Guerrilla History & Urban Exploration

Rome: Looking for the Cloaca Maxima

A story of searching for the oldest sewer in the world, Rome's Cloaca Maxima. This story of our adventures is by my friend & exploration partner Moses Gates. Visit him at http://www.allcitynewyork.com.

“You have made a very big mistake!” Here I was being chewed out, in English no less, by a homeless Gypsy fisherman with a neatly trimmed mustache on the east bank of the Tiber River. My crime? Trying to visit the Cloaca Maxima - the world’s oldest sewer.

Ancient Rome had a problem - a lot of people, even more animals, and no way to get rid of all their poop. To cope with this problem, a rudimentary sewage system was dug around 600 BC, flowing through town out to the Tiber River. True to Roman form, it even came complete with its own goddess, Cloacina, a statue of whom was placed above the part of the Cloaca that now runs underneath the ancient Roman forum. The Cloaca is so old, nobody really knows if it started as a tunnel, or a ditch, or even a natural river. It’s been in use in some form or another ever since, although in modern times its remaining passages were consolidated with the rest of the sewer system of Rome.

I wasn’t quite sure of the big mistake I had made. A little research had led us to the approximate location of the outflow of the Cloaca Maxima. I decided to head over there and see if we could get in. One possible entrance had a couple of guys camped out in front of it, obviously making it their home. One was digging in the mud in front of the entrance with a shovel, so I asked him (as best I could), if it was the Cloaca Maxima. He seemed friendly enough when he gestured to keep walking down the path by the river. But as I turned to walk away, I heard some very rapid, very angry Italian being hurled at me. After repeated “no parlo Italianos,” he said “OK you speak English? - you have made a very big mistake!”

Apparently I had in some way gravely offended some sensibility of his in our brief exchange. I had no idea what to do, or what he would do. Luckily, after a good deal of further berating, he took my apologies enough that I could walk away without fear of further offense. Still, I glanced over my shoulder more than once. He was so mad, I wouldn’t have been surprised to see him running after me, shovel in hand.

Well, here was another obstacle I’d put in our way. Instead of manholes and fences, now we had angry Gypsies to contend with. The next morning Steve and I, armed with our peace offerings of cigarettes and beer, went down to try and talk our way in.

We had determined earlier that day that the tunnel by the Gypsy campsite was almost certainly the actual outflow of the Cloaca. The guy who had yelled at me wasn’t there, but his friend was. He only spoke Italian, Romany, and Russian fluently (got to love Europe, with a trilingual homeless population), but we somehow ended up managing a mangled conversation with him in French. 10 minutes and a couple beers late we were in. Imagine our disappointment when the tunnel ended in a brick wall after 10 feet.

Undaunted, we decided to explore a little further down the river to see if there were any other possible entrances. We were in luck: only a few dozen feet down the river was a sewer entrance, close enough that it might lead to the Cloaca. This time the obstacles were different. There was a heavy gate in front of the entrance, although luckily it wasn’t locked. And there was another obstacle one might associate with sewers: namely sewage. While the other entrance had been kept fairly clean by the Gypsies camped out there, this one had no such caretakers. Flies were swarming all over us as we were up to our ankles in the muck of whatever Romans flush down their toilets trying to pry open the gate. This time it took a little elbow grease and a heck of a strong stomach instead of two beers and decent French to make it in.

Once we were in it got a little better - most of the sewage had caught on the gate at the entrance, and there was only a trickle down the middle of the tunnel. The tunnel itself was big, and looked relatively new. It began to curve toward the direction of the entrance to the Cloaca, giving us hope that it would eventually connect with it, but stopped at a flood gate before very long.

With the Cloaca this close, we had to go on. Luckily for us, there was a ladder. Up the ladder, into the gatehouse, across a catwalk, and down another, much rustier, ladder and we found ourselves in the sewers beneath the Capolitine hill. On we went.

These sewers made the one we were just in look like the Sistine Chapel. We were on a narrow, somewhat slippery catwalk maybe a foot wide right next to the bodily waste of millions. One wrong step and we would literally be up shit’s creek without a paddle.

Still we pressed on to see what we could find. After 50 feet or so a smaller tunnel branched off to the side. This had no sewage in it, and was made out of brick - brick that looked incredibly similar to what ancient Roman ruins were made out of. Could this be the remnants of the Cloaca? We went as far as we could, stopping to take some pictures. The tunnel was only about 5 feet high or so, and ended in a strange chamber, complete with brick arches. We were under the oldest part of the city - even if it wasn’t the Cloaca, it was a fair bet this tunnel was at least a couple millennia old, and was host to the kind of history we had only read about.

We left this strange offshoot behind and carried on. Here was where Steve started to get worried. We had brought an air meter, which would tell us if the oxygen content got too low or if there was anything poisonous in the air. But Steve wasn’t worried about air - he was worried about water. We hadn’t checked the forecast that day. If it started to rain, or even just drizzle, there was a good chance the water level of the sewer would rise considerably. The catwalk was only a few inches higher than the effluence next to us. If it rose just even a little, we would be swimming back out. And if it rose a lot…well, let’s just say I could think of a lot better ways to go. We offered up a quick prayer to Cloacina and pressed on.

A little further and the sewer split in two. The big problem was that this was also where the catwalk ended. The tunnel to the right had no catwalk, and there was a 6 foot gap until the catwalk picked back up on the tunnel to the left. Jumping it was out of the question. We tested the water with the camera tripod to see how deep it was. The river of shit swallowed the 5 foot tripod with room to spare. We were out of options.

We had no idea if our quest was successful - we had been almost exactly in the path of the original Cloaca. Some remnants of it could have been the brick tunnel or the catwalk-less offshoot. The most likely possibility was that it was a bricked up archway that we had passed. But we had gone as far as we could without Hazmat suits. It was hard to head back out without knowing for sure if we’d accomplished our objective, but we couldn’t very well expect a big sign saying “welcome to the world’s oldest sewer!” We negotiated the other ladder and the gate, and made it back to the city before nightfall, passing our old Gypsy friends along the way. We gave a friendly wave and smile, and were honored when we got a slight nod of the head back.

NYC History: The Atlantic Avenue Tunnel

Walt Whitman, writing just after the Atlantic Ave Tunnel was closed:
    The old tunnel, that used to lie there under ground, a passage of Acheron-like solemnity and darkness, now all closed and filled up, and soon to be utterly forgotten, with all its reminiscences; of which, however, there will, for a few years yet be many dear ones, to not a few Brooklynites, New Yorkers, and promiscuous crowds besides. For it was here you started to go down the island, in summer….
…We were along there a few days since, and could not help stopping, and giving the reins for a few moments to an imagination of the period when the daily eastern train, with a long string of cars, filled with summer passengers, was about starting for Greenport, after touching at all the intermediate villages and depots. We are, (our fancy will have it so,) in that train of cars, ready to start. The bell rings, and winds off with that sort of a twirl or gulp, (if you can imagine a bell gulping), which expresses the last call, and no more afterwards; then off we go. Every person attached the road jumps on from the ground or some of the various platforms, after the train starts…. The orange women, the newsboys, and the limping young man with the long-lived cakes, looks in at the windows with an expression that says very plainly, “We’ll run along-side, and risk all the danger, while you find the change.” The smoke with a greasy smell comes drifting along, and you whisk into the tunnel.
    The tunnel: dark as the grave, cold, damp, and silent. How beautiful look Earth and Heaven again, as we emerge from the gloom! it might not be unprofitable, now and then, to send us mortals—the dissatisfied ones, at least, and that’s a large proportion—into some tunnel of several days journey. We’d perhaps grumble less afterward at God’s handiwork.

-Walt Whitman, “Brooklynania” #36, 1861 (Approx.)

