Oak Island Lighthouse
Posted by American Lighthouses on 6th Oct 2020
In the town of Caswell Beach, North Carolina, sits a lighthouse that overlooks the Atlantic Ocean and Cape Fear. The name that is given to this lighthouse is, Oak Island Lighthouse. This lighthouse was built in 1958, and it cost around $110,000.00 to have it built.
Many older lighthouses have spiral stair cases that lead to the top of their tower, however, something that makes this lighthouse a little different is, instead of a spiral stair case, it uses several ship ladders. There are 131 steps to get to the lantern gallery.
The lighthouse’s overall structure is 153 feet tall, but it sits on a little hill that gives it an increase of 16 feet in height. The 128 foot, main tower is built out of monolithic reinforced concrete. A concrete mixing plant was set up on site in order to allow work to continue for 24 hours for 7 days straight, when building it. This was necessary for the type of process that was used when making the lighthouse tower.
The walls of the lighthouse are 8 inches thick, and the inside diameter of the lighthouse is about 16 feet and 5 inches. This diameter is consistent from top to bottom. There is a 3 color pattern that is permanently cast into the concrete. The first 40 feet, at the bottom, is gray, which is the natural color of the Portland cement that was used. The middle 50 feet was poured using white Portland cement and they also used white quartz aggregate to give its white color. The top 52 feet was poured using a gray Portland cement again but this time they used black coloring with it. When it came time to put on the 11 foot aluminum lantern housing, they used Marine Corps helicopters.
Oak Island Lighthouse’s light pattern is 4, 1 second flashes every 10 seconds. The lighting fixture in the lighthouse is made up of 8 aero beacon lighting fixtures. It has 4 fixtures on the top and 4 on the bottom. When it was first operating the bottom 4 fixtures used carbon-arc mercury lamps in 36-inch reflectors, something that was adapted from aircraft spotlights used in World War II. This made it the brightest in the United States and second brightest in the world. However in 1962 some changes where made to the upper 4 fixtures and they became the primary beacon, making it so that the bottom 4 fixtures where not used. This meant that it was no longer the brightest in the United States and second brightest in the world. In April of 2010 all the electrical was brought up to the current codes and the incandescent bulbs where replaced with 1000 watt halogen bulbs.
In 2004 the Oak Island Lighthouse and the property around it was given to the town of Caswell Beach. So the town has the job of maintaining the lighthouse and its property. However, the Coast Guard still kept the job of maintaining the lights in the lighthouse.