mexicans buy shale drilling equipment to build a drag raving tunnel under grand avenue 11510 from the strip club north, only smerican made bokes msy be raced, suffolk county is jealous as nassau county is the site of the first multi laned drag strip for smericsn made bikes only
the sand hogs race the mexicans for bikes et al
who needs a wall when you have a beautiful underhround drag strip
iranians and north koreans send in their drag racers
KFAR SIRKIN, Israel — Israel is building another wall to protect itself from its enemies. But rather than a major eyesore, much of this one will be invisible.
In the coming months, military officials say, the army will be accelerating construction of a subterranean barrier around the Gaza Strip, designed to cut off tunnels running beneath the border into Israel like the ones Hamas militants used to ambush Israeli military posts during the summer-long war of 2014.
Challenged by hostile forces on most of its fronts, Israel is already pretty much walled in. Aboveground fences and sections of concrete wall run along and through parts of the West Bank, a legacy of Palestinian suicide bombings during the second intifada. Formidable steel fences also stretch along the northern frontiers with Lebanon and Syria, the southern borders with Jordan and the Egyptian Sinai, and around Gaza, the isolated Palestinian coastal enclave controlled for the past decade by Hamas, the Islamic militant group.
The approach seems to have caught on internationally. President Trump invoked Israel’s “wall” — without specifying which one — as a model for the barrier he has vowed to build along the United States’ border with Mexico. And the migrant crisis has spurred European interest in Israeli fence-building techniques.
Israeli military officials are being understandably cagey about how the new underground barrier will work, other than to say it will also include an aboveground section and incorporate layers of advanced technological systems. The cost is expected to be about 4 billion shekels (more than $1 billion), according to Israeli news reports, which suggest it will plunge to a depth of about 130 feet.
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Maj. Gen. Eyal Zamir, the commander of the military’s Southern Command, told reporters this week that it would be completed within about two years.
In the meantime, the Israeli military is working to ensure that the project does not prompt the next war.
A Deep Dive Into New York's East Side Access Project
The East Side Access project will link the Long Island Railroad to New York City's Grand Central Terminal. Projected to be completed in 2022, it required construction of about eight miles' worth of tunneling in Manhattan and Queens. Photo: Denise Blostein/The Wall Street Journal
Cities are going down.
To manage relentless growth, urban centers are expanding underground at an unprecedented pace. But it isn’t just the crush of humanity above the ground that is behind the subterranean push. It also is the result of dramatic advances in a field almost as old as civilization: tunneling.
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Engineers in recent decades have developed mechanized and automated systems to chew through deep rock or muck and immediately line an excavation to prevent collapse—all without disturbing the busy city above. That means projects that once would have taken armies of men years to dig now can advance in a fraction of the time and at much lower cost.
Massive robotic worms have been burrowing rail, road and utility tunnels under New York, Singapore and London, little noticed by residents. Washington, D.C. and Indianapolis are boring vast underground cisterns to store rainwater. And Cleveland is punching narrow sewer-pipe ducts through dirt and rock without ripping open streets or lawns.
Even cities prone to seismic activity, such as Los Angeles and Istanbul, are building tunnels thanks to innovations in equipment and techniques. In the Turkish megalopolis, a new roadway under the deep Bosporus waterway includes joints that permit sections of the tunnel to move during an earthquake without structural damage.
Boring machines for London’s new Crossrail rail link are digging 13-mile-long tunnels that cross beneath the city center. PHOTO: CROSSRAIL
“Major cities just can’t function without going underground,” says Joe Guertin, a retired geotechnical engineer who worked on tunnels in the U.S. for five decades, including New York subway projects in the 1970s. “Technology has changed the equation.”
Urban stealth
Not all projects advance smoothly. Under Seattle, one of the world’s largest tunnel-boring machines sat idle for two years until December, undergoing repairs after unexpectedly hitting metal pipes near the start of a highway dig. But Seattle’s experience—which attracted a lot of attention because of the project’s problems and delays—is unusual these days.
“There are tunnel-boring machines all over the world in very complex geology that never get any attention,” says Michael Mooney, a professor of underground construction and tunneling at the Colorado School of Mines.
Indeed, the number of tunnel-boring machines, or TBMs, in operation has surged since 2000. Herrenknecht AG, one of the world’s biggest TBM makers, says it is providing machines for as many as 100 projects annually, up from as many as 20 some 15 years ago.
“The ability to deliver a tunnel on time and on budget has changed a lot…and really pushed the industry,” says Achim Kühn, a spokesman for the privately held German company, whose tunnel-boring machines can cost more than $50 million each.
Few places illustrate the progress more than New York. The metropolis was a tunneling pioneer a century ago, but financial woes after World War II ended that. Today, urgently needed rail tunnels are again advancing.
Few New Yorkers are aware of the underground work that is going on, which makes the city’s top rail tunneler happy. Michael Horodniceanu, president of capital construction for the Metropolitan Transportation Authority, keeps a photograph of central Manhattan streets ripped open to build the Broadway subway line around 1900. The old construction approach, which turned the famously busy thoroughfare into a massive trench, cut off buildings and snarled traffic while the avenue was excavated and resurfaced.
Tunnelers then “weren't concerned with the impact of the construction on the surrounding area,” says Mr. Horodniceanu. Today, upending lives and commerce isn’t an option.
MTA projects now snake through spots with more than 100,000 people per square mile, including along Manhattan’s Second Avenue and posh Park Avenue.
“The technology allows us to go and dig without people knowing we are there,” Mr. Horodniceanu says.
Dramatic savings
Pioneering urban tunnels—including London’s Thames Tunnel, which opened in 1843, and New York’s Holland Tunnel, which opened in 1927—were dug by workers with picks and shovels. Supplying air to workers and fortifying the dig before it could collapse were constant challenges. Tunneling through hard rock required blasting that threatened the buildings above.
