Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Baltimore's Key Bridge struck by cargo ship, collapses

wbaltv.com

Post reply on HN
Print view View original

511–520 of 1001 posts

Re: Baltimore's Key Bridge struck by cargo ship, collapses

#511

Post by mannykannot »

bmelton wrote: post #396
mannykannot wrote: post #283

Earlier quoted context omitted.

> But any preventive measure will have limits as what and how serious an impact it can deal with. The recent grounding of a large container ship in Baltimore's harbor channel demonstrates that a sufficiently massive berm will stop any ship. What's needed is the will to do something about low-probability but catastrophic events (though large-ship collisions, groundings and fortuitously harmless steering failures are f…

Starting from xoa's calculations above, assuming you can pack a berm with well-compacted soil enough that it can absorb 1,000 joules per cubic meter, you'd need a buffer of something like 10 meters surrounding each piling with 3 meters of depth to keep it safe from this kind of impact. That's 10 meters in every direction from the center of the support -- let's assume the support has a thickness of 0 meters for the sa…

Even if it takes 10 meters to get the job done (in practice, ships will not be coming at the piers perpendicularly to the channel), that is far from rendering the channel impassable.

Secondly, I believe riprap would be preferred to compacted soil (though compacted soil did a pretty good job stopping the Ever Given three years ago.)

Thirdly (and rendering the above moot), what's been done around the replacement Sunshine Skyway bridge in Tampa bay (mentioned in other posts here) shows that protection is, in fact, practical.

In view of these considerations, I'm not even going to check if, for example, xoa considered the energy absorbed by the ship (Update: in fairness, I did take a look at what xoa wrote, and I see that it is you who has introduced the figure of 1000 J/M^3.)

For an introduction to a serious engineering approach to this problem, look here:

https://onlinelibrary.wiley.com/doi/epdf/10.1002/stco.200910...

Re: Baltimore's Key Bridge struck by cargo ship, collapses

#512

Post by jordanb »

mlyle wrote: post #507
jordanb wrote: post #495

Earlier quoted context omitted.

The problem is with steering. The rudder on a ship this big is going to be wall of steel several stories tall with gears as big as car. Warships have several independent backup steering options reducing finally to a worm gear at the top of the shaft with a winch handle big enough to put a gang of men on it. But ships like this will have none of that. They will have a small wheel or joystick on the bridge and if power…

> But really if we don't want accidents like this to happen the ship should have redundancy. A 10,000 TEU container ship is one of the largest and heaviest moving structures ever created by man. Why is it acceptable that it is driven by exactly one engine powering one screw in front of one rudder? Perhaps because we have a whole lot of them going and a very low frequency of events like this. Maybe there's some lighte…

> Perhaps because we have a whole lot of them going and a very low frequency of events like this.

This is literally the second major loss of control/allision incident this month.

https://www.tradewindsnews.com/casualties/out-of-control-con...

Re: Baltimore's Key Bridge struck by cargo ship, collapses

#513

Post by 68b329da9893e34 »

wizerdrobe wrote: post #300
millzlane wrote: post #158

Earlier quoted context omitted.

Local to the area. This was devastating news to wake up to. I don't know what's wrong with me but seeing this and knowing there were casualties made me cry. Edit: Maybe I'm just tired and need more sleep.

It’s called being human. I worked next door to the church that was shot up in Charleston and felt similarly moved despite not knowing them, never having been inside the building, and not having even been a Christian at the time. It is a bit strange at some level - not having any true connection beyond proximity but you should probably worry if you _don’t_ at least feel a little something.

[flagged]

Re: Baltimore's Key Bridge struck by cargo ship, collapses

#514

Post by supportengineer »

jordanb wrote: post #495
ianburrell wrote: post #482

Earlier quoted context omitted.

It wouldn't help with this accident, but you would think that the electronics would be on batteries. It wouldn't be too hard to have rack of batteries that would power the lights, instruments, radios, and sensors. Doesn't help if the propulsion or steering go out, but does make easier to know whats going on.

The problem is with steering. The rudder on a ship this big is going to be wall of steel several stories tall with gears as big as car. Warships have several independent backup steering options reducing finally to a worm gear at the top of the shaft with a winch handle big enough to put a gang of men on it. But ships like this will have none of that. They will have a small wheel or joystick on the bridge and if power…

>> worm gear at the top of the shaft with a winch handle big enough to put a gang of men on it

They showed us one such station, on the USS Hornet in Alameda, it it in the officers' dining room.

Re: Baltimore's Key Bridge struck by cargo ship, collapses

#515

Post by sybercecurity »

For those who want to hear up to date news, some local sites are:

WBAL https://wbal.com/ WTOP https://wtop.com/

Two local news radio stations. Fans of The Wire series may have heard WBAL in the background in some of the scenes, it's a Baltimore institution since everyone wants to get traffic updates.

