UK government still too slow on rail electrification

In 2020, Network Rail published its Traction Decarbonisation Network Strategy (TDNS) which presented the business case for a rolling programme to electrify 13,000 single-track kilometres (stk). The Department for Transport then used TDNS to inform the UK’s Transport Decarbonisation Plan which states that “we will deliver an ambitious, sustainable and cost-effective programme of electrification guided by TDNS”.

Yet the UK government’s 2021 comprehensive spending review considered TDNS to be unaffordable. In contrast, the Scottish government is committed to large-scale electrification to decarbonise its railway by 2035. 

Scottish solution

In Scotland the railway is seen as a system. At £2m per stk, electrification is not cheap. However, it provides more powerful, reliable trains which are cheaper to operate and buy.  

South of the border, the focus is rolling-stock decarbonisation solutions by promoting innovation into alternative traction and proposals to significantly increase the bi-mode fleet. These are trains that operate in electric or diesel mode. Although these trains offer an interim decarbonisation solution by making best use of the existing electrified network, they are both overweight electrics and underpowered diesels which are expensive to buy and operate. As rail electrification is the only zero-carbon technology for high-powered transport, focusing on rolling-stock solutions cannot deliver the target of net zero by 2050. 

Regardless of the decarbonisation imperative, it is difficult to see how widespread use of bi-mode trains can be the best whole-system solution or offer the lowest whole-life costs. This does nothing for rail freight for which electrification offers significant benefits. Owing to space constraints, diesel locomotives are typically half as powerful as electric locomotives. Hence, electrification offers heavier and faster freight trains with increased network capacity from the reduced performance differential between freight and passenger trains to enable rail to accommodate additional freight and passenger traffic. 

The view in Westminster is that rail electrification is an expensive business which is best avoided. One reason for the high cost of electrification is evident from the graph showing the electrification mileage delivered each year. Between 2009 and 2014, £200m was invested in electrification. The plan for the following five years was for electrification schemes totalling £4bn. This was an extraordinarily inefficient way to deliver electrification and contrasts with the steady rolling programme in European countries. Hence the Great Western Electrification Programme, and other schemes, were inevitably costly with mistakes made owing to skills shortages. 

Cost overruns

Much of the responsibility for these cost overruns is within the rail industry. Lessons have now been learned. And there have been innovations to further reduce the cost of electrification. One of which is surge arrestors which reduce the required electrification clearances and hence reduce the number of bridge reconstructions required.

The history of electrification is of ups and downs – but it could deliver economic and environmental benefits.