A recent announcement in the press about high-speed trains that are fitted with bogies that can automatically adjust to a change of gauge seems a remarkable achievement.
Whilst there have always been different track gauges in many countries around the world, the challenge of running a train from A to B on one gauge, and B to C on a different gauge has usually involved people, or goods, changing from one coach or wagon to another – and sometimes different stations.
Automatically changing the space between the wheels as the train runs entirely from A through to C, when the tracks are different gauges – wow, that’s new – well, relatively.
Back in 1880s, Brunel’s ‘Broad Gauge’ advocates were at war with supporters of Stephenson’s ‘Narrow Gauge’, and although this did not necessarily result in literal pitched battles between teams of ‘navvies’, the contractors building the lines were occasionally at loggerheads. One flashpoint was in Gloucestershire on a route from Stratford-upon-Avon to Chipping Campden, where, having been forced to build a 1-mile long tunnel near Mickleton, and just to the north-west of Campden. The ‘battle’ involved some 3,000 men, and the Riot Act was read on two occasions, over two days, and Brunel and Marchant both agreed to arbitration. However, the railway company who had appointed Brunel as engineer paid off Marchant and his contractors and completed the tunnel the work themselves. Unsurprisingly the legacy of the disturbances caused concern from all the locals of Chipping Campden, and events even reached the pages of the ‘Illustrated London News’.
The gauge war – waged on both the technology and economic front was partially settled in 1846, and followed from an Act of Parliament, with the exciting title “An Act for regulating the Gauge of Railways”. The reason this was only partially settled, was of course because it made clear that it was illegal to build any new railway that was not to the standard gauge of 4ft 8 ½ins and 5ft 3ins in Ireland. BUT, the exception was Brunel’s 7ft gauge Great Western Railway – oh and various acts of Parliament already passed or in progress relating to various extensions, branches and other lines in the South West, parts of Wales, etc.
Nice, clear and straightforward! The same act also included a clause that prevented any railway gauge to be altered after 1846, used for “the Conveyance of Passengers”. Fascinating, but clearly problematic, and the system of two gauges in England led to the duplication of passenger and goods station facilities in some locations, and the Act also required the GWR to include a third rail where the standard and 7ft gauge lines met.
Gauge disparity around the world has always caused difficulty, and perhaps nowhere more evidently than in Australia, where the various states began railway projects, with different contractors, and engineers leading to long term operational problems. The vast majority of railways are built and operate on the standard gauge – 1435mm – but there are still those differences, whether it is in Spain, India, Switzerland or Russia. In fact, the railways in Russia are built to the Irish standard 5ft 3in gauge, and that’s where the latest techniques and technology to achieve more seamless international train operations with China are being deployed on high-speed services.
The Change of Gauge Made Simple
Back in 2003, an interesting story appeared in the Japanese journal “Railway Technology Avalanche” describing “Gauge-changeable EMUs”. It was stated that these were developed for through-operation between 1,435-mm gauge and narrow-gauge 1,067-mm gauge lines, and the 3-car test train was fitted with two types of bogie, where the back to back distance could be changed on the move. Amongst the attributes needed were the capability to change the gauge while running, the inclusion of traction motors, high-speed running stability, and the ability to operate on routes with sharp curves.
The two types of bogie tested included one where the traction motors were essentially fixed to the wheel centre, which could be moved laterally along the fixed, non-rotating axle. This was achieved by track mounted rails that provided support to the axleboxes, which in turn supported the vehicle body – a locking pin through the axlebox allowed the wheelset to be released and slid along the axle. The second design adopted a single piece wheel and axle arrangement, with a Cardan shaft drive from the body mounted traction motor. With this design, a stopper in a groove in the axlebox fixed the wheels at that gauge, and during gauge-changing operation the stopper was raised by an arm mounted at ground level, with the wheelset then free to slide laterally to the new track gauge.
Each of these approaches required significant changes to the vehicle running gear, and track mounted rails and arms to complete the transition between rail gauges, but none resulted in any production series build of these EMUs.
But, this was not the first application of such novel technology – that honour fell to Spain, where in 1969, the ‘Talgo’ system first appeared. In Spain, the principal track gauge selected was 5 ft 5 21⁄32 in – commonly known as the Iberian Gauge. However, in the 1980s, all new high-speed lines – and especially those on international routes were constructed to standard gauge, which made cross border services to France much more straightforward. The Talgo principle was well established in Spain though, and using the ‘Vevey Axle’ provided these unique, articulated trains with the ability to change gauge without stopping, and of course to cross borders. The system also provides for much higher speeds today, and tilting technology is embedded in the design, and Talgo technology has been developed in recent years and now operates in Finland, Russia, Kazakhstan, and even the USA.
This is what the CAF designed ‘BRAVA’ system looks like in action:
Spain continues to operate an extensive fleet of gauge-changing trainsets between 1435 mm and 1668 mm gauges, but they are limited to a maximum of 250 km/h. So, the development of ‘gauge changing’ trains has progressed quite a bit in recent years, but less so perhaps on really high-speed fixed formation sets, for standard gauge routes, except for the CAF built Class 120 and 121 for Spain.
The most recent addition to the high-speed gauge changing without stopping club is China, where, in October 2020 the state-owned rolling stock manufacturer CRRC Changchun Railway Vehicles, displayed a prototype gauge-changing high-speed train intended for international operation. At 212 m long, the new train is a development of the company’s CHR400-BF design, and intended for international operation between China, Mongolia, Kazakhstan and Russia, at speeds of up to 400km/hr. On top of this, the train is planned to work from different voltages, and with operational temperatures varying from +50C to -50C.
Interestingly, one of the first proposals for a variable gauge wheelset was put forward for the GWR at the end of its ‘Broad Gauge’ era, in 1886, by one John Fowler. Six years later, the ‘Battle of the Gauges’ in Britain was over, and standard gauge was king. As we know, the rest of the world continued to follow a variety of gauges, but perhaps that problem at frontiers, or between different railway companies has finally been laid to rest with these latest gauge-changing trains.