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timbers which, according to Knutron, are generally used for
upright supports. The second type is sawed timbers which
are primarily used for horizontal supports, mainly headers
and half-headers. In his article Knutron also mentions
additional uses of timber in an underground coal mine which
includes mine ties, floor planking, wedges, crib blocks,
construction and repair as well as other smaller uses.
Knutron adds that as that as the coal is extracted from the
coal seam, roof support timbers are set. Depending on the
mine or area in the mine, mine ties will be laid, and the
flooring extended, all of which use timber. It is important to
note that different mines may have different timber
requirements because of the different mining methods they
may employ. For example, a mine using a rail system for
hauling will require wooden mine ties, whereas a mine using
a conveyor for hauling does not.
Underground mining is a dangerous in its nature and as a
result, it is important that the timber used, regardless of the
application, is up to standard and meets certain
specifications. Knutron outlines three main specifications.
Firstly, the timber has to be suitable for the intended use in
the mine; it has to be manufactured to the correct standards
and it needs to be structurally sound. ‘Most mine timbers are
used to support the mine roof. Therefore, strength qualities
are most important in mine timbers. Other qualities such as
durability, elasticity, and ease of construction are also
important,’ he writes.
Treating timber is important to ensure that the timber lasts
for as long as possible. This is not only applicable in timber
construction, but also in timber used for mining. Knutron
points out that the number of times the timber is treated
usually depends on the expected life of a particular mine.
There are many different timbers available on the market,
with some being a better choice for certain applications than
others. In the case for timber in mining, Knutron’s article
highlights that red oak, yellow poplar, basswood and
cucumber are among the prominent choices for timber used
in mining. He adds that the choice of timber is usually
driven by the availability of timber in the local area close to
the mine.
DIFFERENT TIMBER PRODUCTS
Although timber in mining is predominantly used in
underground mines, there are uses for timber in surface
mining operations as well.
According to Robert Stone, Christopher Risbrudt and
James Howard, timber is used for temporary building, props
and blocking as well as other miscellaneous applications in
surface mining operations. The three individuals co-
authored the article ‘Wood products use by coal mines’, in
which they broke down the different categories of timber
products in underground coal mines. The article was
published by the forest products journal and stresses the
importance of wood in the coal mining industry.
Round timber poles are used for upright support in an underground mine.
www.timberiq.co.za
// JUNE / JULY 2019 31