FIGURE 7.-Hood Over Rotary Dump for Collecting Coal Dust During Dumping Operation. Hood Is Connected to an Exhaust Fan. well-maintained tipple. All runways and openings in floors should be provided with toeboards and guardrails. Steep, narrow, wooden stairways are common sources of injuries, particularly when they lack or have poorly constructed handrails. Stairways should be provided with suitable handrails; the risers should be of uniform height to permit easy climbing; and the treads should be of uniform width to permit good footing. Wooden floors and runways in tipples often absorb oil and grease that have dripped from mine cars and locomotives and increase the flammability of the structure. Concrete and steel construction is much easier to clean of oil and grease and is fire-resistant. The fire hazard is thus greatly reduced, the lives of the workmen are safeguarded, and the possibility of interruption of mine operation is decreased. CAR DUMPS A tipple at drift or slope mines usually is located so the dumpingfloor level is somewhat below the level of the mine opening in order to take advantage of downgrade for running cars to the tipple after the motive power has been cut off. Sometimes a trip of loaded cars becomes uncontrollable and is wrecked at the car dump because the rails are slippery or because the motorman has delivered the trip at too high a speed or for various other reasons. When the tipple workmen realize that a trip of cars is running away, they usually make an effort to stop the cars by setting the brakes on the cars or, if the cars are not provided with brakes, by inserting sprags between the spokes of the wheels. In either instance they must run alongside the trip and face the danger of injury by stumbling or by being caught between the car bumpers when the trip strikes the stops for the car dump. At |