N.Z. Marine Beacon Ordered By United States Navy

Press, Volume CVI, Issue 31248, 21 December 1966, Page 23

N.Z. Marine Beacon Ordered By United States Navy

“The Press” Special Service

WELLINGTON, Dec. 20.

A New Zealand - devised marine beacon solving major navigation problems in restricted waters has captured the interest of the United States Navy. Invented by D.S.I.R. scientists at Gracefield, and patented by the Government, the beacon is being produced in Newlands for orders overseas and within New Zealand. The beacon was invented six years ago by Messrs R. J. Barnes and N. J. Rumsey, of the optics section of the D.5.1.R., Gracefield. It was created to solve a problem of a leading light defining the narrow channel and the

bar and reef at the entrance to Porirua Harbour, 'where the first example is still working. Designed to obviate the need for two leading lights in a restricted area where sufficient distance could not be found to provide accurate alignment because the lights could not be placed far enough apart, the beacon is highly directional. It comprises a central white safe section, with green and red sectors to each side of the white. In Use at Napier Similar lights are being used by the Napier Harbour Board for berth dredging, and by an Australian concern laying a subterranean pipeline through a marsh in Spencer’s Gulf. In both these jobs, the lights give the line, with no need for surveyors to continually make measurements and lay leading marks. In its navigational context, the light can be divided into five sectors, with fast-flashing zones outside the three inner sectors, to guide the mariner. The system works like a highly efficient, highly directional slide projector, with lenses and coloured filters, and flashing mechanisms, all illuminated by the one light. Wide Range

Now building the lights in a one-man concern in Newlands, Mr J. C. Ruddick said that the one now under construction was destined for the Mine Defence Laboratory of the United States Navy. Others had been built for the United States Coast Guard, and there was a tender in the offing for the United States Navy. The lights could

be given horizon range, limited only by the earth’s curvature, with powers above 250,000 candle power, or could be of limited range like the one used for close-up work in Napier.

Working on the beacon for the Porirua Harbour entrance, Mr Barnes, a technical officer, and Mr Rumsey, a geometrical optical designer and principal scientific officer of the optics section of the D.5.1.R., produced an entirely new approach to a problem long recognised in navigation. Under consideration at the moment is a horizontal development of the system which might be used as height guidance approach for landing aircraft.