JetTrain

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Bombardier’s experimental JetTrain locomotive toured North America in an early-2000s attempt to raise the technology's public profile.

The JetTrain is an experimental high-speed passenger train built by Bombardier Transportation in an attempt to make European-style high-speed service more financially appealing to passenger railways in North America. It uses the same LRC-derived tilting carriages as the Acela Express trains that Bombardier sold to Amtrak in the 1990s and a similar locomotive, but instead of being powered by overhead lines as is the Acela and most other high-speed trains, it is powered by a combination of small diesel engine for low speed and turboshaft engines for high speeds.

[edit] Description

[edit] Background

Turbine engines use as much as 65% of their overall generated power to run the compressor at the front of the engine. This means that when the engine is set to idle, with no net energy output, the engine is still burning 65% of the fuel it would at full speed.^{[citation needed]} This makes turbine engines attractive in roles where they are run at high power settings for long periods of times, as is the case in aircraft, power generation, or long-range train service. They are generally unattractive in roles where low-power operation is common, which is why they are not found in automobiles, for instance.

When jet fuel was very inexpensive in the 1950s and 60s the mechanical advantages of the engine, its inherent simplicity and very light weight, made up for the increased fuel costs. In spite of their poor fuel economy during low-speed operation, notably in switchyards, the low cost of the fuel meant the engines remained attractive. Several turbine-powered train designs were introduced, including both passenger and cargo engines. Several turbine powered high-speed trainsets were being designed in the 1960s, including the UAC TurboTrain in North America, the British APT and the French TGV.

By the 1970s, especially after the 1973 oil crisis, these advantages were no longer enough to overcome the increased fuel costs, and most turbine based train designs disappeared. Both the TGV and APT switched to all-electric operation, upgrading their busiest routes to support them. In North America, where funding for upgraded rail lines is limited, electric operation is only an option for the busiest routes, and remains rare. Only CN and Via Rail continued to run their TurboTrains into the early 1980s, before they too were replaced with diesel-electric units, the LRC.

[edit] JetTrain

Another change that has taken place over the last few decades is the widespread use and standardization of head end power (HEP) to provide electricity to the rest of the train for running the environmental controls and entertainment systems. Since these power requirements are fairly steady, even while the train is parked, it is not uncommon to use a separate highly-tuned engine just for this role.

The JetTrain expands on this idea by using the same HEP engine to provide power during low-speed operation, bypassing the problems with turbine fuel efficiency at low power settings. Once the train has left the switchyard the turbine engine, a 3,750 kW (5,000 shp) Pratt & Whitney Canada PW150's (called the ST40 in this role),^[1] is started and the train quickly accelerates to operational speed. The diesel can run the train at speeds up to 50 km/h (when empty), and the turbine increases that to 240 km/h (150 mph). The two engines are geared together in a single gearbox which powers a generator to provide power to four traction motors, identical to those in the all-electric Acela Express. The generator is the motor from a TGV train, run in reverse of normal operation where instead of being hooked to electric power and producing rotation, it is rotated and produces electric power.

The major advantage to using the turbines for the high-speed portion is their light weight; the turbine weighs only 400 kg while a conventional diesel of the same power would weigh as much as 10,000 kg. This lowers the weight of the power cars; the JetTrain power car is 215,000 lbs and had an unsprung weight per axle of 5,530 lbs. This compares to the widespread EMD F40PH fleet which weights 260,000 lbs with an axle weight of 8,540 lbs. This reduction in mass per axle places considerably less stress on the rails, allowing the train to operate at higher speeds without changes to the railbed.^[2]

With a single power car towing seven passenger cars, the JetTrain could reach 170 km/h (106 mph), although its maximum "balance speed" was 220 km/h (138 mph). With two power cars, one at the front and one at the rear, the train reaches 240 km/h (150 mph), with a maximum speed of 265 km/h (165 mph).^[3] A complete train normally consists of two power cars, one at either end, along with up to 11 passenger cars. The passenger cars are versions of the ones used on the Acela, tracing their lineage to Bombardier's LRC tilting train introduced in the 1980s. In operation, the JetTrain is highly efficient. Due to its lighter weight and modern engine, the JetTrain has greenhouse gas emissions that are 30% lower than a diesel unit operating at the same speeds.^[4] The engine is practically silent even at full power - in operation the train is the same volume as the all-electric Acela.^[5]

[edit] History

Controls of the JetTrain

The JetTrain originated in a 1997 Federal Railroad Administration (FRA) desire to develop high speed train services on routes outside the Northeast Corridor where route volumes might not be great enough to make electrification an option. The FRA went looking for an industrial partner who would be willing to invest on a 50/50 basis, and FRA spokesman Warren Flatau commented, "Bombardier is the company that stepped up to the plate when we put out the word we were interested in doing this project. We believe that the project holds great potential for bringing about the high speed services that people across the country are expressing a desire for." The final agreement was signed in October 1998, with the FRA and Bombardier each investing $13 million in the prototype, which was built at the new Bombardier Mass Transit Corporation plant in Plattsburgh, NY (on the former Plattsburgh Air Force Base).

The prototype was completed in June 2000. Safety testing started at the FRA's Pueblo, CO test track in the summer of 2001, where it reached a maximum speed of 156 mph. The prototype was then taken on a tour of potential high speed sites. Their primary target was the Florida Overland Express for passenger service between Orlando and Tampa in the United States. In support of this program, the prototype visited Miami on 7 October 2003 and Orlando on the 11th. The system was originally slated to open in 2009, but was denied funding by a referendum in 2004, after the start of detail engineering stages.^[6]

In Canada, Bombardier and Via Rail presented a proposal to use the JetTrain on Via’s busy Quebec City-Windsor Corridor as part of their ViaFast proposal, but were unable to obtain funding from the national government. In January 2008, the premiers of Ontario and Quebec announced a feasibility study for the Corridor, giving high speed trains another chance. The Van Horne Institute has also completed a study with Bombardier regarding the suitability of JetTrain service between the two largest cities in Alberta, Edmonton and Calgary.^[7] Other possibilities included new lines in Texas and to Las Vegas.

In the United Kingdom, the JetTrain has been proposed as a replacement for the 125mph diesel-electric HST.^[8] Australian rail magazines have suggested the JetTrain as a viable option for high-speed rail in Australia to supplement the XPT (a version of the British HST) and Tilt Train.

However, nothing ever came of any of these proposals, and the JetTrain essentially disappeared. It no longer appears on any of Bombardier's current web sites or promotional materials, although it can still be found on older web sites bearing the Canadair logos.

[edit] See also

• Acela Express
• Bombardier Transportation
• Gas turbine-electric locomotive
• Gas turbine train
• LRC (train)
• Turboliner
• UAC TurboTrain

[edit] References

[edit] Notes

[edit] Bibliography

• "Bombardier Unveils JetTrain Technology", Bombardier press release, 15 October 2002
• "Bombardier JetTrain Rolls Into Florida", Business Wire, 7 October 2003
• "JetTrain Locomotive Rolls Into Orlando: Inaugural Visit to Florida by the High-Speed Rail Locomotive", Marketwire, 11 October 2003
• "Quebec - Windsor Corridor Jet Train, Canada"
• "JetTrain Technology", older Canadair page

[edit] Further reading

• American Magline Group, "Technology Comparison: Transrapid Superspeed Maglev and Bombardier JetTrain, December 2002

[edit] External links

• JetTrain Technology, former Canadair/Bombardier official website