Disappearing gun
Encyclopedia
A disappearing gun is a type of heavy (mainly coastal) artillery
for which the gun carriage enabled the gun to rotate backwards and down into a pit protected by a wall (the parapet) or a bunker
after it was fired. This retraction lowered the gun from view by the enemy while it was being reloaded.
It also made reloading easier, since it lowered the breech to a level just above the loading platform, and shells could be rolled right up to the open breech for loading and ramming. Although it had these advantages, the disappearing carriage was also a complicated mechanism. In the U.S., disappearing carriages were mostly withdrawn from active service by the early 1920s.
The disappearing gun was usually moved down behind the parapet or into its protective housing by the force of its own recoil, which (on many models) lifted up a very heavy counterweight. Before firing, the crew tripped a catch on the counterweight, causing it to fall into a well at the center of the gun position and move the gun back up "into battery" (firing position).
Some disappearing guns also used compressed air, while a few were built to be raised by steam.
to improve on existing designs for a gun carriage capable of rising over a parapet
before being reloaded from behind cover. His key innovation was a counterweight
system that raised the gun as well as controlled the recoil
. Moncrieff promoted his system as an inexpensive and quickly constructed alternative to a more traditional gun emplacement.
Buffington
and Crozier
further refined the concept in the late 1880s by incorporating hydro-pneumatic recoil control to assist the counterweight action. The Buffington–Crozier Disappearing Carriage (1893) represented the zenith of disappearing gun carriages, and guns
of up to 16-inch size were eventually mounted on such carriages. Disappearing guns were highly popular for a while in the British Empire, the United States and other countries.
However, in the 1890s, a series of Royal Navy
/New Zealand Division of the Royal Navy
trials carried out in New Zealand
(where numerous disappearing guns had been bought and installed during the Russian Scares
), revealed the virtual impossibility of a small shore installation being hit by a warship, except by chance. Others dispute that the advantages were so limited, and point to the efficiency of such artillery in for example, the Battle of Port Arthur
. In any case, with their protective benefits thus cast into doubt, no further production of the expensive gun carriages was undertaken in New Zealand.
Though effective against ships, the guns turned out to be vulnerable to aerial attack. After World War I
batteries
of disappearing guns were usually casemate
d for protection or covered with camouflage
for concealment. By 1912, the guns were declared obsolete in the British Army, with only some other countries, particularly the United States
, still producing them up to World War I and keeping them active through to the end of World War II
.
at Fort Hancock
, Sandy Hook
, New Jersey
. Built in 1892, the Battery covered the approaches to New York harbor
. Instead of using recoil from the gun to lower the weapon, two 12-inch barbette carriages were placed on individual hydraulic elevators that would raise the 110-ton carriage and gun 14 feet to enable it fire over a parapet
wall. After firing, the gun was lowered for reloading using hydraulic ramrods and a shell hoist. While the operation of the battery was slow, taking 3 minutes per shot, its design allowed an unlimited field of fire.
Battery Potter required a huge amount of machinery to operate the gun lifts, including boilers, steam pressure pumps and two accumulators. Due to the inability to generate steam quickly, Potter's boilers were run nonstop during its 14 year life, creating a significant operating cost. After the proving of the Buffington Crozier carriage, the United States Army
abandoned plans to build several additional gun lift batteries.
was completed in 1877 with two disappearing gun turrets sinking down into barbette
-structures (basically circular metal protective walls over which the gun fired when elevated). This was to combine the ability of the early pivot gun
s to swivel with the protection of more classical fixed naval guns. However, the design was not successful and apparently never repeated. It is thought that both harsh saltwater environment and the constant swaying and rolling of a ship at sea were to blame for problems with the complex mechanism. In any case, heavy gun turret
s soon afterwards entered naval service, making the idea moot.
Artillery
Originally applied to any group of infantry primarily armed with projectile weapons, artillery has over time become limited in meaning to refer only to those engines of war that operate by projection of munitions far beyond the range of effect of personal weapons...
for which the gun carriage enabled the gun to rotate backwards and down into a pit protected by a wall (the parapet) or a bunker
Bunker
A military bunker is a hardened shelter, often buried partly or fully underground, designed to protect the inhabitants from falling bombs or other attacks...
after it was fired. This retraction lowered the gun from view by the enemy while it was being reloaded.
