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Potrero Point

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Potrero Point

Potrero Point San Francisco is the location of the earliest and most important industrial facilities in the Western United States on the eastern extension of San Francisco's Potrero Hill, a natural land mass extending into San Francisco Bay south of Mission Bay. Potrero Point, the point of Potrero Hill, was systematically blasted and cut, its serpentine cliffs removed. The work yielded two square miles of rock for fill and hundreds of acres of flat industrial land east of Illinois street between 20th Street and Islais Creek.


Map of Potrero Point, San Francisco, CA 94107, USA

The region has been in regular industrial use since the 1860s, first as a location of a powder magazine and small maritime industries along the steep shoreline and early industries such as Pacific Rolling Mills, and later the famous Union Iron Works plus shipyards and related production, service and shipping-related industries, coal- and gas-fired power plants and energy generating facilities that eventually became Pacific Gas and Electric (PG&E).

Centered along Twentieth Street at Illinois Street, the site contains the most extraordinary example of an historic industrial village still extant in the West. The first locomotive, typewriter, printing press, cable car equipment, the famous battleship Oregon and steel for many of San Francisco's 19th century buildings came from the Potrero.


Potrero Point, formerly Point San Quentin, was a peninsular extension of Potrero Hill on the south east side of the city of San Francisco. Potrero Point and surrounding areas have changed drastically over the past 150 years, with a small hill being all that remains.

Potrero Point drew the attention of industrialists after the California Gold Rush because it had cheap land isolated from the densely populated city center and because of its natural deep water access. Industrialists and speculators sought to exploit Potrero Point's natural advantages and to overcome the obstacle caused by the swampy Mission Bay. The natural contour of the bay shore was changed by filling, with much of the fill material was taken in the process of blasting away the serpentine hills that once rose above the point. The steep camel-back ridge extending into the bay offered deep water access connected to the Potrero Hills, the site was first cut off by the Third Street cut, and later leveled for land building.

The geography of the bay shore, with Mission Bay cutting off Potrero Point and much of the southeastern portion of the city led to the construction of Long Bridge in 1868. The bridge connected Potrero Point to the city, and extended further south to the Bayshore district. Eventually, Mission Bay was completely developed, and the shoreline south of Potrero Point was altered dramatically to suit the intense industrial construction taking place.

Early history

By virtue of its geography, the point was a natural potrero. The Mexican landowner, Don Francisco de Haro, owned Rancho Potrero de San Francisco and ran sheep and cattle on the land for many years. After the conquest of California by the United States in the Mexican-American War, a protracted legal struggle ensued and the DeHaro family eventually lost their claim to the land.

In 1863, development along the banks of Potrero Point consisted of two powder magazines on the southern side of the steep peninsula, located so as to keep dangerous commodities away from populated areas. Heavy industry first located on the point in 1866 when six wealthy San Francisco industrialists came together to organize the Pacific Rolling Mills with the plan to roll iron from scrap, in the hope of producing homegrown iron products, including railroad iron. Access to deep water was a necessity for delivering coal from Australia to fuel the mills, firebrick and clay from Liverpool and scrap iron from around the Pacific Rim and as far away as England.

There was a lack of level ground at the site, and cutting and leveling the hill and filling in the bay became a top priority. Eventually, two square miles of Potrero Point were removed and hundreds of acres of flat industrial land was created. Within two years and after one million dollars in expenses, foundries, piers, storehouses and wharves were in place, and the first finished iron produced on the West Coast came out of the mill.

San Francisco's population growth increased along with the demand for iron products, and with the growth of railroads and street cars on the west coast, the output from PRM doubled, and doubled again. By 1873, the mill turned out rod, wire, shafts, axles, I-beams, wrought iron and hammered iron of every type needed by the growing metropolis. By the end of the 1880s the mill had five main buildings along three blocks of waterfront and employed a thousand men. Potrero Point quickly became the site for some of California's most important heavy industries, including shipbuilding and the manufacture of mining machinery, while the hill continued to be cut and the bay mudflats filled. Submarines were built nearby the Potrero Union Iron Works shipyards.

