---
kind: "section"
citation: "30 U.S.C. § 870"
title: "30"
title_heading: "Mineral Lands and Mining"
number: "870"
heading: "Trolley wires and trolley feeder wires"
release: "119-102"
date: "2026-07-12"
url: "https://uscodex.org/usc/30/870"
units:
  - "Chapter 22 — Mine Safety and Health"
  - "Subchapter III — Interim Mandatory Safety Standards for Underground Coal Mines"
---

# §870. Trolley wires and trolley feeder wires

- (a) **Intervals for cutoff switches—** Trolley wires and trolley feeder wires shall be provided with cutout switches at intervals of not more than 2,000 feet and near the beginning of all branch lines.
- (b) **Overcurrent protection devices—** Trolley wires and trolley feeder wires shall be provided with overcurrent protection.
- (c) **Location of wires—** Trolley wires and trolley feeder wires, high-voltage cables and transformers shall not be located inby the last open crosscut and shall be kept at least 150 feet from pillar workings.
- (d) **Adequate insulation and guard devices; promulgation of safety guidelines—** Trolley wires, trolley feeder wires, and bare signal wires shall be insulated adequately where they pass through doors and stoppings, and where they cross other power wires and cables. Trolley wires and trolley feeder wires shall be guarded adequately (1) at all points where men are required to work or pass regularly under the wires; (2) on both sides of all doors and stoppings; and (3) at man-trip stations. The [Secretary](/usc/30/802.md?p=a) or his authorized representatives shall specify other conditions where trolley wires and trolley feeder wires shall be adequately protected to prevent contact by any [person](/usc/30/802.md?p=f), or shall require the use of improved methods to prevent such contact. Temporary guards shall be provided where trackmen and other [persons](/usc/30/802.md?p=f) work in proximity to trolley wires and trolley feeder wires.

## Source credit

(Pub. L. 91–173, title III, § 310, Dec. 30, 1969, 83 Stat. 783.)

## Notes

### Statutory Notes and Related Subsidiaries

### Effective Date

Section operative 90 days after Dec. 30, 1969, except to the extent an earlier date is specifically provided for in Pub. L. 91–173, see section 509 of Pub. L. 91–173, set out as a note under section 801 of this title.