Seacoast defense in the United States

Source: Wikipedia, the free encyclopedia.
Baltimore harbor, although built in the 1860s, are broadly similar to early First and Second System forts built prior to the War of 1812, with low earthworks, although mounting much larger cannon and reinforced with masonry. The cannon are 8-inch converted rifles (lined down from 10-inch Rodman guns) and a 15-inch Rodman gun, typical of the post-Civil War
era.
The Statue of Liberty is built on top of Fort Wood of the Second System

Seacoast defense was a major concern for the United States from its independence until World War II. Before airplanes, many of America's enemies could only reach it from the sea, making coastal forts an economical alternative to standing armies or a large navy. After the 1940s, it was recognized that fixed fortifications were obsolete and ineffective against aircraft and missiles. However, in prior eras foreign fleets were a realistic threat, and substantial fortifications were built at key locations, especially protecting major harbors.

The defenses heavily depended on fortifications but also included submarine minefields, nets and booms, ships, and airplanes. Therefore, all of the armed forces participated in seacoast defense, but the U.S. Army Corps of Engineers played the central role in constructing fixed defenses.

Designs evolved and became obsolete with changes in the technology available to both the attacking forces and the defenders. The evolution of the U.S. seacoast defense system is generally identified among several "systems", which are somewhat defined by the styles used, but more so by the events or trends which periodically stimulated new funding and construction. The division of the early forts into the First and Second Systems was made by later historians, and appears officially in an 1851 report by

Chief Engineer Joseph Totten, probably the most prolific builder of masonry forts in American history.[1]

Early defenses

At the beginning of the

pirate raids and foreign incursions. In the American colonies and the United States, coastal forts were generally more heavily constructed than inland forts, and mounted heavier weapons comparable to those on potential attacking ships. Though seldom used, the forts were a deterrent. During the Revolution additional forts were built by both sides, usually to meet specific threats. Those built by Patriot
forces were called Patriot batteries.

First System

When the United States gained independence in 1783, the seacoast defense fortifications were in poor condition. Concerned by the outbreak of war in Europe in 1793, the Congress created a combined unit of "Artillerists and Engineers" to design, build, and garrison forts in 1794, appointed a committee to study coast defense needs, and appropriated money to construct a number of fortifications that would become known as the First System.[2]

Twenty significant forts at thirteen harbors were approved for construction, mostly with traditional low walled structures with low sloped

Fort Constitution in Portsmouth, New Hampshire, Fort Independence in Boston, Massachusetts, Fort Wolcott in Newport, Rhode Island, and Fort Mifflin in Philadelphia.[4]

Lacking trained engineers to supervise the work, Secretary of War Henry Knox placed a number of European engineers under contract.[5] Although some fine forts were constructed, for the most part enthusiasm and funding waned and little work was completed. Most of the partially finished earthworks and wooden structures deteriorated before they were needed to defend against the British in 1812.

Second System

50-pounder Model 1811 Columbiad (7.25 inch or 184 mm bore) and center-pivot mounting designed by George Bomford as an experimental coastal defense gun. This gun was built in 1811 as a component of the Second System.[6][7] Photographed in Clear Lake, Wisconsin.

In 1802, Congress separated the artillerists and engineers into separate corps and directed the Corps of Engineers to create a military academy at West Point, New York. One of the driving forces for establishing the new academy was the need to divorce the United States from its reliance on foreign engineers. In 1807–8, new concerns over a possible war with Great Britain prompted President Thomas Jefferson to renew fortification programs; this has come to be known as the Second System. One event that foreshadowed war was the Chesapeake–Leopard affair.[8]

One common weakness among the typical low-walled open bastion or

star forts was exposure to enemy fire, especially to new devices designed to explode in mid air and rain shrapnel down on the gunners. Gun emplacements which were at an angle to the sea were vulnerable to a solid shot running parallel to the wall taking out a row of guns and gunners with one enfilading shot. In the late 1770s, a French engineer, the Marquis de Montalembert, advocated a major change in the design of fortresses to address these problems. His design protected a fort's gunners by placing most of them in covered casemate walls with openings for the guns. By stacking rows of casemates in high walls more guns could be mounted along shorter walls. This was particularly important for seacoast fortifications, which had only a limited time in which to fire at passing enemy ships. To build these tall forts, walls had to be built of masonry, but be very thick in order to withstand the pounding of cannon fire. Despite the goal of building multi-tiered forts, only a few of these were completed, notably Castle Williams in New York Harbor. Most completed Second System forts generally resembled First System forts, with a one-tier star fort supplemented by water batteries.[9]

The Second System was distinguished from the First System by greater use of Montalembert's concepts and the replacement of foreign engineers by American ones, many of them recent graduates of the new United States Military Academy superintended by Major Jonathan Williams, who not only instructed the new engineers in new ideas of coastal defense, but also designed and constructed a prototype, Castle Williams on Governors Island in New York Harbor.[10]

