The Pantograph Barrier, Part 3 of 4 : Why Speed Matters
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The Pantograph Barrier, Part 3 of 4 : Why Speed Matters

Part One and Part Two of this series discussed the idea of a Pantograph Barrier and why it exists. Part Three will address why the pantograph barrier is significant, and why operating trains above 220 MPH is important.

Railroads were the most important form of transportation during the first few decades of the 20th Century and cities were often built around train stations. From Grand Central Station to the little town train station, they were at the center of commerce and travel. But with the rise of the automobile and the airplane the middle of the 20th century marked the beginning of the decline of trains in North America.

Train travel is still practical and potentially profitable in a couple of use cases though. Outside of the existing North-East Corridor service that is already quite successful, there are many city-to-city trips that trains remain competitive with cars and airplanes. There are some trips that are longer than what some people want to drive but are short enough that trains can compete with airlines on time. This “sweet spot” is for trips between cities that are 300 to 600 miles apart. Driving is convenient in many ways, but it takes many hours to drive that distance. Flying is a hassle, because it may take four hours of waiting to do one hour of actual travel time. Plus not all destinations have direct flights. Passenger trains can fill this travel gap by providing quick, convenient and relatively affordable trips in much greater comfort than flying or driving. Trips such as these are made by trains routinely in much of Europe and parts of Asia.

Of the many reasons people decide to travel by car, plane or train, there are very few that are addressable from an engineering perspective. One area where engineering can have an impact is on the speed of the train. We can reduce the travel time between cities by raising the peak cruising speed of trains. In many places this has already been done to the maximum amount that is safe with the current track geometry, but in other places it is possible to build track that is capable of speeds beyond what current trains are able to do.

For example, take the California High Speed Rail (CAHER) project. The project advertises that the travel time from Los Angeles (LA) to San Francisco (SF) will be 2 hours and 40 minutes with a top speed of 220 MPH. The project has also identified a portion of the LA to SF route as a very high speed section. This section runs from LA to San Jose (SJ) and is about 437 miles long. The balance of the trip is on existing CalTrain tracks.

Looking at other similar rail operations the CAHER project’s advertised top speed of 220 MPH will likely turn out to be a reliable cursing speed of around 190 MPH. This discounted speed provides a significant savings in catenary maintenance costs and increased reliability due to the aforementioned limitations of current catenary technology. Currently, the nonstop trip from LA to SJ will take around 2 hours and 18 minutes travelling at 190 MPH. If we can achieve a reliable cursing speed of 250 MPH (a speed that the track layout would likely allow) or 300 MPH, then the travel time drops to 1 hour and 45 minutes or 1 hour and 28 minutes respectively. This potential improvement could reduce the entire travel time from LA to SF from 2 hours and 48 minutes down to 1 hour and 58 minutes. That is a total reduction of 50 minutes. It may not seem like a lot, but the viability of the project is based on making the train a faster option than taking the plane. A downtown to downtown travel time of under 2 hours would make the CAHER project easily time competitive with flying.

Overcoming the Pantograph Barrier will be essential to being able to increase the speeds of electric locomotives. High speeds over 220 MPH will help facilitate trains as being a more desirable, realistic option for travelers journeying between cities that are 300 to 600 miles apart. In order to do this, current pantograph technology must be improved.

Part four of this series will introduce and discuss a possible solution to the limitations of current pantograph technology: The Balance Force Pantograph.

About the Author

Frank has over 45 years of diverse experience as a Professional Engineer and is registered in 17 states. His experience includes: electric power generation and distribution, microwave communications, public safety radio, SCADA, fiber optic communications and railroad communications. Currently, Frank is a Lead Consultant with MACRO, a division of Ross & Baruzzini, in Chalfont, Pennsylvania. Over the last decade and a half he has provided consulting and engineering services to: SEPTA, AMTRAK, PANYNJ, Caltrain, NJ Transit, Delaware Port Authority, San Diego Transit and many others. In addition, he has 4 patents relating to railroad technology.

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