Signallers generally warn workers in their section using acoustic warning mechanisms such as Tyfon or a multi-tone siren. At night or in tunnels, visual signals such as inspection lamps are used in part. The signal flags used in emergencies also form part of the visual signalling mechanisms.
Acoustic warning mechanisms must drown out ambient noise such as loud machinery or passing trains. This can be achieved by using an appropriately high sound pressure level, and by using tone frequencies that can be easily distinguished from machinery noise. For safety reasons, an acoustic test is always carried out before beginning work in the vicinity of the tracks. In doing so, the safety officer verifies whether all relevant persons can reliably hear the warning signal, even under the most unfavourable conditions.
|