    Underneath Brooklyn’s Atlantic Avenue, stretching west from the busy intersection with Court Street, is an old Long Island Rail Road tunnel. At 21 feet wide and 17 feet high, it was big enough for two locomotives side-by-side. Today it feels more like a natural cave than a man-made tunnel. It once carried passenger trains filled with summertime crowds heading to towns and resorts on Long Island. But after it was closed in 1861, it remained essentially forgotten for well over a century, until a young Brooklyn historian in the 1980s found references to it and eventually tunneled into it.
    The train tunnel was built for a passenger railroad line that connected Brooklyn’s ferry landing at the foot of Atlantic Street with the Long Island Railroad station in Jamaica (now part of Queens). Since it was built for passenger trains and ran underground through a city (the city of Brooklyn), it is the world’s first subway tunnel—predating by many years the famous but short-lived Pneumatic Subway that Alfred Ely Beach built in lower Manhattan in1870. It was also one of the longest train tunnels in the world at the time.
    At the time the tunnel was built in 1844, both steam trains and the city of Brooklyn itself were still quite new. Though Brooklyn had existed as a town for many years, it was only in 1834 that the bill to incorporate it as a city was passed in Albany (over the heavy opposition of New York City). Steam locomotives as well were essentially an invention of the 1830s.  In 1830, Peter Cooper had demonstrated the first practical steam locomotive in the US, a small engine called Tom Thumb that managed to pull a passenger car at 18 miles per hour, showing that the new technology could be far superior to horse-drawn trains.  Over the next two decades, rail lines would not only revolutionize shipping through New York state, but would also facilitate incredible development in the towns and suburbs around New York City. Seeing both the massive immigration-fueled population explosion in New York, and the desire of the wealthier to get away from the crowded, dirt city center, developers began to lay out residential tracts in Brooklyn. Commuters could travel between the two cities via the South Ferry, a ferry line that would lend its name both to the South Ferry station in lower Manhattan and Brooklyn’s South Ferry station at the foot of Atlantic St.
    Companies were chartered to lay individual rail lines, and one of the earliest in Brooklyn was the Brooklyn and Jamaica Railroad Company, chartered in 1832, to lay tracks between what were then two villages. Tracks were laid along what is now the route of Atlantic Avenue, although at the time it was Atlantic Street and extended only slightly east of Flatbush.
    In 1834, the Long Island Rail Road was chartered as well, with plans to run from Jamaica (now queens) westward through Long Island.  The original goal of the Long Island Rail Road was to connect New York and Boston, using ferries to cross both Long Island Sound and the East River. (This plan would end up ultimately seeing little success, especially when an overland rail line was completed through Connecticut, but the company would handle passengers traveling to the new towns and summer resorts that sprang up on the island through the 1800s.) The Long Island Railroad would not finish laying the 94 miles of track that connected Brooklyn with Greenport, where a steam ferry took passengers to a connecting train to Boston, until 1844, the same year that the Atlantic street tunnel was built.  But in the meantime, the new rail lines gave unprecedented access to towns along its route, laying the groundwork for Long Island’s railroad suburbs.
    The first Brooklyn and Jamaica Company trains ran along Atlantic Avenue in 1836.  Within a year, however, the company had leased its tracks to the Long Island Rail Road, which was continuing to lay tracks further and further into Long Island.
    But steam technology was in its infancy, and the locomotives were both weak and dangerous. The engines sometimes exploded violently. From their inception, steam locomotives were not allowed in Manhattan south of 27th Street because of this; as the city expanded north so did the cut-off line, and Grand Central was built at 42nd street because that was the southern terminus for all steam-powered locomotives at the time. The city of Brooklyn likewise forbade any use of steam within city limits until 1839, and so trains were pulled by horses until out of the city limits. Regardless of the ordnance, horses would still have been during the first part of the journey, as the early steam locomotives were not powerful enough to handle the hill between the ferry landing and Court Street, and even after steam was permitted horses still were attached to the train to help it up the grade. (Which created its own problems, as the horses were easily spooked by the loud, clanking, frightening engines; the Long Island Rail Road eventually solved this problem by putting a passenger car in front of the engine, as a buffer between it and the horse teams.)  Local business and residents were not happy with the operation, especially as the railroad expanded. A letter to the editor in the Brooklyn Daily Eagle recalled that, before the tunnel was built, the railroad would send “their locomotives to Smith street, and there stationing one or more on the open street, belching forth their thunder and steam, rendering the whole neighborhood inaccessible; add to this the blocking of up Atlantic street, from Henry street to Smith street with carloads of manure, and the sidewalks and lots with heavy and obstructing material, all permitted to remain as long as possible…”
    Starting on May 24, 1844, the Long Island Railroad began work on the tunnel as an open cut, after the Brooklyn Common Council had authorized the construction of a tunnel “constructed of good materials, with sides having good and substantial stone walls, to be arched with brick or stone,”  The first trains ran through in December of 1844.  In its annual report of 1844, the Common Council described the tunnel:
The whole length of this structure is little more than half a mile. The walls are of massive stone, of the thickness of six feet, and ten feet high. The arch is of brick, twenty-two inches thick, the whole laid in hydraulic cement.
    Light and air came in through three ventilation shafts that rose to the surface, about 17 feet above the roof of the tunnel at the center. (These ventilators—“not to exceed four feet in diameter, and to be constructed with suitable iron railings at least four feet in height,” according to the charter, we capped to a depth of three feet when the tunnel was closed.)
    Although already in daily use for trains, the report noted, the tunnel was not entirely finished; it was expected that another $15,000 worth of work was needed, bringing the total cost of the project to $66,352. “This great work,” the report declared, “will greatly facilitate the operations of the Company, obviate many dangers, and as a work of art will embellish the city of Brooklyn.”  Implicit in this was the fact that lessening the visibility of noisy, smoke-emitting steam trains would help property values in the rapidly gentrifying neighborhood, and that routing the trains through the tunnel would allow for expansion of residential development south of Atlantic Ave.
    Despite the tunnel enclosure, the smoke and noise along Atlantic still aroused widespread opposition from local residents, especially as Prospect Heights developed into a wealthy and prestigious suburb of New York in the 1850s.  New development south of Atlantic, which had been facilitated by the tunnel, now led to calls to close the steam rail line completely, as residents and business complained about the space the tunnel entrances took up in the middle of the street, and the barrier that the rail line created to north-south movement on the local streets. In 1858, Brooklyn banned steam locomotive operations within city limits, a measure aimed specifically at the Brooklyn and Jamaica Railroad line, and despite challenges the ban was upheld by courts the following year. A compromise with the railroad was reached when it was decided that the city would buy the tunnel for the sake of closing the steam line; local property owners adjoining Atlantic street would be assessed for a total of $125,000 to pay for closing the tunnel and repaving the street.  “The consummation of this work,” the Times declared, “offers a great improvement in the street, for which the owners of property can well afford to pay the assessment levied therefor. ” 
    Steam locomotives were completely eliminated by 1860, though horse-drawn train cars ran through tunnel for another year. But by December of 1861 the tunnel had been completely closed, and the street smoothed and restored to a full 120 feet wide.  The two ends were filled in with dirt, but most of the tunnel—about 1,600 feet—was left empty. The railroad tracks and ties were removed, and today the only hint of the railroad that once ran through the tunnel is the corrugated dirt floor, with shallow and time-rounded depressions showing where the railroad ties used to sit.
    A horse-drawn rail line was installed on the surface of the newly smoothed and widened Atlantic Street to connect to the Jamaica station. The Long Island Railroad, giving up on Brooklyn, built a new track (the LIRR Main Line) between its Jamaica station and a ferry terminal at Hunter’s Point in Queens County.
    Considering the incredible growth of Brooklyn over the next decades, perhaps it’s not surprising that the tunnel was so quickly forgotten. Between 1860 (when the tunnel closed) and 1880, the population of the city leapt from 279,000 to 599,000—meaning that well over half the residents had not been alive in Brooklyn when the tunnel had been active just 20 years before. By 1900, when the Borough of Brooklyn had over one million people, the number was somewhere between 5% and 10% of the population. This is the downside of urban development and growth: the past is quickly forgotten. But it does linger on in the realm of urban myth and legend. By 1893, it was the subject of a “romance,” a short story in the New York Times that began:

