Lightships and Lighthouses

by Frederick Arthur Ambrose Talbot

By courtesy of Messrs. D. and C. Stevenson.

AN UNATTENDED BEACON LIGHT PLACED UPON A WILD PART OF THE SCOTTISH COAST.

These lights will run for several months without any human attention, and, by means of ingenious mechanism, light and extinguish themselves automatically.

The machinery includes two oil-engines which drive three-phase alternators, and an air-compressor for working the land siren when required. One of the greatest difficulties arose in connection with the submarine cable which connects the land-station with the sea-tower. Owing to the broken, rocky nature of the sea-bed, the viciousness of the currents, and the heavy seas, the cable had to be of exceptional strength; indeed, it had to be made specially for the purpose. It is a double-sheathed, steel-armoured cable of the heaviest “rock” type, being 11 inches in circumference, and weighing 45 tons per nautical mile. As the current used is three-phase, there are three conductors, which weigh 1,100 pounds per mile, protected by a thick layer of gutta-percha averaging 450 pounds per mile. In the centre of the core are two other wires for switching and telephone purposes respectively. The laying of the cable was a peculiar and exacting task in itself; 6,504 feet had to be paid out. But by waiting for a very calm day and slack water this task was achieved without mishap. In the tower there is a simple switch operated by an electro-magnet, whereby the motor-driven air-compressors are thrown in and out of action. The two compressors are used alternately, so as to keep them in thorough working order; and as they have to be left sometimes for months without being examined, special attention has been devoted to their lubrication.

A visit to this lighthouse is a somewhat curious experience. Climbing the ladder and entering the building, one finds it apparently abandoned. Not a sound beyond the murmuring of the waves playing about the rocks below disturbs a silence which is uncannily tense. Suddenly there is an almost imperceptible click. The keeper at the light-station has moved his switch, and simultaneously that in the tower has closed. The electric motors instantly commence to revolve, with a low grunt at first, but rising quickly to a loud humming as they settle down to their stride, driving the air-compressors. Then comes the ear-splitting, deep-toned roar from the siren overhead, attended by the whirr of machinery in motion. The humming of the motors and the compressors dies down, and in a few seconds absolute stillness prevails once more. The sensation is decidedly eerie. It seems impossible that a silence so intense as to be felt should be interrupted by a click—the result of a slight movement by an unseen hand a mile away—which gives forth such a nerve-shattering din as to convey the idea that Bedlam had been let loose. At the land-station the experience is similarly weird. The keeper moves his switch which brings the tower machinery into action. Presently there is the sharp tinkle of an electric bell. This notifies the keeper that the blast on the tower has been given, but conclusive evidence of this fact does not arrive until five seconds later, when the baying of the siren comes rolling over the water.

A complete check is kept upon the isolated station out at sea. If the electric bell does not ring out at the appointed period, to notify the keeper that the siren has emitted its warning note, he knows that something is amiss. The land-station is brought into service without delay, the intimation to the mariner to stand clear being thrown from Doyle Fort once every ninety seconds. The men on shore take it in turns to mount watch for fog both day and night, and their vigil is checked. There is an electric alarm, which maintains silence only so long as the man on duty fulfils his appointed task and records this fact upon his mechanical register at scheduled intervals. Should he fail to perform this function, there is a frenzied clanging by the alarm-bell, which summons the second keeper to duty.

THE GASFETEN LIGHT: A LONELY BEACON IN SWEDISH WATERS.

This was the first tower to be fitted with the Dalén “sun-valve” in conjunction with the Dalén flasher. Several automatic lights of this type are used to show the way through the Panama Canal.