http://www.nytimes.com/2013/12/20/us/under-seattle-a-big-object-blocks-bertha-what-is-it.html?_r=3&hp=&adxnnl=1&adxnnlx=1387533627-YlNMnV8Pt6kNSnu6ETcNtw&
Under Seattle, a Big Object Blocks Bertha. What Is It?
(http://graphics8.nytimes.com/images/2013/12/20/us/TUNNEL-1/TUNNEL-1-articleLarge.jpg)
QuoteDecember 19, 2013
By KIRK JOHNSON
SEATTLE — A secret subterranean heart, tinged with mystery and myth, beats beneath the streets in many of the world's great cities. Tourists seek out the catacombs of Rome, the sewers of Paris and the subway tunnels of New York. Some people believe a den of interstellar aliens lurks beneath Denver International Airport.
Now Seattle, at least for now, has joined that exclusive club.
Something unknown, engineers say — and all the more intriguing to many residents for being unknown — has blocked the progress of the biggest-diameter tunnel-boring machine in use on the planet, a high-tech, largely automated wonder called Bertha. At five stories high with a crew of 20, the cigar-shaped behemoth was grinding away underground on a two-mile-long, $3.1 billion highway tunnel under the city's waterfront on Dec. 6 when it encountered something in its path that managers still simply refer to as "the object."
The object's composition and provenance remain unknown almost two weeks after first contact because in a state-of-the-art tunneling machine, as it turns out, you can't exactly poke your head out the window and look.
"What we're focusing on now is creating conditions that will allow us to enter the chamber behind the cutter head and see what the situation is," Chris Dixon, the project manager at Seattle Tunnel Partners, the construction contractor, said in an interview this week. Mr. Dixon said he felt pretty confident that the blockage will turn out to be nothing more or less romantic than a giant boulder, perhaps left over from the Ice Age glaciers that scoured and crushed this corner of the continent 17,000 years ago.
But the unknown is a tantalizing subject. Some residents said they believe, or want to believe, that a piece of old Seattle, buried in the pell-mell rush of city-building in the 1800s, when a mucky waterfront wetland was filled in to make room for commerce, could be Bertha's big trouble. That theory is bolstered by the fact that the blocked tunnel section is also in the shallowest portion of the route, with the top of the machine only around 45 feet below street grade.
"I'm going to believe it's a piece of Seattle history until proven otherwise," said Ann Ferguson, the curator of the Seattle Collection at the Seattle Public Library, who said she held out hope for something of 1890s Klondike Gold Rush vintage, when Seattle became the crazed and booming gateway city to the gold fields of Alaska and Canada.
At the downtown storefront museum for the tunnel project, called Milepost 31, visitors are cracking Jimmy Hoffa jokes or spouting theories about buried train engines. Gabe Martin, a sales clerk at a curio shop near the dig site, said he was intrigued by the Prohibition era, when Seattle rode a tide of illegal alcohol smuggled from Canada, and people had reason to bury things, not wanting them found. "Bootlegger stuff," he said.
Mr. Dixon said that efforts to drain water and reduce pressure at the drill head, with a series of bore holes pushed down in recent days, could allow workers to get safe access to the blocked site as early as Friday. But working at atmospheric pressures similar to what a diver would experience, the team could stay down only for short periods, he said, and each visitor would then need time in a decompression chamber.
And there is something of a John Henry's hammer theme to the tale of Seattle's object. Bertha is blind as a mole in front, with no forward-facing windows or cameras, so a kind of spacewalk through air-locked doors is required to get to the front of the machine for inspection. And the removal or breaking up of the object is likely to be done with jackhammers or other old-fashioned tools that a tunnel-digging sandhog worker of generations past would recognize.
If the object can't be broken up below ground, there would need to be excavation down from the street. In any event, Mr. Dixon and other state managers said, the machine's forward progress could be halted for weeks — though they stressed that work is continuing on the ends of the tunnel, and that it is too early to talk about cost overruns or delays. The tunnel is scheduled to be open to traffic by late 2015.