It also made reloading easier, since it lowered the breech to a level just above the loading platform, and shells could be rolled right up to the open breech for loading and ramming. Although it had these advantages, the disappearing carriage was also a complicated mechanism. In the U.S., disappearing carriages were mostly withdrawn from active service by the early 1920s.
The disappearing gun was usually moved down behind the parapet or into its protective housing by the force of its own recoil, which (on many models) lifted up a very heavy counterweight. Before firing, the crew tripped a catch on the counterweight, causing it to fall into a well at the center of the gun position and move the gun back up "into battery" (firing position).
Some disappearing guns also used compressed air, while a few were built to be raised by steam.
Advantages
The disappearing carriage had several principal advantages:- It afforded the gun crew protection from direct fire by raising the gun over the parapet (or wall in front of the gun) only when it was to be fired, otherwise leaving it at a lower level, where it was also able to be loaded easily.
- With its guns in a retracted position (down behind the parapet), the battery was much harder to spot from the sea, making it a much harder target for attacking ships. Flat trajectory fire tended simply to fly over the battery, without damaging it.
- Interposing of a moving fulcrum between the gun and its platform lessened the strain on the latter and allowed it to be of lighter construction while limiting recoil travel.
- Simple, well protected earthen and masonry gun pits were much more economical to construct than the previous practice of constructing the standing heavy walls and fortified casemateCasemateA casemate, sometimes rendered casement, is a fortified gun emplacement or armored structure from which guns are fired. originally a vaulted chamber in a fortress.-Origin of the term:...
s of a more traditional gun emplacement. - The entire battery could be hidden from view when not in use, unlike a traditional fort, enabling ambuscade fire.
Disadvantages
The disappearing gun had several drawbacks as well:- The carriage design restricted maximum elevation to under 20 degrees and thus lacked the necessary range to match newer naval guns entering service during the early part of the 20th century. The additional elevation gained by mounting the same gun on a later non-disappearing carriage increased their range.
- The time taken for the gun to swing up and down and be reloaded slowed the rate of fire. Surviving records indicate a rate of fire of 1 round per 1 to 2 minutes for an 8-inch (20 cm) gun, significantly slower than less complicated guns.
- The improvement in the speed of warships demanded an increased rate of firing. The disappearing gun was at a disadvantage compared with a gun that stayed in position as one could not aim or reposition a disappearing gun while it was in the lowered position. The gunner still had to climb atop the weapon via an elevated platform to sight and lay the weapon after it was returned to firing position.
- Their relative size and complexity also made them expensive compared with non-disappearing mounts.
History
Disappearing guns as a functioning concept were invented in the 1860s by Captain (later Sir) Alexander Moncrieff, who built on his observations in the Crimean WarCrimean War
The Crimean War was a conflict fought between the Russian Empire and an alliance of the French Empire, the British Empire, the Ottoman Empire, and the Kingdom of Sardinia. The war was part of a long-running contest between the major European powers for influence over territories of the declining...
to improve on existing designs for a gun carriage capable of rising over a parapet
Parapet
A parapet is a wall-like barrier at the edge of a roof, terrace, balcony or other structure. Where extending above a roof, it may simply be the portion of an exterior wall that continues above the line of the roof surface, or may be a continuation of a vertical feature beneath the roof such as a...
before being reloaded from behind cover. His key innovation was a counterweight
Counterweight
A counterweight is an equivalent counterbalancing weight that balances a load.-Uses:A counterweight is often used in traction lifts , cranes and funfair rides...
system that raised the gun as well as controlled the recoil
Recoil
Recoil is the backward momentum of a gun when it is discharged. In technical terms, the recoil caused by the gun exactly balances the forward momentum of the projectile and exhaust gasses, according to Newton's third law...
. Moncrieff promoted his system as an inexpensive and quickly constructed alternative to a more traditional gun emplacement.
Buffington
Adelbert Rinaldo Buffington
-Biography:He was born at Wheeling, West Virginia, and graduated at West Point in May 1861 . He was brevetted major in 1865, and was commander successively of the United States ordnance depots at Wheeling, W. Va., and of the arsenals in New York, Baton Rouge, Watertown, Mass., Watervliet,...
and Crozier
William Crozier (artillerist)
William Crozier was an American artillerist and inventor,-Biography:Born at Carrollton, Ohio on February 19, 1855, was the son of Robert Crozier , Chief Justice of Kansas in 1863-1866, and a United States senator from that State from December 1873 to February 1874...
further refined the concept in the late 1880s by incorporating hydro-pneumatic recoil control to assist the counterweight action. The Buffington–Crozier Disappearing Carriage (1893) represented the zenith of disappearing gun carriages, and guns
Artillery
Originally applied to any group of infantry primarily armed with projectile weapons, artillery has over time become limited in meaning to refer only to those engines of war that operate by projection of munitions far beyond the range of effect of personal weapons...
of up to 16-inch size were eventually mounted on such carriages. Disappearing guns were highly popular for a while in the British Empire, the United States and other countries.
