Gathering-arm loaders ... are self propelled and may be mounted on rails, on crawlers, or on rubber tires. The crawler-mounted loader is the most commonly used. It is made up of three main components
(a) the gathering head which is thrust into the coal and which is fitted with two rotating arms to sweep the coal onto the conveyor:
(b) a chain conveyor which runs down the middle of the machine and carries the coal to the rear; and
(c) the crawler chassis which carries a separate motor for each of the crawlers.
In addition, the earth-moving machinery listed below with a capacity exceeding 15 kW must be fitted with a rollover protective structure:
- crawler loaders or wheel loaders,
- backhoe loaders,
- crawler tractors or wheel tractors,
- scrapers, self-loading or not,
- graders,
- articulated steer dumpers.
