Battery Harris

Battery Harris. . , Battery Harris is a concrete gun emplacement that housed two rapid-fire five-inch rifled guns mounted on balanced pillar carriages. The battery was completed in 1900 and was named for Col. David Harris, the commander of an American artillery regiment during the British attack on Baltimore in 1814., Coincidence Range Finder. Originally, Battery Harris had two five-inch gun emplacements. After the guns were removed in 1917 a Coincidence Range Finder station was constructed in the north side emplacement. This station was linked to the three-inch rapid-fire guns of Batteries Lazear and Claggett., For the guns of a coast artillery fort to be effective, the gun crews had to know their distance from the enemy ships. Determining those distances was the responsibility of the soldiers manning the range finding stations. The concrete structure on the left side of Battery Harris was one of those stations. It housed a Coincidence Range Finder (CRF)., As you can see in the picture above, a CRF has a single eyepiece located in the center of the instrument. Images of the target enter the range finder through two windows located at either end of the instrument. those two images are reflected to the center where a prism turns the light toward the eyepiece. The operator adjusts the images until they come into focus as one image. At that point the images are said to be "in coincident". The operator can then determine the distance to the target by triangulating the angles between the two windows and the target., [Captions:] , Each of Battery Harris' guns had an eighteen-foot barrel and weighed twenty-four tons. The image above shows members of a gun crew transporting ammunition from storage to the breech of the gun by hand. The eighty-pound rounds contained the projectile, propellant powder and a primer., The pillar that the gun was mounted on could be cranked up above the parapet when firing and cranked down when inactive., The rapid-fire five-inch guns of this battery and the three-inch guns of Batteries Lazear and Clagett were intended to engage and destroy fast torpedo boats (see the image below), mine sweepers and landing craft that could venture out of the shipping channel and into shallow water near the shore.