Underground lighting in coal mines

The importance of lighting below ground is emphasized and the difficulties associated therewith are outlined. Inadequate or inferior lighting produces nystagmus, and mention is made of the decline in the incidence of new cases since better lighting has been introduced. Changes in portable lamps, with improvements in technique and to suit alterations in mining methods, are reviewed, and descriptions of typical modern equipment and methods of application are included. The importance of photometry in lamp-room practice is discussed. Bulbs and cables for miners´ lamps are considered, and improvements which have been effected in the last few years are indicated. The desirability of extending the use of mains lighting below ground for both the roadways and the coal faces is indicated. Progress in this field is reviewed, together with descriptions of equipment and results obtained. It is pointed out that the economic aspect of the general introduction of mains lighting to coal faces will be an important factor. Developments are hindered by restrictions in the use of aluminium alloys in coal mines.