The Olef Valley Railway ( or Flitsch) or OTB is a 17.8-kilometre-long, single tracked, unelectrified branch line from Kall through the Schleiden Valley above Schleiden to Hellenthal. The line is currently used by tourists; travelling on the heritage railway in the summer months or occasionally by goods trains. However, there are attempts to reactivate passenger services that were ceased in 1981.