Boring Company Giga Texas Tunnel Road Panel Issues, Mitigations & Probable Solutions

[@davidsalisbury50]

Very interesting summary by Joe. Had a read through the comments, some very relevant, some only half right. Time to add my long winded (sorry) thoughts: 1. Fibre reinforced concrete is an excellent technology when used correctly. In this case it was not. I find it almost unbelievable that there was no quality control test on some early samples to ensure they could perform. Maybe there was and they just got their numbers/assumptions wrong. Early examples on site at Giga Texas showed signs of cracking and very poor quality concrete (honeycombing of aggregate showing lack of compaction). If these basic quality control problems were self evident to someone (Dessie Doolan and Dave Johnson also commented at the time) watching them from a drone video, I wonder what quality control was being adopted on site at Bastrop and Giga? Not much, would be my conclusion. 2. The design flaw may have been incorrect calculations, It may also have been in the design assumptions. These slabs have a number of load conditions to meet, often the service loading (in-place) is not the critical one. Manufacture, transport, installation loads, etc all need consideration. The wheeled telehandler used for their installation may be a load condition not designed for. Consider the front wheel point load, carrying the next slab in front of it. running a little off line so the wheel moves from the side to the centre, the opposite wheel climbs the tunnel wall slightly, the load swings, the driver hits the brakes. Suddenly you have a dynamic point load that can be 3x the static load, sitting in the middle of the slab. A lot heavier than a cybertruck wheel at each side. 3. Some close-ups of the broken slabs showed the fibres sticking out. It didn't seem like a lack of fibres to me but hard to tell from these arial shots. 40-50kg of steel fibres per m3 of concrete is a pretty common dosage. 4. Should be nothing to do with the tunnel alignment. The slabs should have been designed with tolerances to suit the universal ring tolerances of the tunnel segments. If not it is back to a design error. They knew the tunnel had a vertical curve and the longitudinal pitch of each tunnel ring varies by 2 inches from widest to narrowest point. 5. Removing the first 3 rings had nothing to do with this invert slab issue. We can see the first 7/8 rings are all in a straight line. these sat on the ground where the TBM was launched from. A concern at launch was the poor quality of the ground right in front of the TBM (it got a lot of rain while waiting for the TBM to launch). I predicted a "dive" at the TBM launched due to this. We can see from the alignment of the 4" pipe that this occurred (not uncommon). TBC can say what they like about having to do this intentionally but the argument doesn't hold water for me. why launch at the wrong angle and cause a misalignment of the thrust forces intentionally in the early stage when you could angle the TBM down 2 degrees and get a straight launch (how it is always done). Very common to have some sacrificial rings at the launch as cracking and displacement often occurs. As Dessie has said, the tunnel lining used fibres (it may also include rebar). They are used worldwide in tunnel segments, often with no rebar. Tunnel segments largely operate in compression so the reinforcement of any kind is fairly redundant. Fibres (especially polypropylene microfibres (non-structural) help a lot to avoid spalling during handling, aid durability and (of ever greater importance, give the rapid increase in electric vehicles) resistance to explosive spalling during a fire. Steel fibres distribute loads and provide a lot of resilience/ductility before failure. Feel free to disagree, I may well have missed something or be way off base with the latest fibre technology. Looks like the have a fix in hand. I hope the steel reinforced replacement slabs have been tested and their design independently checked. Plus some 28-day strength tests, rebar load tests, cement and aggregate supply quality records, mixing, compacting and curing records (basic quality control measures that stop us all falling through the floor).

[@DavidJohnson-tv2nn]

Definitely quality control problems, but my question is... Is fiber a good choice as the only reinforcement (no rebar) when the concrete is likely to be placed in tension... Beams, bridge decks, tunnel road segments, etc.? Can fiber ever be engineered to be safe when concrete in tension under heavy load?