The tunnel is to run north and south along Elliott Bay from Century Link Field, home of football's Seahawks, to a point near the Space Needle on the north, allowing demolition of an elevated roadway and improved crosstown foot and bicycle access.
Economics and geology — two key threads of Seattle's creation — underpin the tunnel's impetus. Planning for the project began after an earthquake in 2001 revealed seismic vulnerability in the elevated viaduct roadway, which was built in the 1950s. Businesses and real estate interests were then sold on the idea that a tunnel, replacing the viaduct, would open access between downtown and the waterfront.
But unlike, say, Boston or New York, where tunnels are common and bedrock is close to the surface, getting to that end point is messy. Seattle's underbelly is more like pudding than soil — a slurry of sand, gravel and clay, all jumbled and compressed by the pressures from a 3,000-foot-thick ice sheet that extended as far as Olympia, 50 miles south. A city famous for being wet also has a high water table, only about four to five feet down.
And because Seattle, as first encountered by European-American settlers, was hardly conducive to being a city at all, with steep, glacier-carved hills rolling right down to the water, the landscape was reshaped from the beginning, with projects to grind down the hills. That in turn created lots of landfill, which went into the waterfront to level it and create land on which the city's commercial center rose.
"It's mind-boggling how much we have altered the landscape of Seattle," said David B. Williams, a geologist and author of a coming book about the making of Seattle's landscape, called "Too High and Too Steep, Reshaping Seattle's Topography."
"The tunnel is just a continuation of that story," he said as he walked north of downtown, where a cliff face showed the layered strata of the geologic past.
Mr. Williams, who blogs about local geology, speculated in a recent post that the remains of a famous shipwreck, the Windward — which foundered in 1875 and was buried near the waterfront — might be the kind of object that Bertha encountered, though he conceded that the machine could probably grind through a wood vessel as though it were paper.
In the end, he said, state engineers are probably right. A rock, huge in size or in a configuration that the machine cannot quite get purchase on to grind, is the most likely culprit. "I do hope it is not," he said. "It would be great to find some new mystery."
Oh ! ! They found my old van I parked back in 69. Thanky ;D
Maybe they found "The Thing" ;D
Maybe THIS (http://www.thelivingmoon.com/forum/index.php?topic=3494.msg49022#msg49022) will interest you, it scared the carp out of me when i saw the original movie..... ;)
Enjoy!
One person said that area was actually backfill and he thought it was an old train engine.that would be a pain to cut through.probly end up with a big wad of metal stuck to the cutting head teeth.
I think you may be right, Robo mate ;D
But those TBM's are pretty strong....we made a car smashing machine for a big scrap company, we figured the best way to deal with hard lumps of steel like engines, gearboxes etc, was to hit them with hammers. We had a huge roller with flailing hammers on it, dozens of them.
These would smash the entire car into small pieces about the size of a pack of ciggies.. :o
Sometimes there would be an LPG tank, or an old camping gas canister in the car, and then,,,BOOM :D
Later, we found half-ball-bearings embedded in the C100 steel hammers, when we took it apart for a refit... 8)
Imagine the force needed to do that :o
ETA; Why the hell they can't just fit a few titanium tubes in the front (with a cleaning mechanism or an iris-type shutter) i don't know. ???
Then they can poke a fibre-optic camera (called an endoscope, you can buy them in toolshops)down the tube & take a look outside, why they never did this, we will never know.
A typical example of the engineers having their heads up theis arses ::)
I hope it at least turns out to be something interesting. I'm working on clearing a paper jam in my printer. So far, I found my missing PetPerks card from PetsMart. Who knows what else the cats threw in there? I really need to get a dedicated computer and printer space.
