Explaining the tunnel system under Liverpool

Excavations have brought to light tunnels under Liverpool but it is unclear why a tobacco merchant created them in the early 1800s:

He also had men build tunnels. One entrance to the system even has been found in the basement of his former house. But why tunnels? Did he ask them to build his tunnels arbitrarily, for no other purpose than to be paid for work? It seems extraordinary. And yet there are no known records from Williamson’s time which offer anything like an explanation for their construction.

Instead, succeeding generations and historians have had to guess – leading to all manner of speculation. Perhaps Williamson wanted secret passages to get to and from buildings in Edge Hill. Or was a smuggler and needed the tunnels to carry out covert operations.

Or maybe he and his wife belonged to a fanatical religious cult that anticipated the end of the world, and his tunnels were designed to provide shelter during the apocalypse. Apparently, someone once made the suggestion casually on television, and the idea since stuck.

Those who have worked on the tunnels have now developed a new, somewhat more satisfying theory. Bridson points out a series of markings in the sandstone that he says are indicative of quarrying. There are channels to drain rainwater away from the rock while men worked, blocks out of which sandstone could be hewn, and various niches in the walls where rigs were once likely installed to help with extracting the stone, commonly used as a building material.

Bridson believes that before Williamson came along, these pits in the ground already existed. But it was Williamson’s idea to construct arches over them and seal them in. Properties could then be built on top of the reclaimed land – which otherwise would have been practically worthless.

I imagine there are interesting things lurking under every major city as evidenced by findings under Paris, Chicago, Seattle, London, and New York.

The land development theory is an interesting one. Williamson could benefit in two ways: by selling the excavated rock from below the surface and then also selling the land above it. Now, there might be separate rights to the above ground and below ground space but no such issues likely hindered Williamson.

When the underground borer Bertha gets stuck under Seattle – for a year

The construction of massive infrastructure underground can be impressive but it doesn’t always go as planned:

A year ago this month, North America’s largest tunnel-boring machine got stuck just 10 percent of the way through a 1.7-mile-long dig under downtown Seattle. Throughout 2014, engineers have been plugging away on an ambitious plan, outlined in a Popular Mechanics feature, to free the mechanical marvel and get the project going again.

But today, Bertha remains stuck under the city. And according to an update from The New York Times, crews monitoring the project to free the machine have noticed something alarming: one inch worth of settling in the downtown district under which Bertha now sits…

Instead, investigators eventually concluded that Bertha was overheating—that grime and gunk had gotten past bearing seals, entered the machine, and muddied the operation. Engineers still aren’t sure why all this happened to the 326-foot-long machine, but they decided they had replace not only the seals but also the $5 million main bearing.

But just getting to Bertha, which sat more than 60 feet below downtown Seattle near the stadium district and the waterfront, posed a serious problem. Crews could go through the painstaking, time-sucking process of disassembling the machine from behind to make the fixes, but instead chose to dig a 120-foot-deep access pit in front of Bertha.

It shouldn’t be too surprising that such a big project could lead to a problem that doesn’t have a quick fix. Putting together a machine this size is notable in itself and getting it back on track likely requires a lot of careful planning and long hours. Yet, these sorts of projects tend to go on without much attention until they are done and people experience the benefits. Unless something goes wrong. It would be interesting to see how Seattle responds to the delay and if someone is blamed for the problems, what kind of negative consequences they suffer.

The dangers of tens of thousands of miles of aging metal gas lines

Big infrastructure failures attract attention but USA Today finds that millions of Americans live near aging gas lines:

About every other day over the past decade, a gas leak in the United States has destroyed property, hurt someone or killed someone, a USA TODAY Network investigation finds. The most destructive blasts have killed at least 135 people, injured 600 and caused $2 billion in damages since 2004…

A review of federal data shows there are tens of thousands of miles of cast-iron and bare-steel gas mains lurking beneath American cities and towns — despite these pipes being a longtime target of National Transportation Safety Board accident investigators, government regulators and safety advocates.

The Pipeline and Hazardous Materials Safety Administration has been pushing gas utilities for more than a decade to replace aging pipes with more resilient materials like plastic, though it’s not required by law. The industry has responded by replacing thousands of miles of pipe, but a daunting amount remains. It can cost $1 million per mile, or more, to replace aging pipe, costs typically passed to customers…

Aging pipes are a high-risk example of the nation’s struggle to replace its crumbling infrastructure, a danger hidden beneath the ground until a pipe fails or is struck by something and a spark ignites a monstrous blast. Natural gas is piped into 67 million homes and at least 5 million businesses, schools and other buildings across the country, with gas distribution and service lines snaking beneath most neighborhoods in American cities.

A long and fascinating look at how gas is delivered to many homes and places underground.

Perhaps the relative lack of outcry regarding this issue is because the events take place at seemingly random times in different places. In other words, a large-scale explosion might draw more attention than the scattered events that do take place. The costs of fixing this are quite high yet given the typical levels of concern about safety, it seems like this will need to happen at some point.

