left click on the image above to enlarge |
The coal seams are usually about 3 metres high and the whole seam is mined on development. The maximum width of an underground roadway is usually 5 metres so that the cavity created appears as alongside (without the pipeline installed). There are two types of underground roadways - headings and cross-cuts (or cut-throughs). Basically the heading is driven in the desired direction and cut-throughs are required to allow the air current ventilating the underground mine |
|
The mining in process in an underground colliery consists of two distinct parts - a development phase and an extraction phase. These two phases can be easiest understood by viewing the drawings following. The coal seams are usually about 3 metres high and the whole seam is mined on development. The maximum width of an underground roadway is usually 5 metres so that the cavity created appears as alongside.
As an underground miner I became acutely aware that delays contributed significantly to lack of availability of the next longwall block for extraction. As money was no longer made during development this process needed to be reduced to maximise the profitability of a colliery. a short a time span as possible These pipelines needed to be extended once a pillar was completed (see PART MINE PLAN) so that the services (compressed air, fresh water, pumpout, etc.) were able to be supplied to the advancing/development faces using only minimal hosing. |
This Longwall Bracket
(above) supports a large-bore gas drainage pipeline (yellow marked)
neatly against the roof and coal rib in an out-of-the-way manner as
possible - again from a single roofbolt! As this bracket, as with
all FACE EMPLACED Brackets, is included in the roofbolt assembly - a
saving of about 150mm in head clearance is realised! |
The main novelty of the
invention is the using of the opportunity of roofbolt installation,
necessary to support the region excavated in the desired roadway direction,
to install these FACE EMPLACED Services Support devices.
Previously these two processes, supporting of the roof and supporting
of services, were conducted separately! .
The
advantages realised by the combination of the two processes are numberous!
.. |
|
To complete the. FACE EMPLACED Services Support device .range as far as brackets are concerned, a bracket capable of supporting main mine belt conveyors, was developed. The thickness of the Bisalloy 80 plate was increased from 5mm to 8mm to add the required strength to support the additional load(s). Again this bracket was designed for GORDONSTONE^ Colliery - for their very high-tonnage, main mine conveyor. |
| Later MESH PLATES were developed to accomodate a new form of roof support - mesh modules#. Basically these FACE EMPLACED Services Support devices were designed to integrate with this new form of roof support. The FACE EMPLACED support device was held to the mesh module using a substantial hook (#24) such as the one shown in the Roofbolt/Bracket Assembly above. The mesh module is then bolted to the roof in the normal manner with at least one roofbolt passing through the nearly-horizontal section of the MESH PLATE.
It was discovered that 2mm thick steel plate was of sufficient strength to support up to 150mm bore pipelines, with two MESH PLATES used to support each approximately 6 metre long pipeline length - with a factor of safety above six. As most piped services in panels do not exceed 150mm in diameter MESH PLATES therefore became the dominant form of services support. |