Again, several fine forts were produced, but generally projects went unfinished, and between the First System and Second System little was prepared to resist the British in the coming

Baltimore was prevented by Fort McHenry and supporting forts and troops. These included shoreline batteries at Forts Babcock and Covington to the west, Fort Look-Out (or the Six-Gun Battery) on the peninsula to the rear in the west, a temporary naval battery across the Patapsco channel to the east at Lazaretto Point, and sunken ships blocking the channels on either side of Fort McHenry, along with 20,000 militia dug in on the east side of the town at "Loudenschlager's Hill" (later "Hampstead Hill" in today's Patterson Park).[11] The intense all-night bombardment of Fort McHenry by the British ships offshore was memorialized by Francis Scott Key, a Baltimore lawyer who witnessed the ferocious attack from one of the vessels, and put down his thoughts watching the barrage—which failed to either destroy the fort or subdue its defenders—in a four-stanza poem, which became known as The Star-Spangled Banner and later became America's national anthem. In some cases even incomplete forts (some with fake wooden cannon barrels painted black pointed out the embrasures) were sufficient to deter attack from the sea. But, undefended and unfortified, Washington, D.C., the national capital, was burned after the land militia forces were routed at the Battle of Bladensburg northeast of the capital in Prince George's County, Maryland. Washington had one fort, which the British bypassed, Fort Washington on the Potomac River just below Alexandria, Virginia, whose commander ordered the magazine blown when the passing British fleet appeared nearby, after the British had already occupied Washington.[12] The present Fort Washington was built on the site of the destroyed Fort Washington in the early 1820s as part of the Third System.[13] Among the many important and historic documents lost in the British burning of the Library of Congress
were the plans to the first Fort Washington (begun as Fort Warburton) and other Second System forts.

Third System

Fort Point
- San Francisco - example of a mid-1800s Third System fort
Fort Pulaski
on the coast of Georgia
Civil War 10-inch Rodman gun at Fort Knox (Maine)

In 1816, following the War of 1812, Congress appropriated over $800,000 for an ambitious seacoast defensive system which was known as the Third System. A Board of Engineers for Fortifications, appointed by President James Madison, visited potential sites and prepared plans for the new forts. The Board's original 1821 report established the policy which would remain in place for most of the 19th century. The original report suggested 50 sites, but by 1850 the board had identified nearly 200 sites for fortification. The Army built forts at 42 of these sites, with several additional sites containing towers or batteries.

The forts were originally intended to mount mostly 42-pounder (7 inch or 178 mm) seacoast guns; however, due to a shortage of these weapons many 32-pounder (6.4 inch or 163 mm) seacoast guns and 8-inch (203 mm) and 10-inch (254 mm) columbiads were mounted instead.

The main defensive works were often large structures, based on combining the

Joseph Totten and former French engineer officer Simon Bernard (commissioned a brevet brigadier general in the U.S. Army) designed the larger forts and key features of most of the smaller forts, such as the Totten casemate, which allowed a good field of fire with a minimal embrasure size.[14]

By the end of the Third System in 1867, 42 forts covered the major harbors along the coastline. While most of the forts were completed, several of the forts—mostly in New England—were still under construction. A few of these forts, such as Fort Preble, Fort Totten, and Fort Constitution, were readied for armament even though they were far from complete.

The Corps of Engineers listed the forts from northeast to southwest, then to the Pacific Coast. The same order is used here for the new-construction forts of the Third System:

In addition, several towers and batteries were constructed in support of the forts or at lesser harbors. First and Second System forts were renovated during the system as well, and readied for the larger cannon prevalent during that period.[17]

Civil War

Again, changes in technology affected design; the higher velocity ordnance of new rifled cannons crushed and penetrated the masonry walls of Third System forts. Severe damage was inflicted to forts on the Atlantic Coast during the

Fort Pulaski in Georgia was forced to surrender after only 30 hours of bombardment with rifled cannon, primarily large-caliber Parrott rifles
.

Many of the larger smoothbore cannon (32-pounder and up) were rifled and equipped with breech bands to support larger powder charges and extend their effective range during the Civil War. This process is referred to as "banded and rifled".

During the Civil War, naval officers learned that their steamships and ironclad vessels could run past Confederate-held Third System forts with acceptable losses, such as at Mobile Bay.