Building large buildings over the Hudson Yards in Brooklyn

How are large skyscrapers and buildings constructed on top of a railroad yard? See the example of Hudson Yards in Brooklyn:

Hudson Yards is the largest private development project in U.S. history, and it’s being built without footings or foundations. Instead, the project is going to sit atop 300 concrete-sleeved, steel caissons jammed deep into the underlying bedrock. Work on the platform broke ground last week, and will take roughly two and a half years to complete. In that time, there’s a lot of engineering to do.

Caissons are a technology borrowed from bridge building, and they are what makes this project possible. The engineers will drill them anywhere from 40 to 80 feet into the Manhattan schist (the dense, metamorphic bedrock that supports the city’s soaring skyline). The caissons are meticulously arranged in the narrow spaces between the tracks. Above, the they will connect to deep-girdle trusses – some up to 8 stories tall – that control and redirect the towering weight overhead. Finally, the slab. “The total punishment is somewhere in the neighborhood of 35,000 tons of steel and 50,000 cubic yards of concrete,” says Jim White, the lead platform engineer. And that’s before they start loading buildings on top.

Building an elevated platform over an active train yard requires clockwork scheduling. White used computer models to coordinate the tempo of his drilling and truss-laying around the rhythm of the rails. “We look at the area of the yard and model in the train traffic, when it moves on an hourly basis and actually design the connections so we can install these 100 foot long trusses when have a window of opportunity,” says White. For the two and a half years it will take to complete the platform, there are only four scheduled track closures.

That is quite a lot of weight over a rail yard. However, such projects are not unknown in large cities where people look to maximize both space above and below ground. Space is at a premium so construction projects need to get creative and allow for a multitude of uses.

The public to ride the mail delivery system once used under London

The Post Office Underground Railway once used below London is set to open soon to the public:

The Post Office Underground Railway—AKA the Mail Rail—was the world’s first driverless electric railway. It launched in 1927 and was used to transport tons of post from one side of London to another, with stops at large railway hubs such as Liverpool Street and Paddington Station, where post could be collected and offloaded for transportation around the rest of the country…

The idea is to create special battery-powered passenger carriages to take people from the car depot and some of the tunnels in a one-kilometer loop. Visitors will be taken 70-feet underground, through Mount Pleasant Station, and will stop to view audiovisual displays recounting the history of the network and what it was like to work down there…

The railways have a 61cm gauge (the width of the track), on top of which small carriages traveled without drivers thanks to electric live rails. In the stations there are two tracks, with carriages going in each direction.

The service continued to operate until 2003, when it was closed down—it had become much cheaper to transport mail by road.

Looks like a cross between a Disney ride and the Tube. I suspect there may just be a tourist market for this ride…see this post from April 2011 about people exploring the system as well as the interest in looking at underground Paris.

Such lines underneath cities may not be all that unusual. Chicago had an underground delivery system as well since it was far more efficient to move some items underground away from the street-level traffic. This was also the impetus behind creating Lower Wacker Drive. How many major cities have such tunnels underground, how many of them are well secured (free from ne’er-do-wells or flooding issues), and are these all tourist opportunities waiting to be opened?

Exploring the meanings of Chicago’s underground Pedway

A Chicago artist and teacher has spent years exploring and analyzing Chicago’s large underground Pedway:

You want to know the best thing about the Chicago Pedway? It’s not that, despite this Polar Vortex winter, you can cover almost 40 city blocks on the Pedway without ever stepping foot outside. It’s not that the Pedway began modestly in 1951 and now stretches through the North Loop, jogs beneath Millennium Park and ventures as far east as the mouth of the Chicago River. It’s not that the Pedway could be regarded as a kind of yardstick of municipal progress, always seeming as though it might extend just a little bit longer someday. It’s not even that the Pedway’s generally mundane, charm-free hallways offer little to see — look, another “For Rent” sign! — and therefore it works perfectly as a daily treadmill for ambulatory meditation…

Where you see putty-colored corridors leading to a job in a cubicle farm, she sees dreams of the American frontier. You pass convenience stores selling gum; Tsen, 38, a native of Cambridge, Mass., passes through a long, winding metaphor for a Chicago never realized — “the by-product of projected futures,” she writes in “The Pedway of Today,” her new, perversely compelling guidebook/consideration of the Pedway’s cultural meanings.

Indeed, Tsen, a graduate of the School of the Art Institute of Chicago and photography/video teacher at Wilbur Wright College on the Northwest Side, has come to see the longtime walkway as her canvas. About four years ago, the Chicago artist — and former Wendella Boat tour guide, who says travel and The Path Not Taken have become the preoccupations of her art — began offering tours of the Pedway (she has since stopped). But she never charged her audiences, she said, because the tours would also quietly double as performance art, as free-associative strolling lectures in which your guide (Tsen) would dole out not dates or landmarks but thoughts on Jules Verne, revolving doors and how the Pedway is like Florence…

Eventually she stumbled across an entrance to the Pedway in the back of the Renaissance lobby, the path itself so low-key that you can see it every day without quite recognizing it. “The Pedway struck me not as the frontier that I had been looking for but a reminder of the glamour of early cities and a promise of future frontiers.” At this point in her guide Tsen asks readers to imagine that it’s 1893 and — though the Renaissance was built a century later — they are relaxing in the lobby before returning home from the World’s Fair, where they “attended Frederick Jackson Turner’s fabled lecture ‘The Significance of the Frontier in American History’ … still pondering his words: ‘The frontier has gone, and with its going has closed the first period of American History.”

