With the ongoing threat of climate change, companies and goverments around the world are trying to find out ways to reduce emmissions within the transport sector, especially within the railway industry. But it seems a lot of people tend to overlook the installation of overhead line equipment when it comes to not just decarbonization, but also to make the railway more reliable in general. And with the introduction of battery and hydrogen trains, the railway industry is more hyped than ever to make the dream of decarbonization a reality.
But it’s not that simple
What a lot of people tend to forget is that electrification of the railways is not just about decarbonization. During an episode of Green Signals, Nigel and Richard said that governments often create a whole lot of patchwork by going over corridor by corridor and seeing what approach would work best. Source
Not only this is a very bad way to expand electrification, but these “case studies” are actually doing more harm than good. Thus why main lines should always have wires. This doesn’t have to be more expensive either, because the country where I live in, The Netherlands has also studies battery trains as a potential solution for certain corridors but later decided OLE was better due to the lower costs and the abdundant electric rolling stock other operating companies have, thus it makes more sense to build new overhead line equipment.
Not only are electric trains faster and more reliable compared to diesel trains, but electric trains are also lighter, and contain fewer parts thus meaning less overall maintenance such as track wear and train inspections. Electric trains are also a lot more quiet. Dual mode trains and locomotives also benefit from this because they don’t need to run on diesel when there’s wires such as with the Vectron Dual Mode and Stadler Euro9000.
And in countries like India, freight trains can carry double stack containers with high-power electric locomotives. Countries like the United States also use double stack containers, but they’re all diesel locomotives and are just not powerful enough to be able to work under a single locomotive.
But why battery trains?
Battery trains are meant to close the gap where equipping certain regional rail lines that don’t get a lot of ridership with overhead wires would be too expensive or impractical, or at yards where the overhead lines end. A recent example are the Cardiff Valley Lines which use partial overhead line equipment. Lines like that often see very little to no freight traffic, making them suitable for battery trains. Another advantage of battery trains is that they can charge under the wire, depending on the overhead voltage.
Using battery locomotives for freight on the other hand, would be very impractical considering those locomotives often require a lot of power to be able to pull a heavy load. They can still be used for lighter shunting tasks, but not for mainline freight as batteries can take up a lot of space and can become very heavy causing extra wear to the tracks. On top of that, batteries can also degrade over time.
Countries like The Netherlands, France and Japan use 1.5kV direct current on their railways, which often isn’t powerful enough to run long freight trains and allow battery trains to charge quickly under the wire. The 3kV DC standard in countries like Belgium, Poland and Spain is a bit better because of the higher voltage. The real advantage comes with alternating current, where 15kV at 16.7hz and 25kV at 50hz/60hz allow for a higher power output with the cost of needing slightly heavier locomotives. Infrastrucuture wise it’s also cheaper to install compared to DC due to the fewer substations needed. And with the high voltage, battery trains can charge a lot faster.
How it’s done right
As explained before, regional services with lower ridership and short OLE gaps can make way for better and more reliable service on those lines, given that the infrastructure allows it. Utilizing battery trains on an active freight line or main line without OLE is just straight up impractical and doesn’t scale very well. You might as well as install OLE on that line. Even though it might be more expensive, it’ll be a lot more future proof.
Countries like Germany, Austria and the Czech Republic show that this approach is possible if done the right way.
However, countries like The United States and Canada don’t seem to understand this quite well. Especially considering most freight companies in the US and Canada are against the installation of overhead wires because “it pollutes the view”. Says who? I think it’s quite the opposite actually, since I think they enhance the view and make the railways seem more modern. Caltrain has done it, and as a result ridership numbers skyrocketed. So if Caltrain can do it, so can the others.
The Freight railways in Australia share a similar problem, but in states like Queensland, electric freight trains exist.
And then there’s New Zealand, which despite has a decent plan, is in my opinion too focussed on decarbonization compared to operational efficiency. Sure, some sections of the line from Palmerston North and Hamilton have been electrified, but then again, batteries don’t have a big range when it comes to freight trains. Full OLE in my opinion would be the best choice despite it carriying the highest initial cost, but the best returns.
Conclusion
People need to understand that electrifying railways shouldn’t be done merely to decarbonize. The economic impacts of electrifying railways often exceed expectations, even when the energy grid isn’t entirely clean. Countries like India and Switzerland have shown that this approach is possible, and that long term investment often brings the best result. That’s not to say that battery trains are entirely useless, but strategic use on regional lines and adequte infrastructure allows those places to be better connected for a future with better mobility.