Charleroi,

BN/ACEC type 6100 6-axle

N°. 7451

—  ligne M2, Gare Centrale

On the right, next to the unused platform there is another track, which is used by the M2 trains out of the city to once pass through the station without stopping, then dissaperaing into an underground loop and coming back up on the other side to stop at the regular center platform.