Francis Scott Key Bridge (I-695) complete collapse after large ship hits it

[Rothman]

I found this source for comparing PDB vs. regular DB:
https://journals.sagepub.com/doi/full/10.1177/0361198118822315

In a regular DB project, a DOT knows clearly what it wants to build, say a bypass. PDB is appropriate if you're not sure exactly what you want to build and you need a contractor who can help first with the concept phase and then progress to the design phase and finally to the construction phase.

Yikes.  Next thing you know, there will be a preferred list for those contractors, too.  DB on freakin' steroids.

As a mentor of mine said, "DB means getting the project done twice as fast for twice the price."  And now, you want the consultant to do scoping and phases I-IV?  Market competition is becoming an oxymoron.

[J N Winkler]

There is also this explainer:

https://www.keybridgerebuild.com/images/resources/Deeper-Dive-Progressive-Design-Build-2023-pidtpk.pdf

Essentially, progressive design-build has the contractor take the design to roughly the 40% to 60% stage, the point at which conventional design-build usually begins.

[bwana39]

Design build is pretty much ubiquitous in Louisiana. In Texas it is fairly common FIGG was doing design build on both the Beltway 8 ship channel bridge (https://www.aaroads.com/forum/index.php?topic=15429.0) (https://www.aaroads.com/forum/index.php?topic=25100.msg2419951#msg2419951)


 as well as the new Corpus Christi Harbor Bridge. (https://www.aaroads.com/forum/index.php?topic=11684.0)

[J N Winkler]

Design build is pretty much ubiquitous in Louisiana. In Texas it is fairly common. FIGG was doing design build on both the Beltway 8 ship channel bridge (https://www.aaroads.com/forum/index.php?topic=15429.0) (https://www.aaroads.com/forum/index.php?topic=25100.msg2419951#msg2419951) as well as the new Corpus Christi Harbor Bridge (https://www.aaroads.com/forum/index.php?topic=11684.0).

AIUI, as a result of its involvement in the FIU bridge collapse, Figg is debarred from working on federally funded projects until 2029.  (As the company is named after its founder, structural engineer Eugene C. Figg, I refuse to go along with the all-uppercase branding.)

[Henry]

They ought to tear down the fucking bridge right now, and build a new one in its place; the remainder doesn't look safe to me, not even as a fishing pier.

[Rothman]

They ought to tear down the fucking bridge right now, and build a new one in its place; the remainder doesn't look safe to me, not even as a fishing pier.

I'll take the opinion of the teams working on the bridge over this rash statement.

[jeffandnicole]

They ought to tear down the fucking bridge right now, and build a new one in its place; the remainder doesn't look safe to me, not even as a fishing pier.

How was the remainder of the bridge affected by the collapse? The pier hit was holding up the structure that collapsed. The approaches were unaffected.

[bluecountry]

I can pretty much guarantee the Key Bridge won't be rebuilt to the original design.

*  When this happens with waterway crossings that have lost spans due to vessel collisions, typically a large fraction of the bridge has survived--this happened with the Tasman Bridge in Australia, I-40 at Webbers Falls in Oklahoma, and the Queen Isabella Causeway in Texas.  The part of the Key Bridge that collapsed represents about half of the over-the-water length but probably at least 80% of the construction cost and nearly all of the complexity.

*  Once the Port of Baltimore reopens, a lot of the pressure to "do something" about the bridge will vanish.  The Key Bridge was one of three major crossings but represented just one-quarter of the capacity.  It contributed a smaller share of the total MdTA revenue pie than the Harbor Tunnel (7% versus 12%) despite their having the same lane count.  The absence of the bridge does not even inconvenience local commuters that much, since the Harbor Tunnel is a relatively close detour.  (The Tasman Bridge is a useful counterexample--its collapse in 1975 turned a five-minute journey from one end of the bridge to the other into a 45-minute trip involving the Bridgewater Bridge much further upstream.  This situation led not only to provision of a temporary ferry, but also construction of the Bowen Bridge midway between the repaired bridge and the erstwhile detour to improve network redundancy.)  It is the ruins of the bridge blocking the shipping channel, and not its unavailability to road traffic, that really drives costs.

*  To rebuild the Key Bridge as-is would be to recreate its safety deficiencies (no shoulders) and its vulnerabilities (piers that cannot be protected without impinging on the shipping channel).  I believe this would be politically completely unacceptable, especially with the precedent set by the Sunshine Skyway.  No politician is going to want to go before the voters and say, "Well, in Florida they can rebuild with better defenses, but here in Maryland we're just going to have to go with the cheap solution that is not actually all that cheap and eat the risks associated with it."

So you would expect the replacement bridge, at the very least, would be 10-12-12-10_10-12-12-10 per side (2 12 foot travel lanes, 2 ten foot shoulder lanes per side) if not more?
If so would this also become the real I-695 vs MD 695?

for 4-lane divided, the inside shoulders can be 6' preferred, 4' minimum.

So at the very least it will be 2 12 foot lanes per side, 4-6 foot inside and 10 foot outside shoulders?
Think they will just go ahead and give it a 3rd trade lane per side?

To the first question, I would hope yes, but then again, (1) it is not an Interstate albeit signed as one (officially MD-695), and (2) MDTA just built the new Nice Bridge with microscopic shoulders, so I wouldn't bet on it.

To the second question, (1) traffic counts really don't justify it (3x,000 AADT is pretty low, especially in MD), and (2) see above  for MDTA's value engineering history.

1.  301 was not part of the interstate system as I-695.
2.  I would think since the Federal government is funding this now they would make this up to full interstate design.

[cockroachking]

1.  301 was not part of the interstate system as I-695.
2.  I would think since the Federal government is funding this now they would make this up to full interstate design.

1. Nor was MD-695.
2. That may very well be the case. We'll just have to wait and see. But I won't be surprised if it isn't.