    “The Atlantic Avenue Tunnel!” exclaimed Bilderhouse, looking up from his writing table.
    “That’s what I said,” replied Furbish. “Don’t you know there’s an old, unused tunnel there, under the middle of the street, extending from the ferry almost to Flatbush Avenue?”
    “Don’t believe it. Never heard of it before,” said Bilderhouse, leisurely resuming his work.
    Fruitlessly searching for an entrance to the tunnel after a dying man tells of treasure hidden there, the hero of the story dozes off at a bar and dreams of the Keats poem “Endymion.” (“A thing of beauty is a joy for ever:/Its loveliness increases; it will never/Pass into nothingness; but still will keep.”)
    By 1911 the myth had expanded, and the Brooklyn Daily Eagle reported that the tunnel might be infested with giant rats and “desperate men,” and that “the popular impression prevails today that it would be a good deal safer to go down into its darkness armed.”  In 1936 a squad of police did their best to get in, after the District Attorney received an anonymous letter that said “If you inspect the old tunnel you might find something interesting.” (It was thought that they might find the body of Bo Weinberg, a gangster who helped the infamous Dutch Schultz expand operations into Brooklyn during prohibition .) They tried cellars along Atlantic Avenue, rapping on basement walls with crowbars, but found no connection. “The place is supposed to be alive with rodents big as behemoths,” Captain John McGowan told the reporter, although Sahib Lineburgh, an inspector with the Transit Commission who had been in the tunnel 20 years before, called the stories “bosh.” When he went in during 1916, he said, he and his men drilled into it both at Court Street and Henry Street. “We put ladders down and went down, carefully, because we’d heard all those legends about poison gas, and pirates dens and rats big as cats.” But they found nothing, though they had to walk through an inch-deep, 56-year accumulation of mold—no rodents, no treasure, and no connection to any buildings on Atlantic Avenue.  The police eventually called on workers to dig an entrance from street level through the ceiling arch of the tunnel.  They found nothing, but the hole they made is still visible in the roof of the tunnel. Another exploration during World War II, due to  reports of German saboteurs hiding in the tunnel, was equally fruitless.  (The closest the old tunnel came to being opened up to the public was probably also during WWII, when the WPA suggested using it as an air raid shelter, but it was not pursued.  )
    Just one of the legends about the tunnel turned out to be true: that it was filled with poison gas. In the late summer of 1980, a 20-year-old railroad buff named Bob Diamond became the first person since 1941 to enter the tunnel. But a few feet in, Department of Environmental Protection (DEP) tests found carbon monoxide.  Carbon monoxide is a well-known danger in tunnels; it’s slightly heavier than air, and over time the carbon monoxide released from cars can seep into underground spaces, creating an odorless, invisible, and absolutely deadly layer of gas.
    Bob Diamond would eventually work to open up the tunnel for tours to the public, which still enter through a nondescript manhole in the middle of Atlantic Avenue at Court Street. That summer, he was still just an engineering student and a railroad buff; he’d spent months researching the tunnel and eventually found plans for it at the Brooklyn Borough President’s office. But he approached city agencies and got them to agree to help him. What he found that day, before the trip was aborted because of the bad air, was the brick arch of the tunnel’s ceiling, creating an open space about three feet high over the dirt filling the tunnel. He couldn’t go any further that day, but he would eventually find that the majority of the tunnel was completely open and untouched.


Whitman, Walt. From "Brooklyniana," a series of twenty-five pieces in the Brooklyn Standard between June 1861 and November 1862. Found in The Uncollected Poetry and Prose of Walt Whitman, edited by Holloway, Emory. Doubleday, Page, & Company, Garden City, N.Y., 1921

Wallace & Burrows. Gotham: A History of New York City to 1898. Oxford University Press, USA, 2000

Horton, Gail. “A Brief History of the Greenport Terminal of the Long Island Railroad” 1992. ONLINE AT http://www.rmli.org/Page/Grennport_History_detail.htm

"Long Island Railroad.” The Times And Commercial Intelligence, June 14, 1838 SCAN ONLINE AT http://arrts-arrchives.com/atlaverr1.html

"Steam on Atlantic Street (Letter to the Editor)." Brooklyn Eagle, December 29 1858, p 2

Brooklyn Common Council, March 29 1844, Ordnance granting permission to the Long Island Railroad Company to construct a tunnel through Atlantic street. SCAN ONLINE AT http://arrts-arrchives.com/tunnel.html

Rogoff, Dave. “Atlantic Avenue (Cobble Hill) Tunnel” May 1962 Bulletin of the ERA's New York Division, online at http://rapidtransit.net/net/faq/nyc/AtlanticTunnel.html 

Brooklyn Common Council Annual Report, 1844, p 177-178, SCAN ONLINE AT http://arrts-arrchives.com/tunnel.html

"The Atlantic Street Controversy with the L. I. Railroad Company." Brooklyn Daily Eagle, December 1, 1858, p. 2

"Brooklyn News." New York Times, December 23, 1861.

"The Atlantic Avenue Tunnel: A Romance." New York Times, January 23 1893, p. 10

"Old Tunnel Eludes Police Explorers." New York Times, July 19 1936.

Gordon, David. "A Transit Legend Lives In Brooklyn." New York Times, February 7 1973

“Eerie Brooklyn Cave May Be Air Raid Shelter.” 1940 article scanned at http://arrts-arrchives.com/tunnel.html

"A Tunnel That Can Keep A Secret." New York Times, August 6 1980.

NYC: Knickerbocker Avenue Extension Sewer

     In the 1880s, Bushwick was one of the most dynamic and thriving neighborhoods in the city of Brooklyn, NY. It was known especially for its many beer breweries. At the time, Brooklyn was still a separate city from New York City, and it was the third largest city in the United States. (New York City, composed at the time of just the island of Manhattan, was the largest city in the country; the five boroughs of today’s New York City would not be joined until 1898.)
     Both Brooklyn and New York City were growing incredibly rapidly. In the single decade between 1880 and 1890, New York City’s population would grow by 24% from 1.2 to 1.5 million, and Brooklyn’s population would grow an incredibly 42%, from 567,000 to 806,000. Stimulated by explosive growth in the region and fueled with cheap labor, the 1880s saw the opening of some of the most incredible engineering works of the century, including the Statue of Liberty (installed in 1886), and the Brooklyn Bridge (opened in 1883). On a smaller scale, Brooklyn’s first elevated railway opened in 1885, with its eastern terminus at the very edge of Bushwick.   
     The same year, the magazine Scientific American featured a completely different kind of engineering project on the cover of its December 12th issue: a massive 12-foot diameter sewer that was being built to carry the combined sewage and stormwater from Bushwick to a new outlet on the East River.
     From the point of view of an average Bushwick resident, this tunnel was not particularly interesting. Bushwick already had an extensive combined sewer system, with the largest sewer main, which ran along Knickerbocker Street, a full 11 feet in diameter . But the outfall for the Bushwick sewer system was into Newtown Creek, a slow-moving stream that had been turned into a canal. The new sewer featured in Scientific American, called the Knickerbocker Avenue Extension, was built to carry the flow away from its current outfall in Newtown Creek to the East River, about two miles away. For the population of Bushwick, nothing would change; their sewers would function as normal. But the new tunnel would keep sewage away from Newtown Creek’s many fright docks, even as the flow of sewage from Bushwick increased with the population. As the Scientific American article explained:
The necessity for the work is apparent from the fact that the present outlet sewer for this section of the city, which drains an area of about 2,800 acres, some of which is very low and flooded by every rain, is discharged upon the low lands at the head of Newton Creek, making a nuisance greatly detrimental to public health and damaging to valuable property in the vicinity. Frequent complaints from people living near this outlet and by the Department of Health rendered the construction of a new outlet absolutely necessary.
     But, the article explains, “although there is nothing new either in the sewer itself or the duty it is designed to perform, the method of building one section of about three-quarters of a mile in length is certainly unique and interesting.”
     This “unique and interesting” method was the technique used in digging the sewer as a deep tunnel (instead of as an open cut) in the section closest to the East River, where higher land meant that the tunnel was about 65 to 75 feet beneath the surface. To bore a sewer as a deep tunnel instead of as open cut was extremely unusual, and to do it the engineers used a new system of modular iron plates that were inserted at the head of the tunnel to support the roof and sides as the digging was done. Well behind the head of the tunnel, the plates were removed (to be re-used at the front) and bricklayers installed the bricks, set in cement, which would form the 12-inch thick walls of the circular tunnel. An iron-framed five and one-half foot diameter “pilot hole” preceded the main tunnel slightly. As the Scientific American article explains:
This method of tunneling not only gives an exact idea of the nature of the material in advance of the main work, but also served to firmly hold the sides of the excavation, preventing caving in; and where the route extends through a street lined upon each side with houses, and, as in this case, at an unusual depth below the surface, it has many advantages…
     At the time, this was all fairly unusual and impressive from an engineering point of view. The engineer Brunei had been the first to use cast-iron plates as lining for his landmark tunnel under the Thames as far back as 1843, and a train tunnel under the Hudson had even been started in 1874 using some of the same techniques (though that tunnel would not be finished until 1903), but the vast majority of urban tunnels were still built with a cut-and-cover method. The Knickerbocker Avenue Extension marked perhaps the first time that this sort tunneling technology had been used for a sewer or drain.
     This technique is actually very similar to how tunnel boring machines function today, with the cutting head and shield at the very front, and reinforcing plates installed directly behind the shield, providing not only support to the walls of the tunnel, but also bracing for the TBM to push forward. Of course today the digging is done mechanically rather than by manual labor, concrete is poured behind the plates to reinforce the tunnel instead of hand-laid bricks, and the debris or muck is taken out on a conveyor instead of pushed by hand along tracks in small carts as it was in the Knickerbocker extension, but the essential concept is the same and is quite different from the earlier methods of digging-and-blasting ahead of any reinforcement, with bracing only after the tunnel had progressed forward.
     I’d read about this sewer and its construction some years back, and had spent some time walking its route above-ground, or at least as close as I could figure it out. I never found the outfall but spent only a little time looking for it, knowing that the original outfall might be gone-- during the 20th century new development has sometimes changed or covered up original river outfalls. But recently a friend stumbled on the outlet completely by accident. This is how the outfall was described at the time it was built:
The outer end of the outfall is 18 feet in width and 6 1/2 feet in height, measured from the center of the invert, the curve of which has a radius of 41 feet; the sides are vertical, and on them rest iron I-beams, 12 inches deep, and varying in length from 20 feet at the outer end to 13 feet where the outfall sewer joins the circular one.
     Today the outermost iron I-beams have rusted to threads, and the breakdown of bricks and concrete at the top of the outfall makes it look like little more than a pile of debris by the water’s edge. The East River is actually a tidal estuary, and at high tide the water comes within six inches of the top of the outfall tunnel—or higher if there are waves or bad weather.