[@tunnellingsalisbury7605]

@@DavidJohnson-tv2nn Generally not. But the technology is advancing all the time. Already used for slabs that span in two directions. Certainly could have spanned the slab width in this tunnel if designed right. My bet would be they didn't think about the temporary load case I described.

[@DavidJohnson-tv2nn]

@@tunnellingsalisbury7605 Thanks for the reply! Not being an engineer I'm at a big disadvantage here. Your suggestion as to the cause seems entirely possible. But there are a couple of questions.... On Joe's 7/29/24 video at the 19: 56 and 20: 02 timestamps.... There are 4 and possibly 5 broken tunnel road segments stacked beside the road. Likely failed even before being installed. But even if they were removed after being installed.... 5 failures caused by unusual loading events? Also, if these failures were caused by the telehandler, why remove all of the road segments and replace them with a design using rebar? Wouldn't it have been easier to just replace the broken segments and stop loading them with 20,000 pounds of heavy equipment? That is... Using smaller lighter forklifts instead? Again, I'm not an engineer so I can be entirely wrong on this.

[@davidsalisbury50]

David, you are right. Maybe they tried to stick with them after a couple of them broke but as more were damaged they decided to cut their losses. My overall view is that TBC’s problems can all be traced back to pitting a failed yoghurt salesman in charge of a civil engineering company. The Giga Texas and vegas photos I see tell me that safety and quality are not top of their agenda unfortunately.

[@iam57yearsold]

Need Dyneema mesh.

[@rudivandoornegat2371]

A little bit strange, because generally there is a quality control department in the concrete industry where they take samples of each production run and do destructive pressure tests.

[@JoeTegtmeyer]

This tunnel was considered very much a test tunnel to try out new procedures, materials and processes, not to mention the new Prufrock-3 TBM. I'm wondering if these panels tried a different material mix or process as part of the test and they ended up not working as planned.

[@BramBiesiekierski]

Only thing wrong with the concrete is they forgot to put the reo bars in

[@seancollins9745]

@@BramBiesiekierski reo bars are heavy and expensive, if you can make up for it with fiber reinforcement it's a cost win.

[@BramBiesiekierski]

​@seancollins9745 Fibre concrete is great in minimising cracks in things like slabs, which have adequete support from the ground. It is terrible in applications where there is any tension. It is NEVER a substitute for reo, only to supplement it. How no one at the company was aware of this is both laughable and frightening. Who ever thought it would be ok to simply omit reo in a bid to save dollars should not be doing any engineering work ever. And any work they have previously done should now be scrutinised. As for the cost. In a priject like this. Reo is the cheap part. Cheaper than the concrete. Cheaper than re-doing the concrete a second time. Cheaper than the labour cost to instal it. Cheaper than the labour cost to remove it and re-install it a second time. To use the excuse that it was to save money makes no sense. Reo is definitely not something you should skimp out on. Age old saying still holds true : buy cheap, buy twice. By once, cry once.

[@jsbrads1]

@@BramBiesiekierski I’m guessing the panels were tested expecting the wheels to be pressing close to the edges and someone put something at the center of the panel. These types of mistakes occur, even engineers make mistakes, I’ve caught some mistakes before they were made.

[@markeidem8436]

Well done Joe! Thanks for the detailed review.

[@JoeTegtmeyer]

Thanks Mark!

[@DavidJohnson-tv2nn]

Some observations and my opinion as to the cause of the failure..... 1) Some of these tunnel road segments began failing even before work was completed. On Joes 7/29/24 video at the 29 :56 and 21 :02 timestamps.... Broken segments can be seen by the side of the road. I believe there were broken segments even earlier. I just don't have date and timestamps. 2) I believe David Salisbury said (he can correct me if I'm wrong) that he would not have chosen fiber reinforced concrete for the road segments due to poor performance under point loading. The fibers are only a couple inches long. 3) All segments were removed from the tunnel. Indicating that the problem went the entire tunnel length not just the entrance. 4) If you look at the broken segment @ 7:06 there appears to be some fiber at the bottom of the slab, though probably not enough. Thus, a quality control problem as well. Missed opportunities.... * This was a new design which probably should have been rejected to start with. Again, because while fiber reinforced concrete is great for ground slabs that are well supported from below.... It doesn't perform well in tension. Not good for beams, bridge decks, etc. That was missed opportunity #1 * Failure to properly test the new design prior to installation of the new segments. Not that hard to put them under a hydraulic press to see how much load they can carry. That was missed opportunity # 2 * Failure to stop work and do testing after it became apparent that there was a serious problem. They walked and drove right by the broken segments and continued installation work until all segments were installed! That was missed opportunity #3.