The urgencies of war required that new forts or improvements be constructed quickly and at low cost. Partially completed Third System forts were finished, but new construction was mostly wood-revetted earthworks. Frequently earthworks were built near a Third System fort in order to supplement its firepower, but often they were stand-alone fortifications. In some cases, cannon from masonry forts were dispersed to earthen bunkers where they were better protected. The fortification of

Angel Island, the Marin Headlands, and Fort Mason. Following the war, work on masonry forts ended in 1867, leaving several incomplete.[18]

Minefields

Robert Fulton used the term "torpedo" to describe an underwater explosive device in 1805. Samuel Colt experimented with electrical firing of the torpedo. During the Civil War, these underwater mines became an important supplementary defense measure. The Confederacy, without a large navy to protect its harbors, relied on mines extensively to deter attacks by Union ships. Electrically fired torpedoes, later termed mines, controlled from mine casemates ashore were developed during and after the Civil War as part of coastal defenses.[19]

Coast artillery weapons during the Civil War

Two of the Civil War's heavy weapons: an 8-inch (200-pdr) Parrott rifle (front) and a 15-inch Rodman gun (rear) at Battery Rodgers, Alexandria, Virginia.

Numerous types of seacoast artillery were used in the Civil War. Except for the 20-inch Rodmans, of which only three Army weapons were built, the following list includes only widely deployed weapons. See Siege artillery in the American Civil War for more information.

Post Civil War to the creation of the Coast Artillery Corps

After the war, construction for several new Third System forts began in New England. These were to be built of stone rather than brick, and designed to accommodate the large-bore cannon developed during the war. However, in 1867 money for masonry fortifications was cut off, and the Third System came to a close.

The vulnerability of masonry to rifled cannon and large-caliber smoothbore cannon and fewer concerns for invasion led to the construction of well-dispersed masonry-revetted earthen fortifications with brick-lined magazines, often located near Third System forts. These were typically armed with 15-inch Rodman guns and 8-inch converted rifles; in some cases, the forts were also rearmed with these weapons. All of the larger Parrott rifles had burst frequently during the war, so few of these were retained in service after the war. Also during the 1870s, a number of new projects were started to include large caliber mortars and submarine mines. However, the facilities for the mortars and mines were never completed, and funding for the new fortifications was cut off by 1878, leaving much of the program unfinished. By the 1880s most of the earthen fortifications were in disrepair.[22]

Monitors for coast defense

USS Monterey, a late 19th-century monitor-style coastal defense ship.

Though coastal defense was generally within the purview of the Army, the Navy became more involved in the late 19th century with coastal defense ships, generally called monitors. These monitors were turreted ironclad warships inspired by USS Monitor; as well as coastal ships which closely followed her design, the term "monitor" also encompassed more flexible breastwork monitors which had a modest armored superstructure and were thus more seaworthy. These also featured modern rifled breech-loading guns.

Monitor-style ships were used extensively in offensive roles during the Civil War, but were impractical for ocean service and offensive action abroad. They were, however, ideally suited for harbor defense with their shallow draft and large guns. Postwar, Civil War-era monitors were dispersed to important harbors, including

San Francisco on the west coast. From the 1870s to the 1890s, larger and more powerful breastwork monitors were produced, such as the Amphitrite class, while the ocean-going navy was slow to make the transition to steel hulls and armor plating. An improvement on the monitor concept was the coastal battleship, such as the Indiana class
of the 1890s.

As a result of the Spanish–American War and the acquisition of Hawaii and the Philippines, by 1900 the Navy was committed to ocean-going battleships, and ceased building monitors; however, some of the vessels remained in service up to World War I in combat-prepared roles, and as training or auxiliary vessels thereafter.

Coast artillery weapons between the Civil War and Endicott period

The Endicott Program was largely implemented 1895–1905. As Endicott facilities were constructed in each harbor defense area, the previous coastal defenses were usually abandoned. Only widely deployed weapons are listed. The larger Parrott rifles had shown a tendency to burst during the war, so only a few were retained in service after the war, in emplacements that took advantage of their long range.

Endicott period

10-inch disappearing gun installation, Fort Casey, Washington state.

As early as 1882, the need for heavy fixed artillery for seacoast defense was noted in Chester A. Arthur's Second Annual Message to Congress as follows:

I call your attention to the recommendation of the Secretary and the board that authority be given to construct two more cruisers of smaller dimensions and one fleet dispatch vessel, and that appropriations be made for high-power rifled cannon for the torpedo service and for other harbor defenses.[23]

Prior efforts at harbor defense construction had ceased in the 1870s. Since that time, the design and construction of heavy ordnance in Europe had advanced rapidly, including the development of superior breech-loading and longer-ranged cannon, making U.S. harbor defenses obsolete. In 1883, the Navy began a new construction program with an emphasis on offensive rather than defensive warships. These factors combined to create a need for improved coastal defense systems.

