Variable gauge

A variable gauge system allows railway vehicles in a train to travel across a break of gauge caused by two railway networks with differing track gauges.

For through-operation, a train must be equipped with special trucks holding variable gauge wheelsets containing a variable gauge axle (VGA). The gauge is altered by driving the train through a gauge changer or gauge changing facility.

As the train passes through the gauge changer, the wheels are unlocked, moved closer together, or further apart, and are then re-locked. Installed variable gauge systems exist within the internal network of Spain, and are installed on international links between Spain/France (Spanish train), Sweden/Finland (Swedish train), Poland/Lithuania (Polish train) and Poland/Ukraine (Polish train).

Several alternatives exist, including transferring freight, replacing individual wheels and axles, truck exchange, transporter flatcars or the simple transshipment of freight or passengers.

Alternative names include Gauge Adjustable Wheelsets (GAW), Automatic Track Gauge Changeover System (ATGCS/TGCS), Rolling Stock Re-Gauging System (RSRS), Rail Gauge Adjustment System (RGAS), Shifting wheelset, Variable Gauge Rolling Truck, track gauge change and track change wheelset.

Overview

Variable gauge axles help solve the problem of a break-of-gauge without having to resort to dual gauge tracks or transshipment. Systems allow the adjustment between two gauges. No designs supporting more than two gauges are used.

Systems

Variable gauge axle DR III for 1,435 mm (4 ft 8 ¹⁄₂ in) and 1,524 mm (5 ft) gauge, developed in 1957

There are several variable gauge axle systems:

• Talgo-RD (from Talgo).
  • The Talgo system has been in revenue service in Portbou and Irun, on the Spanish-French border, since 1968
• CAF-BRAVA (from Construcciones y Auxiliar de Ferrocarriles)
  • The BRAVA system was originally designed in 1968 by the Vevey Company (since absorbed by Bombardier Transportation), a company located in the city of Vevey on Lake Geneva, in Switzerland. The system was originally called the "Vevey axle". The design was subsequently obtained and improved by Construcciones y Auxiliar de Ferrocarriles (CAF).
• DB Cargo–Knorr-Bremse. being developed in 2002 for use between Europe and Russia.
• DBAG–Rafil Type V for freight (from Radsatzfabrik Ilsenburg for Deutsche Bahn).
• Japan Railways RTRI (from the Japan Railway Technical Research Institute) to be used on motorised axles.
• PKP SUW 2000 system produced by ZNTK Poznań for Polish State Railways.
• The Montreux-Oberland Bernois (MOB) railway, Switzerland in preparation by Prose (Manufacturer) of Winterthur 1,435 mm (4 ft 8 ¹⁄₂ in)/1,000 mm (3 ft 3 ³⁄₈ in).

Compatibility

The variable gauge systems are not themselves all compatible. Only the SUW 2000 and Rafil Type V systems are interoperable.

In 2009, at Roda de Barà near Tarragona, a Unichanger capable of handle four different VGA systems was under development.

International traffic

VGA is particularly important with international railway traffic because gauge changes tend to occur more often at international borders.

Gauge changer

A Talgo gauge changing system in Lleida, Spain

A gauge changer is a device which forces the gauge adjustment in the wheels. Designs consist of a pair of running rails that gradually vary in width between the two gauges, combined with other rails and levers to unlock, move, support and re-lock the adjustable axles.

In the Spanish Talgo-RD system, a constant spray of water is used to lubricate the metal surfaces, to reduce heat and wear. A Talgo-RD gauge changer is 20 metres long and 6 metres wide.

Operation

Variable gauge multiple units, or a train including a variable gauge locomotive (e.g. Talgo 250) and rolling stock, may drive straight across a gauge changer. Normally the locomotive will not be able to change gauge, meaning that it must move out of the way whilst the remainder of the train itself passes through. On the opposite side, a new locomotive of the other gauge will couple to the train.

A train (or an individual car) can be pushed halfway across the gauge-changer, uncoupled, and then (once far enough across) coupled to the new locomotive and pulled the rest of the way. A long length of wire-rope with hooks on the end means that the process can be asynchronous, with the rope used to bridge across the length of the gauge changer (to temporarily couple the arriving cars and receiving locomotive, although without braking control from the locomotive to the train vehicles).

