Canadian Coast Guard

Modern Lights

Although the era of mineral oil lamps and optical lenses had brought a great improvement on anything which had gone before, the use of vapour lamps implied a large area of light source with corresponding loss of definition and brilliancy in the optical arrangements. Below a certain size there was simply no way by which a small flame could be made to produce a light of the required density. The advent of the electric filament lamp, which came into use in light stations before the first world war, improved matters considerably and, with dioptric lenses with or without reflectors, a high density light was produced from sources smaller than was possible with vapour lamps. To provide electrical power, diesel generators were installed and gradually the conveniences of modern life, which Canadians living on the mainland take for granted, became available for the light keepers and their families.

Prince Shoal light tower, established in the Gulf of St. Lawrence, 1963.

The production of hand polished optical lenses, always something of a mystique foreign to North America, is an expensive business; the introduction of lenses made of plastic, which dates from about 1960, has greatly widened the sources of supply for lighthouse optics with consequent reduction in cost. With optical qualities superior to glass, the use of acrylic lenses has reduced the size of the light source and improved the quality. This trend has been greatly accelerated by the introduction of xenon lamps and flash tubes. Xenon is an inert gas which, when present as the medium for an electrical discharge, emits a brilliant white light, almost of the quality of daylight. The xenon flash tube, another modern development, produces a light source of very high frequency, of the order of a hundred flashes per second; as the eye cannot absorb a flash of this frequency, but detects only an extremely rapid and bright flicker, the xenon flash tube emits a light of distinctive character which is highly suitable as an aid to navigation. In all of these developments, saving weight, space and time in the operation of lights, a further benefit is derived from automated operation which, free from the continuous manpower demanded by the old lights, permits the advent of planned and systematic maintenance.

In the case of buoys, where the light is subject to constant movement from the waves, the use of narrowly defined beams is a disadvantage. For this reason, and for ease of maintenance, the acetylene gas buoy is still used in the open sea where its wider light path makes it particularly suitable. The electric battery buoy, with high density light and built-in lamp changer, is commonly employed in inland waters. The lamp changer automatically replaces defective bulbs.

The use of radio beacons has now increased to give complete coverage in most Canadian waters. As this type of apparatus is made to function automatically, its use in remote places is particularly suitable. On the Hudson Bay route, for example, where Gordon worried about the paucity of aids to navigation and the deviation of the compass, shipping now relies on the radio beacons which, subject only to annual maintenance, give excellent service during the navigational season.

In addition to radio beacons, the Decca chain was established in 1962, coming under the control of the Department from 1964. This system of position finding, covering the Atlantic coast and Gulf of St. Lawrence, operates from four chains located in Nova Scotia. Cabot Strait, Newfoundland and Anticosti, and provides an accurate service for vessels in coastal areas. A long range navigation system known as Loran, provides a comparable service for vessels on ocean passage. Stations in connection with this system are operated by the United States Coast Guard, under international agreement, with Canadian staff in attendance, with coverage over both Atlantic and Pacific Ocean areas.

An S-61 helicopter of the Canadian Coast Guard lands supplies at Triple Island near Prince Rupert, B.C. When the twin turbo helicopter touches down on the landing pad, relief personnel and supplies will be conveyed from the pad to the lighthouse by overhead jackstay rig. A similar high-wire connects the tower with the boat landing.