30 CFR § 57.14132 - Horns and backup alarms for surface equipment.

---
identifier: "/us/cfr/t30/s57.14132"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "30 CFR § 57.14132 - Horns and backup alarms for surface equipment."
title_number: 30
title_name: "Mineral Resources"
section_number: "57.14132"
section_name: "Horns and backup alarms for surface equipment."
chapter_name: "MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR"
subchapter_number: "K"
subchapter_name: "METAL AND NONMETAL MINE SAFETY AND HEALTH"
part_number: "57"
part_name: "SAFETY AND HEALTH STANDARDS—UNDERGROUND METAL AND NONMETAL MINES"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "30 U.S.C. 811."
regulatory_source: "50 FR 4082, Jan. 29, 1985, unless otherwise noted."
cfr_part: "57"
---


# 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 device shall be maintained in a functional condition.

(b)(1) When the operator has an obstructed view to the rear, self-propelled mobile equipment shall have—

(i) An automatic reverse-activated signal alarm;

(ii) A wheel-mounted bell alarm which sounds at least once for each three feet of reverse movement;

(iii) A discriminating backup alarm that covers the area of obstructed view; or

(iv) An observer to signal when it is safe to back up.

(2) Alarms shall be audible above the surrounding noise level.

(3) An automatic reverse-activated strobe light may be used at night in lieu of an audible reverse alarm.

(c) This standard does not apply to rail equipment.