Battery Decauter

Commodore Stephen Decatur (Library of Congress photo)

"Battery Decatur, formerly known a Emplacement "B" was changed to its present name by General Order 43 dated April 4, 1900." This was the first modern artillery position built for the Defense of Washington. Battery Decatur is named in honor of Commodore Stephen N. Decatur, a native of Maryland who served with distinction during the War with Tripoli and the War of 1812.


Lieutenant Colonel Peter C. Haines was the engineer officer assigned to the Defenses of Washington. Plans for Emplacement "B" were approved in July 1891 and work began immediately. There was no approved plan for a 10-inch battery so those for an 8-inch battery were used for the initial work. The foundation was laid out, personnel assigned and engineering equipment collected at the site. In August, concrete specifications were released and excavation began in September. Construction continued until the fall of 1893 when it was suspended to await specifications for a 10-inch disappearing carriage. The plans were received in July 1895 and active operations began September 26, 1895. By then a small gauge railroad hauled supplies from the dock and a concrete mixing machine was set up at the battery site. The guns and carriages were received in 1896.


Troops were sent from Washington Barracks to mount the guns. In January 1897, Battery G, 4th U.S. Artillery mounted the gun and carriage at position number two. Battery I, 4th U. S. Artillery mounted gun number 1 in February 1897. Battery Decatur cost $128,492.00 when the it was formally turned over to the artillery garrison on July 6, 1899.

10-inch gun on disappearing carriage (NPS drawing)


Battery Decatur was armed with two Model 1888 breech-loading rifles on disappearing carriages. Over 30 feet long, these guns weighed 67,200 pounds and used smokeless powder to fire a 575-pound shell for a distance of 6½ miles. The 196,000-pound carriage was visible above the concrete parapet for only a few minutes. When fired, recoil energy pushed the gun back and downward so that it disappeared from the enemy's view. The recoil motion also raised 73,000 pounds of weight suspended in a pit below the gun. The weights were locked in place while the gun was loaded and when released, they raised the gun back to the upright position where it could be fired immediately. Forty-five feet of concrete and 53 feet of earth protected the crew while they reloaded.

Decatur's guns could fire 15 rounds per hour or approximately one round every 4 minutes. The rate of fire and accuracy was greatly improved with the installation of the fire control system and projectile hoist. By the end of the Coast Artillery period, disappearing guns could fire one round every 15 seconds, or 240 rounds an hour.

Platform connecting gun platforms (Photo by Roy V. Ashley)


In 1902, Battery Decatur was placed out of commission and underwent major alterations to the carriage and modifications to the structure and grounds. A wood staircase, at the south end of the battery was rebuilt, doors were repaired, manhole covers replaced, and floors refinished to improve drainage. Work on a 9-foot platform to connect the two gun positions started in 1903. Chain projectile hoist and electric storage batteries were added in 1904 along with a continuous chain ammunition hoist. In May and June 1905, the battery was turned over to the artillery for use during the joint Army-Navy Exercise. Although the modifications were not completed, the overall appearance of the freshly painted battery had changed. Just before turning the structure over to the artillery, the loading cranes were removed and shot trucks issued for loading the guns.

Moving shell to the gun (NPS drawing)
Coast Artillery Insignia


A Coast Artillery Company consisting of the three officers and about 90 enlisted men was assigned to serve each 10-inch battery. The company was further divided into a fire control (or Range) section and two gun sections. The Range Section operated the plotting board and observation stations while each Gun Section was responsible for the complete service of one gun. Part of the Gun Section was called the ammunition crew and worked in the magazines deep inside the structure. The gun crew served the gun on the platform above.

Battery A, 4th U. S. Artillery was the first company to serve Battery Decatur. They arrived on July 21, 1897 and remained seven years until 1904. The battery was renamed 37th Company, Coast Artillery Corps while they were stationed at Fort Washington. On October 15, 1909, the 119th Company, C.A.C. joined Fort Washington and was assigned to Battery Decatur. The 119th Company served until May 22, 1914 when they were transferred to the Panama Canal Zone.

Phone booth and stairs leading to loading platform (Photo by Roy V. Ashley)


Battery Decatur was constantly improved and updated until 1911. The latest equipment was incorporated into the battery as soon as it became available. From 1912 to 1917 preservation and repairs made up most of the engineer's work at Fort Washington. On January 8, 1904, the post commander was ordered to install uniform white signs on each named battery. The black letters of the sign were to be 6 inches tall.

In 1898 the superior slope was painted with a mixture of alum, lye, cement and lamp black. It was recommended that a plank walkway be laid over this mixture when it was dry so the guard could walk across it without damaging the waterproof surface. Later, the vertical surfaces were painted green and horizontal surfaces painted black to reduce heat and glare caused by reflections off the white concrete.

The ground in front of the battery was maintained to resemble a natural earth slope and care was taken to insure that the exact position of the battery was not easily ascertained from the water. For most of the history of the battery, you could see the river from the gun platforms. In 1898, shrubs and small trees were planted in front of the battery and cedar trees added later the same year. The shrubs masked the exact location of the guns and made the area appear as a garden attached to the Commandant's House. In 1901, the upper branches of the trees, in front of the battery, were trimmed to open a field of view for the range finders. The trees were trimmed again in 1905 and an attempt to control the growth was continued throughout the structure's history.

Battery Commander's Station (Photo by Roy V. Ashley)


A coast artillery battery includes the structures and surrounding grounds used for the emplacement, protection and service of the guns. Battery Decatur's, structures include the Battery Commander's station and lower parade behind the battery. The commander's station houses the instruments for directing the two guns at Battery Decatur. The range crew uses a position finder to determine the vertical angle to the target. They use the angle to find the distance and combine it with the horizontal angle to compute the azimuth and elevation for the gun.

Land defenses at south caponiare (Photo by Roy V. Ashley)


Two unique characteristics of this battery are the land defense rifle ports of the south caponaire and the sunken "road to nowhere" behind the structure. There is no record of why the engineers felt that rifle portholes were necessary but we do know that galvanized iron shutters were placed over the caponaire embrasures in July 1900. The sunken road was originally designed to connect Battery Decatur with the gatehouse of the old fort and the 12-inch battery planned for the south end of the parade ground. The 12-inch battery was not built so the road was never finished.

Battery Decatur was the first modern artillery position constructed for the defense of Washington. When the Spanish American War began in April 1898, this battery and three smooth bore guns in front of the old fort were the only protection for Washington. On February 9, 1897 Battery Decatur also became the first gun fired when four shots were fired up river. Battery Decatur's guns were dismounted in 1917 and sent overseas for use as railroad guns in Europe. The mixture of two different types of concrete and use of river sand has caused this 100-year-old structure to age rapidly. Today, only broken concrete remains to remind us of Battery Decatur's 20-year service to the protection of Our Nation's Capital.

Battery Decatur (Photo by Roy V. Ashley)

Last updated: April 10, 2015

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