All sumps or sump holes, exploratory equipment and oil or gas well production equipment having external, moving parts hazardous to life or limb shall be attended twenty-four (24) hours per day or be enclosed by a steel chain link type fence not less than six (6) feet in height and in addition having not less than three (3) strands of barbed wire sloping outward at approximately a forty-five degree (45°) angle and for eighteen (18) inches from the top of the fence. There shall be no aperture below such fence greater than four (4) inches. Fence gates shall be installed at non-hazardous locations and shall be locked at all times when unattended by a watchman or service person.