IN THE morning rush hour 65,000 people hurry through King's Cross station, intent only on getting from A to B as quickly as possible.And God forbid that the construction workers beavering away at a whole alphabet of locations in between should get in their way.
London's second busiest tube station - only pipped to the post by Victoria - is undergoing a complete redevelopment.No superficial facelift, this is a massive structural redesign. It will not only allow for the increased passenger flow from its immediate neighbour, St Pancras, after the Eurostar terminal is relocated there in 2007 but also conforms to the recommendations of the Fennel Report, which followed the 1987 fire, giving pedestrians clearer exit routes.
Predicted passenger numbers in the morning peak are set to rise to 80,000 in 2007 and again to 92,000 in 2011, when CTRL domestic services begin to run, so an extensive enlargement is necessary.As well as restructuring and renovating the existing station above elevator level, the work involves extending the original tube ticket hall, creating an additional western ticket hall beneath the forecourt of St Pancras station, and augmenting the pedestrian subway beneath Euston Road to mitigate congestion at critical points.The original plans also included an additional northern ticket hall in between King's Cross station and the neighbouring Great Northern Hotel but this is suspended pending a Government review.
With mainline trains and congested roads running above and six of the capital's busiest tube lines crossing below, it's a wonder there's any space at all for the 400 operatives working on the project.Nick Stuart, programme manager for client Metronet, calls it 'a challenge of logistics, progress and sequencing'Metronet alone has over 100 staff working on the project.
Phase One of the work is being undertaken by a Costain/Taylor Woodrow joint venture as principal contractor and is scheduled to finish in 2006.
'Most people don't realise that we're working 24 hours a day on this site. It hasn't closed since we started - every Christmas, every Easter, every night, our guys are working. It means we can keep the station fully operational, ' says project manager Keith Morgan.
Behind hoardings and walls, work has been taking place since January 2001. Like the proverbial swan, life at King's Cross only sails along serenely on the surface because someone is paddling like hell underneath.
The tube ticket hall work is sequenced into 24 'interim stations', each closing certain sections while keeping the station functioning.
'We section an area off, ' says Mark Howard, manager of stage three work.'Then we re-house the station staff, demolish everything, rebuild it, reopen it, then repeat the process at the next point.'
The first step was to relocate all the utilities for the ticket hall through an existing 18th century tunnel running across the site.A 170 m section of the Hotel Curve tunnel was lined and gas and water mains redirected through it, moving them away from the site.
Space wasn't only limited within the existing station.The crown of the brick arch of the Thameslink tunnel roof had to be removed to create enough depth between the road surface and the slab for the new ticket hall.Only 500 mm of space were gained but London Underground head height regulations made this work a necessity.The work was done in a fiveday possession over Christmas 2002 and finished a day early.
Similarly, to construct the slab for the western ticket hall in front of St Pancras station a 74 m stretch of the crown of the 19th century Metropolitan and Circle line tunnel had to be capped off.Traffic management on the busy Euston Road allowed the cut-and-cover operation to take place over 13 weekend possessions.The Grade I listed facade wall of St Pancras forecourt had to be carefully propped and a temporary quickbridge installed to carry two lanes of traffic over excavations.
The 82 m-long structure took a week of night working to install.The team did a trial run in Wales to make sure everything went smoothly.The three-level western ticket hall is structurally complete and at fit-out stage.
The latest version of the ticket hall is interim station seven, unveiled on September 19 to deal with the effects of the 35-week Thameslink blockade.Thameslink trains no longer run through King's Cross station, due to Rail Link Engineering's CTRL work.This means that a major influx of passengers now has to make its way from St Pancras mainline station either to the tube at King's Cross or to the Thameslink station on nearby Pentonville Road. London Underground predicted an extra 15,500 passenger would take this route each morning.To deal with this the contractor has built a 6 m-wide temporary north staircase into the underground, which will channel pedestrians off the road and into the tube as soon as possible.The access subway, somewhat predictably, did not get a clear run. It had to negotiate the Fleet sewer, which runs through the centre of the work.The stairs will remain in use until the northern ticket hall is complete.
These kinds of changes require not only major internal co-ordination with a long list of stakeholders but also result in a long line of commuters, somewhat confused because the station they bustle through bears no resemblance to the structure of the previous week.
Mr Morgan says: 'At the end of the day you can put as many signs out as you like but most people are on auto-pilot, so we put staff out there to direct them.They're wily - if their new route isn't as good as the old one they'll find some way to improve it.
'Despite all the signs people sometimes try to walk across sites.We have 24-hour security at access points.'
The cost of the project has not yet been finalised.The Phase One work is worth 'circa £200 million' to Costain/Taylor Woodrow. Figures ranging from £330 million to £650 million have been bandied around for the cost of the entire programme.
'The higher figure prompted the DfT review, ' says Mr Stuart.'Don't believe either of them, because neither will be right.'