A Digital Journal - San Francisco Public Works
In the Works
August 2024
Not well-known but critically important in San Francisco’s firefighting arsenal are a handful of metal contraptions known as manifolds, which are strategically placed around the City – including on Treasure Island. They allow fireboats to pump water from the Bay to battle big blazes. The City is replacing the network of old ones to bolster resiliency, with a Public Works engineer helping lead the charge.
FEATURE STORIES
High Pressure Upgrades to Vital Firefighting Network
For the first time in nearly a century, San Francisco is overhauling a crucial part of its emergency firefighting apparatus – with the help of some Public Works engineering and design know-how.
SFPD Gun Range: Public Works’ Inspection and Repair Teams Hit the Target
Four times a year, Public Works engineer Alfonso Aguilera grabs a hammer and heads to the San Francisco Police Department’s firearms range for inspections.
Smooth Operation
With the stars aligned, Public Works’ in-house street repair crews jumped into action and made quick work of an expedited roadway paving project in the Marina – earning praise from neighbors.
#LoveOurCity
This month’s Love Our City: Neighborhood Beautification Day had an added bonus: In addition to the volunteer workday projects greening and cleaning the South of Market, our Street Tree Nursery hosted a lively open house, packed with free, fun and family-friendly activities.
Fire crews connect hoses to an existing manifold near Islais Creek.
High Pressure Upgrades to Vital Firefighting Network
For the first time in nearly a century, San Francisco is overhauling a crucial part of its emergency firefighting apparatus – with the help of some Public Works engineering and design know-how.
In the wake of the devastating 1906 San Francisco Great Earthquake and Fire, it became clear the City needed an emergency water supply that can function after a major temblor to aid in firefighting efforts. City leaders devised a standalone system now known as the Emergency Firefighting Water System.
It includes a resilient 135-mile high-pressure pipeline network, a 10.5 million-gallon reservoir at Twin Peaks, two large-capacity storage tanks, underground water storage tanks, also known as cisterns, about 1,600 dedicated high-pressure hydrants, two high-pressure seawater pumping stations and a handful of manifolds that allow fireboats to pump Bay water into the City’s pipelines. Manifolds can also be directly connected to hoses used by firefighters to put out blazes.
A manifold for up to five hoses on the St. Francis fireboat.
In the 1930s, the City began to strategically install the five cast iron fireboat manifolds along its northeastern shore, from Fort Mason to Islais Creek. But some of the existing manifolds are at risk of being destroyed during a major earthquake due to their locations. And additional manifolds are needed to provide adequate access and coverage.
“This is part of our defense against major fires, especially after an earthquake, when there’s no other water sources available,” said Michael Smith, a Public Works engineer who designed the first new manifold, which was installed at Treasure Island earlier this year.
In this undated photo from decades ago, firefighters test a hose tapped into the emergency water system. (Courtesy San Francisco Public Library)
'No one’s made one of these since the ‘30s'
A new mixed-use development is taking hold on Treasure Island, a former U.S. Navy station in the middle of the Bay between San Francisco and Oakland. The artificial island, which was built out of Bay mud and boulders by the Army Corps of Engineers for the 1939 Golden Gate International Exposition, is fed by a domestic water supply that runs through pipes across the Bay Bridge.
If the line is severed during a major earthquake, Treasure Island would lose its water source.
Other manifolds – like the existing one at Fort Mason, which sits on federal land – are situated in precarious locations. The plan is to install new ones in safer locations.
The Fort Mason manifold is located at the end of a 1930s-era pier that hasn’t been seismically retrofitted. During a major earthquake that could lead to far-reaching problems.
The new Treasure Island manifold location is shown during construction.
The fear, Smith said, is that an earthquake may cause the pier to collapse into the Bay. That means not only would fireboats be unable to pump water into the manifold, the shaking also could cause damage to the wider network by dragging piping into the Bay and draining part of the system of precious water.
The reason the original Fort Mason manifold was placed at the end of the pier had to do with the fort’s troop transport ships that once frequented the waters during World War II, Smith said.
“If there was a fire, it was going to be very difficult for a fireboat to go between the freighters,” he said. “So they had to put it as far out as possible.”
The new Fort Mason manifold instead will be placed on land, behind the seawall between Piers 2 and 3.
