Seven Foot Knoll Lighthouse

Seven Foot Knoll Lighthouse. . , Seven-Foot Knoll Lighthouse was the second screwpile lighthouse built by the U.S. Lighthouse Service. It was originally located 15 miles southeast of this location. The 47-foot-high, round, screwpile lighthouse was completed by the Baltimore "ironfounders" firm of Murray and Hazelhurst in 1856 at a cost of more than $30,000. It was construction of rolled-iron plates, drilled and riveted together and supported on nine cast-iron screw-piles. The screwpiles eliminated the need for an underwater masonry foundation., The light at Seven-Foot Knoll marked the outer entrance to Baltimore's busy harbor and was manned until 1948, when the Coast Guard automated it. In 1988, the lighthouse was officially retired and with the help of a barge and 460-ton crane, moved to Pier 5 in Baltimore's Inner Harbor. Today, this National Historic Landmark is managed and maintained by Living Classrooms Foundation with support from the France-Merrick Foundation and other generous founders., [Captions:] , This ca. 1900 image shows the Seven-Foot Knoll Lighthouse in its original location at the mouth of the Patapsco River. Screwpile supports were vulnerable to damage from ice and floating debris. The masonry barrier shown in the image protected the screwpiles from ice flows that moved with the tides. The station was relatively isolated and was resupplied by boats. Lighthouse staff were alloted an extra load of coal to help cope with particularly winter weather at the station., Left: This chart from the 1860's shows the original location of the Seven-Foot Knoll Lighthouse at the mouth of the Patapsco River. The small numbers represent depth soundings.