Why did costs soar on the UK's Great Western electrification project?

1 min read

The Great Western Electrification Project (GWEP) is an infamous chapter in British rail history. The electrified Cardiff-Paddington mainline opened in 2020 after years of delay, with a planned extension to Swansea cancelled amid spiraling costs. In 2009, Network Rail’s cost-estimate had been £1bn, whereas GWEP eventually cost well over £5bn.

“GWEP went horribly wrong,” says UK Railway Industry Association (RIA) technical director, David Clarke. “Government simply couldn’t contemplate that level of cost, so they pressed the pause button and ultimately, the cancel button. In monetary terms, GWEP dwarfed other, more successful projects and led government to view electrification as a basket-case.”

An investigation led by Clarke identified an “absence of clear-thinking, authoritative technical leadership.” The Department for Transport (DfT) purchased electric trains in advance, imposing an unachievable fixed deadline, and Network Rail’s initial cost-estimate relied on data from 1992.

Network Rail implemented a new overhead line system and High-Output Plant System (HOPS) train for installation: both world-firsts which entailed considerable risk. Conservative design led to avoidable bridge reconstructions and created oversized pile foundations which didn’t fit on the HOPS train. Prescriptive specifications limited the ability of suppliers to innovate or offer proven solutions.

These failures were symptomatic of the UK’s boom-and-bust approach to electrification. An intensive period of electrification in the 1980s was followed by a complete hiatus from 1992 to 2009 during which the UK skills-base dissipated.

“We had a 20-year holiday, so anyone still in electrification was working overseas,” says Clarke. “We needed to rebuild our capability. But we got so enthusiastic about electrification that instead of starting with one or two projects, we decided to do nine in the funding period from 2014 to 2019.”

Besides creating a shortfall in skills, this forced GWEP to compete with other projects for scarce delivery resources. By contrast to the UK’s fitful approach, Germany has steadily and efficiently electrified 200 single-track kilometers per year since the 1970s.

“Collectively, we should have recognized the need to pace ourselves,” says Clarke. “Rather than launch into nine projects in a five-year period, one of which overspent and overran quite spectacularly.”

This article was first published in the October 2022 issue of Electric & Hybrid Rail Technology Magazine. Read the full issue here.