Smith had to fashion the manifold in a way that allows it to be easily maintained, repaired and operated. He had to make sure, for instance, that the space between individual outlets and inlets was sufficient. “So firefighters can actually connect the hoses,” he said.
Smith also incorporated a traditional look in the design to give a nod to history.
The Fort Mason manifold project is still in the planning phase. The Treasure Island one, however, already has been successfully installed and because it was the first to be completed, its pattern will be able to be reused for the other new manifolds.
Crews install the new manifold on Treasure Island.
“This is a pilot project,” Smith said. “No one’s made one of these since the ‘30s.”
The project required close coordination and collaboration among the Fire Department, the San Francisco Public Utilities Commission, which operates the City’s Water Department, and the Public Works mechanical engineering team. A consultant performed a finite element analysis of the manifold to make sure it has the right thickness and corners so the structure doesn’t fail under pressure. Public Works’ structural engineering section designed the reinforced concrete blocks that support the manifold.
The process involved lots of reviews and back-and-forth with the fire and water departments, Smith said. “We wanted to make sure we got it right.”
Instead of cast iron, the new manifolds are made out of ductile iron, which is stronger, more impact-resistant and less likely to corrode, Smith said. “So you can use a thinner wall.”
The new manifold – which is about 12 feet long and bolted onto reinforced concrete blocks – includes six 5-inch hose inlets, a 20-inch discharge outlet, two 5-inch outlets for a portable hose system and two 3½-inch outlets to supply hoses similar to a high-pressure hydrant. But unlike a conventional fire hydrant, built to release about 1,500 gallons of water per minute, the manifolds can move about 18,000 gallons of water per minute, arming emergency crews with the needed force to douse big blazes.
Instead of cast iron, the new manifold is made out of ductile iron.
The manifold body is cast from three ductile iron castings with 300-pound flanges. Wafer check and butterfly valves are used for the hose inlets and outlets, respectively. The check valves prevent draining of the manifold when hoses are not connected and butterfly valves allow for the use of hoses.
The new manifold was cast and manufactured by Seattle-based Olympic Foundry. The Treasure Island manifold cost about $500,000 and was primarily paid for by developers of the new Treasure Island neighborhood. Subsequent manifolds are expected to have a price tag of about $300,000 since the original pattern from Treasure Island will be reused.
A new fireboat manifold also is planned in Mission Bay near Chase Center. And, much like at Fort Mason, an existing manifold at Pier 33½ will be replaced because daily exposure to saltwater splashing from the Bay has led to corrosion of its pipe and supports, Smith said.
From dynamite
to cisterns
The fireboat manifolds are an integral part of the larger Emergency Firefighting Water System.
After the violent 7.9-magnitude earthquake rattled the Bay Area in April 1906, firestorms – fueled by broken gas lines – raged for days in San Francisco. The City struggled to put out the blazes without a reliable, functioning water supply. Officials scrambled for alternate solutions.
“Approximately one hour after the earthquake, the San Francisco Fire Department sent a messenger to the Presidio to request an artillery division to assist with the containment of fires,” according to the National Park Service’s website. “Several hours later, artillery troops from Fort Miley arrived in San Francisco and unsuccessfully attempted to control the fires by dynamiting strategic buildings. By noon, the financial district was engulfed in flames and when evening fell the city center had also been incinerated.”
The inferno proved to be even more damaging than the initial shaking. Approximately 80% of San Francisco’s total loss was attributed to the fires.
The remains of the Phelan Building were dynamited on April 20, 1906. (Courtesy of Bob Bowen Collection)
In the decades that followed the catastrophic earthquake, San Francisco leaders have focused on making the City more resilient in the face of the next major quake, from seismically retrofitting public safety facilities to expanding and upgrading the Emergency Firefighting Water System.
Initially referred to as the Auxiliary Water Supply System, it was first installed in 1913. The system was originally proposed by San Francisco Fire Department chief engineer Dennis T. Sullivan in 1903, according to a SFPUC blog. But construction did not begin until 1909.
The City's underground cisterns can be identified by the circular brick demarcations in the asphalt above.
Dedicated Emergency Firefighting Water System hydrants with special color markings dot the City. More than 200 cisterns – large underground water storage tanks with a typical capacity of 75,000 gallons – are also part of the emergency firefighting infrastructure. The cisterns are not connected to the City’s regular piping systems; the stored water is pumped from the cisterns by fire engines to fight fires. They are often easy to spot because of circular brick demarcations in the asphalt.
