# I-40 Bridge (into Memphis) closed for emergency inspection \[update - bridge has been re-opened\] **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [May 12, 2021, 11:39am UTC](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897 "2021-05-12T11:39:44Z")\ **Posts on this page:** 20\ **Page:** 8
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [May 18, 2021, 4:41pm UTC](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897/142 "2021-05-18T16:41:52Z")
> [@Melbourne](#): > > When they jacked up the bridge We get a bit blasé about modern large scale engineering. Then I read a sentence fragment like that & get rocked back. Imagine some construction guy from 1700 or even Roebling in 1850 looking at that whole span while some guy in a white shirt, ugly tie, and hard hat says “So yeah, we jacked it up to slip some new parts under it. No biggee.” _Sacre bleu! Increible!_ ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [May 18, 2021, 7:00pm UTC](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897/143 "2021-05-18T19:00:21Z")
A unique design makes the bridge more vulnerable.This engineer worked on the Memphis bridge a few years ago. [https://www.cnn.com/2021/05/17/opinions/memphis-i40-bridge-crack-future-problems-abdelnaby/index.html](https://www.cnn.com/2021/05/17/opinions/memphis-i40-bridge-crack-future-problems-abdelnaby/index.html) M - for Memphis? Apparently they designed the bridge based on the city’s name? > [@](#): > > For this type of bridge, it’s far preferable that the truss extend below the deck of the bridge at the pier (the upright structure that goes into the river to hold the bridge up) to provide better force distribution. > > But because of this bridge’s unique “M” shape, the entire truss (the arch of the “M”) is above the deck and the pier is in direct contact with the bridge deck (which holds the highway). Because the arched “M” shape also requires the cables connecting the truss to the bridge to be shorter in places, this imposes high stress concentrations at the beams near the pier, specifically [where this fracture was located] ---
**Author:** ![Melbourne](https://avatars.discourse-cdn.com/v4/letter/m/b5e925/32.png) [@Melbourne](https://boards.straightdope.com/u/Melbourne)\ **Post date:** [May 19, 2021, 12:32am UTC](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897/144 "2021-05-19T00:32:36Z")
> [@aceplace57](#): > > A unique design makes the bridge more vulnerable He’s saying that, but I don’t know enough to agree. Particularly that bit about ‘more vulnerable’. Compared to what? To me, it appears to be a cable-stayed box-girder bridge. Like the bridges here in Melbourne: > **[West Gate Bridge](https://en.wikipedia.org/wiki/West_Gate_Bridge)** > > The West Gate Bridge is a steel, box girder, cable-stayed bridge in Melbourne, Victoria, Australia, spanning the Yarra River just north of its mouth into Port Phillip. It carries the West Gate Freeway and is a vital link between the Melbourne central business district (CBD) and western suburbs, with the industrial suburbs in the west, and with the city of Geelong 80 kilometres (50 mi) to the south-west. It is part of one of the busiest road corridors in Australia. The high span bridge was buil... Like all cable-stayed bridges, the ‘cables’ are unequal length, and the support comes partly from the the ‘cables’ and partly from the piers. It’s unusual in that the support cables come from the arch, rather than from pinnacles, but I don’t know that makes it more vulnerable than any other cable-stayed steel-girder bridge. The WestGate bridge, linked above, _did_ fall down during construction – and that might be linked to it being a ‘more vulnerable’ design. Or perhaps he just means that _most_ old bridges don’t have this kind of modern design, and it’s uniquely vulnerable by virtue of being a modern design, designed with old methods. ---
**Author:** ![SCAdian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/scadian/32/3292_2.png) [@SCAdian](https://boards.straightdope.com/u/SCAdian)\ **Post date:** [May 19, 2021, 12:59am UTC](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897/145 "2021-05-19T00:59:31Z")
> [@abcdefghij](#): > > Also, what’s going on with the bottom edge on the left? Although I realize it’s not diagnostic, especially in such a low res image, but that contrast looks very like the crack. > [@Melbourne](#): > > I thought naw, it must be just pixelisation I thought it was just chipped paint along that edge. ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [May 20, 2021, 3:19pm UTC](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897/146 "2021-05-20T15:19:18Z")
