current Electric Railway. As a nation without coal resources for ground-based power stations, their hydro-electric generators were inevitably situ:ited far from the rail tracks. To ease the problems of long distance electricity transmission and to allow simpler transformer substations near the tracks, alternating current was adopted. Thus track-side equipment was notably cheaper than the rotary machines used in England, the USA and Germany. A big problem arose, however, with traction motor design. Westinghouse in America was pioneering alternating current (AC) motors for workshop and stationary machine use, using the three-phase induction motor principle. But there is a big problem with induction motors in that they have a very strong tendency to run at one single speed (the so-called synchronous speed). This is an advantage in many appications but this onespeed tendency was a severe drawback in railway traction. Nevertheless, Italy persevered with the 3-phase system for their railways and in much of the country used it exclusively. By 1928, 2600km of main lines were working on 3-phase AC. Two separate overhead catenary wires hung above the train while the tracks formed the necessary third phase conductor. As you might expect, great difficulties plagued the overhead wiring at track crossovers and points. The advantages of a 3000 volt DC system were finally recognised in 1928, but so extensive was the three-phase AC system that the last of it was not converted to DC until 1971. Currently, nearly 9000km of 3000 volt DC systems provide the Italian nation with an excellent service. Full steam ahead Meantime, neither the English nor the Americans were very enthusiastic about electrified main line railways, except of course for inner city, underground and elevated track sections. Strange indeed is the history of this section of the industry. England, Australia and many other countries slowly increased their electric suburban lines and regarded them as investments in the future, but in the United States the opposite occured. Between 1890 and the World War I, the US railroad companies built close on 40,000km of these small electric commuter systems but by the time of World War II a DECEMBER1987 69 Built in 1944 for the Santa Fe Railroad by the Baldwin Locomotive Works, this 4001tonne heavy freight loco was capable of a tractive effort of 93,000lbs and high speeds. Its height was 4.87 metres and its length was nearly 30 metres. large proportion of these had gone, replaced by the spreading blight of automobile mania. English development up to the 1940s consisted mainly of raising running speeds of steam trains, track straightening, and building some beautiful top class steam locomotives capable of running for up to 600 kilometres without stopping. These locos featured a passageway through the tender to the first carriage to allow a change of crew without stopping, and a scoop below the tender to pick up water from a long trough between the rails while travelling at high speed. The English saw no need for very large tenders, and their relatively flat terrain allowed them to design steam locomotives for speeds over 170 km per hour with little need for particularly high drawbar-pull. Many of their locomotives were of . the 4-6-0 wheel arrangement, meaning four small wheels in a leading bogie followed by six larger driving wheels with no small wheels behind the drivers. With larger designs, a trailing bogie of two wheels might be added to support the extra weight of a bigger firebox. This wheel arrangement is called the 4-6-2 or "Pacific" type and was famed for its fantastic performance hauling the "Flying 70 SILICO N CHIP Scotsman''. Some 2-8-2 locomotives were in use from 1925 and in 1952 a rather strange looking 2-10-0 design took to the rails and was promptly nicknamed the "Decapod". Though the English had electric suburban trains aplenty, and were manufacturing electric locomotives for many overseas orders, they had only six electric locomotives running in their own country as late as 1948. Back in the USA Meantime across the Atlantic, the Americans were similarly concentrating all their efforts on bigger and faster steam locomotives, top class luxury trains, and straighter and stronger tracks. In the 1920s to the 1940s they reached their peak with such well remembered famous trains as the ''Twentieth Century Limited" from New York to Chicago on the New York Central system, and the "Super Chief" from Chicago to Los Angeles on the Atchi son, Topeka & Santa Fe Railroad. Few countries can boast songs eulogising their trains but such hits as "Orange Blossom Special" and "Chattanooga Choo Choo" show the high esteem in which US trains were held in their heyday. From the beginning, the American scene featured 8-wheel bogie freight waggons which were much larger than the 4-wheel goods trucks commonly seen in England. The bogie design also allowed higher running speeds. And the English weren't the only ones developing steam locomotives capable of running long distances without stopping. The Americans, with their heavier trains and mountainous country, were forced into building larger steam locomotives than any other nation. Consider the Union Pacific Railroad which crosses the Rocky Mountains at the 2.5km (8250 feet) high Sherman's Hill in Wyoming. This is via a long, long 104km continuously rising slog upwards at a 1-in-120 gradient. This mountain crossing led to the building of a number of huge steam