INVERCARGILL’S NEW AIRPORT

Southland Times, Issue 23676, 26 November 1938, Page 6

INVERCARGILL’S NEW AIRPORT

Mr Semple Pleased

With Field

“EQUAL TO ANYTHING

IN DOMINION”

METHOD OF OVERCOMING DRAINAGE DIFFICULTIES

(Special to The Times)

WELLINGTON, November 25.

An airport equal to anything in the Dominion will be the outcome of the present operations at the Invercargill flying field, according to the Minister of Public Works (the Hon. R. Semple), who in an interview today outlined the stage of development already reached and the methods proposed to overcome drainage difficulties. Construction of the airport to provide a flying field giving 600 yards of rpn in all directions and a maximum of 900 yards has been completed. “As to the development of the required smooth surface,” said Mr Semple, “a certain amount of difficulty has been me I '. in lowering the water table in the soil so as to provide the firm, dry surface required in the operation of heavy passenger aircraft. xhe existing free water level nearby is very near the surface and provides little or no drainage in the soil. The result is that as the rainfall in Invercargill is very evenly distributed throughout the year an undesirable amount of moisture remains in the soil, considerably reducing its bearing power and it has also retarded the growth of grass necessary to provide a well-knit and tough turf surface. In order to lower the free water level in the area and to improve the conditions for drainage it has been necessary to drain Lake Hawkins to the lowest possible level and simultaneously experiments have been carried out over small areas to determine the most efficient method of stabilizing the surface and bringing about conditions suitable for the development of a firm, dry turf, .These experiments have proved _ that satisfactory results can be obtained from a fairly extensive system of tile sub-soil flrains, fed by a series of mole drains and in turn discharging • to big ring drains, which would surround the whole field. The necessary plant for this work is already on order and the scheme has been designed to include the whole area which may be developed into a flying field. Co-ordinated with this scheme surveys and grading proposals have been completed to increase the size of the airport to approximately IQOQ yards. “It is anticipated that the drainage work will be proceeded with during the coming summer and that shortly after that work is completed the present field will be ready for use,” added the Minister. "It is proposed to begin construction on extensions to provide a bigger field at an early date and this work will continue while the present area is in use. While the area now developed is sufficient for present requirements a full-sized field will provide for Invercargill an airport equal to any in New Zealand and more desirable than most in that it is located very close to the centre of population. It is still free from any serious obstruction to flying and is. in a position in which very steady air conditions can be expected in almost any wind direction.”