However, in the 1890s, a series of Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...
/New Zealand Division of the Royal Navy
Royal New Zealand Navy
The Royal New Zealand Navy is the maritime arm of the New Zealand Defence Force...
trials carried out in New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
(where numerous disappearing guns had been bought and installed during the Russian Scares
Panjdeh Incident
The Panjdeh Incident or Panjdeh Scare was a battle that occurred in 1885 when Russian forces seized Afghan territory south of the Oxus River around an oasis at Panjdeh . The incident created a diplomatic crisis between Russia and Great Britain...
), revealed the virtual impossibility of a small shore installation being hit by a warship, except by chance. Others dispute that the advantages were so limited, and point to the efficiency of such artillery in for example, the Battle of Port Arthur
Battle of Port Arthur
The Battle of Port Arthur was the starting battle of the Russo-Japanese War...
. In any case, with their protective benefits thus cast into doubt, no further production of the expensive gun carriages was undertaken in New Zealand.
Though effective against ships, the guns turned out to be vulnerable to aerial attack. After World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
batteries
Artillery battery
In military organizations, an artillery battery is a unit of guns, mortars, rockets or missiles so grouped in order to facilitate better battlefield communication and command and control, as well as to provide dispersion for its constituent gunnery crews and their systems...
of disappearing guns were usually casemate
Casemate
A casemate, sometimes rendered casement, is a fortified gun emplacement or armored structure from which guns are fired. originally a vaulted chamber in a fortress.-Origin of the term:...
d for protection or covered with camouflage
Military camouflage
Military camouflage is one of many means of deceiving an enemy. In practice, it is the application of colour and materials to battledress and military equipment to conceal them from visual observation. The French slang word camouflage came into common English usage during World War I when the...
for concealment. By 1912, the guns were declared obsolete in the British Army, with only some other countries, particularly the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, still producing them up to World War I and keeping them active through to the end of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
.
Gun lift battery
One unique and even more complex type of disappearing gun was Battery PotterBattery Potter
Battery Potter or "Gun Lift Battery No.1" built in 1892 at Fort Hancock, New Jersey was the world's only disappearing gun battery that used hydraulic elevators to move the guns above a protective parapet wall...
at Fort Hancock
Fort Hancock, New Jersey
Fort Hancock is a former United States Army fort at Sandy Hook, located in Middletown Township in Monmouth County, along the Atlantic coast of eastern New Jersey in the United States. This coastal artillery base played an important part in the defense of New York Harbor and played a role in the...
, Sandy Hook
Sandy Hook
Sandy Hook is a barrier spit along the Atlantic coast of New JerseySandy Hook may also refer to:-Places:United States* Sandy Hook , a village in the town of Newtown, Connecticut* Sandy Hook, Kentucky, a city in Elliott County...
, New Jersey
New Jersey
New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...
. Built in 1892, the Battery covered the approaches to New York harbor
New York Harbor
New York Harbor refers to the waterways of the estuary near the mouth of the Hudson River that empty into New York Bay. It is one of the largest natural harbors in the world. Although the U.S. Board of Geographic Names does not use the term, New York Harbor has important historical, governmental,...
. Instead of using recoil from the gun to lower the weapon, two 12-inch barbette carriages were placed on individual hydraulic elevators that would raise the 110-ton carriage and gun 14 feet to enable it fire over a parapet
Parapet
A parapet is a wall-like barrier at the edge of a roof, terrace, balcony or other structure. Where extending above a roof, it may simply be the portion of an exterior wall that continues above the line of the roof surface, or may be a continuation of a vertical feature beneath the roof such as a...
wall. After firing, the gun was lowered for reloading using hydraulic ramrods and a shell hoist. While the operation of the battery was slow, taking 3 minutes per shot, its design allowed an unlimited field of fire.
