Variable gauge axles.html



Variable gauge axles (VGA) are axles that allow railway vehicles to pass from tracks of one rail gauge to a different gauge. Variable gauge axles are used to allow the running of trains between Spain and France, Europe and Russia, Kazakhstan and China, and Mongolia and China.

There are several alternatives to such a system including transferring the cargo, replacing the wheels and axles, replacing entire bogies and use of transporter wagons, and just transshipment of goods and passengers.

Overview

Variable gauge axles help solve the problem of a break of gauge without having to resort to dual gauge tracks or transshipment.

There are several variable gauge axle systems:

• That of the Talgo- ¹ This system dates from 1968 and is patented.
  • The Talgo system has been in revenue service in Portbou at the Spanish-French border since 1968
  • The Talgo system has been in revenue service in Irun at the Spanish-French border since 1968
• That of CAF- ²³
  • The CAF 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 and was originally called the "Vevey axle" ⁴. The design was subsequently obtained and improved by Construcciones y Auxiliar de Ferrocarriles (CAF).
• That of DB Cargo-Knorr-Bremse. ⁵ being developed in 2002 for use between Europe and Russia.
• That of DBAG-Rafil Type V for freight. ⁶⁷
• That of Japan Railways hoping to include motorised axles. ⁸

Canada

Variable gauge axles were used for a while on the Grand Trunk Railway in the 1860s in Canada to connect 1676 mm and standard gauge without transhipment. Five-hundred vehicles were fitted with "adjustable gauge trucks" but following heavy day-in, day-out use the system proved unsatisfactory. 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.⁹¹⁰

Japan

Japan is working on a Gauge Change Train, using variable gauge bogies. ¹¹

Africa

VGA would be useful in Africa should isolated lines in different countries ever meet, since adjacent countries often use different gauges, 950mm, 1000mm, 1067mm and 1435mm. An important issue is whether VGA can handle more than two gauges or just two gauges. A Cape-Cairo Railway needs three gauges - 1435mm, 1067mm (twice) and 1000mm.

Another use would be for the 1,435 mm (4 ft 8½ in) link proposed to be built by BNSF from Tanzania to Rwanda as an extension of the 1,000 mm (3 ft 3⅜ in) line from the port of Dar es Salaam.

Finland/Sweden

In 1999, a gauge-changer was installed at Tornio at the Finnish end of the dual-gauge section between Haaparanta and Tornio, for use with variable gauge freight wagons.¹² 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 removed¹³ as it required de-icing in winter.¹⁴

Train-ferry traffic arriving from Germany and Sweden by sea uses bogie-exchange facilities in Turku.

Ireland

Currently, the railways networks of Great Britain and Ireland are not linked and there is no train ferry traffic. Variable gauge axles would be one option for crossing the break-of-gauge between the British 1,435 mm (4 ft 8½ in) and Irish 1,600 mm (5 ft 3 in) gauges if an Irish Sea Tunnel was ever constructed.

Comparison with bogie exchange

Time taken

VGA is quite quick as the train is pulled through the "adjuster" at about 10km/h ¹⁵ (2.77m/s) without any need to uncouple the wagons or disconnect (and test) the brake equipment at say 55 seconds per 20m wagon. A 1500m long freight train would take 9 minutes to convert.¹⁶ Bogie exchange might take 10 minutes per wagon. VGA is thus 50 times quicker than bogie exchange. ¹⁷

Spares

VGA always has the exact number of wheels of each gauge and they are always at hand.

Bogie exchange needs a stock of spare bogies of each gauge, which need to be shunted around as required. If there is a tide of traffic one might run out of bogies of the other gauge. Depending on the sophistication of the exchange depot, the wagons may need to be uncoupled for the bogie exchange to take place.

Locomotives

Steam locomotive are generally not gauge convertible, except on a one off basis planned in advance, such as metre gauge Garratts on the Uganda Railway planned for conversion to cape gauge.

While diesel locomotives can be bogie exchanged ¹⁸, this is normally done infrequently due to the complexity of the reconnection of cables and hoses. In Australia, some locos are transferred between gauges every so often. This might happen every few months, a certainly not on individual trips.

By 2004, VGA electric locomotives are starting to become available. ^{19 20 21}

L-9202

• L-9202 is an experimental high speed Bo-Bo dual voltage (3kV DC/25 kV AC) VGA locomotive. ²²

Weight

• a VGA bogie weighs about 1 tonne more than a convential bogie. Also, the brakes are harder to cool. ²³

Timeline

2008

• November 2008 - High Speed trainset for Cadiz to Warsaw. ²⁴

2004

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)^{citation needed}

• 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)^{citation needed} Gauges involved are 1,435 mm (4 ft 8½ in) and 1,676 mm (5 ft 6 in).

2003

• Since 14 December 2003, VGA trains were introduced between Krakow (Poland) and Kiev (Ukraine) instead of bogie exchange. ²⁵ VGA saves about 3 hours compared to bogie exchange. Gauges involved are 1,435 mm (4 ft 8½ in) and 1,520 mm (4 ft 11⅞ in).

See also

External links

• EP1112908 European Patent
• EP0873929 European Patent
• US5787814 US Patent
• Innotrans Show
• BNet
• Panoramio
• AnswerBag
• Variable Gauge Bogie

References