longwall mining




miscellaneous - remote control/automation



Miscellaneous - Remote Control/Automation

Because longwall operations are cyclic and repetitive when running well, it would appear ideal for the use of remote control or even full automation. In fact there have long been attempts to introduce various degrees of automation (remotely operated faces were in existence in the early 1960's), but with limited success.

Most aspects of a longwall can now be monitored reasonably reliably, and it follows could be remotely controlled or automated. Some of the major problems have been:

  • Machine position or attitude is usually measured relative to other parts of the machine itself, to other equipment or the position in space. In fact what is usually required is the position relative to the coal seam as that is what has to be followed (though in some instances even this is not desirable eg sudden changes cannot be followed)

  • There may be unplanned occurrences difficult to detect by monitoring, where a change in operations is required (eg a fall on the face, AFC tilted, etc). If personnel have to accompany machines to observe and frequently adjust things anyway, then there is no great benefit in automation (only more things to go wrong).

There are some aspects of automation in regular use. Most supports are operated, often in batches, by a signal initiated from an adjacent support – when in batches, the sequence for that batch is automatic once initiated. This is referred to as "batch or bank control". The number of supports in a batch is usually restricted to a reasonable distance for observation, around 8 to 10 chocks. Shearers can "learn" a desired cutting profile controlled manually and then repeat that profile automatically as many times as desired.

As a result of, or as part of the ACARP Longwall Automation Project, automation is now becoming a reality with several automated longwalls either in place, ordered or projected. It is expected that by 2011 there will be 11 fully automated longwalls in Australia and the ACARP package is being fitted to some longwalls in the USA.