Francis Scott Key Bridge Collapse

[danstanford]

Originally Posted by hpeer

My knee nerk reaction is that the failure occurred years ago when either a risk analysis was not carried out, or it was done and did not identify this risk, OR the risk was assessed but then no preventative action was taken.

The most predictable thing in the world is that accidents happen. You can not stop that. You can anticipate it and take reasonable measures.

The foundation of risk analysis is setting any risk against a matrix with severity of impact on one axis and likelihood of the event on the other. This process allows you to prioritize the risks you attempt to mitigate or address assuming you cannot address them all.

This catastrophe is the poster child for one end of the spectrum, an impossibly severe outcome from a very unlikely event. The other end of the spectrum might be someone running into another car on the bridge, very likely to happen and not very severe in the big picture.

We should view these things as lessons but avoid the assumption that this kind of risk was not assessed.

[Kettlewell]

The foundation of risk analysis is setting any risk against a matrix with severity of impact on one axis and likelihood of the event on the other. This process allows you to prioritize the risks you attempt to mitigate or address assuming you cannot address them all.

Plus, the risk factors have changed dramatically since the bridge was constructed due to the increasing size of the ships using the channel. The bridge has been hit before, but by much smaller ships.

[AA3JY]

I see it coming ..Who and How as to the removal of this ship and wreckage. Having personally witnessed, from day one, the M/V Golden Ray incident located near Jekyll Island, Ga. back in 2019 how that incident turned into a major ‘Cluster F!$&k’ as far as environmentally and the cost of removal over a two year span.. I hope they learned the lessons from that incident..

[hpeer]

Originally Posted by Kettlewell

Plus, the risk factors have changed dramatically since the bridge was constructed due to the increasing size of the ships using the channel. The bridge has been hit before, but by much smaller ships.

That the bridge was hit before by smaller more maneuverable vessels would make the likelihood of THIS occurrence MORE likely. So the possible occurrence should not have been viewed as an extremely rare possibility. As that it has happened at 35 other bridges indicates.

The MINIMUM question to be asked is “Would the preventative measure been less expensive than economic cost of failure.” So the economic cost is the bridge replacement, loss of the port for that period, tying up vital naval vessels (MSC), impact on rail shipping, and other ports, lost productivity due to sitting in traffic, etc. This is already being projected to impact the Nations economy. We are talking something over 1 billion as a minimum, I have seen no projected upper end estimate. Likely impact, not replacement cost, is probably well over 2 billion.

https://gcaptain.com/baltimore-key-b...nt-in-history/

What is the cost of protective measure? A couple of million each time 4?

Then there is the cost of life. And 6 people died.

Sounds like a failed risk analysis to me.

https://gcaptain.com/baltimore-bridg...l-foundations/

And I will be surprised to see a single bridge engineer argue for NOT installing preventative measures on the replacement span.

[JPA Cate]

One of the vulnerable bridges is the Golden Gate, at the entrance to San Francisco Bay. I would imagine that a cost/risk/benefits analysis would have to be done before any action would happen there, but just think, if in this instance, the tugs had stayed attached, they might well have been able to steer and push/pull the Dali clear of the bridge pediment. I wouldn't be surprised if our major ports come up with something like that that while expensive, is way less costly than having the bridge come down.

Even our British ancestors had to deal with London Bridge needing repairs.

Ann

[Cheechako]

Originally Posted by JimsCAL

There is basically zero chance this will result in tugs being required in a situation like this. Just what do you expect tugs to do with a ship of that size going at 8 knots? Tugs are used to help ships get in and out of tight quarters where they need help maneuvering.

I disagree. Tugs are required in Puget Sound in much more open space than that situation. You see them all the time with a tug fore and aft. It's not uncommon. The channel there at the Key bridge looks fairly small compared with the 1000 ft freighter and the surrounding are you can see bottom in spots. This is a failure of state and local governments to not require tugs through an area like that. They rolled the dice kowtowing to the corporations and lost .... probably a billion $ or much more.
"GENERAL GUIDELINES FOR VESSELS TRANSITING ... Puget Sound​
Feb 15, 2021 — Car ships of any tonnage and all other vessels greater than 38,000 GT should be dispatched with two tugs, T4 class or greater."

