Battery Key

Battery Key. . , Battery Key is a concrete emplacement that housed eight 12-inch mortars mounted on carriages. The battery was named for Francis Scott Key who wrote the Star-Spangled Banner. The mortars were installed at Fort Howard in 1898 in two pits of four mortars each. The pits are separated by the main battery structure which housed a power plant and the munitions storage area. The battery was deactivated in 1927., Any large enemy vessels attempting to approach Baltimore on the Patapsco would have been confined to the narrow shipping channel dredged into the bottom of the river. Of course the mortars of Battery Key were well practiced in targeting that channel. There is very little chance that any battleship or cruiser of that era could have survived the steel rain that Battery Key would have poured on her., The 1890 Model 1 (M1) twelve-inch mortar was the most common type emplaced to defend U.S. harbors. The mortar and its carriage weighed sixty-eight tons and fired projectiles that weighed from seven hundred to one thousand pounds. (See the blue box in the illustration below). The shells had heavy, hardened steel caps designed to pierce a ship's armor before exploding. These mortars fired at an elevation of forty-five degrees, had a maximum range of six miles. The high arcing path traveled by these projectiles brought them down on the target at a steep angle. This "plunging fire" was intended to pierce the deck of a ship where the armor was the lightest., Fort Howard had eight mortars in two pits. Originally, the tactical plan was for all of the mortars to fire shells at the same time. These volleys were thought to increase the chance of a hit on the target. As you can see in the inset image above, the battery floor became very congested when all four mortars were fired at the same time. That volume of fire was later determined to be unnecessary and the mortars were subsequently aimed and fired separately. In addition to the elevation of its tube, the mortar's range was determined by the size of the powder charge that was loaded into its breech behind the shell. The image far left shows a full powder load of ten six-pound bags. Bags could be removed from the load as the distance to the target decreased.