Typical Endicott period 6-inch (152 mm) disappearing rifle at Battery Chamberlin in San Francisco

In 1885, President

Coast Defense Commands in 1913 and Harbor Defense Commands in 1925.[25][26]

By the outbreak of the

4.72-inch Armstrong guns, purchased from the United Kingdom to provide some modern quick-firing medium-caliber guns, as none of the Endicott Program's 6-inch or 3-inch batteries had been completed. Field artillery, primarily 5-inch siege guns and 7-inch siege howitzers, was also deployed, mostly in Georgia and Florida. Many of these batteries were not completed until 1899, after the war was over, and the 8-inch guns were withdrawn within a few years as modern emplacements for them were completed.[28][29]

1901 reorganization

Army leaders realized that heavy fixed artillery required different training programs and tactics than mobile field artillery. Prior to 1901 each of the seven artillery regiments contained both heavy and light artillery batteries. In February 1901, with the Endicott program well under way, the Artillery Corps was divided into two types: field artillery and coast artillery. The previous seven artillery regiments were dissolved, and 30 numbered companies of field artillery (commonly called batteries) and 126 numbered companies of coast artillery (CA) were authorized. 82 existing heavy artillery batteries were designated as coast artillery companies, and 44 new CA companies were created by splitting existing units and filling their ranks with recruits. The company-based organization was for flexibility, as each harbor defense command was differently equipped and a task-based organization was needed. The Coast Artillery would alternate between small unit and regimental organization several times over its history. The head of the Artillery Corps became the Chief of Artillery in the rank of brigadier general with jurisdiction over both types of artillery.[25][30]

Mine planters

USAMP Major Samuel Ringgold, built 1904, which planted practice groups of mines in the Columbia River during the 1920s. (National Archives and Records Administration)

Circa 1901 the Coast Artillery took responsibility for the installation and operation of the

Army Mine Planter Service (AMPS) and Warrant Officer Corps to provide officers and engineers for these vessels in 1918.[31][32] The mine component was considered to be among the principal armament of coastal defense works.[32] When the Coast Artillery Corps was disestablished and the artillery branches merged in 1950,[25] some of the mine planter vessels were transferred to the U.S. Navy and redesignated as Auxiliary Minelayers (ACM/MMA).[33]

Coast artillery weapons of the Endicott period

These weapons were emplaced between 1895 and 1905. Only widely deployed weapons are listed. Most except the mortars, 3-inch guns, and some 6-inch guns were on disappearing carriages, with barbette carriages (also called pedestal carriages) used for the remainder.[34] Although some harbor defenses in less-threatened locations were disarmed following World War I (some of these retained minefields), many of these weapons remained in service until superseded by 16-inch guns and scrapped during World War II.

Taft Board and creation of the Coast Artillery Corps

In 1905, after the experiences of the

dreadnought battleships, a new 14-inch gun
was introduced in a few locations and improved models of other weapons were also introduced. By the beginning of World War I, the United States had a coastal defense system that was equal to any other nation.

The rapidity of technological advances and changing techniques increasingly separated coastal defenses (heavy) from field artillery (light). Officers were rarely qualified to command both, requiring specialization. As a result, in 1907, Congress split Field Artillery and Coast Artillery into separate branches, creating a separate Coast Artillery Corps (CAC), and authorized an increase in the Coast Artillery Corps to 170 numbered companies. In 1907, the Artillery School at Fort Monroe became the Coast Artillery School, which operated until 1946, and in 1908, the Chief of Artillery became the Chief of Coast Artillery.

In an exercise in 1907 at

Grande Island were completed.[38]

Fort Drum

Fort Drum in Manila Bay
, Philippines, was a result of the Taft board program

One of the most extreme fortresses of the early 20th century was

anti-aircraft batteries, and a fire direction tower were also mounted on its upper surface. The 25-to-36-foot-thick (7.6 to 11.0 m) fortress walls protected extensive ammunition
magazines, machine spaces, and living quarters for the 200 man garrison. The extensive level of fortification was not typical of the period, but driven by the exposed location. Although the design predated concerns about defense from air attack, the design proved to be exemplary for that purpose.

After the outbreak of war in the

recaptured the Philippines
in 1945.

Self-propelled torpedoes

Mines as we know them today were frequently referred to as torpedoes in the 19th and early 20th centuries. The self-propelled torpedo as we know it was derived from the concept of the mine, with early submarines and torpedo boats evolving as defensive weapons in the 1890s to deliver torpedoes against attacking fleets. During early development, it was not clear whether submarines and torpedo boats would be in the purview of the Army or the Navy, since the Army was responsible for the use and development of stationary minefields and other fixed coastal defenses. As the range and potential uses of submarines and torpedo boats grew, it became more apparent that these were naval vessels, and both surface- and submarine-delivered torpedoes were an important aspect of naval coastal defense strategies. However, self-propelled torpedoes were not included in the Army's coastal defenses. Shore-launched Whitehead compressed air driven torpedoes were the first deployed, in Europe.

World War I

Submarines and airplanes became more important, with the former being a perceived if not actual threat to U.S. harbors. This concern caused an increase in the use of mines and nets, and demand for superior artillery. However, as the war progressed it became more clear that the enemies did not have the resources to bring the war across the Atlantic, and progress diminished along with concerns. Curiously, despite the rise of air power in

dreadnought battleships, approximately 14 two-gun batteries of 12-inch guns
on a new M1917 long-range barbette carriage began construction in 1917, but none were completed until 1920.

