WIRELESS LIGHTHOUSES

Evening Star, Issue 21216, 24 September 1932, Page 4

WIRELESS LIGHTHOUSES

To the average listener the Morse signals sometimes heard on any particular wavelength are merely "Morse,” a combination of meaningless dots and dashes interfering sometimes with broadcast programmes. But to tho navigator, perhaps groping through a thick fog, it speaks as plainly as a broadcast announcer, and guides him as accurately as tho policeman on point duty guides the traffic. Morse is the invisible beam of the modern lighthouse. Electricity was tried as an illnminant in lighthouses on the coast of England many years ago, but did not prove very satisfactory owing to its lack of penetrating power during hazy weather. The Isle of Slay, which was the only electric lighthouse in Scotland, was converted to incandescent gas in 1924, and although the power of the light has been reduced from four million candle-power to one and a-quarter million candle-power the light can now penetrate further through fog. Tho best light, however, is of very little use during fog, and the mariner has to depend on the bellowing foghorns to conduct him to a haven of refuge. But even foghorns have their shortcomings. The weather influences them to a great extent, and there are “blind pockets,” or silent areas in the atmosphere through which sound cannot penetrate. Wireless has solved the problem. It is true that even wireless is subject to the vagaries of the weather; nevertheless, it is so near the ideal thine that these slight disadvantages are scarcely worth counting. And as wireless is only yet in the experimental stages, so far as lighthouse work is concerned, any minor defects will be put right before very long. The strides made in coastal lighting during the last 150 years are truly tremendous. Prior to 1787 Scotland had only ope coal fire exhibited from a tower on the Islo of May to guard her rugged coast line. To-day there is a lighthouse on almost every headland, and those lights are being made as perfect as tho science of man can devise.

There are seven lighthouse stations in Scotland equipped with wireless beacons, six under jurisdiction of the Northern Lighthouse Commissioners and one under the control of tho Clyde Trust. The latter, which is installed at the Little Cumbrae Lighthouse, is quite a unique affair. It departs from the usual type of beacons installed in British lighthouses, which arc Marconi’s patent, and operate on the Morse code system.

This beacon is really a "talkie” lighthouse. It broadcasts the actual name of the lighthouse, gramophone records being used for the purpose. It also broadcasts the charapteristic blasts of the foghorn, and can give the navigator his exact distance from the lighthouse.

Another type of beacon is the revolving beam beacon. It transmits signals in beams to certain points of the compass. This type has not got a very wide range so far, but has the advantage that vessels which do not carry direction-finding apparatus can use it. The beam beacon is used more in connection with aircraft, but should prove very useful in coastal navigation. The most popular type of beacon, however, is the " Tonic Train ” beacon installed by Trinity House, the Northern Lighthouse Commissioners, and the Irish Lighthouse board. These radio lighthouses have a range of approximately 150 miles. They send out at regular intervals a signal consisting of a characteristic scries of Morse letters, by which a vessel equipped with necessary direction-finder may identify the station and obtain bearings therefrom. If tho vessel is within range of two or more beacons of which the signalling periods are timed so as not to overlap, cross-bearings may he obtained and the exact position of the vessel ticked off to a degree on tho chart. The whole plant is an elaborate affair, a great number of very delicate and complicated instruments being used. The estimated cost of one of these beacons is in tho region of £15,000. A stupendous figure, says the landsman; but if it saves one its burden of precious lives the beacon is well worth that figure.