Key Baltimore bridge collapses after collision

this. the bridge may now be blocking the only deepwater access to a big part of the port

 

It was a microburst.

 

Baltimore’s 366m span steel truss bridge collapses after being struck by container ship | New Civil Engineer

However, engineers have told NCE that it is unlikely that the bridge’s condition would have been the cause of the collapse. A bridge of this type would not have been designed to withstand loads such as that applied when the ship struck its pier, according University of Sheffield department of civil engineering blast and impact dynamics research fellow Andrew Barr. Barr told NCE: “The video doesn't show any obvious structural deficiencies with the bridge, but it will not have been designed to survive a head-on collision with such a large vessel. Bridges in shipping lanes are sometimes designed with strong, stout piers, or additional protective structures around the piers to prevent ships from coming into contact with the bridge structure. It doesn't appear that the Key Bridge had either of these features, although it is also very likely that the size and design of the vessels passing under the bridge has changed considerably since it was completed in 1977.”

Discussing the structure of the bridge itself, he added: “The collapsed part of the Key Bridge is a continuous truss bridge, which means that it was constructed from a single long steel truss over the three main spans, rather than having hinged connections at the intermediate supports (piers). This style of construction is very efficient in terms of the amount of steel required, as loads can be shared between different parts of the structure. In the central span of the bridge the truss is arched, with the road deck suspended underneath on cables. “The collision of a vessel as large as the Dali container ship will have far exceeded the design loads for the slender concrete piers that support the truss structure, and once the pier is damaged you can see from the videos that the entire truss structure collapses very rapidly.

“This is an example of what engineers call progressive collapse, where the failure of one structural element leads to the failure of neighbouring elements, which can't support the new loads placed on them. In this case, the collapse of the pier caused the now unsupported truss above it to buckle and fall. Because this is one continuous truss, the loads are redistributed - the truss pivots around the surviving pier support like a seesaw, temporarily lifting the northern span into the air before the high-tension forces cause this to fail too, and the whole truss collapses into the water.”

Independent bridge consultant and Bridge Owners Forum technical secretary Richard Fish told NCE: “This is a tragic collapse of a major strategic crossing which should have been avoidable. It is reminiscent of the collapse of the Sunshine Skyway bridge in Florida which collapsed in 1980, after being hit by a ship. Although there have been other similar collapses since, the investigation into the Sunshine Skyway by the National Transportation Safety Board had recommended that all major bridges over shipping channels should be protected against collision. “It can’t be seen whether this had been added in Baltimore, but the size of the vessel would suggest that it would be very hard to stop or deflect it hitting the pier. And that pier is such a critical element that once it goes, there would follow the awful progressive collapse that the video clips have shown.

 

As an uneducated observer those piers didn't look substantial enough to take a hit as previously mentioned. Given the fact that it was one continuous truss design it is even more surprising that the piers weren't protected. Similar to lightweight roof construction, if one member fails they all fail as their lightweight components have strength in concert but very little independent of each other.

 

that one was pilot error

Cargo ship that hit Baltimore bridge was involved in Antwerp collision in 2016 (msn.com)

As it did so, its bow reportedly swung around, causing the stern to scrape the side of the quay, significantly damaging several meters of the hull.

The ship was reportedly detained by authorities afterward and docked in Deurganckdok, Belgium. There were reportedly no injuries or adverse pollution.

According to Vessel Finder the weather was fine at the time, and the incident was reportedly blamed on the ship’s master and pilot on board.

 

The stream live feed can be blown up, didn't look like there were any vehicles on the span when it dropped.

 

Except for the construction crew to the right of the frame. You can see the amber flashing lights.

 

I was in civil engineering at UF before changing my major to BCN. I was taking statics and strength of materials at the time of the Skyway collapse, it made for some interesting discussions.

 

Agreed.

That ship is moving and looks to lose power. Then looks to regain some power for a short period where it seems to start heading more at the bridge piling. Then looks to lose power again before possibly getting power again right before contact.

I am not sure if that video is sped up or not. But I am sure a lot is going on once the power went out. Reverse seems an obvious attempt. But not sure that would even be plausible with how big and fast the ship is moving.

I think we will find out what happened. Early looks seem to be some sort of power failure taking away control. But that does not mean things could have been done to avoid what ultimately happened.

Terrible tragedy!

 

LOL I hit a bridge in my boat once of course my boat is just 20' long, did some damage to my boat but didn't put a scratch on the bridge.

 

Wow . . . you can see several automobiles driving over just before the ship hit. Those people have a story to tell. So unfortunate for the others, whose timing was fateful.

 

Yeah, a lot of trucks unloading from that port took that bridge. The other way across the Patapsco on the east side is a tunnel, so a lot of trucks leaving the port can't go through that.

 

I had the motor go out on a 30ft sail boat just after we went under a small drawbridge. The boat started drifting back towards the bridge and I chucked my anchor and got lucky as shit it caught. Stopped about 4 feet away from hitting the bridge

 

Just saw the video on BBC, brutal.

 

Eight construction workers were filling pot holes on the bridge....all 8 fell into the river.

So far 2 have been rescued. I fear the others have been lost.

Supposedly at least 5 cars have been identified as being under water.

What a tragedy.....

 

Well that sucks.

 

As I understand it this ship is small by international standards. Why there are no ultra large ships operating in US harbors …

 

Here's a thread on forum I follow discussing engineering failures/disasters (FAU bridge, Surfside towers, etc.).... usually a good source of info and knowledgeable speculation:
Baltimore Bridge collapse after ship collision - Engineering Failures & Disasters - Eng-Tips

 

Here's the marine traffic monitor. Notice how the ship leans hard right rudder at the time the power goes out...