Operations
Wood in the good
old mining days
The use of timber in mining dates back to the golden days with discovery of gold, coal and other min-
erals, writes Dineo Phoshoko. Timber was predominantly used as pillars in underground mines to sup-
port mines from caving in – African Mining unpacks its various uses in the mining industry.
A
n article by MU Ozbay, JA Ryder
and AJ Jager titled ‘The design
of pillar systems as practised in
shallow hard-rock tabular mines in South
Africa’, explains that pillars have been used
as stopes since the early days of mining.
This article appeared in The Journal of
The South African Institute of Mining and
Metallurgy (SAIMM), where the authors
give a technical overview explaining
that the need to use pillars in a mine is
determined by prevailing considerations
of rock mechanics at shallow depths. An
example of such mechanics are large tensile
stresses in the hanging wall and geological
weaknesses in the hanging wall rock mass.
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.
In coal mining, timber is used as a support
measure for an open coal seam. This is
according to Robert Knutron in his article,
‘A look at the mine timber market in the
Appalachian Bituminous Coal Region’.
“For this purpose, round, split, and sawed
timbers are used,” Knutron writes. Knutron adds 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.
Knutron distinguished between two types
of timber and their different functions: first
there are the round and split timbers which,
according to Knutron, are generally used
for upright supports. The second type is
“Timber is used mainly in mining support
systems to support the walls and rooves
of extraction tunnels,” says Hayley De
Haas, customer relationship manager at
Merensky Timber, a longstanding supplier
of sustainable lumber in South Africa.
She added that many mines also use gum
planks as utility boards for shuttering,
walkways, cages and underground bridges,
particularly in platinum mining.
Timber planks are used to provide roof support in a corridor underground.
40 AFRICAN MINING JULY - AUGUST 2019
Underground mining is 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 must 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
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