Bridge collapse in the US

[PhilH]

I've just been reading a timeline of events taken from the ships black box, apparently just over a minute of power outage was enough to precipitate this disaster. In the same article I noticed this which, given the size and high volume of ships which use this port, to me just beggars belief.

"An official also said that the Key Bridge was fracture-critical, which means "if a member fails that would likely cause a portion of, or the entire bridge, to collapse, there's no redundancy".

On the face of it a disaster waiting to happen.

[MattR]

This video on the bridge collapse from NBC News interviews Kevin Heaslip, head of the University of Tennessee's Center for Transportation Research. My wife is his executive assistant at the CTR.

 

https://www.nbcnews.com/news/us-news/baltimores-key-bridge-couldnt-withstand-cargo-ship-crash-rcna145160

 

 

Edited March 28 by MattR

[Ozexpatriate]

4 hours ago, PhilH said:

"An official also said that the Key Bridge was fracture-critical, which means "if a member fails that would likely cause a portion of, or the entire bridge, to collapse, there's no redundancy".

On the face of it a disaster waiting to happen.

There isn't a bridge in the world with undefended piers next to a shipping fairway that wouldn't catastrophically collapse (at least in part) with a direct hit by a vessel displacing 150 kt.

 

Earlier this thread had illustrations of dolphins around the Forth Road bridge. The adjacent newer (?) Queensferry Crossing has undefended piers (though the centre pier has a small caisson surrounding it). I bet it would collapse catastrophically if directly hit by a vessel like MV Dali. That cable stay tower will fall down with a pier taken out.

 

The bigger question is how effective existing dolphins would be for this size vessel on a direct course aligned with the dolphin and pier.

 

The main span distance between piers of the Francis Scott Key bridge is about 340m. The length of the MV Dali is 300m. Were that vessel completely out of control and broadside on, it pretty much wouldn't fit. (Yes, broadside it wouldn't have had the same momentum. I offer this observation for scale.)

 

The beam of the MV Dali is 48.2 m.

 

Edited March 28 by Ozexpatriate

[kevinlms]

5 minutes ago, Ozexpatriate said:

There isn't a bridge in the world with undefended piers next to a shipping fairway that wouldn't catastrophically collapse (at least in part) with a direct hit by a vessel displacing 150 kt.

 

Earlier this thread had illustrations of dolphins around the Forth Road bridge. The adjacent newer (?) Queensferry Crossing has undefended piers (though the centre pier has a small caisson surrounding it). I bet it would collapse catastrophically if directly hit by a vessel like MV Dali.

 

The bigger question is how effective existing dolphins would be for this size vessel on a direct course aligned with the dolphin and pier.

 

One things for sure, the Harbourmaster that prevented the Australian Antarctic ship from going under the Tasman Bridge in Tasmania, Australia must be quietly smiling at being proven correct! A much smaller ship, but for a bridge that has already been hit and collapsed once.

[Ozexpatriate]

9 minutes ago, kevinlms said:

A much smaller ship, but for a bridge that has already been hit and collapsed once.

The Lake Illawarra (7,274 GRT) was puny in comparison to the MV Dali. 

 

Gross Tonnage (replacing Gross Registered Tonnage) for MV Dali is 95,128.

 

RSV Nuyina* is bigger than the Lake Illawarra, displacing 25.5 kt.

 

Presuming that's the restricted vessel you refer to. The Tasman Bridge fairway span is very small too - only about 70m or so.

 

Edited March 28 by Ozexpatriate

[Jeff Smith]

About the size of a modest sized cruise ship......some exceed 200,000 tons.

[adb968008]

The ship was heading to Sri Lanka, I wonder what does the US export to Sri Lanka ?would this likely be empty boxes ?

[Ozexpatriate]

5 minutes ago, Jeff Smith said:

About the size of a modest sized cruise ship......some exceed 200,000 tons.

Largest in the world: Icon of the Seas: Tonnage: 248,663 GT, 307,895 NT

[ERIC ALLTORQUE]

The falure here lies with who lets the ship sail,it was tripping the power numerous times on its stay in port,it will have been i guess get it our of here to see the back of it for now,its been in trouble before hitting a dockside..

 

 

[adb968008]

Loadstar is speculating General Average maybe declared…

 

https://theloadstar.com/dali-cargo-owners-face-massive-costs-if-general-average-is-declared/

 

This would mean everyone with cargo onboard would be asked to pay a share of the whole costs as a joint enterprise.

 

personally i’m not so sure… the rules say there must be

1. imminent threat

2. voluntary jettison of cargo

3. successful outcome.

With Evergiven, it had to jetison cargo (albeit not lost overboard) to get it free and freed from Egyptian authorities after paying a bribe fine, and so was successful.

 

I guess if they argue taking some containers off when they remove the bridge gantry saves the ship, maybe.. but i’d imagine some lawyers might be floating in the harbour watching that bridge gantry and saying nah those containers can stay on.

 

 

Edited March 28 by adb968008

[melmerby]

21 minutes ago, Ozexpatriate said:

Gross Tonnage (replacing Gross Registered Tonnage) for MV Dali is 95,128.

Gross tonnage is somewhat irrelevant.

116, 851t deadweight is it's maximum all up weight with cargo. (calculated at summer temperatures.)

It's displacement is about 150,000t & capacity is 9962 TEU

[JeremyC]

8 minutes ago, ERIC ALLTORQUE said:

The falure here lies with who lets the ship sail,it was tripping the power numerous times on its stay in port,it will have been i guess get it our of here to see the back of it for now,its been in trouble before hitting a dockside..

