When Tom McCarthy took over as project director on modernisation of the West Coast Main Line (WCML) three years ago the job was pretty much universally accepted as a nightmare. It was over budget with costs up from £2bn to an estimated £13bn and rising. It was late, with its completion date slipping over the horizon. And its scope was over-ambitious, growing and practically undeliverable.
So when, with Bechtel, McCarthy was drafted in to sift through the technical, practical and political mire it was fair to say they found a difficult project.
Perhaps this should not have been surprising. The WCML route modernisation is, after all, Europe's biggest rail renewal scheme and boasts some staggering statistics - 2,650km of track, 2,800 signals, 13 major junctions and 10,000 bridge spans.
But it was crying out to be rescoped and McCarthy's work led to a rethink of priorities by the Strategic Rail Authority.
'It wasn't an affordable job at £13bn, ' he explains. 'We had to get the price down to about £8bn and that required some pretty innovative thinking. There is nothing simple about the job.
We put a plan together and delivered the milestones.' By the end of this first stage of the modernisation project around £6.9bn will have been spent - 85% of this on renewal and 15% on upgrading the track and systems. The result of delivering these milestones will soon be tangible.
A 125mph (200km/h) service will be possible from the New Year, bringing the journey time from London to Manchester to a fraction over two hours, and from London to Glasgow to four and a half. Reliability, the major headache for every passenger, will be substantially improved.
Of course it is not the 140mph service once envisaged but it is still 'airline-challengingly' quick.
Technically, the actual work carried out has not been that challenging, concedes McCarthy, yet the job was extremely difficult because virtually everything - some 50M man-hours - has had to be done at night and over weekends.
There have been blockades, of course - primarily the high profile, 17 week closure around Manchester from April 2003.
But the challenge throughout has been to rip up track and signalling each night and return the railway to the operator at the right time every morning.
'The issue has been in planning and logistics to get the railway running again after each activity, ' says McCarthy. 'West Coast is the busiest mixed traffic railway in Europe.' It carries around 43% of the UK's rail freight and has over 2,000 train movements a day.
When the government decided in November 2001 to pull back from the deal agreed with Virgin Trains to provide a 140mph line, it certainly reduced the technical scope of the engineering.
But it did not make things straightforward. A 125mph line all the way from London to Glasgow is still a massive improvement on the route as was.
The curved Victorian alignment has always been the greatest obstacle to a high speed route between London and Glasgow.
Straightening or superelevating is expensive and often impossible. While tilting trains help passengers cope with high speed cornering, the critical factor then becomes ensuring the track can handle the huge forces imposed, as well as those of slow moving, heavy freight trains.
Use of absolute track geometry (ATG) techniques was one innovation that made this possible. This system involves using heavier materials to help ensure the track geometry does not move under train loading.
It is slightly more expensive to install but 'if it doesn't move it will last longer between maintenance', explains McCarthy.
ATG is not widely used in the UK. Over the last three years, McCarthy says, 'we had to perfect the method - this meant helping to bring our contractors up to meet the specification'.
McCarthy says he has also had to work with contractors to focus them on the absolute need to reopen the railway on time each morning.
'The level of planning is now much better. We now see sufficient contingencies designed in to ensure that the job always gets done, ' he says. 'Our target is zero overruns - the ripple effect of a small delay in the morning is that by the end of the day nothing is on time.' Everyone has risen to the challenge and efficiency has improved, he says, pointing to a recent 3.34km track replacement record set during a 56 hour closure - three times the norm.
The nal £1bn will be spent on boosting capacity, for freight in particular. This will primarily include the £700M Trent Valley four tracking project in the notoriously congested Rugby to Stafford corridor between Lichfield, Armitage and Tamworth. Work will also continue until the end of 2008 on improvements to the power supply across the route, station enhancement at Birmingham, and track capacity improvements at Bletchley, Nuneaton, Rugby and Stafford.
Within the next three years the London to Glasgow journey time will have been cut again, to 4 hours 15 mins.