Due to their experience and training with large guns, the Coast Artillery operated all U.S. Army heavy artillery (

anti-aircraft mission in that war. A number of 5-inch and 6-inch guns were withdrawn from coast defenses and remounted on wheeled carriages for use on the Western Front, with about 72 6-inch (possibly including some Navy guns) and 26 5-inch guns shipped to France. However, due to the Armistice, none of the units equipped with repurposed coast defense guns completed training in time to see action.[39][40][41] Only a few of the 6-inch guns and none of the 5-inch guns were returned to the coast defenses after the war. Most of the 6-inch guns were stored until remounted in World War II, and the 5-inch guns were declared obsolete and scrapped circa 1920.[42]

Railway artillery

8-inch M1888 railway gun with ammunition wagon.

A large-scale program to mount

14"/50 caliber railway guns
to France in time to support the final Allied offensives. However, these weapons' mountings were not suitable for coast defense and they were retired after that war.

Coast artillery weapons of the Taft period and World War I

A new 14-inch (356 mm) gun and improved versions of some Endicott period weapons were introduced from 1905 to 1918, supplementing rather than replacing the previous weapons. The 14-inch guns were emplaced in the new harbor defenses of Los Angeles, Hawaii, the Panama Canal, and Manila Bay in the Philippines. A one-off 16-inch gun M1895 (406 mm) was also deployed on a disappearing carriage on the Pacific side of the Panama Canal in 1914; this was the first 16-inch gun in U.S. service. Only widely deployed seacoast weapons are included in this list.

Between World War I and World War II

12-inch gun M1895 on long-range barbette carriage M1917.
16-inch gun M1919 at Fort Duvall
, Massachusetts, typical of pre-WWII 16-inch installations.

B-17
, which evolved as defensive weapons, turned out to have excellent offensive capacity as well.

Drawdown and reorganization

In the early 1920s several types of weapons, mostly those with only a few deployed, were withdrawn from Coast Artillery service. This was probably to simplify the supply situation. The only widely deployed type withdrawn was the

4-inch/40 caliber Navy Driggs-Schroeder guns (4 guns), and all models of 5-inch guns (52 guns). Twenty-six of the 5-inch guns had been sent to France for use on field carriages.[47] Additionally, approximately 72 6-inch guns withdrawn from coast defenses for field service were not immediately remounted; these were eventually remounted on long-range carriages in new batteries during World War II. Except in a few cases, none of these weapons were directly replaced.[48]

On 9 June 1925 the Coast Defense Commands were redesignated as Harbor Defense Commands via a War Department order.[49] By the end of the 1920s, eight harbor defense commands in less-threatened areas were completely disarmed. These included the Kennebec River, ME, Baltimore, MD, Potomac River, MD and VA, Cape Fear River, NC, Savannah, GA, Tampa Bay, FL, Mobile, AL, and the Mississippi River, LA. It is possible the mine defenses were retained in reserve. Some of these commands were rearmed with "Panama mounts" for mobile artillery early in World War II.[48]

In 1922, 274 Coast Artillery companies were authorized, 188 of which were active. During that year 44 companies were inactivated, but 14 new companies were created for the Philippine Scouts, and a 15th in 1923. The Philippine Scouts, units of mostly Filipino enlisted men and mostly U.S. officers, manned many of the coast defenses in the Philippines and served in other key roles. The General Staff reconfirmed a commitment to artillery and mines as the most practical and cost-effective methods for seacoast defense, as an alternative to a larger Navy or Air Corps. In 1924 the CAC adopted a regimental system, consolidating the companies into 16 Regular Army harbor defense regiments, two Philippine Scouts regiments (one harbor defense, one tractor-drawn), three Regular tractor-drawn regiments, and two Regular railway regiments. These were supplemented by 11 harbor defense and two tractor-drawn regiments of the National Guard, which trained in peacetime for activation in wartime. The total companies authorized remained the same, at 289 with 144 active. There was also a Coast Artillery Reserve of 14 harbor defense regiments, four railway regiments, three tractor-drawn regiments, and 42 anti-aircraft regiments in 8 AA brigades. However, many of the Reserve units had only a small number of personnel assigned, and many were demobilized without activation in 1933 and during World War II, or served in that war with different designations.[50][51][52][53][54] From 1930 to 1932 the army drafted new defense projects for each harbor. In 1931 it established a Harbor Defense Board to supervise the execution of these projects.[55]

New weapons

The rapid evolution of

16-inch/50 caliber Mark II and Mark III barrels. About 70 guns were completed before the treaty went into effect, and the Navy wished to retain most of them for use in future battleships. Initially only 20 guns were transferred to the Army, who built a new version of the M1919 mount for the naval guns. However, only ten of these guns were deployed until 1940, in Pearl Harbor, Panama, and San Francisco. They were known as the 16-inch Navy gun MkIIMI and MkIIIMI in Army service. The 16-inch guns, firing 2,340 lb (1,060 kg) projectiles up to 49,100 yd (44,900 m), were much more effective than any previous U.S. coast defense guns.[58]

Another weapon sparsely deployed in the 1930s would become a bigger part of World War II coast defenses.