Shasta
http://blogs.seattletimes.com/today/2014/01/whats-blocking-bertha-a-huge-steel-pipe/
QuoteA buried steel pipe is mostly to blame for stopping the giant tunnel-boring machine Bertha, which has been stuck since Dec. 6 along the Seattle waterfront near South Main Street.
The long pipe was an 8-inch diameter, 115-foot-long "well casing," used to measure groundwater during studies in 2002 on the Alaskan Way Viaduct replacement project, project officials said.
Matt Preedy, the deputy project administrator for the state Department of Transportation, said he had no estimates about how much time and money it will take to remove the rest of the pipe and to repair damaged cutting tools on the face of the machine.
Nor does the team have a strategy yet for how removal should take place. One possible method is to send tunnel-trained divers to work near the cutter face, under extreme pressures that are exerted by groundwater.
The well site was listed in reference materials provided to bidders as part of the contract specifications, DOT says. "I don't want people to say WSDOT didn't know where its own pipe was, because it did," said DOT spokesman Lars Erickson. However, Chris Dixon, project director for contractor group Seattle Tunnel Partners, said the builders presumed there would be no pipe in the way, because casings are customarily removed after use.
Dixon said the tunnel-machine crew first noticed metal pieces in Bertha's conveyor system in early December — when Bertha's rotation actually shoved a segment of pipe through the surface, prompting crews to remove a 55-foot-long piece. However, the machine kept grinding forward just fine, Dixon said, leading STP to have what he called "a false sense of security" that things would be OK.
But then on Friday night, Dec. 6, the cutting face rotated without catching soil. The team later found unusual damage to cutting teeth, and then on Thursday night an inspection found a pipe fragment jutting through spaces between spokes of the cutter.
A modern tunnel machine can chew through dirt and concrete, but not steel. Even fiberglass rods caused a snag that delayed work several days this summer. Steel could become tangled in the spokes of the rotary cutting head, and in a conveyor screw that pushes dirt from the cutter face onto a belt that moves out the rear of the machine. Dixon said Friday that "we don't know" yet whether any moving parts are jammed.
Downtown Seattle contains some of the most frequently poked and studied ground on earth, which makes the blockage all the more confounding. Five-foot diameter holes were drilled alongside the tunnel path to install concrete pilings that protect the old viaduct; the contractors have used ground-penetrating radar; and geotechnical experts drilled test holes, which didn't hit this particular object.
For the last four weeks, DOT didn't mention the pipe during several news interviews and press conferences. Asked about this, Preedy said Friday that initially, the project's expert-review team thought the pipe was a secondary issue, and that a giant boulder seemed more likely. At 60 feet down, the top of Bertha is in glacial soil, beneath the extent of fill soils and debris that early Seattle settlers dumped near Elliott Bay.
The $1.44 billion tunnel construction, from Sodo to South Lake Union, is about three months behind schedule. But Bertha in November was advancing as fast as 50 feet a day, prompting Preedy to say it's possible to regain time after the steel is removed.
Thanks for the update. I didn't figure that they would find an Alien Base or UFO. Who comes up with these ideas?
If the Subterrene (Atomic) tunnel-boring idea hadn't been shelved, they could have used it to do this tunnel. It would have gone through the steel well casing in no time.
http://atomic-skies.blogspot.ca/2012/07/those-magnificent-men-and-their-atomic.html
I suspect there's a Project Manager(s) getting canned over this. The contract specs covered the exact location of the tunnel, all previous property construction paperwork should have been pulled and reviewed for all the property along the specs. Multi-million $$$ f-up is lost time and possible equipment damage. Seattle taxpayers bend over.
Quote from: micjer on January 06, 2014, 08:16:40 PM
Thanks for the update. I didn't figure that they would find an Alien Base or UFO. Who comes up with these ideas?
Ummm LA TIMES? 1972?