     I’d had a healthy fear of rising tidewaters ever since the time a few years ago when I was briefly trapped in a storm drain by the incoming tide, so we planned our trip carefully around low tide. It was clear from scouting it that this was still primarily sanitary sewage flowing the pipe, and so we loaded up with protection: we bought hip waders, rubber gloves that went up to the elbow, and wore respirators to keep out any loose particles in the air (though the respirators were unwieldy enough that I soon took mine off). We met up at a bar on the corner of the street above the route of the sewer, just a couple hundred feet from the outfall. When we finally walked into the outfall, it was an hour before low tide, and the water was ankle-deep. We ducked under the rusted I-beams and fallen brickwork, but we only made it about 50 feet in before coming to the floodgates.
     These one-way gates are common now on large CSOs (Combined Sewer Overflows/Outfalls); during normal dry-weather flow, the new interceptor will take the entire flow (of mostly sanitary sewage) to a treatment plant, and gates prevent the incoming tide from flowing back into the system. But during storm events the system maxes out, and the pipes to the treatment plant can take only a small portion of the water, which eventually pushes the gates open and jets out into the bay. Normally, to open the gates for inspection, a truck will hoist the gates up using a chain that goes to the surface. We had no truck, but I had a pair of ratcheting truck tie-downs (good for up to 10,000 pounds), and we were able to pull the gate open slightly by alternating the two— we’d attach one to the chain, tighten it up to open the gate 2-3 inches, then attach the second and tighten it to take the pressure off the first and move the gate another couple inches.
     When we finally had the gates far enough open to slip through I was delighted. Ahead of us stretched the 12-foot high, perfectly circular tunnel lined with hard, dark red bricks. Just in front of us, a catchbasin about six feet long and as wide as the entire tunnel was set into the floor. The fast-moving flow of sewage coming toward it down the tunnel was a little over a foot deep, and it flowed into the catchbasin in a small, powerful waterfall. From the catchbasin, as I knew from sewer maps, it flowed into a 3-foot, 6-inch brick interceptor which led in turn to a 7-foot main interceptor that took it, along with the flow from other old Brooklyn sewers, to nearby treatment plant.
     We carefully climbed around the catchbasin, which was filled with roiling gray water that seemed to be waiting for us to slip even a little on the moist, slick, slimy bricks.
     And, finally, we were in the main tunnel. A 12-foot-high tunnel of hand-laid brick running east-west, 64 feet underneath Williamsburg. A pioneering engineering project from the days when the Brooklyn Bridge and the Statue of Liberty were built. But unlike those monuments, the tunnel we were in had probably averaged less than one visitor a year in the intervening 125 years.      Another few steps and we were almost directly underneath the bar where we’d been drinking just before. We walked about three-quarters of a mile, then turned around and came back. The tide was rising, and we came out through knee-high water around our waders, seeing the lights of Manhattan reflected in the opaque water.
     And really that’s the end of my story. Seems anticlimactic, doesn’t it? But in exploring the urban environment, the fact of us being in the place isn’t the story. Even the process of getting into it isn’t really the story, although it often is close to one. The real story is the hidden thing itself, how it came to be and what it meant to the world. We were just there to see it.

NYC: The Brooklyn Bridge

Hart Crane
From “To Brooklyn Bridge”

“O harp and altar, of the fury fused,
(How could mere toil align thy choiring strings!)
Terrific threshold of the prophet's pledge,
Prayer of pariah, and the lover's cry,--

Again the traffic lights that skim thy swift
Unfractioned idiom, immaculate sigh of stars,
Beading thy path--condense eternity:
And we have seen night lifted in thine arms."

         On my 29th birthday I finally climbed the Brooklyn Bridge.
         I had just broken up with a girl I’d been with for years, my longest relationship ever and the only one that seemed to be on track for marriage. We’d even talked about marriage sometimes, but whenever we talked about it I felt my skin start to crawl. For her, it was all she wanted. But I was terrified—terrified that the commitment would doom me to a life of boredom and monotony. After all, how can one single girl, no matter how fun or loving, be complex enough to continue giving me a sense of newness or discovery after decades lived together?
         A birthday brings on self-reflection, and I had been thinking about all these things, although they depressed me and made me worry I was incapable of real love.
         Late that night I found myself at the Patriot, a dive bar in lower Manhattan, slurping up a special birthday shot from a cocktail waitress’s belly button as she lay across the pool table. The whisky and the feel of the soft girl-flesh rushed into my head and suddenly I felt a wave of optimism and happiness. For months I had been feeling trapped, old, tired, bored and boring, caught up in a fast-flowing river where it took all my strength just to stay in the same place.
         But suddenly I knew differently. Today, my birthday, was the first day of the rest of my life, and the entire world of possibilities was open. So when Sunny, between drinks, asked me when we were going to climb another bridge, I had an answer immediately. “Tonight,” I said. “The Brooklyn Bridge.”
         I had wanted to climb the Brooklyn Bridge for years. Over time, though, i had stopped thinking about it as a real possibility. It’s illegal, of course. But it’s also illegal to climb the other bridges around Manhattan, and yet I’d been to the top of all of them. The difference is that with every other bridge around Manhattan it’s possible to go up the towers, either on service ladders or by climbing inside the latticework of girders. Going up the tower in these ways kept me more or less hidden from view. But the Brooklyn Bridge has solid stone towers rising straight up, and there are no ladders. The only way up is along one of the cables, which means the climber would be silhouetted against the sky and highly visible.
         This route also means walking up a sloping steel cable little more than a foot in diameter, using the auxiliary cables at each as handrails. We would do without any of the safety gear that bridge-workers use; though it would be reassuring to be clipped in, I knew it would make us impossibly slow. We had to move fast, which only made the tightrope-walk up the cable more worrisome.
         There’s something particularly spectacular about the Brooklyn Bridge, and it isn’t just because it was an engineering triumph that rivaled the Erie Canal or the Egyptian pyramids. It is absolutely beautiful, with nearly perfect curves and massing. And it connects what were at the time the largest and the third-largest cities in the country– New York City and Brooklyn.
         The towers, 276 feet high, are each made of three pillars supporting huge gothic arches and together form one of the most familiar sights in the world. At the time they were designed, in 1869, they were taller than almost anything else in the country– almost as tall as the spire of Trinity Church, taller than the dome of the Capitol in Washington DC– and far more massive than any other tall structure. The bridge needed to be tall so that high-masted sailing ships could still pass underneath it, going to and from what was then one of the largest and most active ports in the world.
         It was the first major bridge in the world to use steel suspension cables, which were developed by the bridge’s designer, John Augustus Roebling. Steel at the time, however, was still a fairly new development, and was considered too dubious a material for the massive weight-bearing towers. The original design for the bridge had been made in about 1869, and it would not be until two decades later that steel frames were first used to support massive structures: Holabird & Roche’s Tacoma Building in 1889 (the first building with an all-steel skeleton); the Forth Bridge in Scotland in 1890 (the first major all-steel cantilever bridge); and the early skyscrapers of Burnham & Root and Louis Sullivan in the 1890s. So it came naturally to Roebling to design these towers in stone, in the same monumental gothic style he had seen growing up in Mühlhausen, Germany, where he first passed the exam to become a Baumeister, a Master Builder.
         The towers are more massive than they need to be, as are the gothic arches they form over the roadway, and in fact they are partially hollow below the level of the road deck. In this, Roebling was using the language of expressive architecture. “In a work of such magnitude, and located as it is between two great cities, good architectural proportions should be observed,” he wrote. “The impression of the whole will be that of massiveness and strength.”

