What the world’s longest passenger train can teach us about sustainable transport

Welcome aboard a rail journey that’s as far removed from the morning commute as you’re ever likely to get.

At 14:20 on 29 October, 2022, a passenger train made up of 100 coaches pulled out of Preda station on the UNESCO World Heritage Albula Line, in Eastern Switzerland. The train measured 1.9 kilometres (1.2 miles) in length and weighed in at 2,990 tonnes, according to the BBC, which reported the train’s progress along a steep and winding 25km (15.5 miles) journey through spectacular Alpine landscapes.

Running a train of this length is a major test of driver skill, engineering prowess and technical ability. The record-breaking locomotive was assembled using 25 four-car Capricorn units that normally run on the route.

Seven drivers operated the longest passenger train, precisely coordinating acceleration and braking as the train wound down a route with a vertical drop of almost 800 metres. The drivers had to negotiate 22 tunnels and 48 bridges including the spectacular Landwasser Viaduct before reaching their destination at 15:30.

"We all know the Albula Line very well, every change of gradient, every incline," said lead driver Andreas Kramer, according to CNN Travel. "It goes without saying that we're going through the process again and again." He added: "We need to be 100% synchronized, every second. Everyone has to keep their speed and other systems under control at all times."

Another feature of the record-breaking journey was the sustainable use of energy. As the train’s brakes were applied on the descent, regenerative energy recovery systems kicked in to feed electricity back into the 11,000 volt overhead supply cables. It’s a similar system to those used in motor racing and now in use on some models of electric cars.

Rail travel will be an essential part of sustainable public transport networks as the world moves forward in the energy transition. A 2022 report from consultants BCG, Riding the Rails to Sustainability, is clear on the potential of rail transport for helping to achieve the world's net zero ambitions.

“No form of mass transport has more potential to aid in the fight against global warming than rail,” the report states. BCG’s analysts noted that rail is “responsible for 9% of global motorized passenger movement and 7% of freight shipping – but only 3% of transport energy use”, according to International Energy Agency (IEA) data.

“It uses 80% less energy than trucks per ton of freight carried and holds a four-to-one advantage over cars in terms of its emissions intensity. As a result, rail accounted for just 4% of the transport industry’s global emissions in 2019,” they explained.

Despite the green credentials of rail trans;ort, the railways are losing out to other modes of /transport in many countries. The BCG chart below draws on data from a number of national and global sources to paint a picture of the relatively low use of rail for transporting both freight and passengers.

Of course, not all forms of rail transport are sustainable yet, with many locomotives still powered by diesel engines. However, the industry is heading in the right direction on fuel sources, according to the IEA.

As the illustration shows, the use of diesel trains will fall dramatically across most of the world by 2050. Only the United States lags behind on this with rail freight transport to remain heavily reliant on diesel. The railways will also need to reduce emissions across the entire value chain to become a truly sustainable industry.