Historic Structures

Great Captain Island Lighthouse, Greenwich Connecticut

Date added: October 20, 2017 Categories: Connecticut Lighthouse

In the years just before and after the Civil War, the Lighthouse Board, the agency established in 1852 to oversee the nation's navigational aids, undertook a program to modernize the lighthouse system. Many of the existing lighthouses were in poor structural condition, with inadequate lights and poorly trained keepers. The Board replaced the mirrored lamps found in nearly all its lighthouses with modern Fresnel lenses, issued detailed standards for operating the lights, and began replacing the worst structures with substantial new buildings. The first light at Great Captain Island, which had been built in 1830, was plagued by deteriorating mortar and cracked walls almost from the start, so it was a priority for replacement by the late 1860s. Because several other lights were being rebuilt at the same time, the Board turned to a single standardized design for six lighthouses in the Long Island Sound area. Such standardization itself became one of the central practices of the lighthouse service in the late nineteenth century. By designing nearly identical structures, the Board saved time and money at the design stage and achieved some economies of scale in the use ofmaterials. Equally important, the Board's standardized design made it more likely that the new lights would perform better than the old.

This lighthouse design incorporated many significant new features. Like earlier lighthouses, it used substantial masonry construction to provide a bulwark against the ravages ofwind and sea, but in combining the dwelling with the tower, it not only saved material but also made it easier for the keeper to attend the light. This had been a problem with earlier lighthouses, most of which had a separate keeper's house: it was hardest to reach the light in stormy weather, just when the light was needed the most. The new design also made use of iron-plate construction for the tower. In this way it prefigured in a partial way the lights ofthe 1880s, which were entirely prefabricated from iron at a great savings in design, fabrication, and erection. The orb finial on the tower provided ventilation for moisture, combustion products from the lamp, and mercury vapors emitted by some rotation mechanisms. Ventilation was important not only for the keeper's health but also to avoid damage to the optics and structural deterioration caused by fumes and moisture. Finally, the architectural elaboration of the structure ~ the quoins, cornice moldings, and portico ~ while not of any particular architectural style, convey a well-built, carefully designed, substantial appearance intended to present a contrast to the deficient earlier lighthouse structures. Although it no longer has its original optics, Great Captain Island Light retains all ofits historical form, materials, and architectural details and thus stands as a well-preserved example of the standard lighthouse construction of the 1860s. Other lighthouses of this design, all in this area and built in 1867 and 1868, include Norwalk Island and Morgan Point, Connecticut; Old Field Point and Plum Island, New York; and Block Island North, Rhode Island. The lighthouses differ only in minor details, such as the placement ofthe rear ell and the height ofthe basement story.

The 1868 replacement for the original lighthouse on Great Captain Island came about because the rapid deterioration of the 1830 tower endangered a vital navigational aid. Great Captain Island was one of seven major lights which marked the main ship channel through Long Island Sound. Vessels leaving New York would use these lights as a guide to their progress, navigating past each one in turn until reaching the eastern end ofthe Sound. Also, Great Captain Island is the outermost ofseveral islands and shoals which lie offthe coast of Connecticut. With smaller islands and numerous rocks to the east and Bluefish Shoal to the west, the lighthouse served to warn vessels away from certain ruin.

With the growth ofNew York City, the tremendous expansion of commerce which occurred as America industrialized, and the advent ofsteam powered vessels, it became ever more important to establish reliable navigational aids. Throughout the nineteenth century, the tonnage of shipping in Long Island Sound increased. Not only were there more ships using this waterway, but steam-powered vessels (which as early as 1850 made up 15% of the shipping) were larger and faster, making them more endangered by the numerous hazards lying along the edges ofthe shipping lanes. Great Captain Island Lighthouse thus stands as a symbol of the historical development of maritime commerce in Long Island Sound. On a more local level, the lighthouse also recalls the days when the nearby harbors of Connecticut were busy with packet ships, schooners carrying coal and other bulk materials for local industries, oyster boats, and pleasure craft. Great Captain Island Lighthouse was a major landmark for approaching Greenwich, Cos Cob, Greenwich Cove, and Stamford harbors.

Originally, the lantern on Great Captain Island Lighthouse contained a fourth-order Fresnel lens with a mineral oil-fired lamp. This unit was built by L. Sauter & Company of Paris, France. The beacon's focal plane was 73 ft above sea level, from which, according to nineteenth century charts, it could be seen at sea 14 nautical miles away. The Fog Signal House was constructed about 1890. It originally contained two duplicate sets of coal-fired boilers, steam engines, and Tyfon fog whistles that ran on 45 lbs of steam pressure. Fresh water for the lighthouse and the steam boilers was drawn from underground cisterns. The Oil House was built about 1905 to house tanks for fuel oil, which replaced coal as a fuel for the steam engines.

Due to rising costs associated with operating and maintaining offshore lighthouses, the U.S. Coast Guard began to plan for the replacement of the beacon at Great Captain Island during the late 1960s. The facility was discontinued as a manned aid-to-navigation on January 30, 1970. The beacon in the lighthouse was replaced by one on a steel tower, and automated fog signal, generator, radio, and electrical equipment was installed in the Fog Signal House. An electrical transformer was installed in the Oil House. On August 15, 1973, the Coast Guard sold the lighthouse parcel to the Town of Greenwich, which installed a resident caretaker in the structure. The Coast Guard retained an approximately .3-acre fenced parcel containing the modern light tower, Fog Signal House (now called the Sound Signal Building) and the Oil House (now called the XFMR Transformer Building). Great Captain Island Lighthouse was listed in the National Register of Historic Places on April 3, 1991.