         Sunny and I left the bar when it closed. She’s a rock-climber and I’d climbed another bridge with her once before, and even after our drinking I knew I could trust her to handle herself. In the glow of the city after-hours, we walked to City Hall Park and then up onto the long wooden footpath that crosses over the bridge.
         I had walked this path for the first time almost exactly ten years before. I had just come to New York for school; I met a girl and I was in love from the first moment I saw her. On our first date, both of us still new to the city, we had walked across the Brooklyn Bridge. She wore soft black-leather gloves and I loved the feel of her hand in mine. I was completely and absolutely in love, but within a year I had successfully driven us apart because I believed I’d never be satisfied with her if we stayed together too long. She’s happily married now, and just had her first child.
         Marriage— or any relationship of true and mature love— must be a complete partnership, my last girlfriend told me. Two people decide to build a life together, hoping that as a team they can create something far more fulfilling than each could alone. This is how the Brooklyn Bridge was built, too. John A. Roebling designed the bridge, but died (of tetanus, from a crushed foot) early in the surveying process. His son, Augustus Roebling, took over as the main engineer, but was crippled by the bends while working on the underwater tower foundations. After that he watched the work through a telescope from his bedroom window, while his wife carried his orders to the workers and stood in for him at the site. The beautiful bridge that came out of these efforts is a monument to the ingenuity and glory of New York— but it’s also a monument to the commitment of one family, shared between father and son and between husband and wife.
         Sunny, walking along the path next to me, had a husband, but he wasn’t with us that night. Her marriage was on the rocks and would soon completely unravel. Like me, she’d been feeling trapped. Which, on the face of it, seemed like a silly thing for her to worry about. She’s a brilliant university professor, with three postgraduate degrees. She speaks four languages fluently and she’s an excellent rock-climber. And she’s gorgeous, and she can mesmerize a crowd by dancing to country music on a bar– which she’d been doing at the Patriot just an hour before. Her life seemed wonderful. What was she was trying to escape from? What more freedom could she possibly want or even use?
         On other hand, I had just broken up with the girl I loved and now I found myself approaching something I’d passionately wanted to do for years. And it was probably only because her marriage was in trouble that Sunny was willing to come along with me on this foolish quest. There was a connection between our romantic troubles and our willingness to go on an adventure. Why? Because adventure requires some risk— even if it’s just the risk of wasting time— and to risk yourself is to celebrate your independence. If you’re in a partnership, you can’t be so spendthrift with yourself, any more than you can gamble with funds from a company account. But when the life or the money is entirely your own, you can let go of the caution that ordinarily limits you to sensible investments.
         We walked to the middle of the bridge, where the suspension cables reach their lowest point, dipping down close to the wooden walkway. I climbed up first.
         At each end of the bridge, a police car idled at the edge of traffic. Police have been continuously stationed on the bridge since September 11th, 2001, watching for trucks that might be laden with explosives. The entire bridge, with approaches, is a little over a mile long. (The central span, between the two towers, is only 1,595.5 feet.) We were in the middle, which meant that each police car was, at most, about 3,000 feet away– a little over a half-mile. A half-mile is a long way to see at night. But with the bright lights that illuminated the entire bridge, would we be instantly visible as small dark shapes silhouetted against the towers?
         The police seeing us wasn’t even my main worry; I was more concerned with the people passing by. About 150,000 cars cross the bridge every day; that’s about 6,000 an hour, or 100 cars per minute, not including bikers and pedestrians. It was the middle of the night, but traffic still flowed unceasingly. We’d be on the cable for several minutes. How many of the drivers would look up? And how many of them, seeing us, would understand our need for freedom and independence, instead of calling the police?

         Of course, not everyone who risks themselves on the Brooklyn Bridge does it purely for the reward of the accomplishment. Police regularly respond to reports of suicide jumpers. And why would someone want to kill himself? Love, of course. As one of the Emergency Services Unit responders (officer Gary Gorman, in a 2000 interview) explained that, in addition to money troubles, “marriage or failed relationships seem to be the cause of most suicide attempts.”
         A jump from the deck of the bridge, 135 feet above the water, is
 sometimes survivable, so people who want a sure death occasionally jump from the top of the tower we were about to scale. That fall is invariably fatal. “It is hardly necessary to point out to thoughtful men the splendor of a suicide committed from this virgin height,” declared the Brooklyn Eagle in 1877, six years before the bridge was even opened.
         Suicide jumpers led to suicide guards, which are ten-foot-tall sections of fence installed along the cable. Climbing over a fence is no problem on the ground, but 150 feet above the water and fifty feet above the roadway it becomes far scarier. I’ve heard one report of a would-be suicide jumper who became so terrified while climbing over the guards that he changed his mind and decided he wanted to live. I wanted to live too, and I was very careful as I eased my body over the fence and dropped down onto the narrow cable again.

         The cable I stood on, one of the four main cables that supports the bridge, is fifteen and three-quarters inches in diameter with 5,434 individual wires inside. I take the strength of a steel cable for granted, but the bridge builders had had a hard time convincing the citizenry that it would hold the bridge up. Public confidence was shaken even more when it was revealed during the construction that a corrupt contractor had supplied defective steel, some of which was woven into the strands before it was caught. Additional strands of good steel were added to reinforce the cables, and the engineers assured the public that the bridge was not only strong enough, but far stronger than it would even need to be for the load it would carry. Nonetheless, fears of collapse led to a massive panic on the bridge a week after it opened, while sight-seers still crowded the roadways. Pedestrians fled the bridge in a mad scramble and twelve people were trampled to death.
         But more than a century later, the cable below my feet felt steady as a rock. I could feel the smaller cables thrum under my hands with the vibration of the light traffic, but I felt none of the structural vibration that I’ve felt on many all-steel bridges, in which the steel girders are always flexing slightly from the weight and motion of traffic.
         The cable slopes up more sharply as it rises to the towers, and soon I was walking up a steep slope. Roebling designed the bridge so that the weighted suspension cables would still follow a catenary curve, the natural curve that an unweighted rope will take when hung loosely between two points. I feared the slope would become so steep that my feet would slip before I reached the top, but before I had a chance to do more than think of it, I had finished the climb. The cable vanished into the stone wall; inside the tower top, it’s held in an iron cable-saddle on huge rollers. I went up a short ladder, past the overhanging cornice of the tower, and I was at the top of the Brooklyn Bridge.

