A century of guarding SF from attack (photos)

Road Trip at Home: A photo tour of the coastal fortifications that once protected America's most valuable Pacific port.

Daniel Terdiman
1 of 32 Daniel Terdiman/CNET

Raising the gun

SAN FRANCISCO--The days when our greatest fears were that the Japanese or some other then-enemy might invade our coasts or attack from the oceans are long gone, and so it's easy to forget that much of the first half of the 20th century was spent preparing for just such an occurrence. In fact, worries that we had to protect the coasts from attack lasted well into the Cold War.

Yet while many people never knew about that history, or had long forgotten it, the relics of a century of coastal fortifications are still very much in evidence in and around San Francisco.

Today, San Francisco is thought of mainly as a picturesque tourist destination. But for decades, it was considered America's most valuable Pacific port and was home to a wide variety of military installations. As a result, military planners put a huge amount of energy, starting in the Civil War era, into protecting the Pacific coast from invasion or attack.

And that's why there is a treasure trove of old batteries and other remnants of original fortifications up and down the coast in and around the city.

This is a 6-inch disappearing gun that is mounted at Battery Chamberlin, in the shadow of the Golden Gate Bridge, in San Francisco. This battery was meant to protect some of the city's most exposed beaches from direct attack from the open Pacific Ocean. The gun, while an original, was placed at Battery Chamberlin in the 1970s, when the site was opened to the public as a museum.

It was called a disappearing gun because it was meant to be housed low to the ground and invisible to the sea, and was raised up only when firing. When it would discharge its six-inch shell, it would recoil back down low to the ground. The idea was to protect the gun itself from attack, and to keep the lowest possible profile.

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Battery Spencer

Battery Spencer, which is located in the Marin Headlands just north of San Francisco, is one of the most famous spots for viewing the Golden Gate Bridge. It was completed in 1897, and named for Joseph Spencer, who was an army major general during the American Revolution.

Today, there are no weapons left at Battery Spencer, but in its time it had three 12-inch rifled guns. The site was in continuous service until 1943, when the military decided it was obsolete. Its guns were scrapped, and it was closed as a military site. Today, thousands of people walk through and over it in order to get one of the most incredible views of the Golden Gate Bridge possible.

3 of 32 <a href="http://www.flickr.com/photos/90887373@N00/">Ryan Salsig</a>

Fort Point

Just at the south end of the Golden Gate Bridge is Fort Point, which, according to the National Park Service, has "stood guard at the narrows of the Golden Gate for nearly 150 years. It has been called 'the pride of the Pacific,' 'the Gibraltar of the West Coast,' and 'one of the most perfect models of masonry in America.' When construction began during the height of the California Gold Rush, Fort Point was planned as the most formidable deterrence America could offer to a naval attack on California. Although its guns never fired a shot in anger, the 'Fort at Fort Point' as it was originally named, has witnessed Civil War, obsolescence, earthquake, bridge construction, reuse for World War II, and preservation as a National Historic Site.

"Fort Point was built between 1853 and 1861 by the U.S. Army Engineers as part of a defense system of forts planned for the protection of San Francisco Bay. Designed at the height of the Gold Rush, the fort and its companion fortifications would protect the bay's important commercial and military installations against foreign attack. The fort was built in the Army's traditional 'Third System' style of military architecture (a standard adopted in the 1820s), and would be the only fortification of this impressive design constructed west of the Mississippi River. This fact bears testimony to the importance the military gave San Francisco and the gold fields during the 1850s."

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Battery Chamberlin gun

Although this 6-inch gun was not originally at Battery Chamberlin in San Francisco, seen here, the battery was armed in 1904 with four of this type of gun.

In 1917, Battery Chamberlin was temporarily decommissioned because World War I was nowhere near the Pacific Coast, and the U.S. Army needed its troops in Europe. But in 1920, the battery was re-commissioned with two 6-inch guns like this one, each of which had a 10-mile range, and which had a maximum rise of 15 degrees.

It took 25 men to operate each of the guns, and the Army installed bunks nearby so that crews could work week-long shifts.

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Looking out to sea

Battery Chamberlin, seen here from above and behind, is situated along San Francisco's Baker Beach and has a clear view of the Pacific Ocean.
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Defenders of the Golden Gate

This flag hangs inside Battery Chamberlin and commemorates the battery's decades of service. It was finally closed as a military site in 1948, and opened as a National Park Service museum site in 1974.
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The gun and the Golden Gate Bridge

This historical photo, which can be found inside Battery Chamberlin, shows one of the site's original 6-inch guns at the ready, with the Golden Gate Bridge in the background.
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How the disappearing gun works

This graphic explains how the concept of the disappearing gun works. According to the National Park Service, "the disappearing carriage is a unique characteristic of Endicott period [starting in 1885] fortifications. Many larger caliber guns used this carriage. First invented in Europe, it was perfected in America with the addition of a counterweight system. A pair of massive steel arms connect the barrel and a lead counterweight. In loading or 'service' position, the gun is held down behind a protective parapet and the counterweight is suspended above a well. When the gun is released, the counterweight falls into the well, swinging the gun up into firing position. The recoil from firing then pushes the gun back into service position."
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Carrying the gun barrel through San Francisco

This historical photo, found inside Battery Chamberlin, shows one of the original 6-inch gun barrels being carried rails through the streets of San Francisco.
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Expanding gun reach

This graphic shows the range of the big guns during several different periods, including the cannons of the Civil War era, the 12-inch guns of the Endicott period, and the 16-inch guns of World War II.
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Battery Townsley gun 1

Armed with two 16-inch guns in 1939 in preparation for World War II, Battery Townsley, located in the Marin Headlands just north and west of San Francisco, was meant to give the U.S. military a 25-mile range for shooting incoming attackers.

