Thomas Point Shoals Light Station, Annapolis Maryland
Resigned by staff professionals of the U.S. Lighthouse Service, Thomas Point Lighthouse is the last of the manned screwpile, off-shore lights on the Chesapeake Bay. The principle of the screwpile design was first introduced in England in 1838 and later used in the United States in 1854. This method of anchoring a lighthouse was simple, effective, inexpensive and most appropriate for the sandy and muddy bottom of the Chesapeake Bay.
Constructed in 1875 the structure remains virtually intact. The splat baluster railings, the shaped dormer rafter projections and the steel octagonal cupola (bearing the inscription "Atlantic Steam Engine Works, Brooklyn, New York, 1875") are architectural features of interest.
Robert de Cast in The Lighthouses of the Chesapeake gives a date as early as 1825 for the establishment of a light at Thomas Point. The location was a narrow neck of land at the mouth of the South Rivet which is now ' under water. Charts of the area show a lighthouse on the site as early as 1846. The present structure has stood on the shoal since commissioned on 20 November 1875.
The Thomas Point Lighthouse was built on five acres conveyed by the State of Maryland on 28 October 1874. The conveyance of a Use and Occupancy Deed from Governor James Black Groome was authorized by an Act of the Maryland General Assembly of 6 April 1874 which read: "An Act to provide for the relinquishment to the United States in certain cases of title to and jurisdiction over lands for sites of lighthouses, beacons and other aids to navigation, and for the protection of beacons, buoys and floating guides on the Coast and in the Waters of this State."
Thomas Point Shoals Light, standing at the confluence of the South River and Chesapeake Bay, is a hexagonal white wood frame house (18' on each side) supported on a steel framework of nine screw piles. These piles are so called because each is tipped with two blades arranged screw fashion.
The 1 1/2 story house, with light tower and living quarters, is covered with moulded wood siding and a metal roof. The roof is topped with six large dormer windows and a steel octagonal cupola containing the light. The cupola panes are rectangular.
The lighthouse stands in seven feet of water between two areas of stone rip-rap. The height of the focal plane is 43 feet above mean low water. At its base is a steel snow-plow blade for deflecting the ice coming from the north or upper Chesapeake Bay.
The light source is now from a 250 watt electric bulb receiving primary power from an underwater cable. The original light source was probably a Kerosine lamp. The original fourth order fixed glass lens is intact. The brass frame is embossed with the name of the French manufacturer. The light characteristic is flashing white every 6 seconds with red sectors. The rated intensity is 6000 candlepower and the range, 11.9 miles (white).
The fog signal, audible for two miles, is one two second blast every 15 seconds at a frequency of 300 Hz.
The lighthouse remains as built in 1875 with only minor and superficial alterations.