240 COALFIELDS AND COLLIERIES OF ANSTRALIA. 



tension transmission will be about 2J miles. On account of 

 the extent of the workings in this mine, it was found neces- 

 sary to adopt the high tension system, which will admit of 

 one of the motor generator sets being placed about two miles 

 from the mouth of the tunnel. This set will supply current 

 to the various coal cutters along the faces with very little 

 loss in voltage. 



The Mount Lyell Coke Works. 



These works, which are under the management of Mr. 

 Tuxworth, are located at Port Kembla. They consist of 62 

 rectangular ovens, 24ft. long, and 3ft. wide at the ram end. 

 The walls are 5ft. Din. high, and the spring of the arched 

 roof Tin. These ovens, and those at Bellauibi, belonging to 

 the Broken Hill Proprietary Company, are the only ones with 

 side and bottom flues; there are two flues in each wall, and 

 two under the bottom of each oven, along which the gases 

 circulate. Instead of generating heat by burning the coke of 

 the oven, the heat derived from the combustion of gases is 

 utilised. Greater care is required in the admission of air to 

 coals which contain just a sufficient amount of volatile hydro- 

 carbons, than those with an excess of volatile matter. A 

 maximum yield of coke cannot be expected unless one has the 

 best conditions for retaining the heat, and a perfect regulation 

 of air. The coke is quenched in the oven by spraying water 

 on it through a loose perforated pipe connected to a hose. It 

 could be partly or wholly quenched outside the oven, but the 

 cloud of steam given oif would retard operations. An 

 hydraulic ram is used to push the coke out on the coke wharf. 

 The doors of the ovens are raised and lowered by a small over- 

 head hydraulic ram, one on either side of a battery of ovens, 

 which can be run a]ong into position where required. The 

 coal for coking is obtained from the Mount Kembla colliery. 



Wonga Willi Colliery. 



This property is berno* opened up by a local syndicate. It 

 is situated opposite Dapto, and is the furthest south of any 

 colliery in the Southern Coalfield, now that the South Kembla 

 Colliery (which was formerly worked for about three years) is 

 abandoned. The Wpnga Willi has only recently started, so 

 is still in the developing stage. The seam worked is not the 

 Bulli seam operated by the other South Coast collieries, but 

 what is known as the "thick" or "dirty" seam, which is about 

 15ft. thick, and consists of several small seams. Only about 

 5J,ft. of the best of it is extracted, and even this has several 

 bands in it/- This seam is below the "four-foot seam," which 

 is, again, under the "Bulli" seam. 