On long-distance trains in Spain and night trains crossing from Spain into France, the arriving locomotive stops just short of the gauge changer, uncouples and moves into a short siding out of the way. Gravity then moves the train through the gauge changer at a controlled low speed. The new locomotive is coupled onto the front only after the full train has finished passing through the changer.

Countries

Australia

In 1933, as many as 140 inventions were offered to Australia railways to overcome the breaks of gauge between the different states. None was accepted. About 20 of these devices were adjustable wheels/axles of some kind or another, which may be analogous to the modern VGA. VGA systems were mostly intended for Broad Gauge and Standard Gauge lines.

Canada

Variable gauge axles were used for a while on the Grand Trunk Railway in the 1860s in Canada to connect 5 ft 6 in (1,676 mm) and 4 ft 8 ¹⁄₂ in (1,435 mm) standard gauge without transshipment. Five-hundred vehicles were fitted with "adjustable gauge trucks" but following heavy day-in, day-out use the system proved unsatisfactory, particularly in cold and snowy weather. The system used telescoping axles with wide hubs that allowed the wheels to be squeezed or stretched apart through a gauge-changer, after holding pins had been manually released.

Railway operations over the Niagara Bridge were also complicated.

China

• A Patent with diagram (2006) (doesn't seem to say how brake shoes or disc brakes are changed as well)

Finland/Sweden

In 1999, a gauge-changer was installed at Tornio at the Finnish end of the dual-gauge section between Haparanda and Tornio, for use with variable gauge freight wagons. The Tornio gauge changer is a Rafil design from Germany; a similar Talgo-RD gauge changer at the Haparanda end used to exist, but was removed as it required de-icing in winter.

Train ferry traffic operated by SeaRail and arriving from Germany and Sweden by sea used bogie exchange facilities in the Port of Turku.

Germany–Russia

(See Poland)

• 2011 Orders for 3 trainsets placed.

Japan

The Japanese third-generation GCT "Gauge Change Train" EMU on a test run in November 2014

Main article: Gauge Change Train

The "Gauge Change Train" is a project started in Japan in the 1990s to investigate the feasibility of producing an electric multiple unit (EMU) train capable of operating both the 1,435 mm (4 ft 8 ¹⁄₂ in) Shinkansen high-speed network at 270–300 km/h and the original 1,067 mm (3 ft 6 in) network at 130–140 km/h. See U.S. Patent 5,816,170.

The first-generation train was tested from 1998 to 2006, including on the US High-speed Test Track in 2002. The second-generation train, intended to run at a maximum speed of 270 km/h (170 mph), was test-run in various locations in Japan between 2006 and 2013. A third-generation train has been undergoing reliability trials since 2014 in preparation for potential introduction to service on the planned Kyushu Shinkansen extension to Nagasaki.

• 

  The first-generation "Gauge Change Train" EMU in May 2003

• 

  The second-generation "Gauge Change Train" EMU in September 2012

Poland

Poland has SUW 2000 gauge changers installed on international lines to Lithuania and Ukraine used for daily night-trains and some freight transport.

• Since 14 December 2003, VGA trains were introduced between Kraków (Poland) and Lviv (Ukraine) instead of bogie exchange. VGA saves about 3 hours compared to truck exchange. Gauges involved are 1,435 mm (4 ft 8 ¹⁄₂ in) and 1,520 mm (4 ft 11 ²⁷⁄₃₂ in).
• See Ukraine.

Spain

Spain is the largest user of variable gauge systems. Much of the Iberian Peninsula has a different gauge from the rest of Europe. The older lines use 1,668 mm (5 ft 5 ²¹⁄₃₂ in), with new high-speed railway lines and connections to France using 1,435 mm (4 ft 8 ¹⁄₂ in) standard gauge. There are also significant lengths of 1,000 mm (3 ft 3 ³⁄₈ in) lines. Two gauge changes are installed on lines to France and at all entrances/exits leading between the high-speed network and older lines.

In February 2004, RENFE placed orders for:

• Forty-five CAF/Alstom 25 kV AC/3 kV DC, variable gauge EMUs for 250 km/h regional services, between October 2006 and May 2009 (€580 million)
• Twenty-six 25 kV AC variable gauge trains for 250 km/h long-distance services using two Bombardier power cars and Talgo Series VII trailer cars (€370 million) Gauges involved are 1,435 mm (4 ft 8 ¹⁄₂ in) and 1,668 mm (5 ft 5 ²¹⁄₃₂ in).
• Olmedo to Medina del Campo in Valladolid, Spanish test track.
• November 2008 – High Speed trainset for Cadiz to Warsaw.
• July 2009 – Talgo 250 supplied with Voith Turbo SZH-692 gauge change final drives.

