Mines West of the Escarpment and Their Coal Transport
Early coal mines in the Illawarra generally accessed the seams they worked either from the eastern face of the Illawarra Escarpment or (as with the Coalcliff Colliery for example) from the narrow coastal strip below the escarpment. With the growth of the industry however seams had to be pursued to the west – and practical issues of access and product transport dictated that their product coal left the mines at points west of the escarpment, thus obviating the ability to use the gravity incline systems used in earlier mines. Initially, this implied the use of road coal haulage from west of the escarpment to users and other transport below the escarpment. One innovative solution adopted to this situation was to create a tunnel through the escarpment, and transport coal by conveyor over 369m (1,220ft) to the base of the escarpment, for rail transport to users. The tunnel (drift) was named ‘O’Brien’s Drift’.
Early BHP Mines On and Below the Escarpment
In 1935 the BHP Company purchased the Australian Iron & Steel Company (AIS) steel works plant at Port Kembla, and a coal mine (complete with a washery and coke ovens plant) mining the Wongawilli seam at the village of Wongawilli, west of Dapto. The company proceeded soon after with the purchase of the Mount Kembla, Mount Keira/Mount Pleasant and Bulli collieries, all mining the Bulli seam.
The Contract system of mining practiced at each of these mines was progressively abandoned by AIS, except for the Mount Kembla colliery, and the installation of the plant and services required to support a mechanised system of mining commenced at all the mines except Mt Kembla. In 1947 AIS opened the Nebo Colliery from a greenfield site at Mount Kembla and commenced the mechanised mining of the Wongawilli seam.
The coal produced at each of the mines was transported by rail to the Steelworks, while the coal initially mined at the Nebo colliery (and from a small mine opened in the 1940s at the Mount Keira colliery) was transported by road to the coal washery at the Wongawilli colliery. This coal was treated in the washery with the coal mined at Wongawilli and transported by rail to the Steelworks along with the coke produced at Wongawilli.
Following the commissioning of the Nebo surface coal handling plant the coal passing through it was lowered by decline conveyor belt system to an over rail coal storage bin. The coal from this bin was loaded in to wagons and hauled by locomotive together with coal from the Mount Kembla Colliery to the Steelworks. The rail line used was the private rail line acquired by the Company as part of the purchase of the Mount Kembla Colliery.
The introduction of the mechanised mining system at the Bulli and Mount Keira (renamed Kemira in 1954) Collieries, involved the driving of a cross measures drift roadway of considerable length into the mine, from a carefully chosen location on the surface at the Bulli and Kemira collieries. These drift roadways intersected the Bulli seam in the area chosen to commence the mechanised mining of the coal seam. A high capacity rail haulage system using 10 tonne capacity mine cars hauled by diesel locomotives was employed in these drift roadways to haul the coal to a surface coal handling plant for a primary processing and transport by rail to the Steelworks.
The coal handling plants erected on the surface at each of the Nebo, Kemira and Bulli collieries included a ten-tonne capacity mine car rotary dumper delivering the coal to a Bradford Breaker to size the product and remove stone and tramp material, and deliver the end product on to a belt conveyor discharging in to an over-rail coal storage bin. The Kemira valley was chosen as the site for the above plant for the Kemira colliery and the site linked by spur line to the rail line servicing the Nebo and Mount Kembla Collieries. Coal from each of these mines was hauled by rail to the Steel works. The coal from the Bulli and Wongawilli collieries was hauled by AIS locomotives over the company’s private rail from the mine site to join the State rail line at Bulli and Brownsville to be hauled by AIS locomotives to the Steelworks.
By the mid 1950s the AIS Collieries group was composed of five collieries all located on the Illawarra escarpment, and in 1959 the decision was made to develop a new mine to access the Bulli seam near the village of Appin. The development of this mine enabled the Company to access coal leases acquired earlier in the Appin/Douglas Park area, to develop mines that would initially complement and later replace the existing mines on the escarpment proper.
At that point in time the Company recognised that the mines on the escarpment proper would become increasingly uneconomical through having to transport men and materials over long distances to and from the working areas. That reduced the time available at the coal face, and to supply the supporting men materials and services needed to support an efficient mining operation.
The development of the Appin Colliery commenced in 1959, and involved the driving of two inclined drift roadways (the ‘Men and Materials Inclined Drift’ – MMD), from the surface area of the mine site to intersect the Bulli seam some 500 metres below the surface and the sinking of two vertical shafts from the surface to the Bulli seam at a location some distance west of the mine site.
On completion of the sinking of the shafts and the excavation of the MMD the production of coal from the mine commenced in 1962. This coal was hauled from the seam in ten-tonne capacity mine cars to the surface using a direct rope haulage installed in the MMD. This haulage was installed to support the excavation of the inclined drift roadways and to provide the permanent means of access to the mine for personnel and material and was named the MMD Haulage. The coal mined during the early development of the underground workings was delivered to surface in the mine cars, dumped into a bin, and loaded into road trucks for transport by road to the Port Kembla Steelworks.