ARDOT and TDOT have finalized a repair plan. I’m impressed they’re scabbing on 30ft plates. That’s just to protect the crews. The bridge won’t reopen for traffic until the beam is replaced. My local news reported a contractor has been hired. [https://www.ardot.gov/news/21-148/](https://www.ardot.gov/news/21-148/) > [@](#): > > - Repairs will be done in two phases. Phase 1 will consist of two 30 foot plates on either side of the fracture and will allow crews to safely engage in Phase 2 repairs. This phase is expected to be completed by the end of next week. > - Phase 2 repairs will consist of removing and replacing the steel member. This phase is expected to take several months and traffic cannot resume until it is completed. ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [May 20, 2021, 4:51pm UTC](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897/147 "2021-05-20T16:51:40Z")
> [@aceplace57](#): > > steel member Heh heh. Heh. Heh heh. ---
**Author:** ![PastTense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pasttense/32/14550_2.png) [@PastTense](https://boards.straightdope.com/u/PastTense)\ **Post date:** [May 20, 2021, 5:35pm UTC](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897/148 "2021-05-20T17:35:02Z")
> **[A kayaker's 2016 photo raises more questions about how long the I-40 bridge...](https://www.commercialappeal.com/story/news/2021/05/19/memphis-bridge-photos-show-fracture-hernando-de-soto-bridge-began-earlier/5163249001/)** > > The photos, taken in August 2016, seem to suggest the damage to the Hernando de Soto bridge has been around longer than previously acknowledged. > **[Kayaker's photos from 2016 raise new questions about I-40 bridge fracture](https://www.commercialappeal.com/picture-gallery/news/2021/05/19/photos-hernando-de-soto-bridge-2016-show-bridge-fracture/5168417001/)** > > The photos, taken in August 2016, seem to suggest the damage to the Hernando de Soto bridge has been around longer than previously acknowledged. ARDOT doesn’t have drone photos that far back so can’t either confirm nor deny. ---
**Author:** ![eschrodinger](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eschrodinger/32/122_2.png) [@eschrodinger](https://boards.straightdope.com/u/eschrodinger)\ **Post date:** [May 20, 2021, 5:43pm UTC](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897/149 "2021-05-20T17:43:52Z")
From the article posted above by @PastTense: > The states are relying on the four-lane, 71-year-old I-55 bridge to get cars and trucks across the Mississippi River and maintain the flow of commercial vehicles. Engineers are inspecting the I-55 bridge to make sure it can withstand the heavier traffic. Good thinking to inspect the 71-year-old bridge that’s now carrying all of that extra traffic. I hope it wasn’t previously inspected by the same guy who just got fired. I wonder if it was the same guy going all the way back to 2016, or if there’s a more systemic problem. ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [May 20, 2021, 6:50pm UTC](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897/150 "2021-05-20T18:50:56Z")
Yes, The 2016 photo looks very similar to 2019. It certainly seems like the seismic retrofit put stress on that beam. The retrofit project was from 2000-2015. A photo shows the crack a year later. The engineers will be studying this for awhile. > **[Is seismic retrofit to blame for ‘unusual’ failure in Mississippi River...](https://www.newcivilengineer.com/latest/is-seismic-retrofit-to-blame-for-unusual-failure-in-mississippi-river-bridge-14-05-2021/)** > > The fault was found during a routine inspection of the Interstate 40 steel tied arch bridge – also known as the Hernando DeSoto Bridge – that connects ---
**Author:** ![Projammer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/projammer/32/559_2.png) [@Projammer](https://boards.straightdope.com/u/Projammer)\ **Post date:** [May 22, 2021, 12:37pm UTC](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897/151 "2021-05-22T12:37:31Z")
So, for the engineers… Supposing the crack had been discovered when it was only 1/4 the circumference or less. Could it have been welded up and/or scab plating attached for reinforcement or would it have still been necessary to replace it as is the case now? ---
**Author:** ![PastTense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pasttense/32/14550_2.png) [@PastTense](https://boards.straightdope.com/u/PastTense)\ **Post date:** [May 22, 2021, 8:45pm UTC](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897/152 "2021-05-22T20:45:55Z")
No matter when it was discovered there is still the very big question of what caused the crack. If the answer is poor materials in the beam that cracked then fixing or replacing that beam is the solution. But if the answer is massive forces somewhere then other additional changes would probably be needed–otherwise further cracks could well happen. ---
**Author:** ![Ynnad](https://avatars.discourse-cdn.com/v4/letter/y/4491bb/32.png) [@Ynnad](https://boards.straightdope.com/u/Ynnad)\ **Post date:** [May 22, 2021, 9:16pm UTC](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897/153 "2021-05-22T21:16:29Z")
This thread got me to thinking. This is never a good idea. The Hernando de Soto Bridge (the I-40 Bridge) crosses the Mississippi River but it also crosses the Arkansas Tennessee border. How does each state allocate the costs and responsibilities for construction, maintenance, inspections, repair, etc. for the bridge? I am now wondering not only about this particular bridge but other similarly situated bridges. ---