World War I

Union Iron Works output during World War I was important, and included a large number of destroyers. The Shipyards, all ships in progress and the 9,000 workers were commandeered by the United States Navy in August 1917 for the war effort, run by the Shipping Board with the happy acquiescence of Bethlehem Steel, holder of $130 million in Government contracts. From 1917 to 1924, when the government contracts were filled, the Potrero yards turned out twenty-six 1060-ton destroyers, forty 1190-ton destroyers, twelve "S" type submarines and six "R" type submarines, according to Bethlehem Steel (1949). On July 4, 1918, four destroyers were launched and four keels laid at the Union Iron Works yards, and four destroyers launched and four keels laid at the Risdon yards.

From 1914 to 1945 the northern parts of Potrero Point were the scene of major shipbuilding, repair and refitting. The Union yard was continually busy and was the principal yard in San Francisco for repairs. Between the wars, shipbuilding, and especially refitting, continued at the Potrero yards.

World War II

Before 1941, the shipyard at what is now Pier 70 produced some of its best ships. By the late 1930s, though, with war looming, Bethlehem began to modernize and upgrade the Potrero Yard. A number of new buildings were constructed, and by the time World War II began Potrero was one of the most productive shipyards in the country. During World War Two, the government once again took over the Potrero Point yards for the war effort. During the war, up to 4,000 men and women were employed, working three shifts a day. Finding skilled workers during wartime was a huge challenge, and much was done to train new workers, and to organize shipbuilding so that less skilled people could do what the highly skilled people had done before. At the height of the war effort productivity was tremendous: the destroyer escort Fieberling was built in 24 days, start to finish. Though Liberty ships and other simpler ships could be built faster, to build a modern warship in that amount of time was an incredible achievement. During the war, Bethlehem's Potrero yard produced 72 vessels (52 for combat) and repaired over 2,500 navy and commercial craft.

Bethlehem Shipyards, along with Alameda and Hunters Point, managed by Bethlehem, made the San Francisco Bay Area the most productive shipbuilding area in the U.S. during World War II.

Postwar era

After an intense period of ship repair and refitting during the war years, the Potrero point shipyards went into slow decline. From 1947 to 1953, no shipbuilding occurred and the yards became places for ship repairs, upgrades and commercial work. In the 1960s, a staging area for the Bay Area Rapid Transit underwater tube sections was established. In the 1960s, Bethlehem Steel built the largest floating drydock in the world at the Potrero site. In the 1980s, the city of San Francisco purchased the property for one dollar and the Todd Shipyard Corporation bought the plant and the equipment for $14 million and leased the site from the city. Currently, work is carried out under the name San Francisco Drydock Company.

Major businesses

Pier 70 in San Francisco is currently occupied by BAE Systems Ship Repair, which once housed the SS Oceanic, and Sims Group, a metal operator, and the Port of San Francisco currently has plans for redevelopment.

Potrero Generating Station

The Potrero Generating Station, located at the site of the first electrical power plant in California, was a 362 MW natural gas- and oil-fired power plant which supplied approximately 1/3 of the City of San Francisco's power needs. The plant was shut down in January, 2011.

Union Iron Works

The Union Iron Works, located on Potrero Point is the longest running privately owned shipyard in the country. It built the first steel hulled ship on the West coast. It also constructed several famous warships including the Olympia and two Plunger class submarines.

Manufactured gas

In 1872, Pacific Rolling Mills was joined in the Potrero by the City Gas Company, a coal gasification plant built to supply gas for lighting the city. Coal (and later fuel oil) steam generation was used to generate heat, power and electricity. The gas plant in the Potrero was for many years the largest and most important gas manufacturing plant in San Francisco. Construction began in 1870 on lots between Humboldt and Sierra streets (later renamed). Originally a coal-gas works, Springer water-gas generators were added in 1888. By 1905, PG&E had consolidated much of the power generation in the state, including the Potrero works. After the 1906 removal of the coal-gas retorts, the Potrero plant became an oil-gas facility. For fifty years the Potrero plant used gasification to drive steam turbines and power the city of San Francisco.

