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
Harbor of Refuge Light, Lewes, Delaware, April 2008
Flickr Creative Commons photo by reivax

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, most of the surviving examples are active lighthouses.

There are 33 surviving sparkplug lighthouses. Here they are, in (approximate) order of completion:

  1. Duxbury (Bug Light), Massachusetts (1871), Plymouth Harbor
  2. Craighill Channel Lower Range Front, Maryland (1873), Chesapeake Bay
  3. Great Beds, New Jersey (1880), New York Harbor
  4. Borden Flats, Massachusetts (1881), Fall River
  5. Bloody Point Bar, Maryland (1882), Chesapeake Bay endangered
  6. Sharps Island, Maryland (1882), Chesapeake Bay endangered
  7. Stamford Harbor (Chatham Rocks), Connecticut (1882), Long Island Sound
  8. Conimicut Shoal, Rhode Island (1883), Providence River
  9. Robbin's Reef (Kate's Light), New Jersey (1883), New York Harbor
  10. Tarrytown (Kingsland Point), New York (1883), Hudson River
  11. Latimer Reef, New York (1884), Fisher Island Sound
  12. Sakonnet, Rhode Island (1884), Rhode Island Sound
  13. Delaware (Lewes) Breakwater, Delaware (1885), Delaware Bay
  14. Detroit River (Bar Point Shoal), Michigan (1885), Lake Erie
  15. Harbor Beach, Michigan (1885), Lake Huron
  16. Saybrook Breakwater, Connecticut (1886), Long Island Sound
  17. Lubec Channel, Maine (1890), Lubec Channel
  18. Goose Rocks, Maine (1890), East Penobscot Bay
  19. Newport News Middle Ground, Virginia (1891), Hampton Roads
  20. Spring Point Ledge, Maine (1897), Portland Harbor
  21. Romer Shoal, New Jersey (1898), New York Harbor endangered
  22. Plum Beach, Rhode Island (1899), Narragansett Bay
  23. Orient Point, New York (1899), Long Island Sound
  24. Hog Island Shoal, Rhode Island (1901), Narragansett Bay
  25. West Bank (Staten Island Range Front), New York (1901), New York Harbor
  26. Greens Ledge, Connecticut (1902), Long Island Sound
  27. Hooper Island, Maryland (1902), Chesapeake Bay
  28. Peck Ledge, Connecticut (1906), Long Island Sound
  29. Cleveland Harbor West Pierhead, Ohio (1911), Lake Erie
  30. Miah Maull Shoal, New Jersey (1913), Delaware Bay
  31. Brandywine Shoal, New Jersey (1914), Delaware Bay
  32. Thimble Shoal, Virginia (1914), Chesapeake Bay
  33. Harbor of Refuge Breakwater, Delaware (1926), Delaware Bay
Duxbury Pier Light
Duxbury Pier (Bug) Light, Plymouth, Massachusetts, August 2009
Flickr Creative Commons photo by David Sugden

Of the 33 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
Tarrytown Light, Tarrytown, New York, September 2009
Flickr Creative Commons photo by Dan Dvorscak

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

Lost Sparkplugs

Here is a list of sparkplug lighthouses that have been lost:

  1. Whale Rock, Rhode Island (1882), Rhode Island Sound, destroyed by the great hurricane of 1938
  2. Deer Island, Massachusetts (1890), Boston Harbor, demolished by the Coast Guard in 1982
  3. Crabtree Ledge, Maine (1890), Frenchman's Bay, destroyed by a storm in the late 1930s
  4. Old Orchard Shoal, New York (1893), New York Harbor, destroyed by Hurricane Sandy in 2012
  5. Rockland Lake, New York (1894), Hudson River, demolished in 1923 after its foundation failed
  6. Sperry (New Haven Outer Breakwall), Connecticut (1900), Long Island Sound, demolished by the Coast Guard in 1933
  7. Sabine Bank, Texas (1906), Gulf of Mexico, demolished by the Coast Guard in 2002
  8. Elbow of Cross Ledge, New Jersey (1910), Delaware Bay, demolished in 1954 after being heavily damaged by collision with a ship

Saving the Sparkplugs

Sharps Island Light
Sharps Island Light, Tilghman Island, Maryland, July 2004
Flickr Creative Commons photo by Craig Bruce

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. The Coast Guard has acted to place many of them under the National Historic Lighthouse Preservation Act process, with mixed results. Because it would be difficult to provide public access, preservation groups have been reluctant to accept ownership of these lighthouses, so many of them are being auctioned off to private owners. Several of these owners have invested heavily in restoring their lighthouses, but others seem overwhelmed by the task and have made little progress.

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. A complete restoration of the lighthouse was nearing completion in 2012.
  • 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.
  • 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 opened to the public for the first time 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.
  • The Noble Maritime Collection, Staten Island, has taken ownership of Robbins Reef (Kate's) Light and is working to restore it.
  • Westchester County and the Village of Sleepy Hollow are working to restore the Tarrytown Lighthouse.

This makes 11 out of 33 sparkplugs under some sort of community-based preservation or preservation effort. Most of the remaining sparkplugs have been sold into private ownership. In a few cases this has worked well: private owners have restored the Borden Flats and Newport News Middle Ground lighthouses, for example. But in many cases the work has been too great for private owners.

As of September 2018 three sparkplugs were on the Lighthouse Digest Doomsday List: Bloody Point Bar, Romer Shoal, and Sharps Island.

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Posted January 16, 2002. Checked and revised September 19, 2018. Site copyright 2018 Russ Rowlett and the University of North Carolina at Chapel Hill.