[@JoeTegtmeyer]

Thanks David and I'm glad this short video has generated as much interest as it has ... i guess a lot more people were wondering what happened about the tunnel than I had thought! You have a lot of great points and observations here. I do know they very much considered this a test tunnel and it is possible they were testing out something new and they discovered this way of making the panels did not work out, so they are now changing to something different. Part of the fail fast approach they adopted form SpaceX and this is part of trying new ideas.

[@DavidJohnson-tv2nn]

@@JoeTegtmeyer But here's the problem as I see it.... There are certain places where "fail fast" or "move fast and break things" shouldn't be used. Structural engineering is one of them. My understanding is that there are charts and tables that engineers can use to look up the loads that different materials can carry. If they didn't want to look up the information, or thought they could do better.... Then.. Produce one or two tunnel road segments and put them under a hydraulic press to test load carrying capability. Which would have also caught any mistakes in their calculations. It would have saved them a whole lot of trouble in installing, then having to remove hundreds of segments. Thank God nobody was injured or worse in all of this. Hope you can see my point.

[@DavidJohnson-tv2nn]

@@JoeTegtmeyer Another suggestion if I may.... Look up the Titan submersible. Which was an entirely preventable engineering disaster. Again, a misuse of materials for something they weren't designed for. Which everyone can learn from, and why "fail fast" and "move fast and break things" is a really bad idea in certain areas of technology. Thanks.

[@njengakim]

​@@DavidJohnson-tv2nn If they had tested the titan sub autonomously before putting people in it, the tragedy may have been avoided. I also think that there is a misunderstanding of the fail fast system. You fail fast because you have a testing process that ensures failures are discovered quickly. Furthermore from what i have observed Musk companies tend to move quickly with calculated risk. Look at starship testing lots of explosions but risk to life is low. This testing of road surface tiles by boring is with a trusted customer who lets them do this test without serious consequences-Tesla. I think people say fail fast but they dont see the planning behind that ideology and the benfits it brings in the long run.

[@DavidJohnson-tv2nn]

@@njengakim The Titan went on several dives prior to the disaster. Autonomous testing doing a few dives likely wouldn't make any difference in this case. One of the problems of the "fail fast"/"move fast and break things" concept is those who are in charge seem to have a total disdain for authority, regulation, and certification. In the case of the Titan, the CEO refused to get certification because he knew it would never pass. Why? Carbon fiber composites are superior in tension, even better than steel. However, they perform poorly in compression. The arrogant CEO thought he knew better and it didn't end well. Starship.... " risk to life is low"? On the first test flight, do you have any idea how close they came to disaster? When you're going to "fail fast" one of the things you don't want to fail is the Flight Termination System (FTS)! 😊 On the Titan, to quote James Cameron.... ""It's okay to move fast and break things as long as the thing you're breaking is not a submersible"

[@jonathanlanglois2742]

5:00 If there's one thing that's been shown, again and again is that you can't really "prevent flooding" in a tunnel. Most tunnels leak, and most are susceptible to flooding during extreme weather events. It is one of those things that has been shown again and again almost without fail. Being that close to the river, going under a drainage channel and in an area that sometime gets hit by tropical storms, we can expect that the Giga Texas tunnel will eventually suffer a flood event. It happens, its normal, and eventually, the sump pump does its job and catches up.