The gun areas were covered by giant cement casemates intended to protect the guns from aerial attack. One of the big guns was mounted here, though it has long since been taken away.

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16-inch gun at Townsley

This historical photo, found inside Battery Townsley, shows one of the two 16-inch guns that were mounted during World War II at the battery.
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Battery Townsley cutaway

This image depicts the layout of Battery Townsley. Each end of the battery featured one of the 16-inch guns, and the chambers in the interior housed powder, shells, generators, and more.
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16-inch casemated battery

This graphic depicts a 16-inch case-mated battery, such as was found at Battery Townsley.
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Installing gun 1

This historical photo found inside Battery Townsley shows crews installing the first of the two 16-inch guns that were housed at the site.
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16-inch shells

This is a mock-up of one of the chambers inside Battery Townsley, in which the 16-inch shells were kept.
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Overhead ammunition rails

The rails that run along the ceiling of the passageway between the two guns at Battery Townsley were designed to transfer the very heavy ammunition shells.
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Azimuth scope

This is an azimuth scope, from Battery Townsley. It was used to spot the splash of a shot from the 16-inch gun, and then that information was sent back to the plotting room so that the crew could correct for the next shot. No shots were ever fired in anger from Battery Townsley.
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Machine gun nest

One of the most exciting elements of the wide variety of coastal fortifications that can be found in the San Francisco area is the recent discovery of previously unknown World War II machine gun nests, some of which are within feet of roads through the city's Presidio. Here, the machine guns--probably a .50 caliber weapon--were mounted on the pillar that can be seen here, and were most likely placed where they could cover important roads--like this one--or crucial beaches.

The National Park Service is trying to weigh the balance between allowing the public to visit these sites, and the potential danger of damage to delicate areas of having thousands of people walking through.

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Anti-aircraft gun site

At this Marin Headlands site, there was a 40mm anti-aircraft gun during World War II. Today, the pit remains and is accessible to the public--though it is not all that easy to find. This picture shows that crews here had an advantageous field of view out to the Pacific Ocean.
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Machine gun nest at top of hill

This is another World War II-era machine gun nest, this time at the top of a hill in the Marin Headlands. This was placed there mainly to protect Battery Townsley, which is located a bit down the hill.
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Gun at the top of the hill

Another former gun placement site at the top of a Marin Headlands hill. From this location, crews had a wide field of view that included the approaches from the Pacific Ocean, as well as the entrance into the Golden Gate. In the background, you can see San Francisco, and in the upper left hand corner, the Golden Gate Bridge.
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Harbor Defense Command Post

Hidden in San Francisco's Presidio, just across the road from a major trailhead and parking spot, this is the World War II-era Army's Harbor Defense Command Post and Navy's Harbor Entrance Command Post. It is easy to see from the road--if you know it's there.
24 of 32 Daniel Terdiman/CNET

Nisei school sign

This sign commemorates the U.S. military's Intelligence Service Language School, which was based in San Francisco's Presidio, fairly close to Fort Point. From November 1941 to April 1942, 6,000 Japanese-American soldiers attended this school--which trained them in Japanese language skills for the war effort against Japan.
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Nike missiles

From 1954 to 1975, the U.S. Army maintained Nike missile sites in the Marin Headlands, as well as in other parts of the San Francisco Bay Area and in other regions of the country. Today, the site known as SF-88L is the only remaining Nike missile site in the country, and is currently a National Park Service museum. But when it was operational, it was a highly-secure site that maintained both Nike Ajax convention missiles, and Nike Hercules missiles, which could carry either conventional or nuclear warheads.

These missiles were seen as a last line of defense against nuclear bombers with which the Soviet Union might have attacked the U.S. during the Cold War.

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Nike missile sites map

This map depicts the locations of several Nike missile sites during the Cold War period.
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The mascot of the Army's Air Defense Artillery program was a bird called the Oozlefinch. Its motto was "If it flies, it dies," a term that was appropriate given that the program was built around surface-to-air missiles designed to protect American cities.

This Oozlefinch is from the Nike missile site in the Marin Headlands, but another Oozlefinch can be found inside Battery Townsley, which is close by the Nike site but which protected the Pacific coast during World War II, rather than during the Cold War.

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Korean War bomb shelter

This tunnel, found high up above the Marin Headlands--and near Battery Townsley--is a Korean War-era bomb shelter built for the crew of an anti-aircraft battery.
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Korean War gun nest

This is a Korean War-era gun nest, found in the Marin Headlands.
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Battery Mendell

This is Battery Mendell, found in the Marin Headlands. According to the National Park Service, "Battery Mendell's mission was to keep enemy warships farther from San Francisco's harbor than any of the earlier coastal defenses were equipped to do. Built in 1905, the battery was positioned as far west on the headlands as possible and armed with the biggest guns in America. The two 12-inch cannon could hit vessels 8 miles out to sea.

"Battery Mendell was designed for 'disappearing guns' that rose up for firing and then dropped back down behind the protective parapet. That ensured greater cover for both the weapons and troops than older batteries had provided. However, new technology, such as that employed at [the] nearby Battery Wallace...soon enabled high-angle fire. This near doubled the distance guns could shoot."

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Battery Mendell layout map

This is a layout map of Battery Mendell, in the Marin Headlands.
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Battery Wallace

Battery Wallace at Fort Barry was armed around 1918, and disarmed in 1948. It had two guns.

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