12"/45 caliber Mark 5 gun, was also made available to the Army, but these were never deployed by the United States and at least some were sold to Brazil.[59]

Protection against air attack was slow to evolve. Existing batteries were

Japan, most of the limited funds available between 1933 and 1938 were spent on the Pacific coast, especially as several Japanese aircraft carriers
were operational by then. In 1939, the threat of war in Europe prompted larger appropriations and the resumption of work along the Atlantic coast.

M1918
on Panama Mount

A new weapon adopted by the U.S. during World War I introduced road and cross-country mobility to the Coast Artillery. The

155 mm gun M1918 (6.1 inch), closely derived from the French 155 mm GPF (Grand Puissance Filloux, or high-powered gun designed by Filloux), could be towed behind heavy Holt tractors and deployed to provide some protection for areas not part of existing harbor defenses. Each tractor-drawn regiment was authorized 24 of these weapons. Circular concrete platforms called "Panama mounts" were constructed in existing and new defenses to improve the utility of these weapons, particularly early in World War II.[62]

In anticipation of war, additional mines,

anti-aircraft guns were installed in 1940 and 1941. However, due to a general shortage, installation of new anti-aircraft guns at harbor defenses was minimal.[63] After the war began, the entire Western Defense Command was placed on high alert, but Japanese attacks, including two submarine deck gun
attacks and explosive balloons, caused only minor damage.

Anti-submarine nets, naval mines, and controlled mines protected many harbor entrances. Radar and patrol planes could detect enemy vessels at long distances, and aircraft became the first line of defense against intruders.

A coast defense exercise conducted in the

Submarine Base New London) in the defensive plan. Observation, bombardment, and pursuit (fighter) aircraft were included. The submarines had a dual reconnaissance and counter-attack mission; it was determined that these missions should be separated in future.[64]

Coast artillery weapons between World War I and World War II

The majority of Endicott and Taft period weapons remained in service between the wars. U.S. coast artillery introduced between the wars included:

World War II

Main article:
American Theater (World War II)

The

Singapore were locally effective; however, the Japanese simply attacked where there were no defenses and then enveloped the fortifications. Heavily fortified positions such as Japanese Rabaul
and Fort Drum in the Philippines demonstrated tactical success amongst strategic failures.

Fall of the Philippines

The

14-inch turret guns of Fort Drum and the 12-inch mortars of Battery Way and Battery Geary were probably the most effective coast defense weapons in the Battle of Corregidor
, but all but two of the mortars were knocked out before the Japanese landed on the island. The U.S. forces surrendered on 6 May 1942, after destroying their weapons.

Modernization

The outbreak of war in Europe in September 1939 and the

Fall of France in June 1940 greatly accelerated U.S. defense planning and funding. About this time a severe lack of design coordination resulted in the Iowa-class battleship being unable to use the Mark 2 and Mark 3 16-inch guns, and a new gun design was required for them.[67] With war on the horizon, the Navy released the approximately 50 remaining guns, and on 27 July 1940 the Army's Harbor Defense Board recommended the construction of 27 (eventually 38) 16-inch two-gun batteries to protect strategic points along the U.S. coastline, to be casemated against air attack, as were almost all of the older batteries by this time.[60][68]

16-inch casemated gun.
6-inch gun M1905 on shielded barbette carriage at Fort Columbia State Park, Washington state, typical of World War II 6-inch batteries.

The 16-inch guns were only the top end of the World War II program, which eventually replaced almost all previous coast defense weapons with newer (or remounted) weapons. Most of the 12-inch long-range batteries were casemated and served through the end of the war. Generally, each

40 mm anti-aircraft guns.[69][70] In addition to the proposed 38 new 16-inch (406 mm) batteries with a range of 25 mi (40 km), eleven new 8-inch (203 mm) batteries with a range of 20 mi (32 km) and 87 new 6-inch (152 mm) batteries on high-angle shielded mountings with a range of 15 mi (24 km) were projected.[71] All of these batteries had two guns each with heavily protected magazines and plotting rooms and casemated guns (except the 6-inch guns had shielded mountings). Additionally, about 32 8-inch MkVIM3A2 railway guns were deployed. In most cases replacing existing harbor defenses, with wartime changes noted, fortifications were planned for the harbor defenses of:[71][72]

