[2] Between Schaerbeek and Leuven, the line is 4-track; the outer tracks serve local trains with many stops, while the central tracks carry intercity and high-speed trains; these are called L36N, and branch off after Leuven onto a separate route that mostly follows the E40 motorway towards Liege.

This steep incline was initially negotiated with the help of a fixed engine driving an endless rope that was used to haul the trains without the help of a locomotive.

[3] After the late 1860s, special banking locomotives were used and the fixed engine was discarded.

Currently, some trains are powerful enough to climb the incline without a helper and the rest are provided with two locomotives.

The rear engine is no longer removed at Ans in order to save time.