(http://www.thelivingmoon.com/45jack_files/04images/Bases/LATIMES1b_4web.jpg)
http://www.thelivingmoon.com/45jack_files/03files/The_Tubes.html
Who says it was shelved? :D 'shelved' is a code term for 'gone black'
::)
Riddle me this Batman....
Most granite is made of quartz and feldspar. Granite is the common metamorphic rock that these machines tunnel through
Granite is made of three basic materials... mica, quartz and feldspar
Feldspar has a hardness of 6
Quartz has a hardness of 7
Each number is twice as hard as the number before
...yet these machines chew that up like its cornflakes :P
Iron has a hardness of 5.2 Steel a little higher at 5.5 -5.7
SO..
WHY would an iron pipe only 8 inches in diameter stop one of these?
(http://www.jotocorp.com/images/tbm.jpg)
I mean the sheer weight of the machine would snap it like a toothpick
Come on People
Think :P
QuoteThe long pipe was an 8-inch diameter, 115-foot-long "well casing," used to measure groundwater during studies in 2002 on the Alaskan Way Viaduct replacement project, project officials said.
This must be a screw up...an 8" heavy wall pipe would be insignificant to a machine this size. It would chew it up like a gummy worm. Perhaps they meant it was 8" thick well casing? That might be a slightly different story. Either that or this thing is just a huge coffee grinder good for mulching sand and dirt. Even if it DID damage some of the rolling cutters it would have been chewed through by the hardened cutting teeth. The soft-dirt tunnel boring machine pushes along @ 7 Bar hydraulic pressure, this one should be significantly higher.
Well casing pipe is like one to two inch thick wall pipe.but i agree that machine should munch through it.
Somebody is full of feces; I used to work for a well drilling company many moons ago... the roller cone bits we used for dirt and soft rock would rip right thru an iron or steel pipe, seen it happen too many times... those concrete cutters would not even notice that pipe was there...
:o
seeker
I'm a piper by trade...that machine wouldn't have noticed that pipe even existed...Dumbazz yankees...lolololollll....
Quote from: zorgon on January 06, 2014, 09:25:55 PM
Riddle me this Batman....
Most granite is made of quartz and feldspar. Granite is the common metamorphic rock that these machines tunnel through
Granite is made of three basic materials... mica, quartz and feldspar
Feldspar has a hardness of 6
Quartz has a hardness of 7
Each number is twice as hard as the number before
...yet these machines chew that up like its cornflakes :P
Iron has a hardness of 5.2 Steel a little higher at 5.5 -5.7
SO..
WHY would an iron pipe only 8 inches in diameter stop one of these?
(http://www.jotocorp.com/images/tbm.jpg)
I mean the sheer weight of the machine would snap it like a toothpick
Come on People
Think :P
C/mon, Z. Think. The mineral content in the rock and ore is widely dispursed and not refined, not forged. The pipe is chemically engineered and built for strength. You're mashing apples and oranges of extreme natures. And if you read -
QuoteA modern tunnel machine can chew through dirt and concrete, but not steel. Even fiberglass rods caused a snag that delayed work several days this summer. Steel could become tangled in the spokes of the rotary cutting head, and in a conveyor screw that pushes dirt from the cutter face onto a belt that moves out the rear of the machine.
Which makes complete sense. I did done thunk.
Kinda reminds me of my chainsaw when I was cutting wood and hit a nail. Not good either.
Casing is design to withstand external & internal pressure. Casing pipe of any decent length can be bent and made to collapse by that pressure not cutting blades. Not an expert on giant drills but I believe they spin at sufient speed to easily slice through an 8" pipe.
Quote from: micjer on January 07, 2014, 03:42:41 AM
Kinda reminds me of my chainsaw when I was cutting wood and hit a nail. Not good either.
Hardly the same scale :P and your chainsaw has steel teeth hitting steel nails
OP says "Big Object Blocks Bertha" An 8" pipe is a mere toothpick for something the size of Bertha, Cutter teeth are tungsten carbide.... almost as hard as diamond. My carbide tipped table saw cuts through steel bars like butter. I use it all the time cutting pipe
So sorry not buying it :P
Tungsten Carbide blades...