Sounds like a very interesting and interpretive tour. All sorts of large infrastructure and urban projects would benefit from people who know them well enough and are enthusiastic about what they offer to share it with others.

If Chicago tried to advertise the Pedway more, would regular users complain that too many tourists are clogging the passages a la New Yorkers and the subway?

More on luxury basements under London properties

The building of luxury basements under London properties continues:

A lack of room and strict planning laws dictate that the facade of many of London’s picturesque Victorian, Edwardian and Georgian-era neighborhoods must maintain their original character and outward appearance…

“The price per square foot (of basement extension) in areas we work in is probably £400 to £500 per square foot (between $660 and $830 per sq ft). The extra space this brings is probably worth double that,” he added…

“I think for any property with a value over £2 million ($3.2 million) a basement extension is certainly a consideration for the owners,” explained Rob Atkins of London estate agency, Domus Nova. “If you’ve lived in a house for 15 and 20 years and you cannot get a move for the right value then it is an option that can suit that growing family…

“Therefore I wouldn’t be surprised if you see that kind of basement living incorporated in houses for example in Paris, Rome, Vienna or Moscow in the future,” he added.

Without much regulation, it sounds like the incentives are generally there for wealthy owners to create these basements rather than move.

Many of these basements are being built in neighborhoods that are not the oldest in London. At the same time, I would be interested to hear about how such work could interfere with other underground services, whether that is sewers or the Underground or other properties.

Is there any place where this might work in the United States? It would likely have to be in a super-dense area where housing is in high demand. Perhaps Manhattan or San Francisco?

Discovering underground Roman aqueducts

A group of amateurs have been tracing portions of Roman aqueducts hidden from view:

The group, which has been exploring underground Rome since 1996, has completed about 40% of its mission to map the aqueducts.”The famous arched, over-ground aqueducts we see today are just the tip of the iceberg; 95% of the network ran underground,” says Marco Placidi, head of the speleologists group, which is sharing its results with Italy’s culture ministry…

Dropping into the hole, Baldi disappears down the Anio Vetus aqueduct, a 3-foot-wide, 5-foot-high tunnel lined with pristine Roman brickwork. As frogs, spiders and grasshoppers scatter, Baldi reaches a maintenance shaft, complete with good-as-new footholds dug into the bricks that lead up to a narrow opening in the woods 10 feet above. Beyond him, the tunnel vanishes into the darkness…

“We have found Roman dams we didn’t know about, branch lines taking water to waterfalls built in private villas, and even aqueducts driven underneath” streams, Placidi said. “We are able to get up close and [feel we are] right back at the moment the slaves were digging.”

As the article notes, the level of construction here is quite amazing to survive roughly 2,000 years. But, without such underground aqueducts, the city of Rome may not have survived long.

What might happen to these infrastructure marvels? Perhaps they could be turned into tourist opportunities like the tunnels under Paris.

The unfinished “concrete bathtub” Block 37 CTA station

Here is an inside look at the partly completed Block 37 CTA station that was once intended to be home to express service to both Chicago airports:

The superstation, which was mothballed in 2008, runs on a diagonal from beneath the corner of Randolph and Dearborn streets, southeast to the corner of State and Washington streets. I’m not supposed to say how you access the space — security concerns, you know — but let’s just say that a variety of elevators, locked doors and ladders are involved.What’s striking once you get in the space is its size: as long as a football field-and-a-half (472 feet), 68 feet wide and averaging 28 feet high. Call it a concrete bathtub — or an “envelope,” as our tour guide, Chicago Transit Authority Chief Infrastructure Officer Chris Bushell, put it — with rows of support pillars receding into the dim far distance. And all completely unlit, except for some temporary light strung up on the mezzanine and the portable lights we brought along…

The money needed for express train service, likely in the billions, never was obtained. And any private-sector interest melted away when the economy entered its worst downturn in many decades in the late 2000s. So, the city stopped after completing the shell and built no more.

By that time, though, City Hall had spent $218 million — $171 million of CTA bonds, $42 million in tax-increment financing and $5 million from outside grants, the CTA says. And to make the station useable — to connect the tracks, build the escalators, attach all of the needed electrical and plumbing to the outlets — will take an additional $150 million or so, the CTA says.

It’s too bad the city won’t say what they envision doing with this space. Just how long will it stay empty? Because of this, I’m a little surprised Chicago was willing to show reporters exactly what they built. Not only was several hundred million spent, the city still does not have any faster train service to the airports. All together, this is not exactly a shining moment in Chicago infrastructure.

Video of massive project to bring the Long island Railroad to the Grand Central Terminal area

Wired has a new video with some impressive views of the massive infrastructure project underway in New York City to extend the reach of the Long Island Railroad. Watch here. In addition to the images, there is some interesting material toward the end about what it takes to work in this kind of environment. I imagine it has to be somewhat strange to be so far underground for so long…