The Case of the Tilted Clubhouse: A Geographical Detective Story

Today, technologies like Google, Siri, and Wolfram Alpha can answer virtually any question in milliseconds. So it’s refreshing to come across a mystery that takes a little longer to unravel.

I recently found the solution to a minor historical puzzle that’s been gnawing at me for almost two years, ever since I moved to the Dogpatch neighborhood of San Francisco to set up Xconomy’s Bay Area bureau. To find the answer I had to tie together clues from several different sources, including Google Earth.

This amazing piece of free software has been around since 2005 (I’ve written about it here and here), and it’s used by millions of people around the world to explore detailed images of the earth’s surface, the ocean floor, and even the Moon and Mars. But my little discovery reminded me that Google has made many unheralded improvements to the program over the years, including the addition, in early 2009, of historical imagery.

Using a simple slider, a Google Earth user can turn the clock backward and forward for certain locations, revealing pictures of vanished landscapes that are nearly as old as aerial photography itself. It’s a remarkable tool, and by telling my story perhaps I’ll inspire a few readers to experiment with it.

The Dogpatch is an industrial neighborhood bordering San Francisco’s southeastern shore. In the nineteenth century it was home to the city’s shipbuilding trade and associated industries, including steelmaking and gunpowder manufacturing. It reached a peak of prosperity sometime around World War I, spent the next 70 years slumping into decay, and has recently begun to come alive again as a center for tech startups, light manufacturing, hip restaurants, and live/work lofts like the one I rent.

The main drag through the Dogpatch is Third Street. Before the tidal flats in Mission Bay were filled in to create the land that’s now home to UCSF, a huge wooden structure called the Long Bridge linked the Dogpatch to central San Francisco. Third Street now follows the bridge’s path.

The Tilted Houses of Third Street

The mystery was this. One day in mid-2010, I was out walking my dog on Third Street between 22nd Street and 23rd Street, about three blocks east of my apartment, when I noticed that there’s a row of five buildings set at a 40-degree angle to the curb. All the other buildings on that block of Third Street are perpendicular to the street. But these five buildings cut through the block like a slash mark—see the snapshot at left from Google Earth.

One of these buildings is famous, at least to locals: it’s the Frisco Clubhouse of the Hells Angels Motorcycle Club. As it turns out, people in this neighborhood are rather fond of the Hells Angels. Their faux-threatening demeanor helps to keep the peace, which more than makes up for the noise from their choppers.

Once I’d spied the tilted clubhouse, of course, I wanted to know the story behind these odd buildings. On the surface, the idea that builders would place four sets of structures at a 40-degree angle to everything around them seemed like folly or insanity. But I’ve spent enough time staring at maps to know that such anomalies are usually just the remnants of older patterns in the urban landscape, laid out by earlier inhabitants for specific, if long-lost, reasons.

The Old Western Pacific rail line and tunnel under Potrero Hill. Notice the diagonal slash from upper left to lower right.

A brief digression shows that these reasons can usually be dug up. Potrero Hill lies just to the west of my loft building. If you walk around the neighborhood much—particularly the area around De Haro Street, between 15th and 18th Streets (where Zynga used to be headquartered, until its recent move to SoMa)—you’ll notice that there’s a diagonal slice through several blocks, running from northwest to southeast. The slice is even clearer in aerial images on Google Maps or Google Earth. And when you look at those images, the really interesting thing is that the slice disappears at 18th Street, then reappears at 22nd Street—just 100 yards from my west-facing window, in fact.

The obvious inference is that there used to be a railroad line cutting across and underneath Potrero Hill. And a little bit of research on Google reveals that this was, in fact, the case. The Ocean Shore Railroad laid the line and dug the tunnel around 1905. It turned out to be bad timing, as the 1906 earthquake did so much damage to other parts of the Ocean Shore’s trackage that the railroad eventually went bankrupt and sold the Potrero sections to the Western Pacific.

Bad luck struck again in 1960, when a fire inside the tunnel led to its collapse, causing sinkholes in the streets above. After the fire, the tunnel was supposedly filled with cement, and apartment buildings now obscure both ends. (There’s a brief scene in Francis Ford Coppola’s brilliant 1974 film The Conversation where you can see Gene Hackman walking across the still-extant Western Pacific tracks near 15th Street; the plug at the tunnel’s north end is visible in the distance. Check out this amazing image on Flickr.)

What’s interesting to me is that long after the Western Pacific rails were torn up or paved over, the streets and buildings of Potrero Hill still follow their contours. And the longer you spend staring at maps, the more examples like this you find. At least in San Francisco, the urban landscape is like a palimpsest or a leathery skin, crisscrossed with scars that have healed but never quite disappeared.

At first I wondered whether the tilted clubhouse on Third Street might have grown up atop some other abandoned rail line. But there aren’t any traces of such a line on adjacent blocks. I asked a few people in the neighborhood about the oddity, but no one seemed to know the story.

A Google Earth mosaic of aerial images of San Francisco captured by Harrison Ryker in 1938.