Switzerland

Variable gauge axles are going to be implemented on the Montreux–Gstaad–Zweisimmen–Spiez–Interlaken line. Trains will automatically switch from 1,000 mm (3 ft 3 ³⁄₈ in) to 1,435 mm (4 ft 8 ¹⁄₂ in) at Zweisimmen. A trial bogie has been built and tested. It has no axles which allow the bogie half frames holding the wheels on both sides to slide sideways to each other.

Ukraine

As part of a joint bid for the 2012 European Football cup with Poland VGA trains would be introduced across their border.

United Kingdom

John Fowler mentions in 1886 at attempt by the GWR to develop a "telescopical" axle.

Trams ran between Leeds (1,435 mm (4 ft 8 ¹⁄₂ in) gauge) and Bradford (4 ft (1,219 mm) gauge) following a successful trial in 1906 using Bradford tram car number 124. The system was later patented by – GB 8959 of 1906. This system was improved again in patent GB 19655 of 1909 by introducing a locking system acting on the wheel and axle rather than just the wheel rim. This provided a more effective grip where the wheel was free to move along the axle.

Comparison with truck exchange

Time taken

In VGA, the train is pulled through the "adjuster" at about 10 km/h (2.77 m/s) without any need to uncouple the wagons or disconnect (and test) the brake equipment.

Spares

VGA always has the exact number of wheels of each gauge and they are always at hand, whereas with truck exchange, there must be a complete set of trucks of the right gauge and with wheels of the same diameter at the depot.

Truck exchange needs a stock of spare trucks of each gauge, which need to be shunted as required. If there is an influx of traffic one might run out of trucks of the other gauge. Depending on the sophistication of the exchange facility, the cars may need to be uncoupled for the truck exchange to take place.

Locomotives

Steam locomotive are generally not gauge convertible on-the-fly. While diesel locomotives can be truck exchanged, this is not normally done owing to the complexity in the reconnection of cables and hoses. In Australia, some locomotives are transferred between gauges. The transfer might happen every few months, but not for an individual trip.

By 2004, variable gauge electric passenger locomotives were available from Talgo. It is not clear if variable gauge freight locomotives are available.

Electric

• L-9202 is an experimental high speed Bo-Bo dual voltage (3 kV DC/25 kV AC) VGA locomotive.
• Talgo 250 locomotives were also planned to haul dual-voltage variable-gauge trainsets from Montpellier 200 km from the border to Barcelona and Madrid. Two Talgo 250 power cars haul 11 passenger trailer cars.
• EMU

Weight

• A gauge adjustable truck complete with wheelsets weighs a total of about one ton/tonne more than a conventional truck and normally must use disc brakes, which cool more slowly.

History

• 1915. C. W. Prosser. – Argus
• 1921. C. R. Prosser. – Argus Friday 8 July 1921
• 1922. J. Grieve. – Argus 19 July 1922

See also

• Axle track
• AVE
• Bogie exchange
• Dual couplings and match cars
• Gauge Change Train
• INTERGAUGE a form of VGA
• Interoperability
• List of rail gauges
• Ramsey Car Transfer Apparatus
• SUW 2000 a form of VGA
• Wheelset

External links

• A train axle system with variable gauge wheels, patent EP1112908, assigned to Talgo SA.
• Variable gauge bogie for rolling stock, patent EP0873929, assigned to Railway Technical Research Institute.
• Railway axle assembly furnished with automatic change of track gauge and adaptable to conventional freight bogies, patent US5787814, assigned to Talgo SA.
• Variable-Gauge Wagon Wheelsets – Brief Article, International Railway Journal, July, 1999
• European Automatic Track Gauge Changeover Systems, UIC-backed study of different variable gauge systems
• Talgo's variable gauge system explained (in French)
• Talgo's Variable gauge system in action
• UA report
• CFR
• Wishnevski
• Ukraine
• Automatic gauge changing systems in Spain (Spanish)