Lightships and Lighthouses

by Frederick Arthur Ambrose Talbot

A CHURCH AS A LIGHTHOUSE.

A fixed white light, thrown from the tower of St. Philip’s Church, and visible for 18 miles, forms the rear light of the main channel range in Charleston Harbour, South Carolina.

One lighthouse on the Atlantic coast of the United States possesses a pathetic and romantic interest. It indicates the treacherous shores around Cape Henry, and mounts sentinel on the headland at the southerly side of the entrance to Chesapeake Bay, Virginia. The stranger on the passing ship, as he scans the dreary bench of sand rising from the water’s edge at this point, has his attention arrested by two gaunt towers. The foremost is almost lapped by the water; the other is some distance to the rear, and upon a higher level. “Two lights, and for what?” is a natural exclamation. But only one tower—that nearer the waves—throws its glare by night. Its companion behind has passed its cycle of utility long since, but it has not been demolished because of its unique history. It was built in 1789 with bricks and stones brought from England. In shape it is a tapering octagonal cone, and when first erected the waves almost washed its base. But the sea, which eats away the rock and soft soil at some parts, casts this débris ashore here, so that Cape Henry is slowly but surely thrusting its dismal tongue of sand farther and farther into the Atlantic. The old tower fulfilled faithful service until the seventies, when, being considered too far from the water, it was superseded by the shaft rising from the sand-dunes below. After a century’s service the old light was extinguished, to permit the fixed white light of the first order in the new tower to take its place.

The new building, completed in 1881, is likewise octagonal in section, gradually tapering from the base to the lantern gallery. It is built upon what is described as the “double-shell principle,” there being two iron cylinders, one within the other. It is 152 feet in height, and the powerful white beam has a range of twenty miles, while a red beam is cast from one side to mark a dangerous shoal. As a powerful flashing white light of a similar character is shed from a tower on Cape Charles opposite, the mariner has a well-illumined entrance into Chesapeake Bay.

Ice was one of the great difficulties against which the American lighthouse builders had to contend, and they laboured valiantly to mitigate this evil. It caused more damage to their works than wind and wave of the most terrifying violence. The upper reaches of the great rivers are encased with thick ice throughout the winter. When the spring comes round, this brittle armour is broken up, and, caught by the current, is swept toward the ocean, the floes jostling and crashing among one another. When the slightest obstruction is offered to their free movement, the pieces mount one another, forming large hummocks, and the pressure thus imposed is terrific. The “ice-shove,” when it assumes large proportions, is quite capable of wreaking widespread damage.

When the screw-pile lighthouses came into vogue, this danger was advanced as one of the greatest objections to the adoption of this idea. It was pointed out that the ice would pack around the slender legs, and either snap them, or would bring about such severe distortion as to imperil the safety of the superstructure. When Major Hartman Bache undertook the erection of the Brandywine Shoal light in Delaware Bay, he determined to frustrate the effects of this peril. The light, being eight miles from the ocean, was right in the path of the ice-shoves of the Potomac, so the nine iron legs upon which the beacon is supported—eight in a circle and one central—are protected by what is known as an “ice-breaker.” This is a pier of thirty iron piles, which likewise are screwed into the sea-bed. Each pile is 23 feet long by 5 inches in diameter, and they are connected at their heads, and at a point just above low-water, by what are known as “spider-web braces.” The result is that, when a shock is inflicted upon one pile, it is communicated throughout the entire breaker. This system has proved entirely successful, and has protected the lighthouse within completely. The main building, although subjected to heavy attacks by the piled ice, has never been damaged thereby, although subsequently it became necessary to strengthen the ice-breaker, because the onslaughts of several winters had left their mark.

Off the coast of Florida, and in the waters of the Gulf of Mexico, this type of lighthouse is very strongly in evidence, as it was found to be the most suitable for the coral sea-bed. The most notable structure of this class is the Fowey Rocks light, which rises, a flame-crowned skeleton, from the extreme northern point of the Florida reefs. It is in an exposed position, where inclement weather is often experienced. At this point there is not more than 3 feet of water, and the spot is as bad as a mariner could wish to avoid, for no ship could hope to escape destruction once it became entangled in these submerged toils.

The building of this light presented many perplexing difficulties, the greatest of which was offered by the weather. The structure is an octagonal pyramid, with the keepers’ quarters on a lower deck, communication with the lantern being afforded by a winding staircase encircling a vertical cylinder. The light is 110¼ feet above high-water, of the fixed type, with red sectors guarding dangerous shoals in the vicinity, while the white beams can be picked up some eleven miles away.

The integral parts of this building were prepared by three different contractors, were fitted together, and the building set up temporarily, on the mainland, so as to facilitate erection at the site. The work was started in 1876, the first move being the provision of a platform about 80 feet square and 12 feet above low-water, from which to conduct operations. The lower piles were driven about 10 feet into the live coral reef. Extreme care was observed during this operation, the pile after every stroke of the driver being tested with a plumb-line, to make sure that it was being sent home absolutely vertically. If it diverged, however slightly, from the perpendicular, the error was corrected immediately. When the piles had been driven to the requisite depth, the tops were levelled to the height of the most deeply driven pile; then the horizontal members were placed in position, followed by the diagonal bracing.