[@budgetaudiophilelife-long5461]

🙋‍♂️THX JOE 🤗FOR EXPLAINING THE PROBLEM… Years ago, we visited the EDISON home in Florida, They built the pool with bamboo reinforcements, and it had NOT cracked 🤷‍♂️ Interesting 🧐💚💚💚

[@JoeTegtmeyer]

Thanks and I appreciate the added info!

[@dennisschlieckau8723]

Those panels need an arch / crown for compression. I it doesn’t need to be excessive but it needs something to naturally support Compression loads.

[@memrjohnno]

Yep, like an 'arch' but with a very slight curvature.

[@GregoryJByrne]

@@memrjohnno Called camber in road construction.

[@memrjohnno]

@@GregoryJByrne Yep, cheers, I'm no expert obviously but even I knew of the need for such a thing.

[@larryschweitzer4904]

@@GregoryJByrne The camber in road construction is there to provide drainage! The control joints total negate any "arch" strength. The panel to panel reinforcements are designed to slide inside the concrete. A key shape is cast into the edges to prevent vertical displacement. Providing no tension member to counter act any arch effect!

[@greggerypeccary]

But compression comes from them being installed in a tunnel with curved walls... so the walls actually compress it as part of their support.

[@sybo10]

Thanks I was wondering what was going on, tragic mistake on those panels, should of been tested along time ago before insertion, oh well they will fix it

[@memrjohnno]

Just bad optics.....

[@DavidJohnson-tv2nn]

@@memrjohnno I have another word for it. 😊

[@memrjohnno]

@@DavidJohnson-tv2nn lol. It's a crying shame given they had every opportunity to shine given to them.

[@CrazyAmazingDesigns]

It's easy for us to share criticism, but it also seems like they should have known this would be a problem. Makes sense that this could have been an experiment since the tunnels in Vegas haven't broken, but it was a huge miss that they did not load test the panels to rate them for mass production in this tunnel. I'm sure someone working on this will watch this video, and maybe even see this comment. Your tunnel looks nice :). -Nathan R

[@gmoncrieff]

Seems to me that fibres work well in a slab on the ground, but like I mentioned on X, when there are only small contact patches on each side of the tunnel you need the tensile strength of steel rebar to keep them together.

[@JoeTegtmeyer]

I think they are learning a lot about what does and does not work for this application. As mentioned, this was considered a test tunnel, so I think it is possible they were testing something new.

[@kallemyllynen9571]

the fibres should give the concrete slab some tensile strength given they are distributed evenly. the slab can be assumed simply supported from the sides. with tensile strength of 1,7MPa a rough calculation gives bending capacity of 30 kNm for a 200 mm thick slab. a 4 meter wide simply supported slab with 5kPa even load gives approximately 30kNm maximum bending moment with safety factors included. so fiber reinforced concrete could be feasible for this application. sorry for metric units

[@christiankoch4627]

@@JoeTegtmeyer You learn that in 8th grade physics, it's unbelievable that engineers make such mistakes.

[@greggerypeccary]

They're not just hanging from two points, there's also horizontal pressure from the tunnel sides, which probably helps.

[@jamesg2382]

Thanks Joe, much appreciated. Your explanation was clear and accurate, passed my architect sniff test, well done. Best J

[@peterfinfrock2377]

I believe that #4 (1/2" dia.) rebar reinforcement spaced at 12" o.c. each way, 1-1/2" from the bottom of the slab would have been acceptable. They could have also added fiber reinforcement to mitigate cracking. It seems to me they should have installed some rebar or other metal reinforcement.

[@JoeTegtmeyer]

I'm curious to see up close what solution they came up with. Hopefully they will begin delivering some of the newer panels soon and i can get better images of them.

[@josepecanocano1587]

My dear friend, thank you very much for the video, fantastic and a magnificent job, greetings from Malaga SPAIN.

[@JoeTegtmeyer]

Thanks Jose!