         From the ladder I rolled onto my stomach and lay for a moment stretched out on the granite. I felt wonderful. The solidity of the stone this high in the air felt miraculous.
         I looked out over the skyline, brilliant in the cold air, with every spark of light on every building seeming both close enough to touch and impossibly distant and high. I felt awe and ecstasy for the beauty of it, and a deep sadness that I would never see more than the tiniest fraction of the stories behind each one of those lights.
         I rolled over onto my back and watched the stars until Sunny came over the ladder’s edge. We sat first on one side of the tower, looking north along the East River, and then we moved to the south side and looked out toward the Statue of Liberty and the still waters of the bay that once teemed with sailing ships. We both shivered from the cold, but we didn’t want to leave. Eventually I noticed the first faint lightening of the sky to the east, above Queens, hinting at the coming dawn.
         A helicopter passed over the bridge, and with a start we saw the beam of a spotlight stabbing down as the helicopter slowed. We ducked against the edge of the cornice and tried to look like shadows. Even huddled and with my face hidden, I still felt the brightness as the light washed over us. I didn’t think they saw us; the light passed and we breathed again. The helicopter circled lazily, but as it headed back toward the bridge it was joined by another. When the pair had passed over us again in a wide circle, we crawled to the ladder and hurried down the cable. It was far more frightening than going up; now we were forced to look down, and face-to-face with the drop. Another terrifying fence-climb over the suicide guard, and we were back to the walkway. Three helicopters circled now. They were probably looking for suicide jumpers, but I’ve never been so far from suicidal; I felt immortal.

         When the Brooklyn Bridge was built, New York was the busiest port in the world. It was the financial capital of the world and the industrial center of the nation. It controlled the majority of the wealth in a country that was quickly becoming a world superpower. It would soon be the most populous city in the entire world.
         Today the port traffic, always New York’s raison d’etre, is essentially gone. Still a financial center because it always has been, the city has rested on its laurels for nearly a half-century, attracting relatively little in the way of new commerce. Like Paris or Madrid, this city that was once was the center of a world empire will perhaps become just a showcase, an aged grande dame that is essentially a static— though still beautiful— shell of its past power and glory.
         But despite all this, I never worry that I’ll become bored with the city. It will never lose its power to awe and fascinate me, and it is so multi-faceted that I know I could live out my life within it and still never come to the end of newness and possibility. Maybe I’ll find that with a girl someday. Maybe I’ll even tire of New York, aging and changing as it is. But every time I see it laid out before, I fall in love all over again.

London Underground: The Walbrooke Stream/London Bridge Sewer

One of the oldest sewers in London is the London Bridge Sewer. It was built in the 1840s and then integrated into the comprehensive sewerage system that was built under Bazelgette in the 1860s and 1870s. On my final night in London, DS and I went into the sewer via a manhole on a fairly crowded street. It was late at night, but we still had to walk past it the first time because too many cars and people were passing by. Eventually we changed into our waders in a nearby alley, and then opened up the manhole and dove in, praying no cops would happen to be passing at the wrong moment.

As usual, the guys at Sub-Urban had done the original research on this sewer, including researching the chronology of its construction. Reading Nicholas Barton’s The Lost Rivers of London, however, I decided that this sewer was also what remained of London’s Walbrooke (or Walbrook) stream, which was so named because it was the only watercourse that crossed London’s walls at the time when a wall fully encircled the city. (The sewer still passes underneath London Wall Street.) As the only running water to flow under the walls, it must have been important to early London for two reasons: first, as a supply of fresh drinking water, and second, as a sewer which could carry refuse out of the city.

As a freshwater supply, I assumed that there must have been springs that once fed the brook, because how else could enough water be generated to create a consistent stream in the small area of the city? And, in fact, when we got into the sewer, we found that underground springs apparently still flowed in the area, and still fed into the Walbrooke despite the tunnel that now surrounded it. In dozens of places, streams of water came through the brick walls. Some trickled down the sides; others had enough force to spew out between bricks like fountains. All of these streams had apparently forced their way into the tunnel over the century and a half that the sewer had been in use. There was no way to stay dry as we passed through these areas; water dripped from the ceiling, spurted from the walls, and splashed up from the sewage.

As an open sewer for the walled city of London, the Walbrooke must have carried its share of filth even before it was put underground. However, no matter how bad it was back then, we soon found out that today it’s beyond merely disgusting. It was in fact the most noxious, filthy sewer I’ve ever been in. Most of the time sewers don’t actually smell that bad, as flowing water combined with the process of decomposition leaves even human waste smelling more like a barnyard than like a toilet. But the London Bridge Sewer has a very shallow drop compared with more modern combined sewers, and this probably allows a build-up of un-decomposed waste over years. The smell nearly knocked us over when we got into the main channel, where filth and slime came up almost to the crotch of my chest-waders. I was reminded of the name that the explorers from Sub-Urban.com had given it: Stoop’s Limit, so named because even the normally-intrepid explorer nicknamed Stoop, who never balks at anything, finally called a halt in their trip because of the smell.

It was in this sewer, unfortunately, that I found out that my chest-waders had developed a hole near the left knee. When I first felt the wetness along my leg, I though that one of the streams of water from the sides was running down into my waders. When I realized what it actually was, I hit my own limit and called to DS to retreat with me to shallower and drier areas.

In retreating, we found some smaller side-passages. Along the sides of these, a crystalline deposit had built up on some of the old brickwork. I don’t know what mineral it was, but it was gorgeous, especially as it suddenly glittered out of the complete darkness in the light of our headlamps. As I was taking pictures of it, I noticed a tiny, nearly transparent spider that crouched on the crystals.

One other interesting thing about this sewer is that it passes directly underneath the Bank of England. Presumably it is fairly deep where it does so, but it brought to mind the various bank-robbery movies I’ve seen where the thieves manage to find an old sewer tunnel that they use as a base to dig into bank vaults. I’d always thought it was unrealistic, but maybe it’s more of a real possibility than I knew.

