Francis Scott Key Bridge collapse.

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Originally Posted by austastar

Hi,
There is so much information on this collision compared with the Tasman Bridge. We cleared that by 30 minutes on our way home.
Cheers

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We have the internet now! Plus nearly everyone has a camera in their pocket!; this was not the case when the Tasman Bridge suffered a similar fate.

I can remember being consulted about techniques for mapping the situation under the water, with the bridge presumably on top of the sunken ship. There was nothing available off the shelf, certainly not in Australia. I think it was all mapped out by divers, with, as in this case, the priority being to find and retrieve bodies.

Dali ship crew still marooned on stricken vessel in Baltimore

Dali ship crew still marooned on stricken vessel in Baltimore (msn.com)

Andrew Middleton, who runs the Archdiocese of Baltimore's Apostleship of the Sea, told the New York Times that the men now have access to TV, magazines and books while onboard the ship. Reverend Joshua Messick, the executive director of the Baltimore International Seafarers' Center, a nonprofit that provides support to seafarers in Baltimore, told NPR that while all the crew members onboard are healthy, 'they're trying to be very careful about how much information they provide.' 'They're being provided with everything they need, and they're assisting in the efforts with the Coast Guard and Customs Border Protection, the Army Corps of Engineers, everyone that's out there working right now', he added.

Messick also told the BBC that they were 'rattled' and didn't want to tell anyone about what happened. 'They're not saying much at all to anyone who has been in touch with them,' Mr Messick said. 'They didn't have WiFi until Saturday and they didn't really know what the perception of the rest of the world was. They weren't sure if they were being blamed, or demonised. They just didn't know what to expect.'

He added: 'They are also in a very sensitive situation. What they can say can reflect on the company. I would imagine that they've been advised to keep a low-profile for the time being.' Chirag Bahri, the international operations manager of the UK-headquartered International Seafarers' Welfare and Assistance Network, told the BBC that it may be months before the sailors are allowed to go home. 'Maybe after a few weeks, some of the junior ranks may be repatriated home,' he said. 'But it may be that the senior ranks are still required to complete the formal investigation and are kept in the US.'

While the crew has not been allowed off, last week officials from the NTSB were seen getting onto the wreck of the vessel to interview the crew to understand exactly how the crash happened. The NTSB's chair Jennifer Homendy did not say when the crew of the Dali would be allowed to leave, but said they had electricity and food, and appeared to be settling into life aboard the ship. 'The cook was cooking when I got onboard. It smelled very good.' Questions have been raised over exactly how the crash occurred, and who ought to take responsibility.

CBS reported that an unclassified memo from the Cybersecurity and Infrastructure Security Agency (CISA) said the ship reported losing power before it crashed, with Maryland governor Wes Moore backing up the claim. Officials told the outlet that the crew unsuccessfully tried to reboot the propulsion systems, before alerting Maryland Department of Transportation and the Maryland Transit Authority. They said that this alert allowed local officials to stop traffic on the bridge and likely saved lives. But NTSB previously said it needs to undertake its full investigation before it can come to a conclusion on exactly what happened. As for the city of Baltimore, which is still reeling from the devastating bridge collapse, Maryland Governor Wes Moore said a temporary route for ships has opened up near the bridge.

The temporary route is only for small vessels - from memory it has a water depth of only a few metres and an overhead clearance of less than 30m, and the width is also quite narrow. I assume it goes under part of the bridge still standing. It will allow passage of tugs, workboats, barges etc, but not ocean going ships.

Came across this today, so I'm forwarding the URL. for General Information. It also contains a 'True Speed' video.
-- Not suggesting or inferring anything as this is way out of my range of experience.

One question, 'Is it normal to put Hazmat containers right up the sharp end of the ship ? - First on scene of any collision...[bigsad]

Master Helmsman'''s Take On The Baltimore Bridge Incident

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Originally Posted by superquag

Came across this today, so I'm forwarding the URL. for General Information. It also contains a 'True Speed' video.
-- Not suggesting or inferring anything as this is way out of my range of experience.

One question, 'Is it normal to put Hazmat containers right up the sharp end of the ship ? - First on scene of any collision...[bigsad]

Master Helmsman'''s Take On The Baltimore Bridge Incident

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Can't answer your question, except to say that hazardous containers are usually placed on top and as far away from the inhabited end as possible. Also, they have to be loaded with a view to being unloaded without moving other containers when the the ship arrives wherever the container is being shipped to. What the Hazmat is will also have a bearing on its placement.

