platform and points and is occupying track circuits 103 and 701. The points are released to allow another route to be used.
Now that Train 7752 has cleared the platform its description has been cleared from the train description box and a new number, 6460, has appeared. This is the number of the next train to arrive at Oak. The signalman will know from the timetable that this train is scheduled to go into the siding and he must arrange the necessary route changes.
More Trains Arrive
Fig 6 - Two trains are displayed
Fig 6 shows that train 6460 has now arrived at Oak and is supposed to terminate there. Passengers must be detrained and the train checked to ensure no one gets taken into the siding. While this is going on, an Up train, 6458, has also appeared on the "diagram". According to the timetable, this train should arrive at Oak before 6460 but it is running late. The signalman now has to make a choice.
He can set up the route for 6460 to get him into the siding and clear the down line. He wants to do this because there is another train due behind 6460 and he doesn’t want to delay it. On the other hand, he doesn’t want to