At Euston the team had been looking forward to the long holiday weekend for months.
But it was not preparing for a relaxing time off like everyone else - just the opposite. This was when the team rea l ly got down to it .
'At 11pm on the Easter Thursday we began the 'blockades', ' says Tony Webb of Balfour Beatty, and project director for the ú125M ($186M) remodelling of the Euston 'throat' - 2km of multi-track approaches into the station's 18 platforms.
Preparation, design and piecemeal work has been under way for 18 months.
But now, signalling, tracks, ballast, power systems, overhead and third rail, high and low voltage and auxiliary are being ripped out and replaced. New gantries and foundations have to go in for signals and overhead line, there are new telecommunication cables and ducts, complex point interchanges and crossovers and are being rebuilt. Victorian brick retaining walls must be restored or extended for new track alignments and bridges widened.
But through all this, trains have to keep on running. So though the construction team - an alliance between civils contractor Balfour Beatty, client Railtrack, and signalling and M&E specialist Westinghouse - will get continuous possession of parts of the station this summer, the heavy long distance Virgin trains and Silverlink commuter services will continue in and out of platforms, with 600 movements a day, and some 110,000 passengers.
'That will be slightly reduced when we switch to a summer timetable in May, ' says Lindsey Vamplew, Railtrack head of delivery on the southernmost of the West Coast Main Line route modernisation's three zones. 'And there is a small cutback on train numbers in the morning and evening peaks.'
But essentially, remodelling must not disrupt passengers. So weeks of roundthe-clock track possessions - 'blockading' a few platforms at a time - will be sequenced west to east along the station's length, beginning with the least used platforms. Trains will switch to the new line layouts as each part is completed, releasing platforms further down.
By September the bulk of the work will be completed, though the Euston Alliance continues into next year with remodelling, especially for signals, 14km beyond Willesden . Euston and Willesden signa l boxes will go and operations will be concentrated at Wembley where a new control panel will be installed for solid state signalling.
The full contract, including this work, takes the whole project to ú180M.
For Webb there is nothing fundamentally difficult about the civil and structural engineering, or the trackwork.
Complexity lies with organisation and integration of the multitude of tasks the alliance needs to carry out.
'Unlike most jobs where you can run the various functions in sequence, ' he says, 'on railways everything must be done in parallel.' And safely too, adds deputy Alliance project director Dominic Baldwin of Railtrack. All operatives have a minimum of two days' training before being allowed even to step into a 'red zone' close to moving trains.
Disciplines work alongside each other on signals, overhead and third rail power systems, permanent way and 'very complex' telecommunications, and must be aware of how they affect one another.
This starts at design level, also part of the Alliance's remit, where a change in one system can affect the others. Design is done remotely in various offices throughout the UK and even in Australia; electronically transmitted drawings are co-ordinated, examined for interactions and approved for construction at the Euston site office.
But the process continues on site where the disciplines are 'tightly interwoven', says Webb. Civils work for drainage, walkways and cable routes is less tightly linked but must still fit in.
For all these, areas must be assigned, materials made available and machines provided. Rails, 30,000t of ballast, steel gantries and machines must all come in by train; virtually no other access is possible. Some 400 supply trains will be needed over the summer, loaded at a road-fed depot up the line. Each must fit into the operating timetables.
'We have a lot of smaller road/ rail capable equipment, which also comes mainly by train, ' says Webb, including Komatsu PW170, 130 and 95 excavators, Case 988s and 888s, and specialist equipment from Mecalac. There are tampers and a number of laser controlled dozers for spreading sub-ballast.
All this has to get back out again, along with old ballast and so on. Small wonder that the team has looked to the army's Royal Corps of Logistics to see what can be learned, beyond construction planning skills. A one day course at Caterick impressed on everyone the need for robust two way communications. It also confirmed that a control centre for operations, with all the different senior managers together, could help minimise problems by speeding communications.
Train movement co-ordinators will sit alongside signals and construction representatives.
Some 600 of around 1,000 possessions have already been ticked off, for retaining wall work, and blockade preparation. Of 15km of track renewal, 8km has been completed, including some alongside platforms. A century-old steel arch bowstring bridge carrying Regents Park Road has also been extended with a new piled pier and matched in steelwork.
It allows for one more approach track.
With all this experience, maybe that is why the team was 'eager to get on', not too envious of the bank holiday crowds piling on to the trains for the long weekend.
Altered approach When completed, trains will diverge further out than at present at Camden, from three up and three down lines - one more than before.
With new crossovers and points, train routing on to appropriate platforms should be simpler and faster, shaving a couple of minutes off journey times.
Maintenance will be less, especially as most current equipment, dating from the 1960s electrification, is nearing the end of its life.
Despite train speeds sometimes double previous limits, it should all be safer too, though drivers will need to acclimatise to the altered layouts.
'In fact, part of our job is to provide them a virtual reality training programme, ' says Webb, 'because the approaches will be quite different.'