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Baltimore's Key Bridge struck by cargo ship, collapses

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

#771

Post by wiml »

OJFord wrote: post #497
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…

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…

There are specific horn signals (one prolonged, or seven-short-one-prolonged, are what I'd guess would be appropriate here), and COLREGS do explicitly say that you can use whatever you need to get attention in an emergency as long as it's not confusable with some official signal. But as other commenters have noted it wouldn't have been specific enough to get the workers etc to clear the bridge before the impact.

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

#772

Post by pwenzel »

kerbs wrote: post #366
jxdxbx wrote: post #136

Not that it matters to anyone else, but having driven across that bridge dozens of times with my kids, this is just shocking. It’s one of the main corridors in the area. Thank god it happened in the middle of the night, though that’ll be no consolation to the families of those who may have died.

Memories of the Minneapolis bridge collapse. I lived <1 mile from it at the time it went down, and had crossed it earlier in the day on my commute.

I remember standing not far from edge of that shortly after it happened (https://www.flickr.com/groups/35w-bridge-disaster/), and still get a little panicky when I'm in slow traffic on a bridge. This event will affect the city, the port, and its people for a long time.

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

#773

Post by UncleOxidant »

araes wrote: post #541
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…

Current personal suspicion after watching your linked video (excellent discussion by the wgowshipping author) is: Catastrophic engine failure (1:24) causing wide scale power loss. No rudder control, rudder drift, and ship alignment drift (1:24-1:25:30) Power restored and ship reengages prop with bad ship/ruddder alignment (1:25). However, ship is now pushing itself into a further bad turn. Pilot likely stomps the bra…

> Baltimore had $350 million of insurance.

Wouldn't the ship's insurance be the one paying here?

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

#774

Post by reaperman »

delichon wrote: post #705
CydeWeys wrote: post #598

Earlier quoted context omitted.

All pilots are "harbor pilots". Crew members who control the ship outside of port are just called crew members (captain, first mate, 2nd Officer, that kind of thing), never pilot.

There used to be! See William Adams, "the pilot of Miura" or "Miura Anjin", inspiration for John Blackthorne in James Clavell's Shogun.

I don’t know Japanese and havent studied this so hopefully someone can correct me as well. But I dont think it would be right to translate this to the modern meaning of a ship pilot. It more loosely translated to “navigator”.

There are some seemingly good details here[0].

> In Early Modern Japanese there was a word 按針 anjin, literally “searching needle,” which referred to the process of using a compass. At the time, this was the main way in which ships were navigated and so, by extension, the word was applied not just to ship navigation, but also to ship navigators

It goes into more detail about things as well but that is the part that stuck out to me the most.

0: http://japanthis.com/2013/06/20/what-does-anjincho-mean/

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

#775

Post by OJFord »

munificent wrote: post #681
OJFord wrote: post #536

Earlier quoted context omitted.

I suppose I assumed it was compressed air, that once you had a 'full' (at pressure) tank, you could do a certain amount of blowing even without power. But fair point, I don't really know how they work, and if they are actively electric I certainly didn't know that and obviously that wouldn't have worked and so there's the answer.

> I assumed it was compressed air, that once you had a 'full' (at pressure) tank Even so, it probably still requires electricity to activate the solenoids to open the valves or whatever. I'm speculating since I don't know how large boat horns work, but I wouldn't be surprised if they require power.

Oh good point.

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

#776

Post by [deleted] »

UncleOxidant wrote: post #773
araes wrote: post #541

Earlier quoted context omitted.

Current personal suspicion after watching your linked video (excellent discussion by the wgowshipping author) is: Catastrophic engine failure (1:24) causing wide scale power loss. No rudder control, rudder drift, and ship alignment drift (1:24-1:25:30) Power restored and ship reengages prop with bad ship/ruddder alignment (1:25). However, ship is now pushing itself into a further bad turn. Pilot likely stomps the bra…

> Baltimore had $350 million of insurance. Wouldn't the ship's insurance be the one paying here?

[deleted]

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

#777

Post by willcipriano »

UncleOxidant wrote: post #773
araes wrote: post #541

Earlier quoted context omitted.

Current personal suspicion after watching your linked video (excellent discussion by the wgowshipping author) is: Catastrophic engine failure (1:24) causing wide scale power loss. No rudder control, rudder drift, and ship alignment drift (1:24-1:25:30) Power restored and ship reengages prop with bad ship/ruddder alignment (1:25). However, ship is now pushing itself into a further bad turn. Pilot likely stomps the bra…

> Baltimore had $350 million of insurance. Wouldn't the ship's insurance be the one paying here?

Baltimore's insurance will probably sue the ship's insurance if I had to guess.

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

#778

Post by reaperman »

FredFS456 wrote: post #768
dboreham wrote: post #763

Earlier quoted context omitted.

This seems like a system architecture error. Boats do weird shit sometimes and so bridges need to be deigned to not fall down when a boat crashes into them. Requiring a huge boat to be steered to meter resolution when clearly that's not always going to happen is top shelf stupidity. Up there with backup generators in the basement below the water table.

My civ engineer friend says that bridges are supposed to have barriers in front of their pylons for this particular reason - in the event of a collision, the barrier would be destroyed but not the pylon.

I can’t find any bridges which have a barrier that can protect against a fully loaded container ship. I have seen plenty of barriers which would protect against personal watercraft and smaller working ships like smaller tugs/coast guard ships/shrimping boats, etc.

But a loaded container ship at 8 knots is not going to be stopped by anything remotely feasible.

Container ships weigh between 50,000 and 220,000 tons. A US aircraft carrier weighs 100,000 tons.

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

#779

Post by AYBABTME »

jcgrillo wrote: post #555
araes wrote: post #541

Earlier quoted context omitted.

Current personal suspicion after watching your linked video (excellent discussion by the wgowshipping author) is: Catastrophic engine failure (1:24) causing wide scale power loss. No rudder control, rudder drift, and ship alignment drift (1:24-1:25:30) Power restored and ship reengages prop with bad ship/ruddder alignment (1:25). However, ship is now pushing itself into a further bad turn. Pilot likely stomps the bra…

I'm not sure what configuration of props a ship like this has, but in my experience with a 40ft sailboat with a single propeller you have absolutely no rudder authority while reversing. I've read that some large ships also are direct drive--there's no transmission between the engine and the propeller, so "reversing" (if it's even possible) entails shutting down the engine and restarting it in reverse. This can be don…

I docked in reverse multiple times, same as parking a car in reverse. Just need water flowing along the rudder (from motion, not prop wash), but otherwise it's a great way to turn into tight spaces. Gotta be careful about prop walk, which will dominate the controllability until some reverse speed is established. So until you've decelerated to 0 and re-accelerated in reverse, you don't have much control beyond prop walk.

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

#780

Post by OJFord »

DiggyJohnson wrote: post #703
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…

Because horn blasts are very specifically meant to communicate something to other ships. Once you're in "just blast it" mode you're seconds from disaster. I recognize the nobility of your suggestion, but I don't think it could have saved more than couple lives at most, probably none.

Well yeah, they were only minutes away at the point they lost power, there was very little time to do anything at all, that's why I asked. Personally I can't really imagine anyone holding it against them for using the 'signal that's for other ships' 'incorrectly' or 'against protocol' in such a situation. I think the comments speculating that the horn is either purely or in some way (e.g. solenoid) dependent on electricity is more likely the answer. I think a reasonable human in that situation who knows what's going on (that's why I mentioned that they apparently were able to radio/however they mayday that there's an issue) is going to do whatever they can, including use the horn wrong.
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