East coast

Gulf coast

West coast

Other U.S. possessions or overseas

With

8-inch twin turrets removed from Lexington and Saratoga rather than the designed guns. As the areas of combat became more distant from the U.S. and as naval threats were essentially removed, defending harbors against ships became a low priority, and as the new coast defense batteries were completed, almost all of the older seacoast guns were scrapped to become new weapons. Many soldiers of the Coast Artillery were transferred to field artillery, anti-aircraft, or even infantry duties. When the war ended, it was soon decided that seacoast defense guns were no longer needed, and missiles would eventually fill the role. By 1947, most guns remaining in the seacoast defenses were declared surplus and scrapped, and the last weapons were removed in 1950 when the Coast Artillery was deactivated.[73][74]

Other coast defense operations

Two related aspects of seacoast defense in the early part of the war were coastal beach patrols in the continental United States (

CONUS) and the maintenance of mobile forces there to respond to potential enemy raids. The Coast Guard began these patrols after Pearl Harbor, and in early 1942 the Eastern and Western Defense Commands were assigned the equivalent of up to eight infantry regimental combat teams each for both beach patrols and mobile response. With a rapidly diminishing threat after 1942, by mid-1943 these forces were cut back significantly, and were mostly demobilized in early 1944.[75] On the night of 12 June 1942, a patrolling Coast Guard sailor observed German agents landing from a U-boat near Amagansett, Long Island, New York. Communication difficulties precluded an immediate response, but the four agents were rounded up over the next two weeks, along another four landed near Jacksonville, Florida on 17 June. Capture was made easier when two of the agents in New York decided to defect within a few days.[76] They were tried by a military court-martial, with six of the eight executed; one of the defectors received a life sentence and the other 30 years in prison.[77]

155 mm Long Tom gun "Scorpion" of the 4th Marine Defense Battalion in Barakoma, Solomon Islands
.

Besides the Coast Artillery, key islands in the

Okinawa and the Philippines in 1945 while one was activated in Trinidad; the remainder never left CONUS.[79]

Coast artillery weapons during World War II

U.S. coast artillery during World War II relied primarily on weapons purchased between the wars or stored since the aftermath of World War I. Essentially all of the Endicott and Taft period weapons were scrapped by late 1944 as new batteries were completed. The weapons deployed during the later part of the war included:

Postwar defensive missiles

Nike-Ajax missile
Nike-Hercules missiles
BOMARC missile site

Nike surface-to-air missile program was to act as a "last-ditch" line of air defense for selected areas. The Nike system would have been used if the Air Force's interceptor aircraft failed. With some anti-ship capability (especially the later nuclear-capable weapons), these were the last fixed-fortification weapons employed in the United States.[82]

BOMARC missile system following soon after.[82]

With the advent of numerous intercontinental ballistic missiles, the Nike and BOMARC systems were considered obsolete by the mid-1960s and the installations were removed in the early 1970s, ending nearly 200 years of American coastal defense.[82]

