Sparkplug Lighthouses, 1871-1926

Sparkplug lighthouses are cast iron structures built at offshore locations. The keeper's quarters is a round building, usually three stories in height. The round lantern room sits atop the keeper's quarters, and the whole structure rests on a solid foundation, usually a concrete or stone caisson. The Harbor of Refuge Light at Lewes, Delaware, shown at right, is a typical example. Completed in 1926, it is also the last one ever built. Because of their shape, these lighthouses have come to be called "sparkplugs." Before the day of gasoline engines, they were sometimes called "coffee pots." In many places they were called "bug lights," because at a distance they appeared short and broad, rather like a beetle on the surface of the water. Sparkplugs were prefabricated, brought to the site by barge, and put in place by floating cranes. They were a low-cost solution to the problem of providing offshore lighthouses in the sounds and bays of the northeastern and mid-Atlantic states, where all but three of the surviving examples are located.

Harbor of Refuge Light, January 2007 Creative Commons photo by Mike Mahaffie

Surviving Sparkplug Towers

If sparkplug towers were deactivated, they became maintenance problems and hazards to navigation. Before the recent interest in lighthouse preservation took hold, the Coast Guard quickly demolished deactivated sparkplugs. As a result, all but a few of the surviving examples are active lighthouses.

There are 34 surviving sparkplug lighthouses. Here they are, in (approximate) order of completion:

1. Duxbury (Bug Light) MA (1871), Plymouth Harbor
2. Craighill Channel Lower Range Front MD (1873), Chesapeake Bay
3. Great Beds NJ (1880), New York Harbor
4. Borden Flats MA (1881), Fall River
5. Bloody Point Bar MD (1882), Chesapeake Bay
6. Sharps Island MD (1882), Chesapeake Bay
7. Stamford Harbor (Chatham Rocks) CT (1882), Long Island Sound
8. Conimicut Shoal RI (1883), Providence River
9. Robbin's Reef (Kate's Light) NY (1883), New York Harbor
10. Tarrytown (Kingsland Point) NY (1883), Hudson River
11. Latimer Reef NY (1884), Fisher Island Sound
12. Sakonnet RI (1884), Rhode Island Sound
13. Delaware (Lewes) Breakwater DE (1885), Delaware Bay
14. Detroit River (Bar Point Shoal) MI (1885), Lake Erie
15. Harbor Beach MI (1885), Lake Huron
16. Saybrook Breakwater CT (1886), Long Island Sound
17. Lubec Channel ME (1890), Lubec Channel
18. Goose Rocks ME (1890), East Penobscot Bay
19. Newport News Middle Ground VA (1891), Hampton Roads
20. Old Orchard NY (1893), New York Harbor
21. Spring Point Ledge ME (1897), Portland Harbor
22. Romer Shoal NJ (1898), New York Harbor
23. Plum Beach RI (1899), Narragansett Bay
24. Orient Point NY (1899), Long Island Sound
25. Hog Island Shoal RI (1901), Narragansett Bay
26. West Bank (Staten Island Range Front) NY (1901), New York Harbor
27. Greens Ledge CT (1902), Long Island Sound
28. Hooper Island MD (1902), Chesapeake Bay
29. Peck Ledge CT (1906), Long Island Sound
30. Cleveland Harbor West Pierhead OH (1911), Lake Erie
31. Miah Maull Shoal NJ (1913), Delaware Bay
32. Brandywine Shoal NJ (1914), Delaware Bay
33. Thimble Shoal VA (1914), Chesapeake Bay
34. Harbor of Refuge Breakwater DE (1926), Delaware Bay

Of the 34 lighthouses, all but the first few have very similar, three-story designs. The oldest sparkplug, Plymouth Harbor's "bug light", has only two stories in the keeper's quarters. The Craighill Channel range light has a unique, single-story design. The Great Beds, Jeffrey's Hook, and Borden Flats lighthouses have relatively slender towers which must have provided cramped quarters for the keepers. Over the years the towers gradually became wider to allow for more generous crew space. Tarrytown Light, January 2006; anonymous Creative Commons photo

