Audibility of AWS/TPWS alerts

[D365]

The following posts concerning AWS sound levels are from a thread discussing GTR cab safety concerns and the outcome of an Employment Tribunal:

On the cab noise front, at one operator - no names mentioned, may or may not be already in this thread - some of a train class the type of AWS horn fitted is deafening and on others in the same class the type of AWS horn fitted is basically inaudible.

Can't you maybe perhaps order some more of the sounder that can be heard over wind noise instead of the one that can't, so we have fewer missed AWSes?

Ahhh, no, only a wee daftie would suggest that - it's the railway - when they're replaced the inaudible ones have to get replaced with new inaudible ones.....

Perhaps they could standardise the AWS sound by setting a standard volume. Also, do drivers prefer traditional bells or electronic beeps? I'd rather have the AWS sound to be deafening than inaudible.

When fitting a new Class B train protection system e.g. Enhanced TPWS being fitted to Chiltern Class 16x it is mandated by RIS-0775-CCS that a Human Factors assessment is undertaken to assess, among other things, the audibility of AWS and TPWS audible alerts. However I’m not sure how the sound levels are adjusted on a vehicle-by-vehicle basis.

My supplier datasheets for the sounder unit don’t give any indication as to how the adjustments are made on an upgraded vehicle (noting that vehicles with the original specification of TPWS typically retain the AWS horn and bell).

 

[John Webb]

In the fire safety world, the BS 5839 part 1 on fire alarm systems requires that the alarm sounder is a certain level above the background noise of the part of the premises where the sounder is to be fitted. Perhaps the Rail Standards people need to specify a difference in the sounder level that makes it audible above the noise of the moving train but not at a level which is excessive?

 

[frankmoh]

When sat in the very front of a Class 465 or 376 I can hear the AWS warning through the cab door. The 707 not so much. Guess which one of these trains has aircon.