In 1930, transporting natural gas over long distances was employed in California, and natural gas arrived at Potrero. The Potrero gas works were put on standby status until their demolition in the 1950s.

California Sugar Refinery

Claus Spreckels, a German immigrant, began sugar production in 1867. The California Sugar Refinery outgrew its facilities at Eighth and Brannan streets and in 1881, moved to the southern part of Potrero Point where they had deep water access for the ships filled with cane from the Hawaiian island cane farms Spreckels controlled. In the 1890s, Spreckels joined with the national sugar trust. The refinery in the Potrero was renamed the Western Sugar Refinery. The huge Victorian-era brick refinery buildings were in use until demolished in 1951.

California Barrel Company

Among the variety of maritime related industries in the Potrero was a quarter mile long ropewalk and the "California Barrel Company," With five large buildings, the barrel company had three warehouses, a power generating house and the factory itself.

Other businesses

Also dating from the 1850s was the 1,000-foot-long (300 m) ropewalk of the Tubbs Cordage Company at the southern edge of Potrero Point. It was founded by two brothers in the ship chandlery business who realized the west needed rope for its growing maritime industries. They recruited a group of skilled workers from New England who formed the core of the Tubbs workforce for decades. Tubbs imported raw materials from the Philippines and became a world-wide concern. Numerous other maritime related industries had their works at Potrero.


The labor history of the shipyards at Potrero is not well documented. Bethlehem Shipbuilding, like the Union Iron Works, fought hard to keep unionization out of the shipyards. Strikes, some of them protracted, occurred periodically throughout the active shipbuilding period, including during the war years and immediately after. One important strike in the spring of 1941 halted major naval shipbuilding for a month and a half, leading to the intervention of President Roosevelt in efforts to end the strike. Members of the machinist union's local resisted the federal government and their own national leaders and persisted in the strike. They succeeded for the first time in achieving a closed shop at Bethlehem.

Environmental concerns

Beginning in the 1870s, the manufactured gas plants, iron foundries, steel mills, naval and civilian shipyards, steam generating plants, powder magazines, allied maritime manufacturies and a sugar refinery in the Potrero burned tons of coal, coke, lampblack and later millions of gallons or cubic feet of crude petroleum, refined oil and natural gas in dozens of open hearth furnaces, forges, steam boilers, retort kilns, coke ovens, gas generators and sugar boilers.

These industrial concerns, especially the manufactured gas plants(MGPs) that produced gas for gaslight and power, steam and electricity, poisoned the air and bay waters, the soil and the surrounding communities for decades, leaving behind huge quantities of hydrocarbons, sulphur, acids, powdered carbon, ash, slag, manganese, mercury, lead, copper, cadmium, zinc and other heavy metals. The facilities and their outdoor coal and lampblack stores, tar and fuel oil tanks polluted vast areas of bay mud, artificial fill and millions of gallons of fresh and salt water. Constant dumping and dredging of polluted fill spread the problem to the entire Potrero shoreline while approximately two square miles of Potrero Hill was dynamited and dumped into the bay.

The PG&E plant produced millions of cubic feet of manufactured gas per year from coal and later, oil and natural gas. By 1878, it was consuming nearly 300,000 pounds of coal each day and had an ash pit 200 feet (60 m) long to catch flyash and cinders. By 1905 they produced 4 million cubic feet (110,000 m3) of gas per day. By 1911, they had a capacity of 20 million cubic feet (570,000 m3) per day. The first method of manufacturing gas for urban users utilized coal gasification (1870 to 1907), then oil-gas generators (1888 to 1907), water-gas generators from 1904 to 1915, newer oil-gas generators from 1906 to 1924 and still newer oil-gas generators from 1915 until natural gas was discovered and imported into the Bay area in 1930 and the gas plant was placed on standby. The last time it was fired up was in 1953 and the entire MGP was dismantled in the late 1950s.

