The design of electric-drive passenger diesel locomotives in North America is mostly based on freight locomotives. Because of the heavy wear and tear on the line, it is not suitable for high-speed operation. The use of gas turbine vehicles can reduce the fatigue damage of the line by 50%, and according to the gas turbine supplier Turbomeca, gas turbines have the following advantages: light weight, high power/weight ratio; small size; can increase the operating speed on existing lines, standard It can be increased to 200km/h on the FRA6 level line; the total weight and axle load of the locomotive are reduced; the force on the track is reduced by about 25% compared with the traditional diesel locomotive.
Gas turbines can ideally burn a variety of alternative fuels including LNG, VNG and kerosene. In contrast, when a traditional diesel engine uses natural gas, it cannot be ignited by compression ignition, so a small amount of No. 2 diesel must be added or ignited by other means.
Of course, the use of gas turbine locomotives on high-speed corridors will definitely involve a major change in the understanding of traditional locomotives, and there will also be a change in consideration from freight to passenger transportation, which not only refers to the design but also includes two aspects of operation and maintenance.
Different high-speed passages should be equipped with different gas turbine units. It is impossible to use only one general locomotive to adapt to all passages. The configuration according to local conditions should aim at the lowest cost per person kilometer and the best utilization of equipment.
Gas turbines have high efficiency under full load conditions. The efficiency value is close to that of diesel engines, but the partial load efficiency is not as good as the former. The variable speed response of electric drive gas turbine units is worse than that of diesel engines, and the unit weight is much lighter.
In addition, flexibility is also one of its advantages. Components can be used in auxiliary systems, and gas turbine/electric dual-mode locomotives can also be used as another comparable option. In order to give full play to the capacity and efficiency of the gas turbine, it may be an ideal solution to arrange dual engines. Only one engine is required to run when stopping, and the other engine is started when running at full power and high speed. Of the two power bogies, one is mechanically driven and the other is electric. Compared with a single-engine high-horsepower electric-drive diesel unit, the configuration of two gas turbines in a locomotive will still greatly reduce the weight. The power bogie with suspension traction motor and shaft drive can transmit maximum power almost instantaneously and has good external characteristics. This may be a very attractive electric drive gas turbine solution. As for the traction motor, the Turbomeca manufacturer has not yet made a judgment on the use of AC or DC motors. Both options are considered. They believe that the real need for high-speed passenger locomotives is to make greater quality improvements to the AC solution.