[@larryschweitzer4904]

Thank you, great info. I grew up pouring concrete on a wide variety of jobs. I left the construction industry and got a degree in architecture that included some basic engineering courses including concrete construction. Fiber reinforcement had not started by the time I graduated but I continued to follow its development. It has been heavily promoted. Rebar reinforced concrete has undergone quite a few design changes over time as failures show the need. Concrete is brittle and subject to cracking because it has no tensile strength that can be relied on. Therefor all tensile loads are provided by the steel bars. The deformation pattern on the bars is designed to provide "grip" to the entire length. Bringing me to my first question. What provides the "grip" to the fibers? Just the angular random positioning? Your photo of a test sample with fibers sticking out, free of any concrete sticking to them would seem to question their "grip." As you pointed out, there is no visible fiber on the broken roadway panels. Their mode of failure looks like lack of tensile strength. I.E. what ever fiber system was used failed to provide what it is there for. I'm very interested in an engineering analysis of these panels. Samples to a testing laboratory. Can you do a follow up?

[@JoeTegtmeyer]

Thanks and I agree with your assessments and thoughts about the concrete and how it was used in this application. I hope to be able to get additional information and figure out the mitigation steps they actually employ, but getting a actual sample and getting it tested is likely not something I'll be able to do. But, you never know!

[@DAM89]

I hope they're using rebar in the tunnel rings.

[@GregoryJByrne]

I suspect openings between the precast slabs due to changing grade. They could do a fish scale design kinda like the side only the angle would be tilted in the same direction and do a finishing grind to smooth polish the final product? Not sure what the 4 holes are? could be casting or lifting holes? We used to have slots in our runway repair blocks at AES in Germany that we would insert a T lifting bar into slabs for placing. I do remember seeing them placing slabs with a forklift not sure if this was normal operation or not? The slot T bar lifting method would also enable removal of individual slabs for repairs as well. If they made the tunnel lining with just 4 segments they could in theory push off of just 2 while continuing to bore & setting the next two segments in place continuous boring. Either anchor the segments to the surrounding tunnel wall or maintain in place while waiting for the keystone completion segments Or make the segments longer so as to move further for each push but continuous boring is the holy grail/cup to achieving 7 miles per day. "All shall seek shelter under rocks or in caves." Derenkuyu, Capadoccia, Longyou caves, Barbara caves. Good Luck Jesus Loves You!

[@oakenarbor2046]

Excellent work, Joe. Thanks.

[@JoeTegtmeyer]

Thank you!

[@lukeknowles5700]

Great report, Joe! The tunnel's roadway surface, as well as the tunnel itself, needs to be more than strong enough to survive years of use and such things as earthquakes. The seeming fragility of the earlier concrete panels is disconcerting, I don't usually see such deficiencies in Elon's world.

[@DavidJohnson-tv2nn]

His belief in the "move fast and break things" design philosophy absolutely leads to disaster. It's just a matter of time.

[@SandBoxJohn]

It is my understand that fiber reinforcement was developed primarily to reduce the cracking of concrete slabs placed on graded ground surfaces such as driveways, sidewalks, and slab on grade floors. The fibers in fiber reinforcement are not long enough and do not have enough surface area to provide the needed tensile strength the transmit the live load carried by the slab to the points of support.

[@iueofhoiwef]

I have to watch the video again…this isn’t their first tunnel but why didn’t they have this issue with the others? Did they try something new here that didn’t work? WRT the fiber aggregate they added. Or was it the pitch or angle of the tunnel itself? Thanks. There has been very little on this…

[@DavidJohnson-tv2nn]

They tried a new design using fiber reinforced concrete they should never even have considered. My understanding is that fiber reinforced concrete performs poorly under tension. They also failed to properly test the new design. Fiber reinforced concrete has its place. But not in beams bridge decks, tunnel road segments, etc.

[@YouT-DJ]

Thanks Joe!

