THREE KINGS DANGER.

New Zealand Herald, Volume LX, Issue 18345, 10 March 1923, Page 10

THREE KINGS DANGER.

GUIDE TO NAVIGATION.

THE RADIO BEACON. PRACTICABILITY OF SYSTEM. i [BT TELEGRAPH. —PRESS ASSOCIATION.] WELLINGTON. Friday. The Marine Department recently carried out very complete experiments at the Three Kings concerning the application of wireless direction-finding to marine navigation. The Government steamer Tutanekai was commissioned for the purpose, improved apparatus being installed on the vessel. The Minister for Marine, the. Hon. J. G. Anderson, stated th« results to-day. "At present," he said, "there are two distinct principles in the application of wireless direction-finding to marine navigation. These are: (1) By locating direction-finding stations in fixed positions on shore, from which a ship receives her position through the medium of its ordinary wireless set; (2) by installing a directional-receiving apparatus on board ship quit© apart from the usual wireless equipment, and establishing a radio beacon on shore. The No. 1 principle has been fairly extensively applied in the Northern" Hemisphere. It is wholly confined to vessels equipped with wireless. The No. 2 principle is the reverse of No. 1, and is more up to date. It was recently tested by the Marino Department." After dealing with tho nature of the tests and experiments, the Minister continued : "As a result of the tests, the department is satisfied that* the principle advocated under heading No. 2 can be applied in a practical manner. As in the case of a vessel's standard compass, the direction-finding instrument requires to be calibrated on each vessel, and have its errors tabulated. The errors may then be applied in the same manner to that in which compass errors are applied- Regarding its tabulated errors, it was noted that these are fairly constant; also that errors are at a minimum when observations are taken either right ahead or right astern. Tho same may bo said of bearings taken on either beam. _ Errors change from additive to subtractive in succeeding quadrants, when using the 360deg. system, and they follow the simple law that all observed bearings suffer deflection toward the fore and aft line of the vessel. The department is satisfied a radio beacon station with its counterpart ship's direction-finder can be considered a practicable aid to navigation, and of special significance during thick or foggy weather."