Troubled Tube costs City dear

Britain's biggest current civil engineering project is in deep water. Christian Wolmar reports

THE PROBLEMS have steadily increased. A scaffolding pole fell down in a crowded station. A sewer was damaged and had to be relined. Noise complaints meant that working hours had to be reduced.

Then a section of tunnel collapsed, prompting fears for the rest. Then the delays set in. Then the cost overruns, believed to total nearly pounds 200m so far.

And now the biggest snag of all: one of the busiest sections of the London Underground, carrying many tens of thousands of commuters daily, will have to be closed for four months next summer because of further difficulties with Britain's biggest current civil engineering project, the Jubilee Line Extension.

This is the Tube line that London Underground didn't want to build. The first new one for 30 years, it runs from Green Park in central London to Stratford in east London, and is thought to be already pounds 200m over its pounds 1.9bn budget.

Even before construction started, it was dogged by controversy. Cost- benefit analysessuggested that several other proposed Tube schemes, notably the Chelsea-to-Hackney line linking two areas of London with no access to the Underground, and CrossRail, linking both sides of the city centre, would be better value.

But the Jubilee Line Extension has, in the eyes of the present government, a unique virtue: it passes through Docklands, that symbol of free enterprise and commercial development.

The Government has already paid a fortune to give Docklands a road: the Limehouse Link, a 1.1-mile dual tunnel which cost nearly pounds 300m, making it, foot for foot, the most expensive road in Europe. Even though the Jubilee Line Extension offers few benefits to existing parts of London apart from Docklands itself, Tory ministers insisted it should be built. Now the price is becoming clear.

The controversial closure of part of the London Tube network is already provoking a fierce row between London Underground and the City.

London Underground chiefs are meeting this week to confirm that part of the Northern Line will be closed for four months because of fears that work on the JLE underneath the Thames would cause flooding. The southbound part of the line's City branch is being shut from Moorgate to Kennington stations for 16 weeks, starting next July. The decision has infuriated the City, as the closure will disrupt the journeys of at least 30,000 City workers and tens of thousands of others.

Joe Weiss, the City's assistant traffic engineer, said: "We estimate very conservatively that this will cost London commuters at least pounds 500,000 per week in wasted time, but in practice it will be much more because of knock-on effects. Other parts of the Tube network will be overcrowded."

Currently 57,000 people use just two of the stations that will be partly closed, Moorgate and Bank, and over one-third of these come on the Northern Line. Michael Cassidy, chairman of the City Corporation's policy committee, said: "Yet again, City commuters are to be sacrificial lambs for schemes with no direct benefit. I will be speaking to the chairman of London Underground personally about this on Monday."

Another City source said:"They wouldn't have dared close Westminster [another station where work is being carried out on the JLE] next to the Houses of Parliament, which is also next to the Thames, because MPs would have protested."

The Jubilee Line's project construction manager, Mike Smith, admits that it is touch and go whether the completion target for the 53-month contract can be met.

It is not the widely reported notion that the Houses of Parliament are about to fall down because of construction work that troubles Mr Smith. He dismisses that story wearily: "There has been a bit of movement on the Houses of Parliament but no more than expected."

But work on tunnelling at Waterloo - and less seriously at a couple of other locations - had to stop because the system being used, the New Austrian Tunnelling Method, which involves concrete being instantly fired at walls as the hole is dug, was responsible for a tunnel collapse during work on the Heathrow Express near Heathrow airport. After an estimated seven months' delay, work has now restarted using a slightly different method.

It is at Canary Wharf, however, where Britain's tallest building soars up from the Isle of Dogs, that the most lengthy delays have occurred. In essence, it seems a simple site where a vast hole - 280 metres (920ft) long, 32 metres wide and 24 metres deep - is being developed on an abandoned dock for a station.

Almost as soon as work started, there were fears that the coffer dam being used to hold back the dock water was not strong enough and it had to be reinforced, causing several weeks' delay. Then the independent engineering consultants Ove Arup, overseeing the project, decided that the design for the base of the box was inadequate - they were worried that it would crack up under the strain of the water pressure underneath.

The solution was to bore 163 piles, each 24 metres long, deep into the chalk underneath the station to hold the floating box down. As only three piles could be bored each day, and the designs had to be changed, the station became 30 weeks late.

Concrete-laying for this massive base started recently on the Canary Wharf. A team of mostly Irish navvies raked and spread the concrete out to make a neat, flat surface. They will be doing this for the next four months, working in sections until the concrete is 10ft thick.

Even on a cool October afternoon it is hot work, and they complain about their safety helmets to Mike Jackson, the surveyor showing us round. One of them, a balding pot-bellied Irishman in his fifties, takes his off to rub the sweat away and tells Mr Jackson in thick brogue: "Look, it's making me lose my hair. They should have holes in them to keep us cool. All the men hate them." There is resentment because the Sikhs just have turbans.

Mr Jackson warns him gently to keep his helmet on: "They all hate the helmets but they have saved a lot of lives." He admires the navvies' handiwork, which will soon be buried for at least 120 years.

Canary Wharf may be 30 weeks behind schedule but Mr Smith says that this can be caught up. The most pressing deadline is that the tracks are due to be laid in June 1996. Once the trackwork is complete, the line is to be used to transport material for the fitting-out of stations.

Mr Smith remains, as politicians say, "cautiously optimistic": "So far we have managed to absorb the delays into our programme but, of course, now we are getting to the halfway stage, any further hiccups and it will become harder to accommodate changes."