 

 

The Belgium incident was 8 years ago and the ship has, according to some of the Youtube commentators, passed numerous inspections without major defects since and also the crew onboard are unlikely to include any of the same personnel so I don't think we can really draw any conclusions from that incident.

I was at sea as an engineer for over 40 years and I can't think of any ship I was on that didn't, at some point, have a blackout.

[melmerby]

19 minutes ago, adb968008 said:

The ship was heading to Sri Lanka, I wonder what does the US export to Sri Lanka ?would this likely be empty boxes ?

About $340 million, mainly items that would go in bulk carriers, not containers

[Jeff Smith]

Sri Lanka may have just been the first port of call.

 

I was surprised to learn that the US exports a lot of coal although presumably not on this ship.....

[TheQ]

Reading on an American sailing forum,

It became law in America for bridges to have dolphins or other protection to the bridge piers in 1990 after a previous accident.

 

The Baltimore bridge was designed in 1970...

[Michael Hodgson]

28 minutes ago, TheQ said:

Reading on an American sailing forum,

It became law in America for bridges to have dolphins or other protection to the bridge piers in 1990 after a previous accident.

 

The Baltimore bridge was designed in 1970...

Well, chances they'll be designing a new one now.

[Jeff Smith]

Here's the current Tampa Bay bridge completed in 1987 following the 1980 freighter collision which brought down part of the old bridge.

 

[Jeff Smith]

The US Army Corps of Engineers are starting to look at clearing a channel enough to get ships in and out.....  two weeks has been suggested.....

[jjb1970]

Sri Lanka is a major trans-shipment hub and a stopping call for all sorts of container services. 

 

At the moment it's all speculation and nobody outside those involved knows what happened. Ships blackout and have technical problems, it's a part of managing a ship and why they carry qualified engineers.

[Ozexpatriate]

8 hours ago, melmerby said:

Gross tonnage is somewhat irrelevant.

The Wikipedia page for the Lake Illawarra didn't provide displacement - which I find more relevant than all the other (frankly) confusing  GT / NT / DWT numbers.

 

GT was the closest like-for-like comparative number I had at hand (GRT).

 

Edited March 29 by Ozexpatriate

[jjb1970]

The different size metrics are related to whether ships are volume or weight carriers. Ship types like container and vehicle carriers are designed for volume as cargo is light and they tend to cube out long before hitting weight limits. Dry and wet bulk other than gas carriers are weight carriers. This decides whether GT or DWT is the more relevant metric.

[Ozexpatriate]

11 minutes ago, jjb1970 said:

Dry and wet bulk other than gas carriers are weight carriers. This decides whether GT or DWT is the more relevant metric.

The SS Lake Illawarra was a bulk carrier - described on the linked page as "handysized" whatever that means.

 

Apparently I didn't read the article carefully. (I tried a find for 'displacement' to no avail.) Only GRT was listed in the summary panel.

Quote

Lake Illawarra measured 7,274 gross register tons (GRT) and 10,380 tons deadweight (DWT)

 

It still managed to take down a span of the Tasman Bridge over the Derwent River in 1975 - carrying zinc concentrate at the time. Twelve died - five motorists (who plunged 45 m to their deaths) and seven crew when the bridge span fell.

 

Puny compared with MV Dali by any measure. Which had been the point I had tried to make.

[kevinlms]

9 hours ago, Ozexpatriate said:

The Lake Illawarra (7,274 GRT) was puny in comparison to the MV Dali. 

 

Gross Tonnage (replacing Gross Registered Tonnage) for MV Dali is 95,128.

 

RSV Nuyina* is bigger than the Lake Illawarra, displacing 25.5 kt.

 

Presuming that's the restricted vessel you refer to. The Tasman Bridge fairway span is very small too - only about 70m or so.

 

Agreed, the SS Lake Illawarra was puny (it was scuttled as a result of the collision), but I'm sure the victims and their families fail to see the difference!

 

Fact is the Dali probably didn't need to be anywhere near its actual size to have the same effect.

[Ozexpatriate]

5 minutes ago, kevinlms said:

Fact is the Dali probably didn't need to be anywhere near its actual size to have the same effect.

The Francis Scott Key bridge was hit in 1980 - shortly after being built in 1977, but I didn't see a reference to what size ship. There was damage (presumably to what looks like an open caisson around the main piers) but the structural integrity of the bridge was not compromised.

 

The MV Summit Venture (which caused a fatal span collapse of the Sunshine Skyway bridge also in 1980) had a:

Quote

 deadweight tonnage of 33,912, gross tonnage of 19,735, and a net tonnage of 13,948

 

Edited March 29 by Ozexpatriate

[jjb1970]

A handysize bunker is just a term for a smaller bulk carrier. Shipping has all sorts of terms to describe ships by size, the most famous is probably Panamax. Handysize doesn't really mean much as it's not a defined size like Panamax, usually handysize is up to about 30000DWT and handymax is about 30-60000DWT however handysize is also used up to 60000 or so. Which means they are still big ships.

 

For containerships the best indicator is the number of containers they can carry, usually given as the TEU value (twenty foot equivalent unit). However, that value is also somewhat informal as there is no universal way to calculate it and unlike  GT and DWT it is not a certificated value (noting DWT is variable, the figure usually used as DWT is summer DWT).