Horns, Backup Alarms, and Automatic Warning Devices - 30 ...
Horns, Backup Alarms, and Automatic Warning Devices. 30 CFR 5 6. 1 4 13 2 and 57.14132. 30 CFR 77.410 and 77.1605. 56.14132 Horns and backup alarms 57.14132 Horns and backup alarms for surface equipment (a) Manually-operated horns or other audible warning devices provided on self-propelled mobile equipment as a safety feature shall be maintained in functional condition.