[hpeer]

It is interesting that on another thread, in another forum, this tug issue was discussed among 3 captains of similar size vessels. I can not hope to sensibly repeat their arguments about tugs. It dealt with the speed of the vessel and the angle the tug would have to pull. Essentially the tugs would not be able to effect a sufficient force vector (given tugs low speed and ships momentum) to this size ship moving at 8 knots to make a difference. They were all in agreement that the tug would likely not be effective and may get sunk in the maneuver.

I am just repeating what I hear to my ability. The arguments made sense to me.

The also implied the ship needed close to 8 knots for accurate steerage, which I thought high.

It is all academic at this point, for this location. Apparently the bridge just up the road over the Delaware River is getting a collision protection upgrade as this event occurred. Although that upgrade may have been insufficient for this Baltimore accident. Don’t sufficiently recall the Baltimore tonnage but I thin it was 200,000 tins at 8 knots and the Delaware Bridge is 120,000 tons at 7 knots. maybe Philly can not take the bigger ships, the channel is limited to 40’ draft while Baltimore is 50’.

https://delawarecurrents.org/2024/01...orial-bridge/#

[Montanan]

Baltimore Bridge Collapse: Insurers Brace For Possible Historic $4B Payout — Way Bigger Than 2012 Costa Concordia Disaster

https://www.msn.com/en-us/money/news...ea9621e8&ei=77


"The bridge collapse is expected to lead to a string of multi-billion-dollar insurance claims. The Francis Scott Key Bridge, built in 1977, cost over $60 million, equivalent to about $300 million today when adjusted for inflation. The scale of the losses suggests that litigation is inevitable."

[skipperpete]

Originally Posted by hpeer

It is interesting that on another thread, in another forum, this tug issue was discussed among 3 captains of similar size vessels. I can not hope to sensibly repeat their arguments about tugs. It dealt with the speed of the vessel and the angle the tug would have to pull. Essentially the tugs would not be able to effect a sufficient force vector (given tugs low speed and ships momentum) to this size ship moving at 8 knots to make a difference. They were all in agreement that the tug would likely not be effective and may get sunk in the maneuver.

I am just repeating what I hear to my ability. The arguments made sense to me.

The also implied the ship needed close to 8 knots for accurate steerage, which I thought high.

It is all academic at this point, for this location. Apparently the bridge just up the road over the Delaware River is getting a collision protection upgrade as this event occurred. Although that upgrade may have been insufficient for this Baltimore accident. Don’t sufficiently recall the Baltimore tonnage but I thin it was 200,000 tins at 8 knots and the Delaware Bridge is 120,000 tons at 7 knots. maybe Philly can not take the bigger ships, the channel is limited to 40’ draft while Baltimore is 50’.

https://delawarecurrents.org/2024/01...orial-bridge/#

Your memory serves you well hpeer, performing tug boat manoeuvres on a ship at a speed of 8 knots is a highly risky proposition, even more so where the only way to release the tow line is to cut it…. Not easy with Dyneema. The fatal circumstance is called “Girting”.

[requiem]

Originally Posted by Kettlewell

I don't know ship engineering enough to speculate, but doesn't it seem strange that all power can be lost at once like that, and there is no instant backup way to power the rudder system?

This post has a decent summary of the systems involved:
https://forum.gcaptain.com/t/very-sa...dali/68913/260

[Montanan]

Cranes arriving to start removing wreckage from deadly Baltimore bridge collapse

https://www.msn.com/en-us/news/us/cranes-arriving-to-start-removing-wreckage-from-deadly-baltimore-bridge-collapse/ar-BB1kJaHV?ocid=msedgntp&pc=HCTS&cvid=213cc2f1793c4b f2916818980ed9a2a8&ei=18

The largest crane on the Eastern Seaboard was being transported to Baltimore so crews on Friday can begin removing the wreckage of a collapsed highway bridge that has halted a search for four workers still missing days after the disaster and blocked the city's vital port from operating. As the sun rose Friday, a crane could be seen at the site.