And that’s where my puzzle stood, until one evening a month or two ago when I was browsing Google’s Lat Long Blog and found a guest article by my friend David Rumsey, one of the country’s leading collectors of historical maps. I’ve known David since 2005, when I wrote a short feature about him for Technology Review. His blog post was about an amazing set of high-resolution aerial images of San Francisco, captured in 1938 by aerial photographer Harrison Ryker. The 164 prints in the collection cover the entire city at 1-meter resolution—higher than most satellite surveys even today. Rumsey’s team had just finished digitizing, cataloguing, and “geo-referencing” the prints—that is, matching control points on the ground with objects of known latitudes and longitude, so that the digital versions of the photos could be assembled into an accurate mosaic and displayed inside GIS software such as Google Earth.

In fact, in the blog post Rumsey informed readers that the 1938 imagery had just been added to historical imagery layers of Google Earth. I immediately thought of my Third Street buildings. I fired up Google Earth on my Mac, turned on the Rumsey Historical Maps layer, navigated to my neighborhood, and set the time slider back to 1938. Here’s what I found:

1938 aerial photo of the industrial compound between Iowa Street and Third Street

From this astonishing photograph, it appears that there was some sort of industrial compound covering the entire area bounded by Iowa Street, Third Street, 22nd Street, and 23rd Street. The dominant feature was a long building that sliced across what are now four city blocks, at the same angle as the current-day Hells Angels Clubhouse. In fact the clubhouse is visible in the 1938 image, just to the north of the tilted lot, on the Third Street end.

This was a major step forward. But I still had no idea what the structure was; there was no convenient label on the aerial photograph. It reminded me of the Stanford Linear Accelerator (SLAC), a 2-mile-long structure that passes under Highway 280 west of Palo Alto, but I was fairly sure no one was doing particle physics experiments in the Dogpatch in the early 20th century.

The final piece of the puzzle fell into place a few days later, when I was surfing the Web for information on Pier 70, the historic shipbuilding district in the Dogpatch. Back in 2008, a local community group produced a thorough history of the entire Dogpatch area as part of an effort to persuade San Francisco voters to approve a bond measure to rehabilitate the pier. (The measure passed, but the project is still in the planning stages.)

What caught my eye was the engraving at the top of the history document:

San Francisco's historic Dogpatch neighborhood, circa 1865

See the long, thin building cutting across the Long Bridge at the center of the picture? While the engraving is more of an illustration than an actual map, the shape and the location matched up with my proto-SLAC.

And as I read the document, everything fell into place. One of the maritime-related businesses in the Dogpatch, it turns out, was the Tubbs Cordage Company, which made hemp and abaca fibers into rope. “The first structure on the site was a 35’x1,000’, one-story, wood-frame shed that extended in a southeasterly direction from the present-day intersection of Iowa and 22nd Streets to a wharf in the bay,” wrote the group’s historian, Christopher VerPlanck. “The shed sheltered the rope walk, a 1000’ (later extended another 500’) platform used by skilled workmen to twist strands of yarn into ropes.”

The original shoreline of the Dogpatch-Potrero Hill neighborhood

So there you have it: the Tubbs rope shed and the buildings that grew up around it owe their orientation to that of the wharf, which must have stuck out into the bay in a southeasterly direction, just as the engraving suggests. In fact, as the image at right (from the Pier 70 redevelopment plan) shows, the original shore of the Bay crossed Third Street roughly where the Hells Angels Clubhouse is located today, and the rope shed would have been perpendicular to it.

City directories show that the Tubbs Cordage Company was active from 1857 to 1962, so the facility would still have been churning out rope when the 1938 aerial photo was taken. There’s a final clincher to the story: Most of the present-day site is occupied by the San Francisco MUNI bus yard and repair shop, but cutting right through the middle there’s a one-block street called Tubbs Street. That street name and the tilted buildings are the only remaining signs of San Francisco’s rope industry. [Correction/update: A small Tubbs Cordage Company office building, originally located on Front Street in San Francisco, has been preserved at the Hyde Street Pier at the San Francisco Maritime National Historical Park.]

Case closed. Now, for all I know, there’s a reference librarian at the San Francisco Public Library who could have told me the whole story of Tubbs Cordage and the Hells Angels clubhouse right off the bat. But it was a lot more fun to suss out the story my way, using some of the coolest new digital resources and mapping tools. I’m looking forward to more digital hunting trips in the future. Who knows what secrets lurk beneath the streets of San Francisco?

Coda, August 17, 2012: In the amazing-coincidences department, I just learned that David Rumsey owned two of the buildings in the tilted group from about 1978 to 1988. “I had always wondered about the strange angles and thought perhaps 3rd had been re-aligned at some point,” David writes by e-mail. “You really nailed the wharf as the cause.”

Addendum, August 21, 2012: A Dogpatch resident just sent me a link to the photo below, which is from the website of the Potrery Hill History Archive. It shows the Tubbs rope walk sometime after 1857 — the view is from the south and the hill in the background, once known as Irish Hill, is now mostly gone (carted away for landfill). As with all of the images in this article you can click to see a larger version.

Wade Roush is a contributing editor at Xconomy. Follow @wroush

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