Re: Baltimore's Key Bridge struck by cargo ship, collapses

#516

Post by shagie »

Joker_vD wrote: post #473
paddy_m wrote: post #461

Earlier quoted context omitted.

It shouldn't happen. There will be investigations. I think that having a properly operating ship is the captain's responsibility. But the ship's pilot [1] (not captain) should know exactly how the boat will handle and the exact course of action. Pilots are extremely well paid ($200-$400k) and the tests are very stringent. Friends have told me that the Narraganset Bay pilot test involves drawing every shipping navigat…

Where do you get those salary numbers from? The info about this "Dali" ship is not private: [0], and it lists the master's salary as $10,200 per month. [0] https://www.balticshipping.com/vessel/imo/9697428/seafarers

https://en.wikipedia.org/wiki/Maritime_pilot#Compensation

> The Florida Alliance of Maritime Organizations reported that Florida pilots' annual salaries range from US$100,000 to US$400,000, on par with other US states that have large ports. Columbia Bar pilots earn approximately US$180,000 per year. A 2008 review of pilot salaries in the United States showed that pay ranged from about US$250,000 to over US$500,000 per year.

Re: Baltimore's Key Bridge struck by cargo ship, collapses

#517

Post by [deleted] »

pyuser583 wrote: post #499
gumby wrote: post #493

Earlier quoted context omitted.

Yes, they have the responsibility, not the captain, as evidenced by the specific insurance they carry. Of course, lawyers will try to spread the blame around (who chose the pilot, did captain's actions or orders somehow get in the way of the pilot; did captain not ensure engines were working properly...). But the base responsibility lies with the pilot. It probably helps the captain that this was a ship owned and ope…

I thought the pilot only offered “guidance” to avoid responsibility. I learned that from a documentary on the Panama Canal. Is that just a Panama Canal thing? Or should I find better documentaries?

[deleted]

Re: Baltimore's Key Bridge struck by cargo ship, collapses

#518

Post by OJFord »

themerone wrote: post #506
OJFord wrote: post #497

Earlier quoted context omitted.

Apparently (this is just via someone on Reddit who supposedly heard/read it somewhere) the ship mayday'd on losing power hoping the bridge could be cleared. But why not (or did it?) also just blast its horn repeatedly, drawing attention so people on or near the bridge would notice it and realise something was wrong and perhaps even where it was headed? I'm sure it's not allowed generally and not the protocol and what…

Why would a driver think a ship's horn was signaling them?

AIUI most souls on the bridge were construction workers filling potholes, not drivers. But either way I'd have thought a certain amount of horn blowing would catch my attention just for being out of the ordinary, even though it's also not ordinary for ships to (need to) signal me.

Re: Baltimore's Key Bridge struck by cargo ship, collapses

#519

Post by Jun8 »

paddy_m wrote: post #438

Youtube tracking analysis from a knowledgeable mariner. He says that at about 1:24 AM the ship loses power (from video feed) while traveling 8.5 knots. at 1:25.30 power is restored. at 12:25.59 the ship shows smoke. The ship has already drifted in the channel. It is believed that at this time the ship applied full reverse power as evidenced by the black smoke. (My analysis: the ship drifted but hasn't turned in the c…

Relevant discussion on whether Titanic also tried to do a full reverse and, if true, if this was the right decision: https://www.reddit.com/r/titanic/comments/1abvwqt/if_the_tit...

Re: Baltimore's Key Bridge struck by cargo ship, collapses

#520

Post by shagie »

pyuser583 wrote: post #499
gumby wrote: post #493

Earlier quoted context omitted.

Yes, they have the responsibility, not the captain, as evidenced by the specific insurance they carry. Of course, lawyers will try to spread the blame around (who chose the pilot, did captain's actions or orders somehow get in the way of the pilot; did captain not ensure engines were working properly...). But the base responsibility lies with the pilot. It probably helps the captain that this was a ship owned and ope…

I thought the pilot only offered “guidance” to avoid responsibility. I learned that from a documentary on the Panama Canal. Is that just a Panama Canal thing? Or should I find better documentaries?

https://en.wikipedia.org/wiki/Maritime_pilot

Panama is the exception

> Legally, the master has full responsibility for the safe navigation of their vessel, even when a pilot is on board. If they have clear grounds that the pilot may jeopardize the safety of navigation, they can relieve the pilot from their duties and ask for another pilot, or, if not required to have a pilot on board, navigate the vessel without one. In every case, during the time passed aboard for operation, the pilot will remain under the master's authority, and always out of the "ship's command chain." The pilot remains aboard as an important and indispensable part of the bridge team. Only in transit of the Panama Canal does the pilot have full responsibility for the navigation of the vessel.

Post reply on HN