47

C.—2

Millerton Mine. —In the north-east section adjoining the Stockton area the winning-places are nearing the boundary. Two pairs of colliers are engaged on pillar-extraction, and nine pairs on solid work. Dnring the year permission was granted to withdraw the safety-lamps from this section, and naked lights are now being used. Mangatina section : During the year two pairs of colliers were engaged removing top coal near the blacksmith's shop. Across the creek a small area, containing approximately 1 acre out off from the main Mangatina area by an upthrow fault, is being worked. The coal is 40 ft. in thickness, and the overburden varies from 3 ft. to 12 ft. Where the overburden does not exceed 4 ft. stripping is in progress. Sixth west section : This small area, 7 acres in extent, is now being developed. The coal is 30 ft. in thickness, and ten pairs of colliers are employed. Second Mangatina : This section lies to the south of the Mangatina boardinghouse, and has not been worked from the main seam because of an upthrow fault; three pairs of colliers are employed. Fourth west solid section : This section is now approaching what is known as the barren area, and the coal is thinning ; eight pairs of colliers were employed. Third west pillars : Six pairs of colliers are employed in this section on pillar-extraction. The coal is 50 ft. in thickness. Evans Daylight Section : Five pairs of colliers are employed in this section on pillar-extraction. The coal is 30 ft. in thickness, and the overburden varies from 20 ft. to 60 ft. No. 1 Dip Pillars : Four pairs of colliers are employed on pillar-extraction. Indications of heating in this section are still being found. During the period under review two Babcock and Wilcox boilers have been erected at Mine Greek Power-station, making in all eight boilers at the power plant. A three-phase 250 K.V.A., 3,300-volt geherator has been installed for power and lighting purposes. Electric safety-lamps, both cap and hand, have been procured and will shortly be issued to the miners. A new lamp-cabin in concrete and wood, 45 ft. by 24 ft. has been erected to accommodate the lamps and charging-raeks. DENNISTON COLLIERIES. Coalbrookdale. —In the Wareatea section of this mine the workings are still being extended, the main south headings having been driven a distance of 37 chains. So far little ordinary mining has been done, work having been confined to development. This also applies to the headings being driven south-west. This section will in the near future be the main source of output. As the coal is liable to spontaneous combustion the panel system of mining has been adopted, and it is hoped that this method will result in a more complete extraction of the coal. Preparations are well advanced for the extension of the main haulage-system. Wareatea Extended.—The output from this section is maintained from solid workings and pillar-extraction. The solid workings are trending south-west. The area of coal is known to be small, and much faulted. It is anticipated that a holing will be effected to Wareatea section within the next few months. Cascade Section, Calligan's Dip : This area is now practically exhausted. No. 8 Section : The whole of the output is derived from pillar-extraction. During the year considerable trouble with fires has been experienced in this section. Owing to the crushed nature of the coal and the thickness of the seam the stoppings erected have not been effective. The stoppings are in places 20 ft. high and 0 ft. in thickness. During the latter part of the year it was found necessary to seal off a large portion of this area and shorten the haulage. As the roof in the vicinity of the latest fire-stoppings is of an exceedingly hard nature it is only a matter of time when another retreat will be necessary. To attempt to extract the pillars as the matter now stands will be a difficult undertaking. Ironbridge Mine. —Coal-winning operations in this mine are now confined to pillar-extraction in Kruger's, Kiwi, and No. 1 sections. In Kruger's section twelve pairs of colliers are engaged in pillar-extraction. In the lower part of the section, known as Kruger's Right, pillars are being prepared for extraction. The top seam, 6 ft. thick, and the bottom one, approximately 20 ft., are separated by 1 ft. to 2 ft. of fireclay and mudstone. The top seam was pillared some years ago, also the top portion of the bottom one, leaving a sufficient thickness below to be again worked. This is now being done by opening out narrow places 6 ft. to 9 ft. wide, and 6 ft. to 7 ft. high. The coal roof thus formed appears to be effective in keeping up the waste ground overhead. No. 1 section : Three pairs of colliers are engaged on pillar-extraction. The coal is from 16 ft. to 18 ft. in thickness, and is not liable to crush, as the main roof breaks readily. Kiwi section : Five pairs of colliers are engaged on pillar-extraction. The coal-seam in this section is over 30 ft. in thickness and of an extremely hard nature. In consequence of the thickness and nature of the coal the upper portion is being worked first, leaving the lower portion to be extracted later. Deep Creek (New Mine). —This mine consists of a series of small areas of coal, in each of which development has been rapid. Owing to breaks and gutters in the roof the main headings in the Cliff section had to be stopped. It is intended to commence driving a pair of new headings more to the centre of the field. Kiel's Flat: This section has been opened up during the year. In all twenty pairs of colliers are employed in the Deep Creek new mine sections. Workmen's Cottages : Seventeen new cottages have been erected by the Westport Coal Company during the last eighteen months, thus establishing a new township called Marshallvale on the plateau between Denniston and Burnett's Face. Clydevale Coal-mines (limited), Seddonville.—The plant to be used in the working of this mine is now in course of erection. It is intended to commence operations in the most northerly portion of the lease, from which point to a site near the State Mine bin an aerial ropeway of a capacity of 40 tons per hour (mono-cable system) is being erected. Trestles for the ropeway are constructed of steel and vary in height from 12 ft. to 70 ft. There are thirteen of these trestles, the longest span, 10 chains, being across Chasm Creek. A bin of 600-ton capacity has been erected at the. railway. To facilitate the transport of coal from the mine-trucks to the aerial a second bin of 100-tons capacity has been erected at the upper end near the mine. From this bin a tramway, 9 chains in length, has been laid to the mine-mouth. At the present rate of progress coal should be produced by the end of May, 1925. Regan and O'Brien's Mine. —AH pillars having been extracted from this area the mine is now closed. Shortly after the mine was abandoned fire was discovered in the fallen ground, and attempts were made by the parties interested in the adjoining properties to seal off the fire, but only with partial success. Prospecting is now being carried out on the northern portion of the lease. Dove's Mine (Old Cardiff). —Coal-winning during the year has been confined to pillar-extraction. On the 6th September a fire broke out in the portion of the lease known as Regan and O'Brien's Mine ; stoppings were erected, and a line of pillars extracted to sea! off the fire. Coal Creek Mivs. —Work during the year has been confined to pillar-extraction in the south-western portion of the area. During the latter portion of the year mining operations were suspended owing to slackness in the coal trade. Cardiff Bridge Mine.—The workings in this colliery are now trending south-west, but no particular plan of development is in progress. From a point near the mine-mouth where a gully forms a natural bin a flume has been constructed to the bin at the railway. This flume is approximately one mile in length, and is built of 12 in by 1 in. planks supported on frames. The bottom of the flume is lined with iron plates i n - in thickness. So far this method is successfully dealing with the output of 600 tons per week. Westport-Mokihinui Mine.—This party has made very little progress during the year, coal-winning being principally confined to winning outcrops and bottom coal. Zealandia Mine. —Only 302 tons of coal were won during the year, mining operations having been suspended. Murray's Mine, —Slackness of trade has caused the closing-down of this mine.