BR's question of timing that keeps the stock rolling: Today's new rail timetable will put theory to the test. Christian Wolmar reports

THE 100 planners who draw up British Rail's timetable will be holding their breath today when the new winter schedule comes into force.

Although they have computers to try to ensure that they have not routed two trains to be at the same place at the same time, only the operation of a timetable shows up unnoticed hazards. Already the first supplement has been issued.

The timetablers do not like to admit it but the published volume is one of the longest works of fiction since Bleak House. The trains operate to an unpublished timetable that is calculated in half minutes and is frequently several minutes adrift from the published version. Take the 8.50am from King's Cross to Edinburgh. The timetable says it should arrive at York at 10.42 and leave a minute later. In fact, it is supposed to get there at 10.41 1/2 and leave three minutes later. By the time it gets to Edinburgh, it is advertised at 13.27 but is timed to reach it by 13.20. As Mark Fulford, one of the compilers of the timetable, put it, 'it helps us keep to the schedule. If we advertised it at 13.20 and it kept getting there two minutes late, people would complain.' The process of drawing up a timetable starts about 18 months before it comes into force when marketing staff examine demand and look at the potential for improvements, such as extra stops or even extra trains. The provision of an extra train on one route, though, is likely to lead to the cutting of another elsewhere.

There is no one Mr Timetable. Instead, a number of planning managers work at various offices for BR's three constituent parts, InterCity, Regional Railways and Network SouthEast, in 30 centres around the country, drawing up parts of the timetable and occasionally negotiating when their routes cross.

Mr Fulford has been in charge of table 26 for a decade. The table stretches over 42 pages and gives the timings for the InterCity trains on the east coast route from King's Cross to Scotland and adjoining routes such as Leeds and Hull.

Mr Fulford, who started with BR 30 years ago as a booking clerk and now boasts the title InterCity Services Planning Manager, admits that table 26 changes little from year to year. All the Sunday times, however, are different to allow for engineering works.

In fact, the Sunday timings change completely again in January as the engineering works move to different parts of the line.

Another major demand on his time is trying to accommodate marginal changes that seem simple but which, as he puts it, 'have a wave effect through the system'. The marketing men, sharp-suited young chaps who pepper their conversation with expressions like 'demand profiles', had hit upon the idea of the 12 noon King's Cross to Aberdeen making an additional stop at Peterborough.

A two minute stop adds six minutes to an InterCity train's time and that immediately had a disastrous knock-on effect. 'We had to move six other trains just between Peterborough and York,' Mr Fulford said. Therefore, for the time being, the 12 o'clock Inverness train still does not stop at Peterborough. InterCity largely has priority over the local trains of Regional Railways, though Mr Fulford tries to resolve conflicts with his counterparts at Regional Railways amicably. 'I know I may need their help one day, so I try to do the best for all of us.'

There is a minimum of a four minute gap - or nearly eight miles for a train travelling at 125mph - between InterCity trains to ensure that they hit green lights every time. The gap could be reduced to three, allowing more flexibility in the timetable, but Mr Fulford suggests that would result in more delays when things go wrong.

After privatisation, it is unclear how such conflicts between train timings would be worked out. It is even unclear who would employ Mr Fulford, the new track authority, the winner of the east coast route franchise or even InterCity if it remains. 'Slots' may be sold to the highest bidder. Fitting in the demands and priorities of possibly a host of private operators and franchise-holders with those of BR will be an unenviable and politically charged task.

(Photograph omitted)