“The cisterns are separate structures that the Fire Department can use to siphon water from,” said Smith who has been with Public Works for 34 years and does much of the Emergency Firefighting Water System design work for the department. “But then this emergency firefighting system has no building connections. And all the pipes and hydrants are dedicated specifically and designed to not only survive an earthquake but function after it.”
Designated bond program pays for resiliency measures
Much of San Francisco’s race for a more resilient city is funded via a special, voter-approved bond initiative, known as the Earthquake Safety and Emergency Response (ESER) program. The bonds have also been used to pay for the manifold relocations.
Three times, in 2010, 2014 and 2020, voters gave strong support to a series of proposed funding measures under the ESER umbrella. Public Works has been involved with the ESER program since its inception, providing design, project management and construction management services. The department’s trades workers also have worked on the projects.
Manifolds allow fireboats to pump Bay water into the City’s pipelines.
Among other things, the bond program has funded renovations to police stations and fire houses, the construction of a new Medical Examiner facility and Public Safety Building and critical upgrades to the Emergency Firefighting Water System – from building additional cisterns to addressing seismic vulnerabilities.
The most recent ESER bond passed in 2020. About $153 million of the $628 million bond is allocated for further expansions and seismic upgrades to the vital components of the Emergency Firefighting Water System. Many of the improvements focus on bolstering the system’s capabilities in the City’s western neighborhoods.
PUBLIC WORKS
BY THE NUM83R5
2024 -YEAR TO DATE
8,682
POTHOLES
FILLED
4,692
TREES
PRUNED
388
CURB RAMPS
CONSTRUCTED
368
NUMBER OF BLOCKS RESURFACED
16,446
TONS OF DEBRIS COLLECTED
Public Works painter Steve Thumas moves the mechanical lift closer to the truss for a fresh coat of epoxy.
SFPD Gun Range: Public Works’ Inspection and Repair Teams Hit the Target
Four times a year, Public Works engineer Alfonso Aguilera grabs a hammer and heads to the San Francisco Police Department’s firearms range. There, his ears get to work.
Aguilera, part of the department’s structural engineering team, uses a hammer, in a method known as hammer sounding, to tap the overhead steel-frame truss that holds up wooden baffles at the outdoor range. The baffles, dimpled with round indentations, keep stray bullets from ricocheting and leaving the range.
“You want to hear a nice ding or a clear ring,” he explained of his hammering technique. “If you hit a truss member and you hear a thunk – if it sounds dull – then I need to take a closer look.”
Public Works steamfitter James Aylsworth explains how the gun range overhead truss works.
The hammer sounding serves as an extension of the visual inspection he performs.
What he’s mainly looking for are signs of corrosion – cracked paint on the steel tubing, for example, is another sign of rust – that can make the truss vulnerable to failure. A truss member failed due to extensive corrosion in 2016. While no one was injured, the level of corrosion discovered from the failed truss member prompted the quarterly inspections.
The SFPD shooting range is located down a long driveaway off of John Muir Drive near Lake Merced in the City’s southwest. While the range is closed to the public and out of public view, the sound of gunfire provides a reminder of its presence. The Police Department uses the range to train and recertify officers in firearms use.
Originally opened in the early 1940s, the range was renovated five decades later when the truss was added. Eventually, the Police Department would like to build a new indoor firing range when funding becomes available. Until then, the game plan calls for regular upkeep of the existing facility. That’s where Public Works comes in.
The SFPD gun range opened near the Lake Merced shore in the 1940s.
Our engineers provide routine structural inspections, our architecture bureau handles project management and our specialized trades workers from our Bureau of Building and Street Repair perform the needed repairs and upkeep, including carpentry, welding, painting, roofing and electrical work.
After Aguilera’s last inspection found severe corrosion in steel pipe segments on two trusses, a welder with our Steamfitter Shop went to work making repairs and a painter, wielding a roller, applied a fresh coat of epoxy to protect against the salty air. The firearms range sits near the Pacific Ocean.
Public Works steamfitter Larry Daniels welds a steel pipe for the truss.
Each 5-foot section of pipe requires eight welds, and each weld is closely assessed by an outside inspector brought in to watch over the job as the work is underway.
