COAL MINING

Southland Times, Issue 20791, 4 June 1929, Page 2

COAL MINING

METHODS IN NEW ZEALAND. “Coal Mining in New Zealand” formed the subject of an interesting lecture given last night in the Technical Institute by Mr J. b. Haynes, manager at the Rotherham Main Colliery, under the auspices of the Rotherham Technical Institute Engineering Society. Mr Hayes, who was engaged in mining in New Zealand from 1907 to 1911, was able to deal with his subject from personal experience. Though greater in extent that Great Britain, said Mr Hayes, New Zealand contained only a ver ylimited area of sedimentary rocks deposited during any coalforming age. Its coals were principally of the cretaceous era. A great proportion of the country was composed of igneous and metamorphic rocks. The accompanying earth movements had had a decided effect upon the coal either prior or subesquent to deposition. This, and the lacustrine theory largely explained the “pockety” nature of the coal deposits, and the great variety, both in thickness and quality, to be found within the same seam. Adding to dislocation by faulting the ravages of extensive denudation, and considering also the enormous mountain masses hurled up by igneous action, they would readily imagine that nothing like the extensive coalfields of Great Britain existed in New Zealand. Dealing with the mines with which he was acquainted, Mr Hayes said they were entered by adits, the surface haulage roads continuing underground without- interruption. The seam was, in places not less than 30ft thick, while in others it was not “tub height.” At one spot the seam, about 30ft thick, was found to be lying directly upon a 12ft seam. Here the lower seam was entered, “bords” being driven directly under those in the seam above. 'Working to the rise, the gradient was found to be less than that of the seam above, so that in the course of a few hundred yards a pair of headings could be driven, with over 100 ft of sandstone cover, under the bed of a river, on the cliffs above which the upper seam out-cropped. Mr Hayes dealt fully,with the methods of mining and mine surveying in New Zealand generally, his lecture being illustrated by means of a number of slides loaned by the New Zealand Government Department in London, as well as those he had prepared himself.