See also

Notes

  1. ^ Wade, p. 185
  2. ^ Wade, pp. 22-24
  3. ^ Wade, pp. 55-60
  4. ^ Wade, pp. 10-13
  5. ^ Wade, pp. 14-15
  6. ^ Ripley, Warren (1984). Artillery and Ammunition of the Civil War. Charleston: The Battery Press. p. 71.
  7. ^ Wade, pp. 137-139
  8. ^ Wade, pp. 115–44
  9. ^ Wade, pp. 130–31, 241–46
  10. ^ Wade, p. 152
  11. ^ Wade, pp. 178-179
  12. ^ Wade, pp. 177-178
  13. ^ Weaver, pp. 123-124
  14. ^ Weaver, pp. 3-5, 11-12
  15. ^ Fort McClary, Kittery Point, Maine
  16. ^ Also called Fort Taber
  17. ^ Weaver, pp. 5–9, 16–17
  18. ^ Weaver, pp. 53-54
  19. ^ National Park Service, Torpedo Defense - COAST DEFENSE OF THE POTOMAC
  20. ^ Ripley, pp. 17-44, 71-86
  21. ^ Ripley, pp. 109-136
  22. ^ Berhow 2015, p. 8
  23. ^ Chester A. Arthur, Second Annual Message to Congress
  24. ^ FM 4-15, Coast Artillery Field Manual - Seacoast Artillery Fire Control and Position Finding, U.S. War Department, 1940, Government Printing Office: Washington, DC.
  25. ^ a b c d e Coast Artillery Organization – A Brief Overview, Bolling W. Smith & William C. Gaines
  26. ^ Fort and Battery list at the Coast Defense Study Group website
  27. ^ Berhow 2015, pp. 180–183
  28. ^ Congressional serial set, 1900, Report of the Commission on the Conduct of the War with Spain, Vol. 7, pp. 3778–3780, Washington: Government Printing Office
  29. ^ Berhow 2015, pp. 86–87, 92–93, 201–219
  30. ^ Berhow 2015, pp. 423–427
  31. ^ Army Warrant Officer History
  32. ^ a b Ft. Miles, Principal Armament - Mine Field Archived 2012-02-27 at the Wayback Machine
  33. ^ Auxiliary Minelayers at NavSource.org
  34. ^ Berhow 2015, pp. 68–200
  35. ^ Allan R. Millett, Semper Fidelis: The History of the United States Marine Corps, (New York City, NY: The Free Press, 1991).
  36. ^ "4.7"/50 Mark 3 Armstrong at NavWeaps.com". Archived from the original on 30 September 2015. Retrieved 13 October 2015.
  37. ^ "6"/50 Mark 5 Armstrong at NavWeaps.com". Archived from the original on 8 October 2015. Retrieved 13 October 2015.
  38. ^ Berhow 2015, p. 222
  39. ^ US Army Coast Artillery Corps in World War I
  40. ^ Handbook of Ordnance Data, November 15, 1918, pp. 86-88
  41. ^ * Crowell, Benedict (1919). America's Munitions 1917-1918. Washington, DC: Government Printing Office. pp. 73–75.
  42. ^ Williford, pp. 92-99
  43. ^ US Army Railway Artillery in WWI
  44. ^ Hogg, pp. 139-140
  45. ^ Berhow 2015, pp. 70–71, 200–226
  46. ^ Smith, Bolling W. (Fall 2019). "The Driggs-Seabury 15-pounder (3-inch) Masking-Parapet Carriage". Coast Defense Journal. Vol. 33, no. 4. Mclean, Virginia: CDSG Press. pp. 12–18.
  47. ^ 69th Coast Artillery page at CAC WWI History site
  48. ^ a b Berhow 2015, pp. 200–226
  49. ^ Berhow 2015, p. 432
  50. ^ Berhow 2015, pp. 473–477
  51. ^ Coast Artillery Regiments at CDSG
  52. ^ CAC regiments 1-196 at the CDSG
  53. ^ National Guard CAC regiments 197-265 at the CDSG
  54. ^ Organized Reserve and Army of the United States Coast Artillery Regiments at CDSG
  55. ^ Kaufmann & Kaufmann 2004, p. 346
  56. ^ Miller, Vol. II, p. 109
  57. ^ Ordnance, pp. 147-149
  58. ^ Berhow 2015, pp. 61, 227–228
  59. ^ Berhow 2015, p. 227–229
  60. ^ a b Conn, pp. 45-55
  61. ^ Berhow 2015, pp. 194–195
  62. ^ Berhow 2015, pp. 190–191
  63. ^ Conn, p. 47
  64. ^ ""Minor Joint Army and Navy Exercises – Harbor Defenses of Long Island Sound", Coast Artillery Journal, July 1930, vol. 73 no. 1, pp. 18-26" (PDF). Archived from the original (PDF) on 2018-09-22. Retrieved 2018-07-26.
  65. ^ The Doomed Philippine Inland Seas Defense Project
  66. ^ Account of the 8" railway guns in the Philippines, 1940-42
  67. ^ Friedman, pp. 311-313
  68. ^ Berhow 2015, pp. 176–177
  69. ^ Berhow 2015, pp. 80–81, 256–258
  70. ^ McGovern and Smith, p. 43
  71. ^ a b c Berhow 2015, pp. 229–231
  72. ^ Kirchner, D.P., CDR USN and Lewis, E.R., Capt USAR (January 1968). "American Harbor Defenses: The Final Era". United States Naval Institute Proceedings. {{cite journal}}: Cite journal requires |journal= (help)CS1 maint: multiple names: authors list (link)
  73. ^ Conn, pp. 47-54
  74. ^ Lewis 1979, p. 132
  75. ^ Conn, pp. 100-101, 107-110
  76. ISBN 978-0-307-42755-7
    .
  77. ^ Conn, pp. 99-101
  78. ^ Indicator loops website
  79. ^ Stanton, pp. 449-450
  80. ^ Cold War AAA Defenses of New York City at American Forts Network
  81. ^ "US Army AAA Gun Site Program 1951-59 at Ed-Thelen.org". Archived from the original on 2020-09-16. Retrieved 2019-01-11.
  82. ^ a b c Morgan & Berhow 2002

References and further reading

  • Berhow, Mark A., ed. (2015). American Seacoast Defenses, A Reference Guide (Third ed.). McLean, Virginia: CDSG Press.
    ISBN 978-0-9748167-3-9
    .
  • Browning, Robert S., III. Two If by Sea: The Development of American Coastal Defense Policy (Praeger, 1983)

External links

Wikisource has the text of The New Student's Reference Work article "Coast-Defense".
Wikimedia Commons has media related to Coastal artillery in the United States.
Wikimedia Commons has media related to Forts in the United States.
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