In 1946, a suitable site for a mine to be developed in the outcrop of the (No3) Wongawilli Seam, was prospected in the Mount Keira mine pit top area. Whilst several sites were found to be unsuitable, a site was chosen adjacent to the Mt Keira Road. Mining commenced in the outcrop of the seam at that site in April 1946, using a Jeffrey 29L coal cutter, and L400 coal loader, and a battery locomotive. A train of 6-tonne capacity drop bottom waggons was used to haul the coal mined to the surface, to be dumped into a 300-tonne capacity storage bin. The coal from this bin was loaded in road trucks and delivered to the Wongawilli Colliery washing plant, where it was washed and mixed with the coal produced at the Wongawilli Colliery.
A second loader and cutter unit was installed in October 1946. The mine workings had by that time advanced some 125 metres from the portal, and were encountering deteriorating roof conditions, and surface water entering the workings. After advancing some 870 metres from the surface, the continuing bad roof conditions and ingress of water led to further mining of the of the seam being abandoned, and the mine was closed in September 1950.
The underground mining plant was removed, and the surface coal storage bin was dismantled and along with the mining equipment, transferred to and installed at the abandoned Mount Pleasant Colliery mine site.
The coal storage bin was re-erected, and a cutter and loader mining unit commenced mining from the outcrop of the Wongawilli Seam at the Mount Pleasant Colliery in 1951/2. The coal mined was hauled to the surface in wagons by battery locomotives and dumped into the coal storage bin, from where it was loaded into road trucks and transported to the AI&S Port Kembla Steelworks. This mining operation at Mount Pleasant Colliery ceased in 1956. The reusable equipment and plant was transferred to the Kemira Colliery, and the remaining items scrapped.
In 1976, a proposal to mine the No. 3 Seam at the Kemira Colliery was adopted to supply Wongawilli Seam coal to the Port Kembla Steelworks, to support the steelmaking operations at that plant.
The development of the Wongawilli Seam was commenced by driving an exploratory entry into that seam from the Kemira Drift roadway where it intersected the Wongawilli Seam, some 507 metres inbye of the existing 7Right area Bulli Seam coal loading bin. This entry enabled the coal mined during the initial development of the Wongawilli Seam to be hauled to the Kemira surface coal handling plant using the existing underground to surface diesel locomotive coal haulage system.
Prior to the commencement of this development, the Bulli Seam workings in the abandoned Mount Kembla Colliery mine workings above, were drained of the accumulated water in them. This water was initially directed into the adjacent abandoned workings of the Mount Pleasant Colliery and later into a pipeline installed in the Kemira Tunnel, to be treated and discharged on the surface.
In 1977/78, two development entry roadways were driven in the area of the Wongawilli seam noted earlier, adjacent to the intersection of that seam, with the Kemira Tunnel. A Staple shaft was raised up from the Wongawilli seam to the Bulli seam workings above in the Kemira Colliery, to provide for the ventilation of the planned mining operations in the Wongawilli seam.
The development roadways in the Wongawilli seam were initially driven using a Joy 1CM3 Continuous Miner, chosen for its ability to the drive roadways in heavy roof conditions. It was later replaced by a Jeffrey Heleminer, a modern fixed head continuous miner. A small capacity coal storage bin was excavated above the Kemira Tunnel to allow the coal mined to be discharged into 10-ton mine cars and hauled through that Tunnel, to the urface coal handling plant.
A two-heading roadway mining layout was chosen, to provide a rail track and a return airway, for the installation of a conveyor belt, and an intake ventilation airway. These roadways were driven to a location, chosen to drive a cross-measures drift roadway, 220 metres in length on a rising grade of 1 in 25 from the Wongawilli seam up to the Bulli seam above, using a Alpine AM50 Model road heading machine. This roadway intersected the existing Kemira Colliery transport roadway and provided both men and materials access to the Wongawilli seam, and an intake airway for the planned Bord and Pillar and longwall mining operations in the Wongawilli seam. The driving of the above drift, by employees of the colliery, commenced in June 1980, and was completed in October 1980.
A 1200-tonne capacity Wongawilli seam coal storage bin was excavated above the Kemira Tunnel, approximately 200 metres outbye of the existing Kemira Colliery 7 Right Area coal loading bin in the Tunnel. A contract to construct the above bin was awarded to Coya Constructions Pty. Ltd., who commenced the excavation of the bin in August 1981 and completed the work in September 1982. The bin was linked by a belt conveyor to the Bord and Pillar and later the longwall panels, to accept the coal mined in those areas.
To provide the required quantity of ventilating air for the longwall mining operations, modifications were made to the ventilation fan mounted on the surface, at the Calyx shaft to increase its ventilating capacity, and a 4.5 metre diameter Staple Shaft was driven underground to link the Wongawilli seam to the overlying Bulli Seam.1
Mining commenced in the Wongawilli seam in 1977 and five Bord and Pillar panels were developed, followed by the extraction of the pillars, using the Wongawilli System of Pillar extraction. Coal from the 1200 tonne storage bin was loaded into 10-ton mine cars and hauled by diesel locomotives to the surface coal handling plant. A conveyor belt was later installed in the Kemira Tunnel to replace the diesel locomotive rail haulage system delivering the coal to the above plant. While the installed conveyor belt system eliminated the need for rail haulage by mine cars, the trackwork in the tunnel was retained for men and materials transport.
The longwall mining of the Wongawilli seam led to a total of five longwall blocks being successfully extracted. In 1982 a downturn in the coal and steel industries, resulted in the mining operations being reduced, along with major reductions in the mines workforce. These changes led to a 16 day stay- in strike by members of the Kemira mining unions, an industrial event that attracted nationwide attention.
Some four million tonnes of coal had been extracted after seven years of mining the Wongawilli Seam, and mining ceased on the 9th September 1991. Whilst a final longwall block (LW6) had been developed for extraction prior to terminating the mining of that seam, that block was not extracted as a decision was made by management to remove the longwall equipment, and have it transferred to the Tower Colliery.
1Robert Spires-History of Kemira Colliery 1857-1984 2
Coal News, March 1994
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