Mechanical SBB CFF FFS signals outside the transport museum in
Luzern. From left to right:
Distant signal (disk type) announcing
a stop signal (if the signal shows clear, the disk is turned to a
horizontal position, thus invisible for the train).
Shunting signal
in position "shunting forbidden" (the other position, "shunting
allowed", has both bars in the vertical position).
Main signal
showing "clear without speed restriction".
Main signal showing
"Clear with speed restriction" and the additional meaning that
the train goes into another track than it would with only two arms
in the diagonal position.
Luzern (Verkehrshaus), 2003-02-11
photo: Ralf Gunkel