Advancing coal faces extend  the boundaries of the mine.
 The roadways must follow the faces because they serve men, materials and  coal and they must circulate air.
 There must be a steady flow of fresh air underground.
 Fresh air flows down the downcast shaft , along all the roadways and  through  all the workings of the mine and is finally drawn up the  upcast shaft by a fan.
 If the air was left to itself it would find the shortest route between the  two shafts leaving much of the mine without ventilation.
 So the flow of air must be guided through the whole of the mine.
 It is drawn down the downcast shaft, along the intake roadways to the faces and from there it travels along the return roadways to the upcast  shaft and so to surface.
 
 The upcast shaft is boxed in at the surface to prevent the air from short circuiting.
 Doors are placed across some underground roadways to guide the air flow.
 Where an intake airway crosses a return airway an air crossing is constructed to keep the two airflows separate and thus preventing a short circuit.
 The deeper the mine the hotter the air will be because as you go down the rock temperature rises. It gets warmer on its journey through the mine as  men and machinery give off heat.
 Without an adequate supply of fresh air work would be impossible.
 
 One shaft takes men and supplies into the mine, the other brings the coal out.
 Large steel skips are wound up and down the shaft on steel ropes which are  attached to the winding engine drum.
 
 Roadways serve many purposes, they ventilate the mine; they carry electricity, compressed air and water to all parts of the mine and they  act as arteries for men and supplies and coal.
 Without supplies a mine cannot survive. Equipment and other materials including the arches for the roadways have to be constantly fed into the  mine.
 
 Coal comes directly from the face onto a conveyor along the maingate and  from there onto a system of conveyors along the main roadways.
 At the end of its run the coal may be discharged into minecars or into  bunkers.
 Great metal skips raise the coal and can carry up to 20 tons of coal at a time.
 When the coal reaches the surface it is conveyed to the preparation plant.
 
 The flow of coal through the system must keep pace with production from the coal faces so information on the faces and the conveyor system is fed  to a surface control station where difficulties can sorted out without  delay.
 
 Gone is the long walk inbye to the workplace so wasteful of time and  effort. Men can now travel by manriding trains or by manriding conveyors leaving only the last bit to walk to the face.

A tube traveller goes down about 80 feet, a miner thousands of feet.
 Three Post Office towers about 1900 ft, represents the average depth of a mineshaft.
 From the pit bottom the miner travels several miles to the coalface finally reaching it by a gate road from the main roadway. The gate road  used by men and materials is called the "Tail Gate". There are two gate roads to every face and the other is called the "Main Gate". The main gate is used for conveying coal.
 Most coal faces are "Longwall" coal faces. A longwall coal face is simply a long wall of coal usually 200 yards in length. It may be less than 3 feet thick; it may be more than eight. The thickness of coal is the height in which the miner works.
 Getting the coal off the face is roughly like slicing a bacon joint.
 As each slice of coal is "sheared" off the face the roof supports are advanced up to the newly exposed coal to hold up the roof over the working  area and thus allowing the roof to collapse behind the extracted supports.
 These powered supports are hydraulic working on the same principal as a car jack.
 The gate roads running down to each end of the coal face are supported  with permanent steel arches. On the side where the coal has been extracted these arches are strengthened with packwalls built with rocks either packed in bags or blown in by machine. Arches and packs have to keep up  with the advance of the face.