In 1874 the Sandy Hook Proving Ground was established as a weapons testing area, primarily for coast defense weapons.
This was operated by the Ordnance Department and was organizationally separate from Fort Hancock.

In 1890 construction began on the artillery batteries at Fort Hancock, which was named for Major General Winfield Scott Hancock in 1895.
These resulted from the large-scale Endicott Program, which in 1885 proposed a new, comprehensive system of forts defending port cities.
Fort Hancock was one of the first forts built and prototyped several weapon installations.
The first batteries begun at Fort Hancock were Battery Potter and Battery Reynolds (later Reynolds-McCook), initially the "Gun Lift Battery" and the "Sandy Hook Mortar Battery", both of which were built with high walls all around for land defense, a feature not found in most subsequent US installations.

Battery Potter
Battery Potter was the prototype battery for the steam-hydraulic gun lift carriage.
The Endicott Program centered on disappearing guns, which would remain concealed behind a concrete-and-earth parapet until raised to fire.
Most of the weapons in the program were mounted on Buffington-Crozier disappearing carriages.
However, early on there was doubt that this carriage could successfully raise and lower a 12-inch (305 mm) gun.
The alternative developed for this was the gun lift carriage, essentially a barbette carriage mounted on a hydraulic elevator.
A steam plant powered the hydraulic system.
One advantage of the gun lift carriage not found in most US disappearing gun installations was 360° all-around fire.
Battery Potter (known as "Gun Lift Battery No.
1" until named in 1903) received its first gun in 1892 (a 12-inch (305 mm) gun M1888, Watervliet serial no.
11, the first operational gun of the Endicott Program) and was completed in 1894, but for some reason was not accepted for service until 1898, possibly due to extensive testing.
The gun lift system proved expensive to build and operate, as the steam plant had to be running continuously to provide pressure for elevator operation.
Other early 12-inch gun installations were on simple non-disappearing barbette carriages until the M1896 Buffington-Crozier carriage was developed for the 12-inch gun.
 Although a few installations such as Battery Torbert at Fort Delaware were begun as gun lift batteries, these were completed with disappearing guns, and Battery Potter was the only gun lift battery completed.
In 1903 Battery Potter was named for Joseph H. Potter, a Civil War general.
By 1907 several additional batteries were completed at Fort Hancock, and with the construction of Battery Arrowsmith under way to cover its sector, Battery Potter was disarmed.
Three spare gun lift carriages were modified as barbette carriages, designated Altered Gun Lift Carriage M1897, and emplaced at Fort Flagler (2) and Fort Worden (1) in the Puget Sound area of Washington state.

Battery Reynolds
Battery Reynolds (half of which was renamed as Battery McCook in 1906) was a battery of sixteen 12-inch caliber mortars in the "Abbot Quad" arrangement.
This was designed to place the mortars as closely together as possible, in the hope of scoring multiple hits on an enemy ship by firing simultaneously in a bracketing "shotgun" pattern.
The battery had four pits in a square arrangement, with four mortars per pit, also in a square.
The pits were separated by a traverse, which were the ammunition magazines and storages areas that ran the width and breadth of the Battery.
These were built of concrete and backfilled with sand and vegetation.
The entire Battery was surrounded by a high concrete wall covered with earth for land defense.
This arrangement was used at a number of Endicott forts.
However, simultaneously reloading the mortars in each pit proved cumbersome.
Four mortars - the mortar closest to the magazine door in each pit - were removed and emplaced in the adjacent Navesink Highlands.
In later Battery design, the pits were first built with open backs for the four mortars, and then ultimately redesigned to be ar
In 1874 the Sandy Hook Proving Ground was established as a weapons testing area, primarily for coast defense weapons. This was operated by the Ordnance Department and was organizationally separate from Fort Hancock.
In 1890 construction began on the artillery batteries at Fort Hancock, which was named for Major General Winfield Scott Hancock in 1895. These resulted from the large-scale Endicott Program, which in 1885 proposed a new, comprehensive system of forts defending port cities. Fort Hancock was one of the first forts built and prototyped several weapon installations. The first batteries begun at Fort Hancock were Battery Potter and Battery Reynolds (later Reynolds-McCook), initially the "Gun Lift Battery" and the "Sandy Hook Mortar Battery", both of which were built with high walls all around for land defense, a feature not found in most subsequent US installations.
Battery Potter
Battery Potter was the prototype battery for the steam-hydraulic gun lift carriage. The Endicott Program centered on disappearing guns, which would remain concealed behind a concrete-and-earth parapet until raised to fire. Most of the weapons in the program were mounted on Buffington-Crozier disappearing carriages. However, early on there was doubt that this carriage could successfully raise and lower a 12-inch (305 mm) gun. The alternative developed for this was the gun lift carriage, essentially a barbette carriage mounted on a hydraulic elevator. A steam plant powered the hydraulic system. One advantage of the gun lift carriage not found in most US disappearing gun installations was 360° all-around fire. Battery Potter (known as "Gun Lift Battery No. 1" until named in 1903) received its first gun in 1892 (a 12-inch (305 mm) gun M1888, Watervliet serial no. 11, the first operational gun of the Endicott Program) and was completed in 1894, but for some reason was not accepted for service until 1898, possibly due to extensive testing. The gun lift system proved expensive to build and operate, as the steam plant had to be running continuously to provide pressure for elevator operation. Other early 12-inch gun installations were on simple non-disappearing barbette carriages until the M1896 Buffington-Crozier carriage was developed for the 12-inch gun.  Although a few installations such as Battery Torbert at Fort Delaware were begun as gun lift batteries, these were completed with disappearing guns, and Battery Potter was the only gun lift battery completed. In 1903 Battery Potter was named for Joseph H. Potter, a Civil War general. By 1907 several additional batteries were completed at Fort Hancock, and with the construction of Battery Arrowsmith under way to cover its sector, Battery Potter was disarmed. Three spare gun lift carriages were modified as barbette carriages, designated Altered Gun Lift Carriage M1897, and emplaced at Fort Flagler (2) and Fort Worden (1) in the Puget Sound area of Washington state.
Battery Reynolds
Battery Reynolds (half of which was renamed as Battery McCook in 1906) was a battery of sixteen 12-inch caliber mortars in the "Abbot Quad" arrangement. This was designed to place the mortars as closely together as possible, in the hope of scoring multiple hits on an enemy ship by firing simultaneously in a bracketing "shotgun" pattern. The battery had four pits in a square arrangement, with four mortars per pit, also in a square. The pits were separated by a traverse, which were the ammunition magazines and storages areas that ran the width and breadth of the Battery. These were built of concrete and backfilled with sand and vegetation. The entire Battery was surrounded by a high concrete wall covered with earth for land defense. This arrangement was used at a number of Endicott forts. However, simultaneously reloading the mortars in each pit proved cumbersome. Four mortars - the mortar closest to the magazine door in each pit - were removed and emplaced in the adjacent Navesink Highlands. In later Battery design, the pits were first built with open backs for the four mortars, and then ultimately redesigned to be ar
Fort Hancock, New Jersey