(http://www.firsteditionproducts.com/sites/817/library/tung_carbide_blade_several.gif)
Cut through steel like butter....
http://www.youtube.com/watch?v=oLnPvWvP1Js
http://www.youtube.com/watch?v=oLnPvWvP1Js
Hmm, the blue teeth on the cutting heads are made from super high carbon steel, something like 4% i think.
This is much harder than normal steel, and as has been said, the pressure is enourmous.
TBM's push themselves forward on massive hydraulic rams, so i don't see a pipe of any size being that much of a problem.
In fact soft pipes from copper or lead could give bigger problems, getting smeared over the cutting head & render it useless.
Like if you try to cut perspex too fast with a hacksaw ;)
But if it's a steel girder, then it's much harder, almost as hard as the cutting head. The bits of rock & mud are usually mixed with water & pumped out, it's more efficient than a conveyor ;)
But then again, steel doesn't mix very well, & the pumps won't like it either :P...it has to be something bigger & thicker than a steel pipe, i reckon :)
Ok you have convinced me. Took a look at pic of machine with men standing beneath. Visualizing an 8 inch pipe....agree .... toothpick.
Sooooo what stalled it?
I made parts for TBM's in the past, so i know the humungous amount of pressure behind them, they could cut through almost anything.
QuoteSooooo what stalled it?
Something big, like Norval's car, or maybe they hit a crystal skull ?
;D
Probably hit a wall of a gummy matter and it just packed up the blades and wont eject well So the entire head is covered in a goop of sticky matter and it cant push though it anymore. Just sits there spinning in the goop. Something like Tar would gum it up, Nothing to cut! Ever tryed to cut peanut butter or wet cement? So i am now going in the opposide dirrection, not hard but very soft and sticky. A big gooy mess. They hit the bloob...
If I drill a hole with my diamond tipped drill it will zip though anything it hits as long as it is hard, Hit wet cement and it will stop dead and twist the drill ot of my hands. All the flutes fill with the wet cement and there is no exit way left. Then it hardens due to friction and stalls the drill. Even some very dry items like cement dust or brick dust will do this if water is hit at the same time. The drill mixes them and it creates a slurry very fast that fills flutes and stops it.
Deuem
Surprisingly the local news is being very quiet about this month long halt to the tunnel project for some reason?!?! That a "pipe", or even as it was said above, "fiberglass rods", could stop this big Bertha motha, , , , or even "mucky muck" ;D , I am doubting it.
, , , , and it twasn't me car either, , , maybe they hit an entrance to a D.U.M.B. ;)
This link should provide some entertainment for us, , , , provided they can get it to go again. Link on that page to a live cam also.
http://www.wsdot.wa.gov/Projects/Viaduct/About/FollowBertha
I dont think stalling techniques will work this time its been over a month. There is a reason for this and its not a steel pipe which is absurd this thing eats granite like butter. They may had hit an old buried nuclear military Silo.
Remember a guy named Ray Wartel (Spelling)British who lives in Vegas? He used to travel up and down the highways outside of Vegas and towards Area 51. He stated one time that he would see Silos just come up out of the ground that were massive in the desert and they would always last 9 minutes.
These silos I thought could had been military silos holding nuclear weapons. Or possibly the ETs landed in these Silos which come up out of the ground.
But in Seattle being its on the coast which is where you would launch you nukes that this could perhaps be a buried silo that is made to withstand a nuclear blast I'm only throwing some theories out here. Or yes it could be an Alien Base or a D.U.M.B.
At 7:45 you will hear ray talk about Silos that come up out of the ground for 9 minutes then go back down what was Ray talking about.? Also this man shot possibly the most famous UFO video ever seen from Vegas in broad daylight.
