RAILWAY GAUGES The history of Track Gauges is a Saga of Human Ambition, Errors,Stupidity and Lost Opportunity. Most people believe that there is only one "gauge" standard on a railway, for we all think of railways as being broad, standard, medium, or narrow gauge. There are in fact three standards to which the term "gauge" applies, each vital to the safe and efficient functioning of the railway.With today's premium on container and Trailer Railer (trailer on Bogies) freight, and on maximising suburban line capacity, each "gauge" also has vital commercial and social implications. The three "gauges" are: A: The track gauge and its derivatives, the back-to-back dimensions of wheel sets and check rails at points and crossings. B: The rolling stock gauge (or maximum moving dimensions), from which are derived the static and dynamic car envelopes. C: The structure gauge, also loosely known as the clearance gauge. All three are to some degree interdependent , on narrow-gauge tracks excessively wide cars will tip over and excessively high ones blow over, but as we shall see, to a lesser extent than people imagine. Trains must also pass through tunnels without scraping things -- which, as we shall see, they have done -- or, if the windows are open, without removing the head of foolish passengers who ignore the by-laws. But, within limits, there has always been a large degree of freedom of choice in all three kinds of "gauge", and it is this freedom that we will examine. With freedom there comes licence, and there is no greater monument to the stupidity of some railway engineers in the past than their teaming up with politicians to create not three but at least twenty-four different track gauges for regular commercial use. Several gauges have come into use for the most trivial reasons. At least one was created by an engineer's error, another by adding up and dividing by three. Of the remainder, many ware created by the "human weaknesses of stupidity,xenophobia,and bloody- mindedness in engineers, soldiers, politicians, and officials. The track gauge is the distance between the inside faces of the rails, measured (normally) 16mm below the top or running surface and parallel to the sleepers. It is not the distance between the rail centrelines. This error is reputed to have been the cause of the Italian medium-gauge standard of 950mm, that is, the international metre gauge standard, but wrongly interpreted as centrelines between 50mm wide rail-heads. The list printed with this article has all the railway gauges (correctly measured) known to have been in commercial use, from 2140mm down to zero; gauges in brackets are no longer used anywhere Countries printed in bold face have adopted that gauge as one of their standards. With tongue in cheek, we have also listed the smallest track gauge -- zero. But what was the largest?. If we ignore proposals for locomotive-drawn ship-cradles, such as the Nicaragua shipway alternative to the Panama Canal,the most credible claimant is the 3.0m (9ft 10in) chosen for a high-capacity, high-speed electric project to run from the Donetz Basin coalfields in the Ukraine region to the USSR and from the Balkans and Vienna to Paris, via Berlin and the industrial heartland of Nazi Germany. Obeying Hitler's orders, and working under the direction of Dr Wiens between 1940 and 1944, a team of the Reichsbahn's best engineers diverted much-needed wartime resources to designing and running component tests for a giant-sized superrailway. Electrified at 50kV 50Hz, it was to operate trains 5.4m(17ft 8in) wide and 6.85m (22ft 6in) high.These were the body dimensions of double-deck cars and electric locomotives, high-ceilinged ships on rails for passengers, with double-deck engine rooms in the traction units. Locomotives with a maximum mass of 375t for 16,000kW, and operating in multiple unit,were to pull 1000t passenger trains at 250kin/h, and 10,000t freight trains at 100km/h. Electric railcar sets (eight cars for 29,000kW) of similar cross-section were to have double bogies and electric braking for a 3km stopping distance from 250km/h. Contrary to some opinions,this project was taken seriously. Happily for humanity, other events intervened,but the problems of wheel/ rail contact stresses with 35t axleloads at 250km/h would have been interesting, since today's superspeed TGV lines in France operate at half this figure. Given what we now know about railway technology, however, nothing else in the scheme seems to have been impossible. If the Reichsbahn's supertrain was to be a great step forward it could justify its super- gauge. But how can one explain the previous muddle? In the 1930s,the north of England was served by railways built under George Stephenson's inspiration and already starting to form networks. Their gauge can be traced back to the horse-drawn colliery tramways and from there, it is claimed, back to the paved rutways of ancient Rome; it is still today's standard gauge of 1435mm. In southern England, Isambard Kingdom Brunel set his sights on greater stability and higher speed for the Great Western,choosing 7ft for his wheels and a quarter inch lateral clearance: 7ft 1/4in (or 2140mm) between the rails. He achieved both, but only until 1892. In 1836, a littleknown horseworked