The detail found in Working Timetables includes the timings at every major station, junction, or other significant location along the train's journey (including additional minutes inserted to allow for such factors as engineering work or particular train performance characteristics),[2] which platforms are used at certain stations, and line codes where there is a choice of running line.
In the beginning of commercial railways, the timetable was the authority for a train to be at a particular location at a specified time, subject to any restrictions imposed by the rules, regulations and engineered safety controls (which were originally minimal).
Most German motive power is now equipped with an electronic WTT, known as the EBuLa or "Elektronischer Buchfahrplan" which is kept constantly updated by GPS and is displayed on a screen in the driver's cab.
[8][9] This also incorporates speed restriction and non-standard signal stopping distance data from the "Langsamfahrstrecken" document, the near-equivalent of which in British terminology would be the Sectional Appendix.
The railway historian Jack Simmons suggests that the WTTs are only a set of instructions issued to staff and indicate intended, not actual, train operations, and that this should be borne in mind when using them for historical research.
[10] However, Simmons also notes that, read with care, "they show us how railways were made to work, in normal service, as no other documents can.