The MGPs were built on unpaved soil, their waste stream of coal dust, unburned carbon and lampblack were reused as fuel, dumped into the bay to the east or sent south by the trainload where it was mixed with soil and quarried stone to fill Islais Creek and build new land on bay mud from Army Street (now Cesar Chavez Street) to Candlestick Point east of what is now Third Street. Standard practice of the day was for cinders and ash from the furnaces to be given away or sold for road grading.

The PG&E property in the Potrero lacks a continuous seawall, allowing bay tidal action to twice daily flush the polluted fill. The underground remnants of the shipyards, steel mills, sugar refinery and coal and oil gas production at the mills and the two MGPs is a labyrinth of highly polluted buried coal tramways, distribution tunnels and conduit, remains of huge ash, coal and coke storage pits, coal bunkers, foundations from fuel oil holders, acid and boneblack storage, wooden catchments, fuel lines, underground storage tanks, concrete vaults and sumps. Many were abandoned in place and simply filled in.

These industrial artifacts lie among thousands, if not tens of thousand of wooden piles and railroad ties, abandoned wharves and piers, chemically treated against limnoria and other creatures. The piles are a reverse porcupine of Douglas fir poles, many up to one hundred feet deep, contaminated with a wide array of wood preservatives from arsenic to lead to creosote to crude oil, providing a study in the history of wood preservation technology. Removal would create a direct vertical channel to the deepest bay muds and leaving them in place will continue the downgradient flow of tainted ground water into the bay.

Historic Station A, the huge 1910 brick edifice visible from the surrounding neighborhood, once a state-of-the art oil-fired electrical generating facility, provides evidence of the constant rebuilding in the area as technologies changed. Station A was abandoned in 1979 and remains saturated with PCBs and other pollutants.

Previous dredging at the shipyards during the 1970s was required to be deposited at sea beyond the waters of the state of California. The environmental legacy includes pollution from the Navy's tenure during both world wars through the 1960s and includes illegally dumped wastes in the pier 70-72 landfill.

On top of the historic pollution, more recent insults in the Potrero include sandblasted lead paints in the shipways, leaking waste barrels and underground diesel oil storage tanks. In 1986, the shipyard was sued by the city for mishandling PCB-laden electrical equipment and periodic discharges of raw sewage.

Currently, the city uses the area for storage of towed and abandoned automobiles that leak fluids onto broken pavement that drains toward the bay. The Pick Your Parts Auto Dismantler resides on dirt lots adjacent to the working Mirant power plant, and a toxic dump exists at what was called the Wilson Warehouse to the north.

Numerous trucking companies and a truck marshaling yard, covered by asphalt and pierced by pollution test wells, lie directly north of the PG&E (now Mirant) power plant on former Naval ship building ways that were backfilled in 1970 with construction rubble, soil, concrete and non-permitted wastes. Chemicals found in limited testing in bay mud and in the old Navy slips include hydrocarbons, benzene, toluene, ethylbenzene, chlorobenzene, and xylene. Other wastes identified include paint, oil, batteries, thinner, adhesives, herbicides, acids, and unknown 55-US-gallon (210 L) drums. The two major owners of the filled land in the Potrero are the Port of San Francisco and PG&E, before selling out to Mirant. The environmental liabilities still belong to PG&E.

The Potrero Hill, Dogpatch and Hunter's Point neighborhoods abut the Potrero Point industrial district. The Port of San Francisco has failed in its responsibility to preserve remnants of this once-thriving industrial village, for a hundred years the most important heavy industry site in the west, now suffering vandalism, earthquake risk, exposure to the elements and official neglect. The Port claims they cannot landmark a working shipyard, but the San Francisco Drydock Company has relinquished all of the historic properties and most of the land back to the Port.

Historic buildings

Potrero Point is eligible for the National Register as an historic district for its contribution to three war efforts (Spanish–American War, World War I & World War II) and because of the 19th century buildings that remain. Some of the buildings are individually eligible for landmarking for their architectural and historic merit. Worthy of historical landmark status are the 1917 Frederick Meyer Renaissance Revival Bethlehem office building, the Charles P. Weeks designed 1912 Power House#1, the 1896 Union Iron Works office designed by Percy & Hamilton and the huge 1885 Machine shops.


Potrero Point Wikipedia

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