DIN 21325:2012-02

Sleepers are intended to hold the tracks of the mine cars in their defined position and to transfer the forces of the tracks resulting from the imposed loads onto the track bed. Accordingly, their length and cross-sectional dimensions as well as their quality and condition for the grade and durability of the track are of importance. In order to ensure sufficient support and fastening of the track, the length of the sleeper shall not be less than 1,7 times the track gauge. Wooden sleepers are characterized by low mass, good elastic behaviour as well as good insulation properties. A disadvantage of many types of wood is the susceptibility to cracking, fungus and wear. Sleepers made of oak and beech wood as well as of red ironwood and similar types of wood are called hardwood sleepers, those made of pine and larch wood are called softwood sleepers. Hardwood sleepers shall be preferably used for the installation of track systems in underground mining. Using mechanical means shall prevent rupture of oak and beech sleepers, for example, connectors or head plates. The standard specifies the dimensions and designations for wooden sleepers used in mining, the types of wood to be used, technical quality and delivery requirements and basic processing instructions. The standard has been prepared by NA 008-05-01 AA "Grubenbahnen" ("Mine railways") at FABERG.