Rotten warning system
A rotten warning system , also an automatic warning system , or ATWS for short , is a technical safety device that is used during track construction . It warns the construction site personnel, the so-called Rotte , of the approaching train and usually consists of a series of signal lights and acoustic warning signals that are mounted on steel rods or tripods at the edge of the track bed every 30 meters. There are wired and wireless systems that are activated when a train approaches, for example by a wheel contact in the track bed. As long as the gang warning system is activated, the construction site personnel must stay away from the relevant track and let the train pass.
The rotten warning system emits rotten warning signals which, like all signals , are regulated in the railway signal system . There are different acoustic warning signals with different meanings:
- long continuous tone (mixed sound, consisting of different high tones): Caution! Vehicles are approaching on the neighboring track.
- two long tones in succession in different pitches: clear work tracks!
- Two short tones at different pitches at least five times in quick succession: Clear the work tracks as quickly as possible!
need
In order to keep the blocking times of mainline tracks as short as possible during work, a lot of construction work is carried out " under rolling wheels ". This means that the track is not or only briefly closed for work. The purpose of the warning system is to secure construction site personnel from the traffic and to warn them in good time to clear the tracks.
Noise pollution
An automatic gang warning system is very loud (97 to 126 dB ) due to the system, so that it can be heard by the track workers who are to be warned, even in the vicinity of noisy work machines and with hearing protection on. This is a burden for residents on the tracks during the work. Modern systems adapt to the ambient noise level (mandatory from 2019) and only warn with full sound pressure in very noisy surroundings . Even with a reduced volume, this is still very uncomfortable.
Resilience
Very high demands are placed on a rot warning system with regard to failure safety (functional safety) . An individual warning system worn on a man that does not pollute the environment alone (e.g. a button in the ear) cannot meet these requirements or could only be used in special constellations. It can only expand the collective warning with a rotten warning system, but not replace it.