London Underground: the River Fleet

Day 1 in London, November 14, ----, 3:30pm local time.
         Ah! London! Sewers!
         I’m sitting right now in a Starbucks in central London, where I popped in to use the bathroom and hang out for a few hours while I wait for my friend to finish work. As I flushed the toilet, it occurred to me that I might see those same turds again in a few hours. Tonight we’re going to visit part of London’s sewer system: the River Fleet, a tributary of the Thames that flowed through central London until it was put underground—and connected to the sewer system— in the 19th century.
         I just arrived in London a few hours ago, flying in from New York. My friend and exploring partner goes by the cryptic name of DS. I met him at his office and dropped off my bags of gear– chest-high rubber waders, gloves, camera, tripod, flashlights, headlamps, spotlights (for light-painting photos), an air meter, even an inflatable inner tube for a possible rafting trip along an underground river in Northern England.
Day 2 in London, November 15, ----, 7am local time.
         Was in the River Fleet last night and into this morning. Just got back to DS’s place. I want to tell the story of our night, but I think I have to start with the river itself:
         THE RIVER FLEET flows from two underground springs in northern London, in Hampstead Heath (a large park on the North-western part of the city) on each side of Parliament hill. The western source starts at the Hampstead Ponds, and the old course of the river just to the south is marked by Fleet Road. The second source is in the northern edge of the park, on the grounds of Kenwood House. A longer series of ponds, the Highgate ponds, show where this spring flows along the eastern side of the park.
         The two springs unite just north of Camden Town. In 1826, it was recorded that the river at this point was 65 feet wide. The Fleet had always one of London’s bigger rivers—the name itself is thought to have been derived from a word meaning, basically, “big enough to float a large boat”—but by the 19th century it was deeply polluted, serving as a drain and sewer for the entire area.
         This was going to be my first time into the London underground. DS and I met with another urban explorer, who goes by the nickname Loops. The manhole that was our goal was a square hatch in the middle of the sidewalk, next to a stoplight on a busy street. It was well after dark on a weeknight, but people walked by constantly. Some were headed toward the hotel just down the street; others were simply walking. At one point when the coast seemed clear, a couple came meandering along the sidewalk. They were obviously and enthusiastically on a date. They held hands and lingered, leaning into each other and stealing a quick kiss. They were moving at a snail’s pace. A dozen feet from the hatch, they stopped completely and admired the ornate stone building next to us. We had already put our rubber waders on, and we sat on a low wall across the street and tried to look inconspicuous in the rubber suits. Finally the sidewalk was empty. We walked over, as quickly as possible in the rubber waders. As DS and I stood casually, Loops knelt down to try to undo the latch that normally prevents anyone from opening these hatches from the top.
         We were here at this relatively early hour because of the tide. The Thames is an estuary in which high tide rises more than twenty feet above low tide. I don’t know how that’s possible; I think it’s because water flowing down the river hits the incoming tide, and the conflux creates tides much higher than I’ve seen on the east coast of the US. But because of this, the final portion of the Fleet is completely flooded from mid-tide onward.
         The hatch was what DS called an “easy-lift.” The hinged square cover was far easier to raise than a heavy manhole—at least, once it was unlatched. Loops was still struggling with it, his headlamp on now. DS bent down to help him. Eventually he threw down the tool he’d been using, and with one finger jammed through the tiny hole he was able to jimmy the latch. We raised the hatch, and then the heavy grill just beneath it.
         I went down the ladder into a small, dry brick tunnel. DS was just behind me. From the bottom of the ladder I looked up: a small square view of the night sky, and then it disappeared as Loops lowered the grate and the hatch cover. In the sudden darkness, the scrape and clang of the metal grating echoed ominously off the Victorian-era brickwork around us. But we were in! I was elated.
         It’s the incredible brickwork that makes the London underground so amazing. The sewer system was constructed under the engineer Bazalgette, who researched and planned in the 1850s and started construction of the hundreds of kilometers of brick tunnels in the 1850s. Thousands of workers dug tunnels and laid brick and stone to make the sewers for the rich and burgeoning metropolis.
         Although few ever saw it, Bazalgett’s sewer system was one of the engineering marvels of its day. Round brick tunnels ranging from six to twelve feet in diameter hold mainline sewers, as well as rivers like the Fleet that had become so polluted that they were best put underground. Round tunnels flow into even vaster tunnels shaped like an upside-down horseshoe, with gently concave floors. Smaller channels were often oval or egg-shaped. (With the smaller end of the egg’s profile pointed downward, this shape keeps sewage flowing faster even when it’s low flow, and that helps reduce silt build-up.)
         These were built not only for sewage and wastewater, but also to drain the city of rain or snowmelt. Because of this, the tunnels often seem needlessly huge. In most of the Fleet, the tunnels range from eight feet up to twenty feet high. The flow of sewage and water we encountered, however, was rarely more than one or two feet high. But in heavy rains these tunnels could fill up almost completely. In manhole shafts, markers ran up the sides with markings every meter, showing that the water could potentially rise much higher even than the top of the tunnel.
         When Bazalgette designed the sewer system, one of the most important things he did was create a system of five “interceptor” sewers, which ran parallel to the Thames at various distances and intercepted the water from the north- and south-flowing sewers to carry the sewage to a treatment plant. Previously, the sewage had flowed directly into the Thames, near where drinking water for the city was withdrawn. Bazalgette’s new system probably saved an incalculable number of lives from disease.
         But when it rains, the flow vastly increases. The rainwater mixes with the human sewage. The treatment plants and interceptor sewers are unable to handle the load. As the flood of water and sewage comes through the tunnel, it rises over the small diversion dams that normally direct it into the interceptors, and a flood of untreated sewage is released directly into the Thames.
         This is a problem common to almost every older city, and is one of the most serious public health issues for urban waterways. Cities try to deal with it in a variety of ways; London is beginning to work on a gigantic deep-underground tunnel which will serve as a reservoir or holding tank for excess sewage when it rains, which can then be slowly released and treated in dryer weather. It should be ready in about 2020. In the meantime, every time it rains, raw sewage is released with the rainwater into the Thames.
         Of course this is an imperfect system, but cities are organic growths that re-use and build on their past. Therefore almost nothing in an older city is going to be perfect, because the systems and infrastructure in use are so often leftover from an earlier period of growth. It’s imperfect, but nonetheless I love seeing the sort of cut-away view of both the history and the physical structure of a city that you get from seeing old underground systems in a modern city.
         Cities that are planned and built in the modern era—like many Australian cities-- always have separate storm drains systems (for rain) and sanitary sewage systems, so they can avoid this problem. But in a large city like London or New York, it’s basically impossible to add in a new separate system for stormwater. The cost is prohibitive and urban populations would never accept the city-wide shutdown that the construction would cause. But this highlights even more what an incredible thing Bazalgette did in constructing the system in the first place—perhaps the largest infrastructure project London has ever undertaken, a masterpiece of Victorian-era brick and stonework that is still fully in use today.
         The bricks inside the Fleet looked as if they had been laid just yesterday. Hard-fired dark bricks formed the floor, sometimes changing to large flagstones. As the tunnel changed shape and size, we could see that the arches were made with four, five, even six layers of bricks. I couldn’t believe the amount of work that had gone into this.
         When we first came in, the water was about two feet deep. Our manhole opened into a small network of access tunnels that led in one direction to the equipment that could raise or lower huge floodgates. Now the gears everything else was almost unrecognizable underneath a swollen, flaking layer of rust and a coating of black, oleaginous mud.
         In the other direction, the tunnel led us into a set of ladders and catwalks that led down into the main tunnel itself. It was incredible: near the outfall here, it was a giant chamber easily twenty feet high and equally wide. The exquisite brickwork vied for my attention with the sheer architectural wonder of it.
         Though most of the standing water near this of the Fleet’s tunnel seemed relatively clean, we quickly encountered sewage when we passed the interceptor tunnel a few hundred feet upstream. A steady stream of obvious sewage flowed into the interceptor, making a waterfall that roared and pounded in the confined space. A four-foot high dam stretched across the main tunnel of the Fleet to prevent it from flowing through the outfall and into the Thames. But it was clear that with even a little bit of rain the water level would rise enough to go over the dam, flowing into the Fleet tunnel and then into the Thames.
         I had on chest-high waders, and was glad of it. Loops and DS both just had hip waders, essentially crotch-high boots. They were easier to move in than my rubber suit, but it occurred to me that if I fell I’d probably be able to stay dry– but if they fell, the high boots would immediately fill with water. The slime that coated everything made it impossible to walk on the sides of the concave floor without slipping, so we trudged along the center. The water would only have been shin-high if it had been standing still, but with the heavy current it splashed past our knees.
         Wading through sewage is a nasty business. In purely sanitary sewers, the water is often a bilious green-brown. (“Sanitary sewers” is the official term for pipes that carry raw sewage, to distinguish them from the cleaner storm drain tunnels designed only to carry rainwater runoff.) In combined sewers, as were built in the Victorian era, street runoff often dilutes the sewage so that the smell is not so bad, and you can sometimes go many steps at a time without being reminded that you’re in a sewer. But the worst part of venturing into sewers is seeing something recognizable: tampons, condoms, maxi-pads, streamers of half-disintegrated toilet paper, or the occasional turd bobbing in the water. We saw all of these as we trudged upstream. The smell was bad, but not awful; only a little worse than I’ve smelled around pigsties or slaughterhouses.        
         But neither the smell nor the sight of floating turds could detract from the excitement I felt. This was the great Fleet River; it had been flowing along into the Thames since before the Romans first established Londinium. The intersection of the Fleet and the Thames was one of the reasons that London had become London, a great city built on a foundation of water-borne trade.
         After the great fire of London, Christopher Wren (the great architect behind St. Paul’s Cathedral) had designed at least one bridge over the Fleet, and I eagerly looked at the walls when the tunnel changed shape or size to see if I could tell where it had been integrated into the tunnel when the Fleet was put underground. I don’t know if I saw it, but what I did see was a palimpsest of London history from Victorian times to the present: old stone arches, Bazalgette’s amazing brickwork, flagstone floors in some tunnels, new sewer line connections of metal pipe, ancient sewer connections of brick tunnel that had been sealed up, because the building or possibly even the entire street that they had served no longer existed. Ancient, rusted ladders led to 19th-century manhole shafts capped by heavy iron covers. Newer ladders, visible in access rooms ten feet to the side of the main tunnel, led to stainless-steel hatches like the one we came in.
         Beyond all this I could see the ancient history of London. With a deepwater port on the estuary of the Thames, all that was needed for the growth of a great city was freshwater rivers. Some would be used for drinking water, others as canals to transport goods. The rivers could also be used for waterwheels to run mills—something the tidal Thames could not do. The Fleet and its companion rivers provided all of these things. And the city grew until it was the center of a world empire, and then it became so large that the small rivers that had fed it were now nothing more than impediments, loose threads in the urban fabric that blocked traffic and occupied valuable real estate. So the rivers were put underground, and as always happens in cities, history and the past were eaten up as the city built for the present and the future. Except that the past is still there– it’s just hidden away, and you have to work a little harder to see it.
         We were done by about 3:30am. We had almost let ourselves get trapped by the rising tide, and in the final section before our exit, the water was so high that it came over the tops of Loops’ waist-high boots. The rising tide made it impossible for us to visit the southernmost section of the river tunnel, even though our exit manhole was so close to it. We would come back the next week at low tide to see the impressive outfall space, a gigantic brick-arched chamber with massive iron doors hanging at one end to serve as one-way valves for the water.
         We stayed in the access tunnels a little longer, wiping down our muddy, sewage-covered gear and packing up for a quick exit out the manhole. Even in that short time, we could see the tide visibly rise in the tunnel near the outfall.
         When we got out DS walked to his office, where he would wash in the bathroom and sleep a few hours on the couch before he had to wake up for his day job. I walked to the nearest Tube station, and had to wait two hours outside the station for the mornings first train. It was absolutely freezing as I waited, especially in my wet clothes, and I sort of wished I was back underground where it’s always warm.