Hooper Island Light, September 2006 Creative Commons photo by Craig Bruce

Lost Sparkplugs

Here is a list (perhaps incomplete) of sparkplug lighthouses that have been lost:

1. Whale Rock RI (1882), Rhode Island Sound, destroyed by the great hurricane of 1938
2. Deer Island MA (1890), Boston Harbor, demolished by the Coast Guard in 1982
3. Crabtree Ledge ME (1890), Frenchman's Bay, destroyed by a storm in the late 1930s
4. Rockland Lake NY (1894), Hudson River, demolished in 1923 after its foundation failed
5. New Haven Outer Breakwall CT (1900), Long Island Sound, demolished by the Coast Guard in 1933
6. Sabine Bank TX (1906), Gulf of Mexico, demolished in 2002
7. Elbow of Cross Ledge DE (1910), Delaware Bay, demolished in 1954 after being heavily damaged by collision with a ship

Saving the Sparkplugs

Sharps Island, MD; NPS photo by Candace Clifford

Preservation of sparkplug lighthouses is not an easy business. The iron towers rust and deteriorate quickly if they are not painted regularly. The towers are exposed to damage from waves, winter ice, and collision with ships. It was ice that pushed the Sharps Island Light over at a 15° angle in the winter of 1976-77 (see photo at left). A winter storm toppled the former Crabtree Ledge Light in Maine. Rust and decay caught up with the Deer Island Light in Boston Harbor, demolished in 1982. Some of the sparkplugs are close to shore, but most are several miles out in the water, too far for convenient access. Most remain under the ownership and management of the Coast Guard, which (understandably) would prefer to transfer them to local management or replace them with easier-to-maintain skeletal towers. Trying to save these interesting towers will be a major challenge for lighthouse preservationists in the next decade or two. As of mid 2005, three sparkplugs had failed to find new owners through the National Historic Lighthouse Preservation Act process. These three lighthouses, Hog Island Shoal in Rhode Island and Wolf Trap and Newport News Middle Ground in Virginia, may now be sold at auction. In 2002, three sparkplugs were on the Doomsday List: Plum Beach, Sabine Bank, and Sharps Island. Since then, Plum Beach Light has been completely restored and Sabine Bank Light has been demolished. Sharps Island Light remains on the Doomsday List.

Despite these difficulties, there have been a number of successful efforts to preserve sparkplug lighthouses.

• In Plymouth, Massachusetts, Project Bug Light led restoration projects for the Duxbury Light in the mid-80s and again in the mid-90s.
• In Lubec, Maine, public pressure convinced the Coast Guard to restore the Lubec Channel Light in 1993-94 instead of demolishing it.
• At Sakonnet, Rhode Island, the Friends of Sakonnet Point Lighthouse restored the abandoned sparkplug light and reactivated it in 1997.
• In 1999, the Portland Harbor Museum took control of the Spring Point Ledge Light, which is linked to shore by a breakwater, and opened it for guided tours.

Several more preservation efforts are now underway.

• In Michigan, the Harbor Beach Lighthouse and Breakwall Preservation Society is working to preserve Lake Huron's only sparkplug tower.
• In Delaware, the Delaware River and Bay Lighthouse Foundation has taken ownership of the Harbor of Refuge Light and is working to restore the building. Since 2003 the lighthouse has been open for public tours. In 2004, DRBLHF expanded its preservation efforts to include the nearby Delaware Breakwater Light, and that light is opening to the public in the summer of 2005.
• In Rhode Island, the Friends of Plum Beach Lighthouse carried out in 2003 the difficult task of restoring and reactivating a sparkplug tower inactive for nearly 60 years.
• The city of Warwick, Rhode Island, received the title to Conimicut Light in September 2004 and is moving ahead with plans for restoration.

This makes 9 out of 34 sparkplugs under some sort of preservation or preservation effort. The Coast Guard will be moving to divest sparkplug lighthouses as quickly as possible under the National Lighthouse Preservation Act, so it will necessary to generate many new preservation efforts over the next few years.

Return to the Lighthouse Directory index

Posted January 16, 2002; revised May 29, 2005. Site copyright 2005 Russ Rowlett and the University of North Carolina at Chapel Hill.