Crossrail, the new east-west London railway designed to bring relief to jam-packed commuters, announced Friday that it is postponing its scheduled December opening by the better part of a year.
Crossrail Ltd. said services on the central section of the line, between Paddington station in west London and Abbey Wood in the east, will begin "in autumn 2019," with the rest of the line opening as soon as possible after that.
It said in a statement that the railway — which will be named the Elizabeth Line after Queen Elizabeth II — needs more time to finish "final infrastructure and extensive testing."
The 73-mile (118-kilometer) line is one of Britain's biggest infrastructure projects for decades and has cost around 15 billion pounds ($20 billion). It will provide a new link between Heathrow Airport, the city center and the Canary Wharf business district and includes a 13-mile (21-kilometer) underground section through the heart of the city.
Crossrail chief executive Simon Wright said the new line "is one of the most complex and challenging infrastructure projects ever undertaken in the U.K."
The firm said work on the central tunnels and on developing software had overrun, cutting into the scheduled testing time.
Builders say Crossrail will add 10 percent to central London's rail capacity — easing the journeys of commuters who now pack the Underground's overstuffed Central Line — and bring a 42 billion- pound ($55 billion) boost to the economy.
The decade-long construction project has also been one of London's biggest archaeological digs, uncovering everything from 68,000-year-old mammoth bones to the remains of a Tudor manor house and the skeletons of 14th-century Black Death victims.
The delay means more months of cramped conditions for transit riders — and a loss for operator Transport for London, which had been counting on Crossrail fares to help plug a hole in its finances.
Gareth Bacon, chairman of the London Assembly Budget and Performance Committee, said the situation "is basically a shambles."
Bacon said Transport for London "already has a 1 billion pounds operating deficit for this year. Hundreds of millions further will be lost in the coming year."
Rail historian Christian Wolmar, who has written a book about Crossrail, predicted that despite the teething pains, Crossrail would be a hit once commuters accustomed to London's stuffy subway system experienced its huge stations and super-long, air-conditioned trains.
"Yes, it's a disappointment, and today is a day when there will be lots of negative publicity," Wolmar said. "But when it opens, it will all get forgotten and people will think, 'This is absolutely amazing. Why can't we have some more railways like this?'"