In 1896, half of the soldier barracks and a set of officers' quarters were demolished inside the fort. The parade ground was excavated and thousands of piles were steam driven, to support a foundation for a concrete three-gun battery as a way to modernize the defenses protecting ports along the Delaware River. Construction halted for a brief period before resuming in August 1897. This main battery was designed by Army engineer Lt. Col. Charles W. Raymond, assisted by Lt. Spencer Cosby. The new Endicott structure was a three-story reinforced concrete emplacement, which was built from 1894 to 1900 to support three 12-inch breech-loading rifled guns on disappearing carriages. These guns, mounted in 1900, had a range of approximately 10 miles. The three-gun battery, later named Battery Torbert after Maj. Gen. Alfred Torbert, is one of two three-story Endicott batteries in the United States, the other being Battery Potter, with unique gun-lift carriages, at Fort Hancock, New Jersey. The unusual height of Battery Torbert was due to being initially designed for gun-lift carriages. On top of the fort, flanking the 12-inch battery, were two smaller rapid-fire batteries, which protected the short-range sectors around the island and the mine field. These positions were later named Battery Allen and Battery Alburtis, and were armed with two 3-inch M1898 guns on retractable masking parapet mounts each. They were built in 1899 and accepted for service in 1901. Outside of the fort, engineers built additional rapid-fire batteries, which were later named Battery Dodd and Battery Hentig. Battery Dodd was added as an emergency measure after the outbreak of the Spanish–American War in 1898. It had two 4.7-inch 40 caliber guns purchased from the United Kingdom; at that point few of the Endicott batteries were complete and it was feared the Spanish fleet would bombard the US east coast. The battery was completed in 1899, after the war was over. Battery Hentig had two 3-inch M1903 guns and entered service in 1901.