[@JoeTegtmeyer]

You're welcome!

[@Chris_In_Texas]

I had a neighbor that did the same thing with his driveway vs ours that use rebar. He has cracked up so much more than ours. I would t use fiber based concrete at least when building residential for sure as many smaller concrete companies don’t have the expertise.

[@kkarllwt]

1/2 inch basalt rebar 2 inches up from the bottom and the fiber would have solved this problem 12 inches on center.

[@DanaOredson]

I wonder if they will have to replace panels in Las Vegas.

[@stadsimkerijhengeloe.o.4300]

Concrete without (enough) steel renforcerend is a great liability. In the Netherland we saw many carparks collapse because of concrete mixed with balls. Just to make it lighter. But is was dangerous. Also an hospital and many office buildings are built this way and the problems could be great. Concrete without steel is a big mistake when loads are not 100% stable, Like cars.

[@aussie_al]

The Chinese have been building like that for years. They call it Tofu-dred. They don't seem to care that buildings and bridges just collapse. If it wasn't so serious, it would be comical. I hope the person who suggested or supervised the fibre concrete can get a job in the next few years.

[@hungtuanbui9669]

Great video and updates 👍😄

[@JoeTegtmeyer]

Thanks!

[@freddymax5256]

I wondered how much cheaper a bridge over the highway would have been?

[@ffbells]

Nothing in road construction costs more than a bridge. Highly unlikely the DOT would allow a privately owned bridge over a public road.

[@melleblanc971]

Wouldn't you try a "few" of a new design panel to prove the process....these guys are lucky they have a bottomless pit of cash to burn at Austin. Is this the first car tunnel they have built?? Huge $$$ cost, still never ending construction/rework, very limited production...that is giga texas! Tesla is very lucky to have giga Shanghai cranking non stop.

[@billyrio3767]

Completely unacceptable fiber panel performance. No wonder so many employees are fired.

[@User-xxvvww]

I hope the used rebar in those rings. Trying to cut corners in cost saving often times costs you in the end.

[@TeslaElonSpaceXFan]

❤❤

[@JoeTegtmeyer]

Thanks!

[@ericdelevinquiere9902]

I was going to make a joke with Sika and concrete but… Fibers have been added to concrete for a very long time, would love to know what went wrong. Back in the days I always stuck to steel given the option because of lack of convincing data (my opinion).

[@brianjohnson2650]

Well done!

[@JoeTegtmeyer]

Thank you ... I appreciate that!

[@accessiblenow]

Thks

[@mervynleach1362]

Having addressed the benefits of fibre reinforced concrete, I wonder what the dis-benefits or dis-advantages are.

[@DavidJohnson-tv2nn]

Doesn't do well when placed under tension. 😊

[@andreandre1051]

Merci👍👍👍

[@rachellynn1507]

Did anyone get fired or reprimanded for the fiasco of the road panels❓️ If it's a factory setting, then the form templates would be so that a worker wouldn't need to set foot into the concrete. Thus the rebar wouldn't be pushed to the bottom.

[@TheByard]

The rebar should be installed on spacer blocks to ensure a designer cover to rebar, usually 50mm. I just love to watch the video of driveway contractors stamping mesh in by foot. I wonder why most of them crack.

[@designpaulf]

If you were going to fail a slab, then the section as shown would be ideal. How ironic. Now if the slabs were an inverted catenary curve to place the slabs in compression would be an improvement. It seems other approaches ie. trusses and light weight removeable panel sections would be more efficacious

[@jeremytaylor3532]

They could use basalt rebar reinforcement. This is inexpensive durable and non rusting. Much better than kitty hair.

[@JeremeyHowlett]

No rebar in a surface panel that is only supported on the sides, what could possibly go wrong.

[@rajarampejaver6689]

I still feel that this tunnel is not a cost effective idea. It would have been better to have vehicles FSD drive themselves under the southern bridge to a designated spot in the western lot. Also, locating a data center in the extension is not a good idea, I am sure that it will be gone in 2-3 years.