Machines began replacing human tunnelers in the 1950s, after American mining engineer James Robbins built a giant auger to eat through shale for a hydroelectric dam in South Dakota. The tunnel-boring machine, a cylinder with cutting wheels protruding from its circular face, dug up to 10 times as fast as traditional methods.
But most cities sit on softer ground that can collapse after excavation, like sand on a beach. Many urban tunnels must run below the water table in saturated, fluid earth. Even mild subsidence can damage pipes, rail tracks or buildings above. So during the 1970s, Japanese and German engineers learned to use water and air pressure to stabilize the ground around a borer. They developed tunnel-boring machines that could robotically install precast concrete tunnel-lining panels immediately behind the cutting face, leaving a nearly completed thoroughfare in their wake.
The savings from automation can be dramatic. Mr. Horodniceanu says the MTA recently had to manually dig a particularly difficult 120-foot tunnel at a cost of almost $1 million per foot. By contrast, tunneling 3 miles under Second Avenue with giant machines cost about $19,000 per foot, he says.
“The fact we can utilize TBMs makes a hell of a difference,” he says.
Other recent advances in tunneling technology include precision guidance to thread around existing infrastructure and electronic monitors to track vibrations, which let tunnelers stop at the first hint of trouble. Advances in chemistry allow engineers to thicken loose ground or soften hard terrain.
These innovations have enabled tunneling in areas once considered impassable. Miami recently dug a traffic tunnel beneath a busy waterway by eating through a mix of saturated ground and porous coral rock that previously defied affordable excavation. The dig was “wildly successful,” Prof. Mooney says.
New technologies, analytical tools and materials have “facilitated the design of tunnels under adverse conditions,” says George A. Munfakh, director of geotechnical and tunneling at engineering firm WSP-Parsons Brinckerhoff. With science and technology, “the engineering and economics of urban tunneling have definitely changed.”
Mr. Michaels is an editor for The Wall Street Journal in Germany. He can be reached at dan.michaels@wsj.com.
Military commanders are insisting that the wall is meant only to defend Israelis, and emphasizing that it will be built in Israeli territory, in the hope of removing any justification for Hamas to attack the construction teams and set off another round of fighting.
On Thursday, nearly three years after the end of the last devastating war, military officials distributed aerial photographs and GPS coordinates of two residential buildings in Gaza that they said concealed entrances to Hamas tunnel networks.
General Zamir said those buildings would become legitimate military targets in wartime, endangering the occupants. One of the buildings is six stories high and went up in the last two years, according to the military, while the other is home to a Hamas member with five children, and connects to a nearby mosque. They were, he said, just two examples of “a whole bank of targets.”
“We see that Hamas is deterred and restrained, and is reining in others,” General Zamir told reporters in a telephone briefing. But, he added, “Our intelligence shows without any doubt that Hamas is building its infrastructure for the next round of fighting in the civilian arena.”
Relative calm has prevailed along the border since the 2014 war, which was the third between Israel and Hamas in six years. But General Zamir said the situation was “potentially explosive,” and could deteriorate at any moment.
Israel’s technologically advanced army invested heavily to combat Hamas’s lower-tech weapons. Israel developed the Iron Dome air defense system to knock out the crude rockets Hamas and other militant groups fired at its cities. Faced with the precision of Iron Dome, Hamas went underground and focused on building tunnels.
Hamas officials insisted they would not be fazed by Israel’s subterranean wall. “The threats of the occupation do not frighten the resistance,” Hazim Kassim, a Hamas spokesman, said in an interview on Thursday, referring to Israel.
He added, “Judging by previous experience, the resistance will find ways to overcome these obstacles.”
The army’s publicity campaign follows a three-month pilot project on an initial part of the new barrier. About 1,000 civilian contract workers will be involved in the construction.
In 2014, after 50 days of fighting, Israel said it had put dozens of Hamas tunnels out of commission, including several extending into Israeli territory, threatening nearby civilian communities. Some had been used to attack soldiers.
Israel says Hamas has since worked feverishly to rehabilitate and expand its tunnels and stock of rockets, even as Gazans suffer a continual humanitarian crisis, including a dire lack of electricity in a scorching summer.
To contend with the challenges of underground warfare, Israeli soldiers now use virtual-reality systems to simulate fighting in tunnels and train in mazelike, concrete tunnel networks constructed to mimic those in Gaza.
On a recent weekday at the Sirkin Army base in central Israel, about a dozen soldiers from a special combat engineering unit donned virtual-reality headsets in a classroom as trainers walked them through a simulation. They virtually filed through a narrow tunnel, one behind the other. With the flip of a switch they could fill the tunnel with misty fumes or bathe it in the green light of night vision. At one turn, they came across a virtual Hamas militant digging in fatigues and a red-checked kaffiyeh.
The military’s showcasing of such training to reporters is all part of the psychological warfare Israel and Hamas have been engaged in for years.
In an interview at the Sirkin base, Brig. Gen. Oshri Lugassy, the departing chief engineering officer, said that there were now “hundreds of kilometers” of tunnels running under the Gaza Strip. Since 2014, when the extent of the underground challenge was exposed, the engineering corps has acquired dozens more heavy mechanical tools, drills and bulldozers, he said.
Israeli residents of areas bordering the Gaza Strip have long complained of hearing the Hamas tunnel diggers at night. By now, General Lugassy said, his engineers have earned “a doctorate in noises.” He said most of the “digging” people heard turned out to be a storeroom door slamming in the wind or even a small creature that munches on grass roots.
Still, “if you hear it at night,” he acknowledged, “you are convinced they are digging under your house.”
