Bombardier ALP-45DP

Several non-electrified commuter lines are located between New York City and several cities in New Jersey. However, since the crossing under the Hudson River can only be used by electric locomotives, passengers used to have to switch from diesel-powered trains to other trains. In order to ensure an uninterrupted journey, New Jersey Transit originally ordered 26 passenger locomotives with fully-fledged diesel and electric power trains from Bombardier in Kassel in 2008, with options for a further 63. Because Canadian operator Exo, then AMT, which operates commuter rail services around Montreal, had the same problem with the Mount Royal Tunnel, they joined NJ Transit and ordered 20 with an option for 10 more.

Bombardier based the ALP-45DP on the ALP-46, which was an all-electric locomotive and is closely related to the European TRAXX locomotives. The designation stands for “American Locomotive Passenger”, 4 axles, 5 megawatts, “Dual Power”. All the equipment had to be accommodated in a four-axle locomotive with a maximum axle load of 72,000 pounds anyway. Since the locomotives were only to be used in push-pull trains with cab cars, a second driver's cab was not required.

Like the ALP-46, the power train for electric operation is based on that of the TRAXX 2E, which is used in Germany as class 186 and enables a top speed of 125 mph or 201 km/h. In the ALP-45DP, however, it only delivers 5 megawatts. In order to achieve an output of more than 3,000 kW in diesel operation, the choice fell on two light, fast-running twelve-cylinder engines from Caterpillar, each with its own generator. These are designed in such a way that if one engine fails, the locomotive can still be used with the other. The top speed is limited to 100 mph or 161 km/h in diesel mode.

The power train is designed in such a way that the change between the modes can even take place when running and there is no interruption to the power supply of the train. However, the NJ Transit locomotives were manipulated in such a way that the change can only take place when stopping at a station in order to prevent them from gliding along without power during the 100 seconds required for this. Regardless of the current operating mode, up to 1,000 kW can be diverted to supply the passenger cars, which reduces the power available at the wheel to 2,039 kW in diesel mode.

At NJ Transit, the first delivery replaced the various passenger variants of the EMD GP40. After the first batch, 17 more were ordered in 2017. In 2020, another eight were ordered to replace Alstom's older PL42AC. At Exo, in 2019, the part of the line they traveled in electric mode was integrated into the new driverless metro. They are now only operated in diesel mode.