**Author:** ![squeegee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/squeegee/32/14537_2.png) [@squeegee](https://boards.straightdope.com/u/squeegee)\ **Post date:** [May 22, 2021, 10:29pm UTC](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897/154 "2021-05-22T22:29:54Z")
It’s a bridge on an interstate. Doesn’t that automatically make it the Fed’s coin? ---
**Author:** ![kenobi\_65](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kenobi_65/32/13178_2.png) [@kenobi\_65](https://boards.straightdope.com/u/kenobi_65)\ **Post date:** [May 22, 2021, 10:33pm UTC](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897/155 "2021-05-22T22:33:20Z")
> [@squeegee](#): > > Doesn’t that automatically make it the Fed’s coin? Even if that’s true, the actual work is contracted by, and/or performed by, the states’ Departments of Transportation (or the equivalent). ---
**Author:** ![Great\_Antibob](https://avatars.discourse-cdn.com/v4/letter/g/e47c2d/32.png) [@Great\_Antibob](https://boards.straightdope.com/u/Great_Antibob)\ **Post date:** [May 22, 2021, 10:48pm UTC](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897/156 "2021-05-22T22:48:08Z")
It’s been noted in several of the articles that for the two Memphis bridges the agreement is the Arkansas side is responsible for the inspections and Tennessee for maintenance and repair. I imagine this particular split came because the Tennessee side is the largest city in the state and the Arkansas side is swamp land for several miles. The wear and tear is due more to Memphis than anything else in the region. In this case, however, Arkansas and Tennessee will be splitting the costs of the emergency repairs. Considering the inspection failures, this is fair. They certainly don’t just build bridges and figure those issues out later. Those issues are settled well ahead of construction. There’s not a universal method to split costs but it’s often in both states interests in these cases to split costs as fairly as possible - building and maintaining bridges are no-brainers in economic impact. ---
**Author:** ![ASL\_v2.0](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asl_v2.0/32/3525_2.png) [@ASL\_v2.0](https://boards.straightdope.com/u/ASL_v2.0)\ **Post date:** [May 23, 2021, 12:27am UTC](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897/157 "2021-05-23T00:27:17Z")
> [@Great\_Antibob](#): > > I imagine this particular split came because the Tennessee side is the largest city in the state and the Arkansas side is swamp land for several miles. I quite enjoy the flat/open terrain of West Memphis and it’s environs. A welcome break from the hundreds of miles of more rugged terrain to the east. Tennessee may well be my least favorite state to drive through. ---
**Author:** ![Projammer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/projammer/32/559_2.png) [@Projammer](https://boards.straightdope.com/u/Projammer)\ **Post date:** [May 23, 2021, 8:29am UTC](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897/158 "2021-05-23T08:29:46Z")
[Kayaker’s photos show crack in closed I-40 bridge in 2016](https://www.5newsonline.com/article/news/state/kayakers-photos-show-crack-in-closed-i-40-bridge-in-2016-arkansas-tennessee/527-dd0bcf0f-e460-4720-ab03-91b5e713d83b) This was the highest resolution photo I was able to locate at this time, but it’s likely had the size reduced to make it web friendly. I’m hoping to find the original somewhere to see what it looks like zoomed in. ---
**Author:** ![PastTense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pasttense/32/14550_2.png) [@PastTense](https://boards.straightdope.com/u/PastTense)\ **Post date:** [May 23, 2021, 3:40pm UTC](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897/159 "2021-05-23T15:40:52Z")
The best I’ve seen is [![](https://www.wspa.com/wp-content/uploads/sites/53/2021/05/bridge-web.jpg?resize=1536,1151) ](https://www.wspa.com/wp-content/uploads/sites/53/2021/05/bridge-web.jpg?resize=1536,1151) ---
**Author:** ![Projammer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/projammer/32/559_2.png) [@Projammer](https://boards.straightdope.com/u/Projammer)\ **Post date:** [May 24, 2021, 8:22am UTC](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897/160 "2021-05-24T08:22:02Z")
Much better. Thanks. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [May 24, 2021, 1:22pm UTC](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897/161 "2021-05-24T13:22:00Z")
> [@ASL\_v2.0](#): > > Tennessee may well be my least favorite state to drive through. Took me two days each way traveling from Arkansas to New Hampshire. I recall the speed limit was 55 or 65 instead of the Arkansas 75 MPH. [Previous page](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897.md?page=7) [Next page](https://boards.straightdope.com/t/i-40-bridge-into-memphis-closed-for-emergency-inspection-update-bridge-has-been-re-opened/941897.md?page=9)