Battery Potter required a huge amount of machinery to operate the gun lifts, including boilers, steam pressure pumps and two accumulators. Due to the inability to generate steam quickly, Potter's boilers were run nonstop during its 14 year life, creating a significant operating cost. After the proving of the Buffington Crozier carriage, the United States Army
United States Army
The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...
abandoned plans to build several additional gun lift batteries.
Naval artillery
At least once, the concept was also attempted for conversion to a naval use. HMS TemeraireHMS Temeraire (1876)
HMS Temeraire was an ironclad battleship of the Victorian Royal Navy which was unique in that she carried her main armament partly in the traditional broadside battery, and partly in barbettes on the upper deck.-Design and construction:...
was completed in 1877 with two disappearing gun turrets sinking down into barbette
Barbette
A barbette is a protective circular armour feature around a cannon or heavy artillery gun. The name comes from the French phrase en barbette referring to the practice of firing a field gun over a parapet rather than through an opening . The former gives better angles of fire but less protection...
-structures (basically circular metal protective walls over which the gun fired when elevated). This was to combine the ability of the early pivot gun
Pivot gun
A pivot gun was a type of cannon mounted on a fixed central emplacement which permitted it to be moved through a wide horizontal arc. They were a common weapon aboard ships and in land fortifications for several centuries but became obsolete after the invention of gun turrets...
s to swivel with the protection of more classical fixed naval guns. However, the design was not successful and apparently never repeated. It is thought that both harsh saltwater environment and the constant swaying and rolling of a ship at sea were to blame for problems with the complex mechanism. In any case, heavy gun turret
Gun turret
A gun turret is a weapon mount that protects the crew or mechanism of a projectile-firing weapon and at the same time lets the weapon be aimed and fired in many directions.The turret is also a rotating weapon platform...
s soon afterwards entered naval service, making the idea moot.
See also
- Coastal artilleryCoastal artilleryCoastal artillery is the branch of armed forces concerned with operating anti-ship artillery or fixed gun batteries in coastal fortifications....
- Seacoast defense in the United States
- Specific installations
- Australia
- Ben Buckler Gun Battery, BondiBondiBondi could refer to:-Places in Australia:* Bondi Beach, New South Wales, a beach and suburb in Sydney, Australia* Bondi Junction, New South Wales, a suburb and commercial centre in Sydney, Australia* Bondi, New South Wales, a suburb in Sydney, Australia...
, New South WalesNew South WalesNew South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales... - Flagstaff Hill FortFlagstaff Hill FortFlagstaff Hill Fort, was a fort at Flagstaff Point, Wollongong, New South Wales, Australia.-History:Constructed between 1890-1891, the fort was built with a disappearing gun emplacement. The fort was dug-out of the hill using face brick walls and then earth was placed over the tunnels...
, WollongongWollongong, New South WalesWollongong is a seaside city located in the Illawarra region of New South Wales, Australia. It lies on the narrow coastal strip between the Illawarra Escarpment and the Pacific Ocean, 82 kilometres south of Sydney...
, New South WalesNew South WalesNew South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales... - Fort QueenscliffFort QueenscliffFort Queenscliff, in Victoria, Australia, dates from 1860 when an open battery was constructed on Shortland's Bluff to defend the entrance to Port Phillip. The Fort, which underwent major redevelopment in the late 1870s and 1880s, became the headquarters for an extensive chain of forts around Port...
, Port PhillipPort PhillipPort Phillip Port Phillip Port Phillip (also commonly referred to as Port Phillip Bay or (locally) just The Bay, is a large bay in southern Victoria, Australia; it is the location of Melbourne. Geographically, the bay covers and the shore stretches roughly . Although it is extremely shallow for...
, Victoria, with a recovered gun from South Channel Fort - Fort NepeanFort NepeanFort Nepean is a former defensive facility occupying part of Point Nepean, Victoria, Australia. It was part of a network of fortifications, commanded from Fort Queenscliff, protecting the narrow entrance to Port Phillip.- Background :...
, Port PhillipPort PhillipPort Phillip Port Phillip Port Phillip (also commonly referred to as Port Phillip Bay or (locally) just The Bay, is a large bay in southern Victoria, Australia; it is the location of Melbourne. Geographically, the bay covers and the shore stretches roughly . Although it is extremely shallow for...
, Victoria - Fort ScratchleyFort ScratchleyFort Scratchley is a former coastal defence installation and now museum, located in Newcastle East, a suburb of Newcastle, New South Wales, Australia. It was built in 1882 to defend the city against a possible Russian attack. However, its guns were not fired in anger until 8 June 1942, during the...
