The History of the Chatham Lighthouse

The Chatham Lighthouse, an iconic landmark on Cape Cod, has a rich history dating back to 1808. Here's a look at its evolution:

Early Years and the "Twin Lights":

• 1808: The original Chatham Light Station was established as the second lighthouse on Cape Cod. To distinguish it from the Highland Light in North Truro, two wooden towers were built about 70 feet apart. These "Twin Lights" also served as a range to help ships navigate the shifting channels. The towers were placed on movable skids, allowing them to be repositioned as needed due to the ever-changing coastline.
• 1841: The wooden towers, having deteriorated, were replaced by two 40-foot brick towers.
• 1857: The brick towers were equipped with Fourth Order Fresnel lenses, using lard oil for fuel.

Erosion and Reconstruction:

• The lighthouse faced significant challenges due to erosion. By the 1870s, the bluff was eroding at an alarming rate, threatening the towers.
• 1877: Two new, more substantial towers were constructed further inland. These were made of cast iron with a brick lining.
• Late 1879 - Early 1881: The old south and north towers succumbed to erosion and tumbled onto the beach.

The End of the "Twin Lights" Era:

• With advancements in rotating lenses, twin lights became unnecessary for navigational purposes.
• 1923: The north tower was moved approximately 12 miles north to Eastham, where it became known as Nauset Light, replacing the last of the "Three Sisters" lights. The remaining south tower at Chatham was fitted with a rotating lens.

Modernization:

• 1939: The U.S. Coast Guard took over responsibility for all lighthouses, including Chatham Light. The light was electrified, and its intensity increased significantly.
• 1969: The original Fresnel lens and lantern room were replaced with a larger lantern housing a modern rotating aero beacon with a much higher candlepower.
• 1982: The lighthouse was automated.
• 1994: New aerobeacons were installed, displaying two white flashes every 10 seconds, visible for 24 nautical miles.

Present Day:

• The Chatham Lighthouse remains an active aid to navigation under the U.S. Coast Guard.
• The site also serves as the headquarters for Coast Guard Station Chatham.
• The original lantern room and Fresnel lens are preserved and on display at the Chatham Historical Society's Atwood House Museum.
• During the summer, the Coast Guard Auxiliary offers tours of the lighthouse.

The Chatham Lighthouse stands as a testament to the evolving technology and the constant battle against the forces of nature on Cape Cod, safeguarding mariners for over two centuries.