Light steel rails used as minecart track in mining

The Role of Narrow Gauge Railway Mine Tracks

Narrow gauge railway track is the basic part of coal mine rail transportation and one of key conditions of coal, gangue, material, equipment and personnel transportation in the process of coal mine production. Its function is to spread the concentrated load of the wheel to the ground or underground rail pad. For the smooth and high speed running of cart and other vehicles moving along the mine track, the quality of mine track design, construction and maintenance is the most basic guarantee for safe driving.

Classification of Coal Railway Mine Track

According to the gauge differences, the existing narrow-gauge railway track in coal mine is divided into 3 kinds: 900mm, 762mm and 600mm. According to the transportation situation, it is divided into main transportation and general transportation lines.

Light Mine Track Size

Size	A	B	C	t	Weight (kg/m）
GB 6kg	25.4	50.8	50.8	4.76	5.98
GB 9kg	32.1	63.5	63.5	5.9	8.94
GB 12kg	38.1	69.85	69.85	7.54	12.2
GB 15kg	42.86	79.37	79.37	8.33	15.2
GB 22kg	50.8	93.66	93.66	10.72	22.3
GB 30kg	60.33	107.95	107.95	12.3	30.1

The Structure of Railway Mine Track

The Railway Mine Track components consist of two major parts:

1. Construction under the track (subgrade and ancillary equipment -- drainage and protection and reinforcement equipment, etc.);
2. Track superstructure (track bed, rail sleeper, rail track, rail switch, rail fasteners, safety equipment).

Basic Conceptions of Railway Mine Tracks

The rail track gauge refers to the distance between the two rails head and the rail track center line on the railway line. (See Figure 1)

1. Measuring point of track gauge
   Due to the circular arc on both sides of the rail head and wheel flange, the contact point between the wheel rim and the rail varies with the rail type. The narrow rail moment is measured at 13mm below the rail top.
2. Spacing
   In order to avoid the wheel stuck along the two rail rolling, reduce the wheel and rail friction between the gap of flange and mine track, there should be a certain amount of space, this gap is called spacing.
3. Allowable error of rail track gauge
   The error of the railway track gauge is allowed for the cart operation has great pressure and impact on the railway, so it is impossible for the railway moment to always maintain the nominal gauge stipulated in the standard. In addition, according to Coal Mine Safety Regulations, errors will also occur during construction. After the widening of the straight or curved section, the width shall not exceed 5mm and the narrowest shall not exceed 2mm.

Horizontal, Triangular Pits and Mine Track Safety

In order to ensure the smooth running of the cart and make the two rail track uniformly bear the load, the top surface of the 2 steel rails should be located at the same level on the straight track to maintain the smooth running and uniform wear of the train. Therefore, it is stipulated that the horizontal error of the top surface of the two rails shall not exceed 5mm. Within the extension of two meters, the top surface of the two rails changes horizontally in opposite direction. First, the left side is higher than the right side, and then the right side is higher than the left side. The difference in level is more than 5mm, which is called the triangle pit. This would leave one of the four wheels in the air, and if a large lateral force happened to occur on this wheel, it would cause the floating wheel rim to climb along the rail and cause a jump.

The Mine Track Horizontally Uneven Surface

Mine Track longitudinal unsmoothness, the occurrence of potholes or convex phenomenon, known as the rail track uneven surface . Due to the water storage remains in mine roadbed, the status of roadbed changes, unevenness of the tamping firmness on roadbed, and the different tightness of the connecting fasteners, will cause the uneven subsidence of mine track, resulting in the uneven rail track surface.

The main transport lines require visual smoothness, the allowable difference between the height and height of the rail surface with 10m chord is 10mm, and the tilting winch way is not more than 15mm, but the design variable slope point is not subject to this limit.

Direction of Mine Track

The direction refers to the extension of line plane position, which means no matter the rail track is straight on the straight section or not, or the track is circular smooth on the curve section or not. During the inspection, select points within 5m before and after the rail joint shall be inspected. The straight line should be visually straight. The inner side of the rail should not exceed 10mm with 10m chord. The curve should be visually round and straight, with the adjacent positive vector difference of 2m chord inside the outer orbit, no more than 2mm in radius with mine track with length above 50m long, and no more than 3mm in radius below 50m. If you need Mine Track or Mine Track Rail Fasteners, please feel free to contact us now!