slate tramway had been built in Wales by James Spooner. It ran between the slate quarries at Blaenau Festiniog and the coast at Portmadoc with a gauge of (nominally) 2ft or 600mm; the cars were coupled and, on a superbly aligned steady 1 in 90 grade, descended by gravity and wore horsedrawn back up the hill. Nobody took any notice until 1863 when Spooner's son Charles built two tiny 0-4-0 steam engines to replace the horses and pulled 60 empties up the hill. Here wore engines that really worked, engines are still running today on this "Great Little Train of Wales" for tourist traffic. Suddenly, there was a real alternative to standard gauge. In the next decade, a host of narrow/medium gauge projects arose. All of them sought to lower construction costs, and most of them confused the key issues: curvature dictated by gauge, and construction standards. In the last century, and right up to the building of the great transalpine main lines, it was generally accepted that the minimum radius of curvature was about 100 times the track gauge Below this figure exceptionally high rolling resistances and heavy woar would result from axlewinding and internal slip effects (something which has never worried street railways all that much). At the turn of the century, the Nilagin mountain line in India and the Rhaetian Railways' famous Bernina line in Switzerland, both metre gauge, were built to exactly 100m minimum radius curves. Before this the Gotthard line in Switzerland, 1435mm standard gauge (opened under steam in 1882), had used 300m radius -- more than double the accepted "100 times" minimum. GAUGES in AUSTRALIA The old New South Wales Government Railways' Blue Mountains line had accepted, despite a constrictive ridge alignment, nothing sharper than 12 chains, 241m or 168 times the standard gauge. Only the worst New South Wales Government Railway branch line had five chain radii -- 70 times gauge.Most branches used eight chains (161m or just over the 100 times rule). Now sharp curvature enables close contouring of hills, and this massively decreases earthworks and bridging costs .The narrow gauge permitted this,and from 1863 there was proof positive that steam engines could pull the trains. Queensland chose 3ft 6in (1067mm) in 1863 and opened on it in 1867 in a determined attempt to build pioneer lines across the Great Dividing Range to the unsettled plains beyond. The attempt, the world's first, was astonishingly successful: two and-a-half to three times as much rail could be provided on the same budget as contemporary New South Wales (which, it must be pointed out, included the Blue Mountains and the Main South). Under Sir Julius Vogel's great public works-driven settlement program of 1870, New Zealand, which until then had only two short provincial standard- gauge lines (one abandoned) and one 1600mm broad gauge system, did the same. So did South Africa from 1873, in order to build quickly from Cape Town to the Kimberley diamond fields. The Irish 1600mm gauge arose from the arithmetic of desperation. It was the average in a dispute between 4ft 81/2 inches, 5ft and 5ft 6 inches proposals finally settled by a committee. New South Wales had an Irish engineer, caught 1600ram fever from him, and passed it on to Victoria and South Australia. Then New South Wales sacked the Irishman and hired a Scot. He switched to standard gauge leaving Victoria, waiting for its order of engines from England, in the lurch. Melbourne refused to change; Adelaide stuck with Melbourne. Tasmania and New Zealand contracted 1600mm from Victoria, but switched to 1067mm. South Australia remains substantially infected, although Australian National are working on that. Today in the new millenium all states share a Trancontinental Standard gauge rail link. NO LOGIC. In 1871, the Denver and Rio Grande opened for business on the 3ft (914mm) gauge, with 300 ft or 91.4m radius curves. British India planned to do the same, but, intending to metricate, settled on the metre gauge to feed its costly broad-gauge trunk lines. It had already used 1067mm in 1865-1868. Continental Europeans bought the idea of the metric system; the tidy numbers were attractive to many. East Africa was issued with secondhand Indian engines and was metre gauge. There was, therefore, a credible rationale for the 2ft, standard and a something-in-between gauge on cost grounds. But there was no sound logic for earlier decisions justifying Braithwaite's 5ft (1524mm) on the Eastern Counties Railway in England and the Czar's choice of it. (He had hired Braithwaite and feared invasion on the 1435mm. As Stalin did later, he sadly underestimated the reconstruction capabilities of the Military Railway service of the German Army.) Anyhow, Russia and later Finland contracted Braithwaite's disease. So did the US Erie and the old south. And so did Mongolia a century later, with Stalin as the carrier and China pushing up from the south on standard gauge.. The 5ft 6in (1676mm) gauge seems to stem from the old Indian Army's fears of their trains being blown over, although there is no record of a standard-gauge train capsize at the time The colonies convinced the Viceroy, Dalhousie, who had been in charge of railways at the Board of Trade and was all for a standard, and