[@davidrucker7695]

I wish back in July, Elon would have said the tunnel would be in operation in two weeks. Then I would say they are right on schedule :).

[@sagecoach]

They could have cast a crown top and the bottom of the slabs in the shape of an arch making the load forces compressive. Buy they never asked me and this is not Rome. (Take as humor I hope.)

[@bobcaruso1954]

The mesh material can be made from recycled wind mill blades.

[@gpsfinancial6988]

It turns out that no reinforcement isn't the best reinforcement!

[@linuxmill]

concrete in bending need to be pre-stressed. the panels in bending are in tension on the bottom and that will definitely fail unless it is preloaded in compression. ME 101

[@tunnellingsalisbury7605]

Short slabs of this size don't require prestress. A 12mm x 150mm x 150mm (1/2" x 6" x6") mesh in the bottom third would have been perfectly adequate.

[@mumblinge5892]

An example of the Musk way of doing things.

[@paull5997]

колонны классные 1:03 / 10:46

[@rory-red]

rebar rusts and slowly rippes the concrete apart from rust expansion the fiber reinforcement will never do that.

[@donsturtevant2396]

They make fiberglass rebar & coated steel bar. No more spalling

[@DavidJohnson-tv2nn]

Fiber also performs poorly under tension!

[@jeremytaylor3532]

Basalt rebar is the best solution. No rusting, low cost, high strength. Kitty hair mix can be used with them.

[@dantheman9167]

Steel mesh rusts over time.

[@jolive3743]

tsk tsk, what's it been 6 months now....coulda dug it by hand

[@davidsalisbury50]

9 months, they started site work for the tunnel 28th December 2023.

[@JohnboyCollins]

Kinda depressing so many efforts by the Boring Company to innovate in tunneling have failed. And using FRC is such a minor win anyway why bother tbh.

[@linuxmill]

the failure looks like a burst failure to me

[@christopherpardell4418]

The Boring Company is incompetent. But his is just the tip of the incompetency iceberg. Elon thought boring smaller tunnels would be faster. Its not. But they ARE too small to afford proper ventilation for any substantial length. Okay for electric vehicles, that won’t pump carbon monoxide into the low parts of the tunnel, but a death trap if one of those EVs catches fire. And not suitable for any fuel burning vehicle. These narrow tunnels also fail to allow an escape path should there be a vehicle fire in the tunnel. ( he would have to bore a SECOND parallel tunnel for that. ) Given what a Tesla fire LOOKS like. ( plenty of videos online ) would YOU want to be the Las Vegas tunnel when the chauffeured Tesla in front of or behind you bursts into flames?

[@CliveMills-fi1ch]

Haha am I the first lol Good job Joe

[@howardsimpson489]

Just as well his rockets work sometimes.

[@pierreblattner4527]

If Mr Musk could do a little less stupid politic he could have more time for the problems by Tesla and tunnel Cie!!!!

[@bryanwhitton1784]

Well, I doubt that Musk would be designing the concrete used for the roadway in the tunnel but I can't disagree with your assessment of his politics.

[@DavidJohnson-tv2nn]

@@bryanwhitton1784 He hired the engineers who used fiber reinforced concrete in their design where it should have never been used. Then failed to test their design prior to installing the road segments!

[@bryanwhitton1784]

@@DavidJohnson-tv2nn Amen to that. But he seems to have a penchant of liking people that cut schooling early and try and learn on their own. So no big surprise that their training was incomplete.

[@SherriNDallasTX]

Dont you support his efforts to stop all the censorship that America has been doing so intently over the past several years?

[@DavidJohnson-tv2nn]

@@SherriNDallasTX Freedom of speech doesn't mean the right to call fire in a crowded theater. It would also be nice if he would have respect for the court and obey the law! Being a billionaire doesn't make him exempt from the rules! I'm sure you've heard of the situation in Brazil?