locomotives, including the massive 4-8-8-4 "Big Boys" which developed 7.46 megawatts of power. These locos had two sets of eight driving wheels and four cylinders. They were also articulated so that they would go around bends. The Santa. Fe Railroad from Chicago to California crosses the Rockies at the 2.4km (7590 feet) high Ra ton Pass which is approached by a very long 1-in-33 gradient. This beautiful example of the steam loco designer's art enabled Santa Fe heavy freight trains to run at express speeds over thousands of kilometres. Those driving wheels are more than two metres in diameter. To conquer such obstacles the railroad as early as 1909 obtained the world's first four cylinder articulated Mallet type steam locos whose drawbar pull or tractive effort exceeded 100,000lbs. Early articulated models were not stable enough to run at high speeds, but later efforts in the late 1930s could run at passenger speeds. Known as the Mallet design, it became a symbol of the enormous size of all large US railroads. Towards the end of the steam era, the Santa Fe Railroad purchased some beautiful examples of the locomotive art, typified by the 2900 class, a 4-8-4 type with a huge tender carried on sixteen wheels, and the equivalent freight model, the 2-10-4 type 5011 class. Each tender carried 32 tonnes of fuel and 120 tonnes of water. To achieve express speeds the driving wheels of the 2900 class were just over two metres in diameter! (To give you an idea of how big that is, it's about the height of a standard domestic door!) These locomotives often ran for as much 2850km before being taken off the train for running service. Although the Santa Fe Railroad operates no electric locomotives, diesel electrics were introduced as early as 1935 and progressively in- creased in numbers until the steam era finally ended in 1959. American electric triumphs Over in the eastern side of the United States, the Allegheny and Appalachian mountains in Virginia and Pennsylvania proved to be a formidable barrier to the locomotive builders of the Chesapeake & Ohio, Baltimore & Ohio, the Virginia and the Pennsylvania Railroads. Before the first two of these amalgamated, they purchased some amazing steam motive power, including the only 2-6-6-6-0 type locomotives ever built. These claim the record for the highest power output of any steam locomotive. But the Virginia and the Pennsylvania have a more important reason to be included in our story for they both introduced electric locomotives early in the piece. The Virginia Railroad probably will hold forever its distinction of operating locomotives having by far the highest drawbar pull or tractive effort. The purpose of their line was A 1950s vintage American diesel-electric locomotive at Kingston, Rhode Island, in 1975. This loco was typical of many which replaced steam in the USA between 1940 and 1960. DECEMBER 1987 71 Pride of the Pennsylvania Railroad were the fast and powerful GG1 class electric locos. They showed the USA the capabilities of electric traction. to haul West Virginian coal up and over the Alleghenies and the Appalachians to the seaports of Chesapeake Bay. For the downhill and level coastal section of the route, their 15,000 tonne trains used one 2-10-10-2 compound steam loco having a drawbar pull of 783 kilonewtons (176,000 lbs), the highest figure for any steam locomotive ever built. For the uphill sections they cut the train into 5000 tonne sections each headed by (wait for it!) a triple-unit electric locomotive having 1234 kilonewton (27.7,500 lbs) drawbar pull, the highest figure achieved by any loco ever built. For climbing the 220km single track mountain section, mostly at a gradient of 1-in-30, traffic schedules were arranged so that loaded up-trains never had to stop at crossing loops, but slogged endlessly uphill at a steady pace, all trains of empties having to wait 72 SILICON CHIP where required. Little wonder that their plant earned the name " The Transportation Factory' ' . Contrast this with modern diesel electric locomotives rated singly at 50,000 to 80,000lbs of drawbar pull, intended to be coupled in groups of two, three, or more as needed. Eventually the Virginia Railroad was incorporated into a larger system, the Norfolk & Western Railway. The Pennsylvania RR The Pennsylvania Railroad, dating from 1831, went through a number of name changes and amalgamations before coming to its final 1874 form when , with 17,000km of track, it was the largest in the United States. It is important to our story, because it has featured high speed expresses hauled by electric locomotives over long distances for about 50 years. That's if we include the years since their acquisition in 1971 by the Government-sponsored Amtrak organization. The Pennsylvania RR purchased from the General Electric Company many wellengineered electric locos, including the legendary GGls which were top-class units lasting from the 1930s to their final replacement in 1981. These large and powerful machines, 24.23 metres (79 feet six inches) long and 4.57 metres (15 feet) high weighed in at 213 tonnes. Interestingly, their classic streamlined curves were created by the famed French-born industrial designer Raymond Loewy who also designed the Studebakers of the 50s. They are now replaced by newer electric locomotives, but more about that in a future episode. Grateful thanks to Santa Fe Railroad; Conrail; Amtrak; Swedish Railways; and the SRA of NSW for data and photos.