Usually when I see a video where the narrator says: "here I have MY whatever", I just turn it off! Regarding the emergency generator he basically has it correct, EXCEPT that what he shows is just just the distribrution circuit breakers; he forgets to mention that the feed to the steering hydraulic pump(s) will be via a magnetic contactor, which will probably need to be either manually started, or perhaps via a power dependant PLC type of program also requiring power.

I doubt that any "suction", or cross water flow, would have much affect on a 100,000 ton vessel, in that situation, making it lead to what has been suggested.

Funny you should say that.... yes to two ships parallel / close / at way >+ steerage, but ?? in the way he phrased it, my first reaction was same as :-

'COVID came from bats via pangolins at a wet market'.

sort of reliability...[bigwhistle]

With the commercial disruption & damage - and continuing till bridge is replaced, it's a stretch to accept that it's merely 'Lady Luck' being so brilliantly malevolent.

Emergency Generators:

Some people seem to think that the emergency generator on a ship is the ultimate power source when the main power supply is suddenly lost, and that it will instantly provide back up to the whole ships electrical system. That is far from reality, as it is only big enough to supply mandatory safety systems, although those systems will vary depending on the type of ship, which will dictate how big the generator has to be. On a cargo ship it is usual to find the emergency generator is around 850kVA to 1,000 kVA, sometime a lot less.

Another misconception is: it is an engine driven generator, not a UPS. The first thing that must be considered; is the auto starting system set to automatic? It is usual to have a selector switch to enable the generator to be test run without switching it to the load. The most common practice, at least while at sea, is to test run the generator weekly, usually done in conjunction with the weekly safety drills, such as fire and lifeboat drills. IF that selector switch is not returned to the auto position after a test run, then it is not going to start!

The auto start and transfer sequences are initiated via some form of voltage sensitive relay, be it a simple contact, or some electronic sensor. Whatever it is it is part of the engine control system module, which in addition to actually starting the engine, also monitors the running parameters, such as oil pressure, cooling water etc. By regulation there has to be two separate means of starting the engine. Two separate isolated battery banks if electric starters, a hydraulic accumulator if that is what is used, or may be a combination of both. I have never seen one on an emergency generator, but I suppose air starters could also be used, in which case there would probably be an air supply reservoir similar to that used for the main ships engine.

All being correct the engine will fire up and come up to speed. Once running the generator output will have to match the set points as regards voltage and frequency. The governors on these engines are usually set to bring the engine straight up to operating speed without any warm up period. Not good for a cold engine, and also because of the governor setting, it is not unusual for the engine speed to overshoot and take some time to settle at the correct speed.

Once all set parameters are met the auto transfer switch will close and connect the generator to the emergency switch board busbar. This transfer switch has to be both mechanically and electrically interlocked with the normal incoming ships power breaker, usually referred to as the “bus tie” breaker. This is to ensure that there is no possibility of power feedback to the normal ships electrical system.

Although with everything being in order, and what may appear to be a fast or rapid transfer of emergency power, the actual time involved while this process is happening is such that all systems normally fed from the emergency switchboard, including the steering motors, will all “drop out” on under voltage. The result being that there is going to be a frantic effort involved in getting most of them back on and running! Human nature being what is, this is where complete panic can set in!

Well, who'd a - thunk ? Another little container ship has a power hiccup, near an important bridge...[bigsad]

NYC's 'Verrazzano Bridge, 3 tugs already in attendance - and 3 more needed to calm everyone down... APL Quingdao. - Malta registered and operated by a large French company. Happy ending this time, now anchored near the bridge.

Are these 'power losses'. a normal occurrence ? Gosh, this makes the second attempt on a big bridge in the US. (Discounting the recent errant barge / smaller bridge contact...)

Quote:

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Originally Posted by superquag

Well, who'd a - thunk ? Another little container ship has a power hiccup, near an important bridge...[bigsad]

NYC's 'Verrazzano Bridge, 3 tugs already in attendance - and 3 more needed to calm everyone down... APL Quingdao. - Malta registered and operated by a large French company. Happy ending this time, now anchored near the bridge.

Are these 'power losses'. a normal occurrence ? Gosh, this makes the second attempt on a big bridge in the US. (Discounting the recent errant barge / smaller bridge contact...)

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They would be if the Galley Oarsmen hadn't had a night out on the tiles, then they could get up to Design Speed. Job done.
:rulez: