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Fox3WheresMyBanana wrote: ↑

Tue Mar 26, 2024 9:22 pm

In 40 seconds, to put out a Mayday, attempt to regain power, drop anchor, and make a final attempt to stop and/or steer clear, sounds like the crew and pilot did their best.

More than that

Chapeau to them all

NTSB B-Roll - Aerial Imagery of Francis Scott Key Bridge and Cargo Ship Dali [7:31]

I've wondered if Titanic maybe hadn't sunk if they hadn't tried to steer away from the iceberg, hitting it sideways, and had hit it more directly, resulting in fewer compartments being flooded. The ones that were supposed to keep it floating.
It's hindsight of course.
Could it be that they had also managed to avoid the bridge support if they had done less? Except for the Mayday.
Hindsight and speculation, of course.

I know it's hard to get a sense of scale, but the structure seems to be very lightweight.

Thought the same. Especially the supporting pillars.

The topic of redundancy is not really relevant to bridges such as these. If you take out one of the two pylons, of course it is going to collapse. This is a similar truss bridge: https://en.wikipedia.org/wiki/Hart_Bridge and it too will not survive having one of its pylons removed. This Wiki article explains that you cannot weaken or remove any bits of the truss structure: https://en.wikipedia.org/wiki/Continuous_truss_bridge.

As Archer says, all this waffle about 'redundancy' is just that. A simple look at the way the bridge spans the navigation route will tell anybody that removing (or even just damaging) a pillar will cause collapse, even if it had been made more 'redundant'. Indeed, I've heard the 'talking heads' now wittering about the lack of 'fenders' on the pillars. It would have to be some 'fender' to absorb a ship collision of this size

It is just amazingly fortunate it happened in the middle of the night or the death toll would have been in the hundreds.

Well.... there are so-called dolphins, which are structures placed in line with the pylons and designed to absorb an impact thereby safeguarding the pylon: https://en.wikipedia.org/wiki/Dolphin_(structure)
The problem is that a 95T vessel with some speed on it is not something a bit of concrete will easily stop.

Ferzackerly, Sir! (Only?) 95T at 8 kts = ???? Cruelty to dolphins.

Shome mishtake shurely? The Dali is showing as 95,000 gross tons - not one of the biggest, but big enough!

I recall talking to the captain of a supertanker some years ago, and listening to his explanation that the sheer kinetic energy of the vessel means that it cannot stop quickly. It is clear that the crew did everything they could to prevent an accident, but the vessel had other ideas. I doubt if 'dolphins' or even sperm whales would have any significant effect in trying to stop or divert a vessel of this size and weight. There are ample examples on YouTube of large vessels out of control carving their way into quaysides, like a hot knife through butter.

The US has form for ships hitting bridges. Somewhere deep in the internet is a clip of an ocean-going vessel hitting an elevating bridge and then catching fire.

Safety investigators to probe whether dirty fuel contributed to Francis Scott Key Bridge collapse

https://www.fox10phoenix.com/news/safet ... e-collapse

Witness recounts deadly bridge collapse
Georgio Cominos witnessed the deadly bridge collapse from his home just minutes away. He describes what he felt and heard when the bridge went down.

A safety investigation into the Francis Scott Key Bridge collapse in Baltimore, Maryland, will include whether contaminated fuel was a factor in a cargo ship losing power and crashing into the bridge.

Investigators had not boarded the ship, a 948-foot-long container ship called the Dali, as of late Tuesday while it remained stuck on a pillar of the collapsed bridge, and the vessel could stay there for weeks. Rescue crews spent much of Tuesday searching for potential survivors, but officials announced that the search and rescue had been turned into a recovery operation.

The lights on the Dali began to flicker about an hour into the ship's trip early Tuesday. A harbor pilot and assistant reported power issues and a loss of propulsion prior to the collision, according to a Coast Guard briefing report.

"The vessel went dead, no steering power and no electronics," an officer aboard the ship said Tuesday. "One of the engines coughed and then stopped. The smell of burned fuel was everywhere in the engine room and it was pitch black."

The ship did not have enough time to drop anchors to stop drifting, according to the officer, and crew members issued a mayday call before the crash happened.

Blackouts at sea are uncommon, but they do happen and have long been viewed as a major accident risk for ships on the water.

One cause of ship blackouts is contaminated fuel that can create problems with its main power generators, said Fotis Pagoulatos, a naval architect. He said a complete blackout could result in a ship losing propulsion and that smaller generators can kick in, but they are unable to carry all the functions of the main ones and take time to start.

National Transportation Safety Board chief Jennifer Homendy said during a press conference that the investigation will include reviews of the operations and safety record of the ship and its owner and operator.

Crews will look at securing recorders from the vessel to try and learn what happened leading up to the crash.

"This is a team effort," Homendy said. "There are a lot of entities right now in the command post."

The ship, made by South Korea’s Hyundai Heavy Industries, has had more than 20 port state control inspections — reviews of foreign ships in national ports —since it was built in 2015, according to data from Equasis, an international shipping database.

None of the inspections led to a detention, which could happen when a ship is considered unfit to travel. But deficiencies were listed in two of the reviews: one in Belgium in July 2016 that described hull damage and another in Chile in June 2023 that described an issue with the ship's propulsion and auxiliary machinery.

The U.S. Coast Guard completed a review of the vessel in September 2023 and did not find any issues.

For its trip Tuesday, Singapore-based Synergy Marine Group operated the vessel, which was carrying cargo for Danish shipping giant A.P. Moller-Maersk. The ship departed from a terminal at the Port of Baltimore and was heading to Sri Lanka. A Singaporean company, Grace Ocean Pte., owns the ship.

Two tugboats helped the ship move out of the terminal Tuesday, but they pulled back early in the trip, according to port officials. Two pilots and 22 crew members from India were aboard the ship during the crash, according to Darrell Wilson, a spokesman for Synergy Marine.

The ship was moving around 9.2 mph, according to authorities, a typical speed for vessels traveling in the area. Ships as large as the Dali must maintain a certain speed to avoid being pushed around by winds and currents.

The bridge collapse is expected to result in a multibillion-dollar string of insurance claims, covering the loss of the structure itself, the disruption to businesses using the port and more, according to insurance analysts. Victims of the crash could also file claims against the ship operator.

The bridge was built in 1977 for more than $60 million, which is around $300 million today when adjusted for inflation.

PP

Inevitably the local media started talking about how safe the Bay Area bridges are, and we are reassured that they're much safer than the one that collapsed, being designed to withstand earthquakes and similar major upsets. They also pointed out that a lot of the bridge supports are in relatively shallow areas, so a ship that size would run aground before getting close, and that when a ship did bump the Bay Bridge back in 2007, it was stopped by the protective fender structure around the support, which wasn't damaged.

The crux of the problem would appear to be the lack of an uninterrupted power supply to the Dali's rudder and associated controls.
Even with the engine(s) gone, being able to maintain steering would have made this accident avoidable.

Is the Dali one or two propeller boat? I think in term of differential thrust.

The vessel appeared to be turning towards the bridge when it hit. I wonder if an anchor that might have been dropped was pulling the bow around...

John Hill wrote: ↑

Wed Mar 27, 2024 8:41 pm

The vessel appeared to be turning towards the bridge when it hit. I wonder if an anchor that might have been dropped was pulling the bow around...

I heard initially he drooped anchor, and I believe they are at the front, so that combined with strong currents...... I can see that hapening.

However, as we are both skippers, we know it would be at the forefront of the Captain's mind as to the turning effect of which, or both, anchors to drop.
Nobody wants the anchor chain wrapped round the bow.

Of course, we don't know if it was possible to choose which.

The track seems to indicate a slow turn to starboard. I think it more likely that either a starboard rudder deflection just before power was lost, or the effect of wind/current, was the factor which led to the collision with the south tower, rather than an anchor drop.
The turn does start where power was lost, forty seconds before the bridge tower strike, as I described earlier. I very much doubt an anchor was dropped at that point.

I think the ship was turning before the anchor was dropped, you can sea the splash of the anchor just before the ship struck. I fancy the the rudder was over to starboard when she lost power and couldn't be moved after that.To get the emergency steering gear moving would take some time because people would have to get to the steering flat right at the back of the ship, ten minutes probably.. With a ship that size until the anchor bit into the sea bed and got a grip it wouldn't pull the bow round and their wasn't time for that on this occasion.I only saw one splash and that seemed to be the port anchor but I am sure they would have intended dropping both.

Makes sense.
And of course dropping the port anchor first is also correct.

The remaining question, given the recent information about the ship having serious electrical problems in port, is do the crew get several thousand Brownie Points for doing everything possible when the crisis happened, but lose several million BPs for setting sail with an unsafe ship in the first place.