Remember this is 1993
http://www.youtube.com/watch?v=2fBYwDjIoEU
Quote from: zorgon on January 06, 2014, 09:25:55 PM
(http://www.jotocorp.com/images/tbm.jpg)
Here is a pic of part of the pipe that got pushed out by Bertha. Doesn't look like something that would stop it .
http://www.flickr.com/photos/wsdot/11827998735/in/photostream/
I don't think the work crew really believe that the pipe is what has stalled the project. This is from their own website...
Reminder about the steel pipe
Much attention has been focused on the steel pipe fragment that was seen protruding through an opening in the machine's cutterhead on Jan. 2. While we believe the pipe may be a contributing factor to the tunneling slowdown, it's important to remember that the overall cause won't be known until our investigation is completed.
http://www.wsdot.wa.gov/projects/Viaduct/
The section of pipe, although smallish compared to Bertha, could stop an operation...it doesnt clear free of the cutter head like stone or other geological materials, and to let it stay in the head and drive the drill down on it could cost a poopload of money to fix in labor terms, and also parts terms.
Best to stop, yank it out, and blame the whole slowing on an unseen circumstance to divert attention away from the mapping crew, who shouldve seen it on the GPR.
Standard op procedure for contractors...play the disinfo and blame game to save face and keep their jobs intact.
, , , , , and they are still stalled and very little word on WHY as yet. ::)
Jan. 28 update: SR 99 tunneling machine inches forward
Posted on Jan 28 2014 4:08 PM
Seattle Tunnel Partners pushed the SR 99 tunneling machine forward approximately 2 feet today. Doing so allows crews to build the next concrete ring of the tunnel. Workers are now testing systems and evaluating the machine to see what maintenance might be needed before they resume tunneling.
http://www.wsdot.wa.gov/projects/Viaduct/
This ain't got nothin to do with berthas troubles but...
Way back in the early 90s I was sent to christmas valley oregon for a cat litter plant pick up. It was in the middle of nowhere. I got loaded and asked how to get back to the main highway which was 395 to 20.
The guy goes, well ya go down here to the dirt road there and take that north. Don't worry bout it being gravel and such cause it will bring you out on the highway. I go ok.
I drive over to the dirt and gravel road and start the journey. I notice its light gravel with the looks of a grader brushed it out with excess ground pushed up either side of the path. There was big thick power lines running along this path and I said to myself, well, since they have power lines running along side this gravel path, it must go somewhere I shouldn't worry bout.
A few miles up the way I see cattle standing around and as I get to them a couple a cows decide to play in the road and run in front of my truck looking over their shoulders every now and then. Than its only a little baby cow running in front a me as it obviously was having fun.
Nothing to worry yet cause those high power lines are still running along side the gravel path. Then up the way I see they stop and cross the road and go down into the ground where a little shack with a man door entry was standing.
I wonder what was underground out there that needed high power lines to go down underground. Ya, I found the highway just like the guy said I would.
So whats this got to do with big bertha, I dunno, just another weird story we'll never know about.
Jan. 31 update: Further evaluation required before tunneling can resume
Posted on Jan 31 2014 8:33 AM
As we reported earlier this week, Seattle Tunnel Partners (STP) pushed the SR 99 tunneling machine forward approximately 2 feet on Tuesday, Jan. 28. Moving the machine forward allowed crews to further test the functionality of the machine and determine if they could resume full-production mining. It also created sufficient space to build the next concrete tunnel liner ring on Wednesday, Jan. 29.
When the machine moved forward, crews saw indications of above-normal temperature readings in part of the machinery, similar to readings encountered before crews initially decided to stop mining on Dec. 6. On Wednesday, STP made adjustments and mined an additional 2 feet. The above-normal temperatures persisted, and STP made the decision to stop and perform further evaluations.
Over the next week, outside tunneling experts brought in by WSDOT will meet with the WSDOT and STP project teams to review the situation and determine the best path forward.