On completion of the second inclined drift a 600 tonne per hour capacity, single lift seam to surface steel cord conveyor belt was installed as the permanent seam to surface coal haulage system for the mine. The coal delivered to the surface by the drift conveyor was delivered to a surface coal storage bin by an elevating conveyor. The coal from this bin was loaded into road trucks and delivered by road to the Port Kembla Steelworks.
It is of interest to note that the coal storage bin was erected on the southern perimeter of the surface area of the mine site. This site is thought to have been deliberately chosen to accommodate at some time in the future the transport of coal from this mine and other AIS mines planned for this area by rail along a company owned rail line, reaching from the Appin /Douglas Park area to the Illawarra escarpment near Mount Keira.
A small coal preparation plant having the capacity to treat two million tonnes of coal per year was later erected on the Appin mine site to treat the coal mined prior to its transport by road to Port Kembla.
The O’Brien’s Drift Conveyor (OBD)
The construction of the OBD facility commenced in 1963 and included the erection of a Road Truck Unloading Station (TUS) adjacent to the Harry Graham Drive roadway in the Mount Keira area, an underground storage bin and belt conveyor system, designed to load the coal delivered by road on to a belt conveyor installed in a decline tunnel roadway some 2024 metres in length, linking the site to rail loading storage bins in the Kemira Valley. The decline tunnel roadway was extended beneath the TUS to the west, by a tunnel driven under the Harry Graham Roadway to a building housing the decline conveyor belt drive system.
Following the excavation of the decline conveyor roadway, the conveyor support structure and conveyor belting was installed along with a rail mounted rope haulage powered transport/ maintenance carriage located in the roadway adjacent to the decline conveyor.
In the Kemira Valley the decline conveyor belt and structure emerging from the decline roadway was linked to conveyor terminal head pulley to discharge coal into two 1800 tonne capacity over rail coal storage bins. Coal from these storage bins was loaded into rail wagons, and hauled the AIS private rail line, to the Steelworks. Details of the drift and conveyor system may be seen here.
In 1996 two additional storage bins were excavated beneath the TUS complete with conveyor feed belts, increasing the combined storage capacity at that location to 3000 tonnes and the ability to receive and load three distinct types of coal on the decline conveyor belt system.
The O’Brien’s Drift (OBD) facility brought to an end the use of road trucks by AIS, on the Mount Ousley and Wollongong area road systems, when delivering coal mined at the AIS collieries west of the escarpment, to the Steelworks, and the Port Kembla Coal Terminal.
On completion the facility handled coal delivered by road from the Appin Colliery and the Corrimal Colliery skip hoist located adjacent to the Mount Keira Road. In 1978, AIS commenced the development of the Tower Colliery at Wilton, and in 1979, the Cordeaux Colliery located adjacent to the Mount Keira road, west of the escarpment. The production of coal from Tower commenced in 1978, and from Cordeaux in 1979. The coal from both of these mines was transported by road to the O’Brien’s Drift and transferred by the drift conveyor to over rail storage bins in the Kemira Valley for delivery by rail to the Steelworks. A detailed event timeline covering the development of these facilities may be found here.
It is of interest to note here the comments made earlier in these notes in respect to the siting of the Appin Colliery surface coal storage bin, and the possibility that it would have facilitated a rail connection to that operation from other mines.
The material excavated from the driving of the OBD declined belt conveyor roadway, and the tunnel under the Harry Graham Drive HGM was placed adjacent to and west of the (HGM) to create an embankment, suitable for the laying of a rail line extending in a north west direction. The construction of this embankment could suggest that AIS did have plans for a rail line, that would deliver coal from their mines west of the escarpment (eg Appin) to the OBD facility.
As a final comment on the above in 1972 AIS entered in to discussions with Clutha Development to purchase that company’s collieries in the Burragorang Valley. This proposed purchase was subject to AIS receiving approval from the NSW State Government to construct a private rail line from the Burragorang Valley to Port Kembla. The State Government refused to grant that approval, and AIS abandoned their proposed purchase of the Burragorang Valley collieries.
Following the closing of the Corrimal colliery in 1986, followed by the Cordeaux and Tower collieries in 2001, haulage of coal to the OBD ceased.
The Appin Colliery, (now named Appin East) is linked to the mine workings of the former Tower Colliery. Coal produced in the Appin East Colliery is transported by underground conveyor to the bulk skip hoist and coal preparation plant located on the site of the now abandoned Westcliff Colliery, owned by the South32 Company. The coal processed in this plant is once more transported by road to the Port Kembla area.