. . .

the Biden administration for approving $60 million in immediate aid. President Joe Biden has said the federal government will pay the full cost of rebuilding the bridge.

[requiem]

Originally Posted by hpeer

It is interesting that on another thread, in another forum, this tug issue was discussed among 3 captains of similar size vessels. I can not hope to sensibly repeat their arguments about tugs. It dealt with the speed of the vessel and the angle the tug would have to pull. Essentially the tugs would not be able to effect a sufficient force vector (given tugs low speed and ships momentum) to this size ship moving at 8 knots to make a difference. They were all in agreement that the tug would likely not be effective and may get sunk in the maneuver.

Curious which style of tow they were considering. My own very quick reading suggested that indirect towing would be able to impart plenty of force to redirect the ship, and works best with speed in the 6-10 knot range. It also suggested towing indirect is much less common in US compared to other regions.

A description of indirect towing:

Indirect towing is a way of enlarging the exerted force when turning and/or decelerating the tow. This mode applies only to the trailing tug, here referred to as the stern tug. The tug is made fast to the vessel by a towline and is dragged by the assisted vessel. The tug uses its thrust to maintain a sheered position relative to the tow’s heading whilst the towing force is generated by the drag forces acting on the tug’s hull and transmitted via the towline. The drag forces on the tug can be substantially higher than the bollard pull when the speed through the water is greater than 6 knots (approx).
With the towline at a large angle to the tug's centre line, indirect towing is a potentially dangerous manoeuvre. Indirect towing requires a highly skilled tug master to achieve the high towline forces without girting and capsizing the tug. The advent of the purpose-built escort tug, designed for exerting such high loads, has made this operation much more controllable and therefore much safer.

...and video:

https://www.youtube.com/watch?v=N13vYXN5F7Q

[Cheechako]

I have seen two tugs here in Puget Sound. One is near the bow and one on the opposite quarter near the stern. Both are attached to the ship, . I think in that situation, the tugs are controlling the ship. May be more a maneuvering situation.

[mbianka]

Some of the timeline from the ships data recorder:
https://youtu.be/-rxKQ8Tr94s?si=kfcGjj8YfUBTMxM3

[Uricanejack]

Originally Posted by hpeer

It is interesting that on another thread, in another forum, this tug issue was discussed among 3 captains of similar size vessels. I can not hope to sensibly repeat their arguments about tugs. It dealt with the speed of the vessel and the angle the tug would have to pull. Essentially the tugs would not be able to effect a sufficient force vector (given tugs low speed and ships momentum) to this size ship moving at 8 knots to make a difference. They were all in agreement that the tug would likely not be effective and may get sunk in the maneuver.

I am just repeating what I hear to my ability. The arguments made sense to me.

The also implied the ship needed close to 8 knots for accurate steerage, which I thought high.

It is all academic at this point, for this location. Apparently the bridge just up the road over the Delaware River is getting a collision protection upgrade as this event occurred. Although that upgrade may have been insufficient for this Baltimore accident. Don’t sufficiently recall the Baltimore tonnage but I thin it was 200,000 tins at 8 knots and the Delaware Bridge is 120,000 tons at 7 knots. maybe Philly can not take the bigger ships, the channel is limited to 40’ draft while Baltimore is 50’.

https://delawarecurrents.org/2024/01...orial-bridge/#

waste of time asking 3 ship captains most will have little idea. Those 3 clearly didn't have a clue.
A harbor Pilot might have a clue.
If you want to know.
Ask a tractor Tug Skipper. What they can do.
Better yet as The Skipper who does ship escort.

Can an Escort tug make a difference. Yep
Why don't they Use Escort Tugs. Tugs are Expensive. 99.9% you don't need them.
0.1% Damn it wish we had a Tug.