, NewcastleNewcastle, New South WalesThe Newcastle metropolitan area is the second most populated area in the Australian state of New South Wales and includes most of the Newcastle and Lake Macquarie Local Government Areas...
, New South Wales - Henry Head BatteryHenry Head BatteryThe Henry Head Battery is an artillery battery located on the northern side of the entrance to Botany Bay at Henry Head, La Perouse, New South Wales, Australia.-History:...
, SydneySydneySydney is the most populous city in Australia and the state capital of New South Wales. Sydney is located on Australia's south-east coast of the Tasman Sea. As of June 2010, the greater metropolitan area had an approximate population of 4.6 million people...
, New South Wales - Steel Point Battery, VaucluseVaucluse, New South WalesVaucluse is an eastern suburb of Sydney, in the state of New South Wales, Australia. Vaucluse is located north-east of the Sydney central business district, in the local government areas of Waverley Council and the Municipality of Woollahra....
, SydneySydneySydney is the most populous city in Australia and the state capital of New South Wales. Sydney is located on Australia's south-east coast of the Tasman Sea. As of June 2010, the greater metropolitan area had an approximate population of 4.6 million people...
, New South WalesNew South WalesNew South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales... - Signal Hill BatterySignal Hill BatteryThe Signal Hill Battery was constructed in 1892-3 at Watsons Bay and is adjacent to the Signal Hill Lighthouse on Old South Head Road.-History and description:...
, Watsons BayWatsons Bay, New South WalesWatsons Bay is a harbourside, eastern suburb of Sydney, in the state of New South Wales, Australia. Watsons Bay is located 11 km north-east of the Sydney central business district, in the local government area of the Municipality of Woollahra....
, SydneySydneySydney is the most populous city in Australia and the state capital of New South Wales. Sydney is located on Australia's south-east coast of the Tasman Sea. As of June 2010, the greater metropolitan area had an approximate population of 4.6 million people...
, New South WalesNew South WalesNew South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales... - South Channel FortSouth Channel FortSouth Channel Fort is a 0.7 ha artificial island in southern Port Phillip, Victoria, Australia, 6 km north-east of the town of Sorrento. It was part of a network of fortifications protecting the narrow entrance to Port Phillip....
, Port Phillip, Victoria
- Ben Buckler Gun Battery, Bondi
- Canada
- Cape SpearCape SpearCape Spear, located on the Avalon Peninsula near St. John's, Newfoundland, is the easternmost point in North America , excluding Greenland and the portions of Alaska west of the 180th parallel of longitude . Cape Spear is close to Blackhead, an amalgamated area of the City of St. John's, about...
, NewfoundlandNewfoundland and LabradorNewfoundland and Labrador is the easternmost province of Canada. Situated in the country's Atlantic region, it incorporates the island of Newfoundland and mainland Labrador with a combined area of . As of April 2011, the province's estimated population is 508,400...
- Cape Spear
- New Zealand (Armstrong Disappearing Guns)
- Fort Jervois (Lyttelton), one mostly intact BL 6-inch Mk VBL 6 inch gun Mk VThe BL 6 inch gun Mk V was an early Elswick Ordnance Company breech-loading naval gun originally designed to use the old gunpowder propellants...
and one working-order BL 8-inch gunBL 8 inch Mk I - VII naval gunThe BL 8 inch guns Mark I to Mark VII were the first generations of British breech-loaders of medium-heavy calibre. They were initially designed for gunpowder propellants and were of both 25.5 and 30 calibres lengths.-History:... - North HeadNorth Head, New ZealandNorth Head is a volcanic cone forming a headland within North Shore City, New Zealand, in the suburb of Devonport at the east end of the Waitemata Harbour ....
(North Shore, Auckland), one remaining gun barrel with mostly intact carriage - Taiaroa HeadTaiaroa HeadTaiaroa Head is a headland at the end of the Otago Peninsula in New Zealand, overlooking the mouth of the Otago Harbour. It lies within the city limits of Dunedin...
(Dunedin) one restored BL 6-inch Mk VBL 6 inch gun Mk VThe BL 6 inch gun Mk V was an early Elswick Ordnance Company breech-loading naval gun originally designed to use the old gunpowder propellants...