pressed for 1676mm. It was chosen, and the first company railway opened in 1853. Iberia and Argentina followed, and by 1880 the gauge situation in the "standard" range was a mess. It was the same in the "medium" range, with 914mm, metre and 1067mm, and each group of engineers spreading their own True Faith. But worse was to follow. The Italians misread the specification, creating their gauge of 950mm, 50mm too narrow. It is still in use on the Vesuvius circumferential line and in the ex-ltalian colonies. Then the Turks (perhaps egged on by the Germans in fear of Franco-British metre gauge imports) pressed 50mm too wide; the Arabian 1050mm is also still with us, although increasingly irrelevant as the Arabs standardise. The origin of the Swedish 2ft 11in (891mm) is totally obscure a misreading of the ruler in the dim light of the northern winter, perhaps?. The Irish 3ft (914mm) was imposed by the British government on the basis of Isle of Man experience ARMY COUP In 1873, the Indian Army struck once again: It claimed that the thriving 2ft was too narrow and the metre gauge too wide. This was proved wrong when metre-gauge trains resupplied the army through waist-deep torrents in a shingle creek bed in Baluchistan during the Afghan war in 1876. But by then they had pressed a military standard of 2ft 6in (762mm) on India. Cyprus and Britain also specified it, as did many other European systems. Then came World War One. The Germans,Austrians and French' had found 600mm fine and standardised on it; once again, the British General Staff was caught with its riding breeches down. In 1915, it hastily ordered 600mm equipment, most of it from America, "in order to use the enemy's tramways when their trenches are overrun" (another tragic piece of optimism). It used its 762mm military equipment, mostly from India, in Allenby's successful campaign in Palestine. By then T.E. Lawrence had blown up all the militarily relevant parts of the 1050mm, anyway. Meanwhile, continental engineers building industrial lines found 762mm a rather messy figure and introduced 750mm, which was nobody's "standard" but looked tidier. The proliferation of what the French call "metric" gauges (914 to 1067mm) was encouraged by a confusion between choosing narrow gauge and choosing light construction standards. The two went together in the early days because narrow gauge meant sharp curves and low civil works costs For no good reason, a standard/wide-gauge line usually meant a quasi- European railway with not only more earthworks but heavy bullhead or fiat- bottom rail in the 35-40kg/m class. The exceptions are rare. In India, the Oudh and Rokikund railway was built on Dalhousie's broad gauge, but down to 8t axleloads with 20kg/m rail-metre gauge standards on broad gauge track, with light 0-6-0 engines and through-worked 2 axle freight cars. The equipment was English but the inspiration American; from the eadiest days, the Eastern US railroads had nailed light wrought-iron rail on to timber ties and operated much the same light axle loads on standard-gauge track. As the US and its railroads grew, so did their axle loads: up to 80,000 Ib (or 36.3t) plus hammer-blow from the final generation of steam trains, and calling for 77kg/m rail (the world's heaviest). But the standard gauge was held. It was the Civil War (where the South was always desperately short of iron and engines)and business and not government direction that forced the American non-standard 1524, 1676, 1740 and 1829mm gauges to give way to the standard gauge. ON TO MEXICO. The US narrow gauge never really consolidated its position outside Colorado; in 1942, 64 per cent of the : 2250km narrow gauge left in the US was in that state, even though an early aim of the promoters had been to build on the narrow gauge right through to Mexico City. The very light constructional standards did indeed permit a link. But with cars only half the length and two-thirds the width of those finally achieved on the medium gauges elsewhere in the world, US narrow gauge simply could not compete with standard-gauge lines. Then the mines gave out, and the roads improved. The railroads perished except for some spectacular museum or tourist lines. There is no practical advantage between the standard and the three broad gauges save one: a broader gauge permits a bigger electric traction motor between the wheels. This capacity has been used only by electric locomotives for example, those built for Victoria, Brazil, India, and Spain by English Electric some 30 years ago.But the basic motor was the "minimum" broad gauge motor: for the Victorian and Brazilian 1600mm. The Russians are believed to use their marginally- broad gauge to its full limit on some electric locomotives, but not on all of their diesel- electrics, at least some Of which have 1435mm gauge traction motors, and the extra benefits for them are nil. Only in India are there suburban electric cars built to the maximum car width potential of the broad gauge (12ft or 3.65m), with "three plus three" across seating. Everywhere else, broad-gauge passenger and freight cars are no wider than the widest comparable standard gauge cars: 3.05m. The only "benefits" of the broader gauges go not to the railways but to the suppliers of axles, bogie