London Underground: the Tyburn River

The Tyburn River
         The Tyburn was one of London’s smaller rivers, nothing like the size of the Fleet or the Westbourne rivers I visited in the city. But I had long looked forward to seeing it, more than any other part of London’s underground. Integrated into this river’s history are two of London’s most important landmarks: Westminster Abbey, which was a nucleus of London a thousand years ago, and Buckingham Palace, a cultural center of London in the modern era.
         Until early in the second millennium A.D., the Tyburn split into two wide, marshy streams just before flowing into the Thames, and the area between them was called Thorney Island. Westminster Abbey was founded in 1065 A.D. on this island. And today, with its course drastically changed and channeled underground by the developing city, the Tyburn River flows deep underneath the grounds Buckingham Palace.
         I was fascinated by the idea of being in a forgotten tunnel underneath such a well-known landmark as Buckingham Palace. I’d be under the noses of the celebrated guards, and they’d never know it. The thousands of tourists that flock every day to see the home of Britain’s royal family would never see what I was going to see, even though it’s only a few dozen meters from the home of the Queen. And this unique experience, shared by so few others, is no small or meager thing. In fact, considered in purely structural and engineering terms, I’m sure that it could rival the Palace itself– the Tyburn’s tunnel stretches for kilometers, with parts as large as ten meters across, and is composed of something like two million hand-laid bricks.[1] But it’s hidden in two ways: physically invisible from the surface, and also unnoticed in the same way that our heartbeats or breathing often go unnoticed. We see the surface layers, whether looking at bodies or at cities, and we often forget the structure behind the surface, just as we often forget the history that underlies the present. But in the Tyburn, as happens with so many historical sites in cities, physically venturing underground and the imaginative process of looking back into history became inextricably linked for me. In both ways, this river would help me in my quest to see new layers of London.
         In London’s early days, the Tyburn River flowed from two small sources in Hampstead (north London). The first was the “Shepherd’s Well” along what is now Fitzjohn’s Avenue, and the second was on the grounds of Belsize Manor. Belsize Manor is gone, but its old location is hinted at by a half-dozen streets in South Hampstead with Belsize in the name (Belsize Road, Belsize Court, etc).
         From these sources, the Tyburn flowed in a generally south-easterly direction; first along the eastern side of Hyde Park, then through the area where Buckingham Palace now stands, and then onward to the site of Westminster Abbey. There it split into two marshy channels, which formed a soggy moat around the slightly higher land of Thorney Island on which the Abbey would grow.
         Because it was so close, the Tyburn was one of the first streams to be diverted to provide drinking water for London. By 1236, the clean water of the upstream Tyburn was already being carried in a conduit to the city. A half-dozen different schemes for bringing its water to the city would be tried in the next few centuries, including one in which three and a half miles of leather pipes were used to transport the water.
         The diversion of the water for other uses, combined with the Tyburn’s small size and the closeness of its sources to the growing city, quickly turned it fetid. With diversions upstream, the flow decreased and the now-small stream became a default sewer for those who lived along it. By 1611 London had made itself independent of local water sources by building an aqueduct to Hertfordshire, but the Tyburn– at least its southern half– had probably ended its usefulness as drinking water centuries before that.

         The river’s course was also drastically changed by the city. Instead of running toward the site of Westminster Abbey, it was channeled further south and ran into the Thames near the site of the Vauxhall Bridge. What’s fascinating to me is that, in fact, it’s impossible to say for sure when the change took place. The amount of London’s growth that predates any complete plan or written record of the city shows clearly how organic a city’s growth is over time. The historian Nicholas Barton places the change in the Tyburn’s course sometime between 951 and 1663. But exactly when, or why, it was changed, or if it was a natural process that happened over the centuries, remains murky.
         Today, the Tyburn is a sewer flowing through a brick tunnel. Officially titled the King’s Scholar’s Pond Sewer, it’s about three meters in diameter when it passes underneath Buckingham Palace. Walking through it we saw many side channels– some go only a short distance to manhole shafts, some connect to side-street sewer lines. There are also consistent tap-ins (individual sewer pipe outlets) from buildings built above the tunnel. Which one of these outlets or side channels ran from Buckingham Palace, I can’t say. But it is likely that at some point we were wading through the Queen’s shit—a more personal side of royalty than most tourists get to see.
         South of Buckingham Palace, we took a look at the surface to orient ourselves. It was now about 3am, and we felt safe in carefully raising a sidewalk manhole to peer out. But a moment after DS stuck his head out, he pulled it back and closed the cover; we were just outside Victoria Station, another of London’s landmarks and probably a bad place to be seen coming out of a manhole.
         In its final section south of Victoria Station, the river follows the winding course of Tachbrook Street. The street is named for a brook that was, essentially, the drastically diverted remnants of the original Tyburn River in the area closest to the Thames; when the tunnel was built it followed this same general path. The original outlet for the tunnel was near Vauxhall Bridge, but a series of floodgates cut off this final connection to the river except in extreme floods. (Wastewater in the tunnel is diverted into a series of interceptor sewers, which carry it east to treatment plants.)

         The many centuries of human involvement in the course of the Tyburn had shrunk it to no more than a small stream long before it was covered, and I expected to see nothing more than the continued small round tunnel. But instead, the passage opened up into a series of much larger galleries. Intricate brickwork curved up into magnificent arches, and lines of heavy stones high in the walls showed where part of it had been originally constructed as an open canal. Ancient, slime-encrusted interceptors carried away the small channel of sewage that ran down the center of these huge spaces. This had clearly not been just a work of pure functionality, as so much urban infrastructure is today; it was in its way a monument to the city and an expression of its glory.
         The floodgates that shut off the southern end of the river—each widely separated from the other– were modern and made of bright steel, incongruous against the dark brick. The first we had passed was mechanized, and we went through it only after Z scouted the tunnel beyond it for the rest of us. (Not knowing if it might close behind us and trap us, I had been too timid to go further until he determined there was a manhole further ahead we could use as an emergency exit.) The second was a closed steel flap weighing tons, and we made it through with brute force and careful squeezing—though crawling through the narrow gap we made brought us face-to-face with the sewage.
         But the third, closest to the river, was firmly and perhaps permanently shut. We couldn’t follow the river to its end. But we had already followed it through a good thousand years of London’s past, and I was quite happy as we made our way back to the silent pre-dawn streets above ground.
Please Note: The Credit for the research and archeological work in uncovering these rivers and their history belongs entirely to others, not me, in particular the extremely dedicated folks at www.sub-urban.com.
The people represented through these websites have my deepest thanks for exploring these rivers and their history and for guiding me around: www.sleepycity.netwww.sub-urban.comwww.silentuk.com; and Loops.
For further reading: The Lost Rivers of London, by Nicholas Barton.

[1] This is a very, very rough guess, based on the size of the tunnel and the number of layers of brick. I didn’t actually count them all.