As an extra step to ensure safety, an outside inspector checks each weld to make sure it was done correctly.
The whole operation likely will be needed again in the not too distant future due to the steady assault on the metal in the marine air environment. Aguilera will have his eyes and a hammer ready to start the process again.
Public Works’ street repair crews grind the Fillmore Street roadway before applying a layer of fresh asphalt.
Smooth Operation
Earlier this month, Public Works crews made quick work of an expedited paving project in the Marina – just in time for the start of a new school year.
Public Works Bureau of Building and Street Repair crews began repaving Fillmore Street, between Lombard Street and Marina Boulevard, on July 29, coordinating closely with the San Francisco Municipal Transportation Agency.
With a goal of finishing the job before students returned to nearby Marina Middle School on Aug. 19, our crews worked diligently and efficiently, finishing the repaving effort by Aug. 6.
Crews hustle to wrap up the paving job before Marina Middle School students return to classes after summer break.
“The stars aligned for this repaving job,” said Therese Topacio, a project manager with Public Works’ Street Resurfacing Program who spearheaded the effort. “It's rare to pave this many blocks in a short amount of time without running into coordination conflicts.”
Key to the successful project was great teamwork between Public Works’ Operations Division, the SFMTA and Public Works engineer Nilofar Dhapa, Topacio added.
The lightning-fast paving effort earned praise from a resident, too, who thanked City officials via email.
"Appreciate all of the coordination by city workers that showed when San Francisco wants to rally we can get it done!” he wrote. “This is the way!”
The project is part of a larger Public Works initiative to continuously upgrade and maintain San Francisco streets.
Fillmore Street in the Marina gets paved with asphalt for a smoother surface.
The department’s Street Resurfacing Program follows industry best practices by preserving streets in good condition instead of letting them deteriorate. This approach is the most cost-effective.
Extending the life of a block in San Francisco that is in good condition can cost as little as $50,000. By comparison, the price to completely reconstruct a block in very poor condition can be as much as $500,000 or more.
Public Works uses in-house Bureau of Building and Street Repair crews and outside contractors to perform the paving work. Last fiscal year, Public Works resurfaced more than 500 blocks, adding to the total of more than 8,000 blocks of the City’s nearly 13,000 that have been resurfaced in the last 15 years.
San Francisco’s strategic approach to maintaining roads has paid off: The City’s independently rated Pavement Condition Index (PCI) score recently increased to 75, a rating deemed “good” by the regional Metropolitan Transportation Commission (MTC).
This rating puts San Francisco at the top among large Bay Area cities.
Volunteers add new mulch to the landscaping at the Rincon Hill Dog Park.
#LoveOurCity
This month’s Love Our City: Neighborhood Beautification Day had an added bonus: In addition to the volunteer workday projects greening and cleaning the South of Market, our Street Tree Nursery hosted a lively open house, packed with free, fun and family-friendly activities, including bucket truck rides, pizza making, planter box building, tours, an art exhibit and more.
The Public Works-run Street Tree Nursery, which opened last fall, features a central growing area for young street trees, outdoor gathering spaces, landscaping, a classroom and offices. Located on Fifth Street, between Harrison and Bryant streets, the facility took root on a vacant Caltrans parcel, tucked between freeway ramps.
A young street tree replaces barren concrete sidewalk on Fifth Street in SoMa.
The open house, held on Aug. 17, gave visitors a chance to learn more about the Street Tree Nursery operation and celebrate what is emerging as a community treasure.
The day also brought out dozens of volunteers to work alongside Public Works crews on a variety of neighborhood improvement projects in the South of Market. Among them: mulching, weeding and removing litter from the Rincon Hill Dog Park at Bryant and Beale streets; planting street trees on Fourth and Fifth streets; removing graffiti near freeway ramps; and weeding and pruning along the Harrison Street streetscapes.
Neighborhood Beautification Day events are held one Saturday each month in a different supervisorial district. Next month, on Sept. 21, we’ll be cleaning and greening the Bayview, Potrero Hill and other District 10 neighborhoods. Kickoff is at 9 a.m. at Bayview K.C. Jones Playground, 1601 Armstrong Ave.
Bring your friends and family, or come solo to make new connections. The work is fun and meaningful.
