Half-a-century after being saved from Dr Beeching’s axe, the last line on the tube map which still uses diesel trains is about to prove that electric dreams really do come true.

The London Overground line between Gospel Oak and Barking – lovingly nicknamed the “Goblin” – will shortly be welcoming a series of swanky new four-car electric trains, doubling capacity by replacing the current two-car diesel service.

Unless you’re a regular passenger on the leafy route that trundles over rooftops from suburban Crouch End, via Tottenham and Walthamstow, the Goblin’s story will likely have passed you by amid a constant flurry of news about Crossrail’s construction and Thameslink’s new timetable. But it’s is a story worth telling: this is a railway that has defied the odds to survive numerous changes in management, crumbling infrastructure, passenger declines, and a laughably botched upgrade, until finally reaching the proverbial light at the end of the tunnel.

Back in 1964, a chunk of what is now the London Overground orbital network was under threat of closure from the government, amid the notorious axe of British Rail chairman Dr Beeching. In reaction to this a rail users’ group was formed which successfully campaigned to save the Goblin route, after highlighting its value to London commuters.

But although it avoided closure, the railway was left to rot for decades. “British Rail basically didn’t spend a penny on it for 50 years,” explains Glenn Wallis, secretary of the Gospel Oak to Barking Rail Users’ Group and a former signalman on the line. “As far as they were concerned there were always more important things to spend money on.”

The trains were unreliable, station facilities were closed down, and, as a short railway that avoided major interchanges and mainline stations, the Goblin remained obscure. “It was known as the ‘forgotten railway’,” says Glenn, who worked on the line for 29 years. “There was one year in the early 1990s when they didn’t even have anyone managing it. We had to organise our own rosters.”

Glenn alleges that TfL never wanted to run the line, such was its troubles. “But then the government told them they had to – so the line was sort of tacked on to the rest of the Overground network.”

The transfer from the former Silverlink franchise to TfL finally went through in November 2007, and the simple fact of putting the Goblin on the tube map seemed to give it a new lease of life.

“Most people didn’t know where the line went or what it did. But when it went on the tube map, with cheaper Oyster fares, passenger numbers began to explode.”

Even as the line’s fortunes turned, the rail users’ group kept plugging away, demanding further improvements. Stations were spruced up, the line gained new walk-through turbo trains, and services began running every 15 minutes.

But there was still one major obstacle preventing the Goblin from expanding further. “It was the only line on the tube map not to be electrified,” said Glenn. “We knew it had to happen.”

A geographically accurate map of the route, including the proposed eastern extension. Image: Pneumaman/Wikimedia Commons.

Funding for the electrification upgrade was finally announced by the government in 2013. It would enable four-car trains to run instead of two, providing a major boost for a line that was by then carrying 10,000 passengers daily and had become severely overcrowded.

Alas, nothing is ever simple with the Gospel Oak to Barking line. Glenn explains: “After the electrification of the East Coast Mainline in 1989 there was no money for anything, so we lost all of our experts in electrification. That’s why they’ve cocked it up.”

The Goblin’s electrification work was supposed to be completed in eight months, at a cost of £133m. It began in June 2016 and necessitated a part-closure of the line that summer, followed by a longer, full closure ending in February 2017. When the line finally reopened, Network Rail admitted that the work was still not complete and more closures were needed to get the job done.

The heights of station platforms and bridges had apparently come as a surprise. Materials arrived late. “The design work had errors in it,” said Glenn. “When the steelwork turned up, it didn’t fit and had to be scrapped.” Then there were the severed sewers; images appeared on social media of portable pumps being wheeled along rails in Walthamstow after the tracks were flooded.

Network Rail apologised and promised “a full review into what went wrong”. The Goblin’s long-suffering passengers endured yet more closures last autumn and winter. Finally, by May, it was confirmed that the electrification work had belatedly been completed.

After decades of neglect, the Goblin had at last caught up with the rest of London’s tube and rail services – the electric dream had come true.

Well, almost. In a noble effort to take the heat off of Network Rail for its handling of the upgrade, Transport for London now admits that new electric trains for the Gospel Oak to Barking line have been delayed because of “software issues” and will instead be introduced “later in summer”. But what’s a few more months when you’ve been waiting for half-a-century?