HOPPER-TRAIN (EN: bunker-train; DE: Bunkerzug; FR: silo-train; ES: tolva-tren; RU: бункер-поезд) is the underground transport installation, which is made of the pivotally connected sections-platforms with high lateral boards (without the terminal walls) on the wheeled-railway chassis. The hopper-train is purposed mainly for the hauling of the rock mass, which is broken-out within the tunneling stope during one cycle. On the bottom, or on the special guides within the upper part of the lateral boards of the hopper-train, there is situated the transport-distribution installation, with the help of which the rock mass, which is loaded from the terminal part of the hopper-train (ore, rock) is distributed uniformly throughout the entire length of the hopper-train. The underground mine locomotive (or the traction system) moves the hopper-train to the point of unloading (ore chute, receiving hopper of the underground mine hoist, ore or waste dump on the surface), where the rock mass is unloaded with the help of the same distribution installation or through the flip-down bottoms.

(Table) The major technical characteristics of the hopper-trains
The type of the hopper-train The voluminous capacity of the hopper, cubic metres The performance of the loading, cubic metres per minute The dimensions, metres The mass of the train, tonnes
width length the height during the transportation
Of the scraper type 20 0.6 1.05 28 1.5 18
32 0.8 1.35 28 1,9 21
Of the conveyor type 12 1.2 0.92 17 1.4 16
20 2.5 1.05 33.5 1.5 22
32 4 1.35 35.5 1.6 35

The type of the hopper-train is usually determined by the type of the transport-distribution installation (Table), which is used; they distinguish the scraper and conveyor hopper-trains.

Within the scraper hopper-trains, the lateral connection between the sections is performed with the help of the pivotal beams, and allows to pass the curvatures with the radius of 12 metres or more. On the lateral walls of the sections, there are fixated the traverses for the limiting of the movement of the scraper and of the ropes along the vertical plane. In case of the usage of the scraper hopper-train, the time for the loading of 20 cubic metres of the rock mass is 40-60 minutes, the time for the unloading is 30-35 minutes. The main disadvantage of the hopper-train of this type is the relatively poor performance of the scraper installation, which is decreasing the indicators of the work of the loading machines. There are more promising the conveyor hopper-trains (of the bottom scraper, tabular, or vibrating types), which ensure the continuous loading and unloading of the rock mass. The total duration for the cycle, which comprises loading, movement, and unloading, with the distance for the hauling of 1 kilometre, is approximately 40-60 minutes. The hopper-trains of this type work within the mine workings with the cross section of 4-12 square metres, and haul up to 60 tonnes of the rock mass.

The modern hopper-trains are effectively used within the structure of the complexes of the tunneling equipment in case of the railway transportation of the rock mass; the usage of the hopper-trains is also possible for the hauling of the ore from the ore chute or from the loading point to the near-shaft place. The hopper-train ensures the optimal organization for the tunneling works, the increase for the productivity of the labour, and for the speed of the conducting of the mine workings. The total duration for the removal and for the transportation of the rock mass, in case of the usage of the hopper-train, decreases (in comparison with the usual machinery of the railway transport within the underground mine) by several times.