- Fort Jervois (Lyttelton), one mostly intact BL 6-inch Mk V
- Philippines
- Fort MillsFort MillsFort Mills was the location of US Major General George F. Moore's headquarters for the Philippine Department's Harbor Defenses of Manila and Subic Bays. This was one of the locations at which, under the National Defense Act of 1935, coastal artillery training was conducted.-References:*McGovern,...
, Corregidor IslandCorregidorCorregidor Island, locally called Isla ng Corregidor, is a lofty island located at the entrance of Manila Bay in southwestern part of Luzon Island in the Philippines. Due to this location, Corregidor was fortified with several coastal artillery and ammunition magazines to defend the entrance of...
, Manila Bay, Luzon - Fort WintFort WintFort Wint was part of the harbor defenses of Manila and Subic Bays built by the Philippine Department of the United States Army between 1907 and 1920 in response to recommendations of the Taft Board prior to the non-fortification clause of the Washington Naval Treaty...
, Grande Island, Subic Bay, Luzon
- Fort Mills
- South Africa 9.2 inch disappearing gun in Fort Wynyard, Cape Town. Visible in Google Earth at coordinates 33° 54.136'S 18° 24.807'E.
- Thailand
- Phra Chulachomklao Fort, Bangkok, seven Armstrong BL 6 inch gunsBL 6 inch gun Mk VThe BL 6 inch gun Mk V was an early Elswick Ordnance Company breech-loading naval gun originally designed to use the old gunpowder propellants...
on hydropneumatic disappearing carriages, all in working condition
- Phra Chulachomklao Fort, Bangkok, seven Armstrong BL 6 inch guns
- United Kingdom
- Flat HolmFlat HolmFlat Holm is a limestone island lying in the Bristol Channel approximately from Lavernock Point in the Vale of Glamorgan, but in the City and County of Cardiff. It includes the most southerly point of Wales....
, Bristol Channel, Wales - Fort CumberlandFort CumberlandFort Cumberland can refer to:*Fort Cumberland *Fort Cumberland also known as Fort Beauséjour*Fort Cumberland Fort Cumberland is located in Cucumber Land, Cumber is short for Cucumber. Fort Cumberland was founded by Johnson Merrell, a moonshiner in 1687...
, Portsmouth, England - Crownhill FortCrownhill FortCrownhill Fort is a Royal Commission fort built in the 1860s in Crownhill as part of Lord Palmerston's ring of land defences for Plymouth. Restored by the Landmark Trust, it is now open to the public.-History of the fort:...
, Plymouth, England
- Flat Holm
- United States
- Battery ChamberlinBattery ChamberlinBattery Chamberlin is an artillery battery in the Presidio of San Francisco, San Francisco, California, United States. The battery is named in honor of Captain Lowell A...
, Presidio of San FranciscoPresidio of San FranciscoThe Presidio of San Francisco is a park on the northern tip of the San Francisco Peninsula in San Francisco, California, within the Golden Gate National Recreation Area...
. Only Buffington-Crozier disappearing carriage still operating. - Battery PotterBattery PotterBattery Potter or "Gun Lift Battery No.1" built in 1892 at Fort Hancock, New Jersey was the world's only disappearing gun battery that used hydraulic elevators to move the guns above a protective parapet wall...
, Fort HancockFort Hancock, New JerseyFort Hancock is a former United States Army fort at Sandy Hook, located in Middletown Township in Monmouth County, along the Atlantic coast of eastern New Jersey in the United States. This coastal artillery base played an important part in the defense of New York Harbor and played a role in the...
, Sandy HookSandy Hook, New JerseySandy Hook is a barrier spit, approximately 6.0 miles in length and varying between 0.10 and 1 miles wide in Middletown Township in Monmouth County, along the Atlantic Ocean coast of eastern New Jersey in the United States. The barrier spit encloses the southern entrance of Lower New York Bay...
, New JerseyNew JerseyNew Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...
. This is only remaining steam hydraulic battery. - Fort CaseyFort CaseyFort Casey State Park is located on Whidbey Island in Washington state. Admiralty Inlet was considered so strategic to the defense of Puget Sound in the 1890s that three forts, Fort Casey on Whidbey Island, Fort Flagler on Marrowstone Island, and Fort Worden at Port Townsend, were built at the...
, Washington - Fort Hunt, VirginiaVirginiaThe Commonwealth of Virginia , is a U.S. state on the Atlantic Coast of the Southern United States. Virginia is nicknamed the "Old Dominion" and sometimes the "Mother of Presidents" after the eight U.S. presidents born there...
- Battery Chamberlin
- Australia