Shortwall Mining

The shortwall mining system originated in Australia and is, in essence, a combination of the continuous mining and longwall mining concepts. 

In fact, eqnipment costs may also be reduced by employing the development equipment during the retreat from the face. However, it should be noted that the passes along the coal face are restricted to one direction only (cf. the longwall mining system) since the mining machine is not nsnally adaptable for cutting in both directions. 

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Shortwall Mining. This method is used in relatively few underground mines. It involves the use of a continuous mining machine and movable... 

A modification of this method, using a continuous mining machine on faces up to 150 ft long, is known as shortwall mining. It uses the roof support system of self-advancing chocks developed for longwall operations. 

Room and pillar techniques are used to extract most of die trona. Conventional blasting methods as well as drum (ripper) and borer mining machines are employed. Longwall and shortwall mining techniques which involve hydraulically supporting the overburden wliile undercutting the trona seam have recently been introduced. In these methods, die hydraulic supports are advanced after the trona is extracted. Eventually the previous cut caves in. These newer techniques allow over 70% recovery of die ore compared to 50% recovery for conventional room and pillar methods. 

Chock Large hydraulic jacks used to support roof in longwall and shortwall mining systems. 

Ramani, R.V. 1981. Longwall-Shortwall Mining, State-of-the-Arts. New York Society of Mining Engineers (SME). 

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