The Endicott Board
The period following the Civil War saw revolutionary improvements in artillery, particularly in Europe. Smoothbore, muzzleloading guns of iron that used black powder were replaced by rifled, breechloading guns made of steel and firing smokeless powder. Annual reports of the United States chief of engineers in the early 1880s reflect the opinion that these new weapons had made American coast defenses, once the strongest in the world, obsolete. A West Point professor writing at the time noted that the forts had become, "not only weak, but absolutely more dangerous to the defenders than to the enemy." A hit from a modern ship's gun would have turned Fort Adam's granite walls into splinters as deadly as shrapnel.
Recognizing this weakness, Congress added a provision to its 1885 Fortifications Appropriation Act requiring the president to appoint a special board similar to the earlier Bernard Board to study the issue of coast defense. In May of that year, President Grover Cleveland appointed a board headed by his secretary of war, William Crowninshield Endicott. The board, which included civilians as well as military and naval officers, became known as the Endicott Board. The board issued a comprehensive report in January 1886 that recommended a coast defense system consisting of modern ordnance mounted in up-to-date concrete fortifications. Implementing the board's report represented an incredible challenge. At the time, for example, the United States had no ordnance facility capable of manufacturing such modern steel artillery pieces. The cost of implementing the board's recommendations was estimated at $126,377,800, a figure that shocked Congress. Rather than implement parts of the report's recommendations, Congress failed to enact a fortifications appropriation at all for the next two years. Once started, work proceeded slowly, but was given an impetus by the outbreak of the Spanish-American War and scares of bombardments by the Spanish fleet along the eastern seaboard.
Construction of the new system required the cooperation of several branches of the Army, the engineers who designed and built the fortifications, the ordnance experts who designed the guns and supervised their emplacement, and the artillerymen who manned the guns. The artillery had not yet split into field artillery and coast artillery. The engineers were forced to balance cost against protection in designing the new forts. As a result, they once again rejected armored casemates and turrets-which afforded gun crews great protection-in favor of open emplacements of concrete banked on the sides facing the enemy with thick layers of earth and sand. This type of fortification offered reasonable protection from direct fire that would be expected from an enemy ship. Such emplacements had the added advantage of being very difficult to spot from the sea. Added protection was expected from the manner in which the new guns were to be mounted.
Armament for the new coast defense system can be grouped into four classes. First, large caliber guns would perform the traditional role of attacking enemy warships. Designers of the gun batteries were confronted with the problem of protecting the gun crews from enemy fire. Having rejected armored casemates and turrets because of cost, engineers found a compromise solution in the form of a gun mount known as the disappearing carriage. The disappearing carriage was a complex mechanism that allowed a gun's barrel to project over a high concrete parapet for firing. When fired, the gun's recoil caused it to descend below the parapet where the crew could load the next round. In the loading position, the crew was protected from direct fire by the concrete parapet and as much as forty feet of sand and earth in front of it. While providing relatively cheap protection, disappearing carriages had several important weaknesses. Obviously they offered no overhead protection. Additionally, technical considerations limited both the traverse and the range of guns mounted on this type of carriage. To overcome this disadvantage, some guns continued to be mounted on barbette mounts. Second, were seacoast mortars. Instead of firing directly at an enemy ship as would a gun, a mortar lofted a large caliber shell toward an enemy ship along a high trajectory. Rather than hitting a ship on the side, where the armor was thickest, a mortar shell would pierce the ship's relatively weak deck and explode deep within the vessel. The mortars' high trajectory also allowed them to be emplaced well back from the shore line where they were relatively protected from the flat trajectory fire from ships' guns. Because the target could not be seen by the gunners, however, mortars required a sophisticated system of observation and fire control. Third, were electrically-fired mines, which had assumed an increasingly important role in coast defense. Finally, small-caliber, rapid-fire guns were developed to deal with a new threat, the swift torpedo boat that could sneak into an anchorage and wreak havoc. These guns could also cover minefields to prevent an enemy from sweeping them.
The Endicott Board recommended twenty-seven ports be protected under the new system. New York and Boston were first and third in order of priority.