Old and new signal models

The highly informative web site of Roland Smiderkal describes signaling on SBB in detail. Here's a brief overview of the old and new lineside signal models.

The old signal model on SBB (see Smiderkal's corresponding page) consists of a number of red, green and yellow lamps that together indicate whether the track ahead is clear and the speed limit either at this signal or the next one.

In contrast, the new signal model on SBB (again here, see Smiderkal's corresponding page) consists of a triangle of the three colors and a number indicating the speed limit either immediately beyond this signal (if the lamp is green) or beyond the following signal (if yellow). The number is the speed limit divided by 10; in other words, a display of "6" means 60 km/h.

Within the interlocking plant at a given station, the new and old signals cannot be mixed.