Text 12. Underground surveying for details

The traverse that has been run through the mine is the base for determining the details and, when plotted, forms the skeleton on which the map is built. The traverse alone gives little idea of the workings. The details are required in order to record and describe the excavation that has been made. The notes for the details are usually recorded on the right-hand page of the notebook opposite the stations which form the base traverse, so all the data for the given area are together. The traverse notes on the left-hand page are recorded very openly so as to allow plenty of room for the sketches and details to be placed opposite them. In addition to the notes for the size of the workings the surveyor should note the peculiarities of the ore face, as “8-ft. lean ore,” “3-ft. rich ore”, etc., and if the workings pass from one kind of rock to another, he should note the point of change. By observing these geological features as the mining progresses, a vast amount of geological data is accumulated and accurately located for future study. The cost of taking this, while running a survey, is very small, but it might be very costly to get it at a later time. Many of the features would not be observed after the walls were covered with smoke and dirt, and where the mine was flooded or the timbering had rotted and the ground had caved in, they could not be obtained at all.

The details can be determined by the methods that are common on surface surveys, namely, by distances, by angles, and by radiating sights. The work of collecting the data, however, is complicated by the peculiarities of mining and by the darkness.

(1370)

NOTES:

• traverse (or survey) - съемка;

• sight – отсчет, отметка, маркшейдерский знак;

• surveyor – маркшейдер, топограф, землемер.

Text 13. Types of locomotives used underground

The more extensive size of mines led to replacement of manual labour by the use of horses and the increasing use of mechanical power for haulage. Gradually rope haulages worked by the steam engine, and later by the compressed-air engine, and electric motor, replaced both manual and horse haulage; and these in turn have been superseded to some extent in recent years by the use of conveyers and locomotives.

The utility and high efficiency of locomotives under suit­able conditions has long been recognized in many countries. Four types of locomotives have been used extensively in ad­vanced coal-mining countries, viz, the electric-battery loco­motive, the trolley locomotive, the compressed-air locomotive and diesel locomotive.

Considerable interest has been shown in recent years in the application of trolley locomotives in some countries, the use of which was prohibited by local Regulations. The recognition of the advantages of this type of locomotive and the pos­sibility of eliminating to a large extent its dangers, has led to the removal of this embargo.

(930)

NOTES:

• electric-battery locomotive – аккумуляторный электровоз;

• trolley locomotive – троллейный электровоз;

• compressed-air locomotive - воздуховоз;

• diesel locomotive – дизелевоз, тепловоз.