frames, and sleepers, who sell more material. Most manufacturers would prefer to standardise, and some decline to quote. There is no practical advantage in a wider gauge than metre. Metre gauge cars have been run (as on French colonial systems) as wide as those on the Australian standard gauge. While some 1067mm electric locomotives have maximum-capacity traction motors exploiting the useful 67mm difference, all the diesel-electrics and most electric multiple units have the manufacturer's standard metre-gauge motors. However, since 1067mm got in.. first, and the British are originally to blame for the metre gauge, we can regret that 1067mm was not made the "medium" gauge standard -- and that without being accused of too much bias towards Queensland. HEAVY WORK Of the sub-medium' gauges, by far the heaviest work is done on the original 600mm gauge (on the cane trams in Queensland and elsewhere). Once again, there has never been a technical case for having any other gauge in the 381-762mm range. With steam, diesel and electric, nothing practical has been done on any of them that has not been done better on 600mm. This includes speed; the Festiniog had substantial chaired 25kg/m bull head track and bogie steam locomotives (Double Fairlie types) that ran at up to 56km/h. So there we have it: three justifiable gauges, and all of them rooted in significant technical developments as far back as 1825, 1836 and 1863 -three gauges that could have done the work of 24. Our forebears' record is not good. The present generation's form is no better, In the 1970s, the San Francisco BART chose 1676mm instead of standard gauge for a new subway system. The reason: so that the trains were more stable and wouldn't blow over, It was a last hurrah for the old Indian Army and Viceroy Dalhousie of 120 years earlier, It was even conceivable that Bombay could have sold them a more substantial and reliable train. But then Bombay was wired on the international standard voltage of 1500 Vdc. BART chose a non-standard 1000 Vdc, just for the hell of it. The equipment didn't work. It also chose a new signal track circuit voltage; the signals didn't work either. Australia now has a standard link from Brisabine to Perth via Melbourne and Adelaide Gauge standardisation in Australia from 1930 (Brisbane link) to 1982 (Adelaide) has eliminated the worst nonsenses where gauge interrupts traffic flows. The exception is,of course, the Melbourne-Perth link. Here Australian Nationai's automated bogie exchange facility at Dry Creek -where the consultants got it superbly right - has reduced delays and costs to a minimum. It will be interesting to see how far private ownership of the new RoadRailers develops, and freight is trucked by forwarders from Melbourne to Adelaide(instead of being reuted in wagons and bogie-exchanged at Dry Creek) for RoadRailing across the Nullarbor. Gauge standardisation of the Melbourne-Adelaide link?. All railwaymen and many key shippers waited years for this final link in standardisation to put all the intersystem traffic of consequence on standard gauge noises are promising. In tandem with this, almost all of Australia's inland/port traffic (some Westrail bulk grain excluded) is already on standard unbroken gauge. LOST CHANCE. Hindsight suggests that Sir Harold Clapp's great vision of the 1930s of standard gauge infill and inland links would have proved largely unnecessary today, and not all that commercially attractive. Some lines would in fact be a liability. More fascinating is what almost happened in Queensland when the Federal Government financed the Mount Isa/Townsville line upgrading some 25 years ago. The dominant traffics are copper to the coast and coal and oil inland, overlaid with some stock to the coastal abattoirs, and mostly container-based merchandise for the inland towns.It is not widely known that the Commonwealth offered to pay for upgrading this line on standard gauge. Had the Queensland Government accepted, it is highly probable that most of the subsequent Central Queensland coal developments would have followed on 1435mm. Progressive relaying of all Queensland Railways tracks on long three-rail sleepers and, finally, gauge conversion of at least the key trunk routes (including the North Coast but probably not the Brisbane suburban and South -Western area) would have logically resulted. Meanwhile, the Queenslanders have shown us the real possibilities of medium gauge in terms of bulk tonnage and, on the Gold Coast project, 160km/h design speeds. Only a few would exceed this on standard gauge. On the Sishen/Saldanha Bay line, the South Africans have recently run a 71,000t test train,having previously run elsewhere a 260km/h passenger train speed trial. So there is plenty of potential in what a former Queensland Railway Chief Civil Engineer once described as "1067mm, the standard gauge.. here in Queensland". Still, the rejected Mount Isa offer remains a tantalising reminder of a watershed opportunity for radical change - an opportunity lost. This Item apeared in Railways of Australia NETWORK magaxine in the July / August issue of 1990 Australia tody has a Standard Guage link from East to West and most states still use their origial Gauges for Secondery Lines and smaller branch lines.