How do I implement a railway flow?

[corrado1972]

Hello,
I never usedt qwt before now: how do I implement a graph like this one? :
http://www.opentrack.ch/opentrack/im...TrainGraph.gif


What I know: on the y axis I'll have stations, (integer values) on x axis I'll have time.
Each train will be a sequence of pair values (time, station).

Please, show me the way: I'll go ahead by myself :-)
thankyou all!