STP crews and tunnel engineers are operating the world's largest tunneling machine in complex conditions. Although their investigations to date have provided a great deal of information, we will not be able to definitively identify the issue or issues facing the machine until tunneling experts complete their review. We will provide additional information as it becomes available.
http://www.wsdot.wa.gov/projects/Viaduct/
Well it looks like it is more than a well casing that is the problem. Back to the drawing board.
http://www.youtube.com/watch?v=Uxv0RgacNfY
http://www.youtube.com/watch?v=ra9ySLPI4mU
A clogged cutterhead
QuoteTunnel workers performed 158 hours of hyperbaric inspections between Jan. 17 and Jan. 28. They found that many of the cutterhead openings were clogged with dirt and other material. A clogged cutterhead can affect the tunneling machine's performance in the same way that a major obstruction would affect its performance. Once the hyperbaric work was completed, it was determined that a major obstruction was not the cause of the mining difficulty. The more likely cause was the clogged cutterhead.
http://www.wsdot.wa.gov/projects/Viaduct/
Looks like it wasn't an underground UFO base after all! ::)
Now it is being said that it will take months to fix some bearing seals and other maintenance, uhmmm k, , who the F hired these dweebs?!?!? :P
ohhhh I forgot about the incompetency syndrome. ::)
, , and Bertha is still sitting there. Now they are going to did an 80 foot dia. hole down to it and work on it for the next 6 MONTHS ! !! ::)
So the obstruction was a fantasy and the real problem is an equipment maintenance issue? What a mess. I'm using my polite voice.
Shasta
Giant crane to lift 4 million pounds of tunnel drill Bertha
http://seattletimes.com/html/localnews/2025473456_berthacranexml.html
To rescue the world's largest tunnel-boring machine — and the future of the Highway 99 project — you need one of the world's strongest cranes.
The Mammoet Co. has been gathering and erecting steel parts since September from Malaysia, Europe and Canada, to prepare to lift 4 million pounds along the Seattle waterfront sometime in the next few weeks.
That's where tunnel drill Bertha has been stranded underground for more than a year, awaiting front-end repairs.
There's no crane that just does this. This modular lift tower was custom-engineered to fit the limited space next to the Alaskan Way Viaduct, and to steer its payload within millimeters of a target.
"That's why I like working for this company. It's like a big Lego box full of stuff," said Jaroen van Kooperen, the 37-year-old project manager responsible for the high-tension lift.
Millions of dollars are being devoted to a few moves — to lift the damaged drive assembly, spread the pieces over the ground, and eventually return the refurbished section to the repair vault 120 feet below.
http://www.youtube.com/watch?v=mfdITDPt6nI
Those things can cut trough just about anything. I want to know what really stopped this thing. Not buying it was a small pipe :P
What stopped it?
FOCLMAO, , , , ,
Brilliant modern engineering skills I think, , , , :P
If I was still a King County tax payer I'd be a little bit miffed about this cluster.
Published on Apr 6, 2017
On April 4, 2017, one of the world's largest tunneling machines chewed through more than 1,000 tons of concrete and fiberglass to end a 1.7 mile journey underneath downtown Seattle. With a drone's eye view, this video shows the raw power of Bertha's breakthrough - start to finish.
https://www.youtube.com/watch?v=sLum1jxW1ls
https://www.youtube.com/watch?v=t5szTFyUUgo
Nice So they finished the project. I forgot to follow up on this. Did we ever find out what stopped it?
Why in hell are they digging that far beneath Seattle for God's sake, did I read that right above, can't find the quote now; must be jumping timelines at a quick pace. ???
I should actually read the thread I know. Will do.
Quote from: zorgon on June 22, 2017, 10:04:20 PM
Nice So they finished the project. I forgot to follow up on this. Did we ever find out what stopped it?
Yeah 8) They let the cutter head clog up, which in turn caused it to overheat and fried a couple of seals and bearings ::)