Top
Best
New

Posted by DamnInteresting 8 hours ago

Loose wire leads to blackout, contact with Francis Scott Key bridge(www.ntsb.gov)
245 points | 98 commentspage 2
dopamean 6 hours ago||
I know a little about planes and nothing about ships so maybe this is crazy but it seems to me that if you're moving something that large there should be redundant systems for steering the thing.
gk1 6 hours ago||
There are.[1] Unfortunately they take longer to employ than the crew had time.

[1] As it happens I open with an anecdote about steering redundancy on ships in this post: https://www.gkogan.co/simple-systems/

dopamean 6 hours ago||
Thanks for this comment!
cjensen 5 hours ago||
Shipping is a low-margin business. That business structure does not incentivize paying for careful analysis of failure modes.

Seems to me the only effective and enforceable redundancy that can be easily be imposed by regulation would be mandatory tug boats.

protocolture 1 hour ago|||
>Seems to me the only effective and enforceable redundancy that can be easily be imposed by regulation would be mandatory tug boats.

Way it worked in Sydney harbour 20+ years ago when I briefly worked on the wharves/tugs, was that the big ships had to have both local tugs, and a local pilot who would come aboard and run the ship. Which seemed to me to be quite an expensive operation but I honestly cant recall any big nautical disasters in the habour so I guess it works.

dboreham 2 hours ago|||
> mandatory tug boats

Which there are in some places. Where I grew up I'd watch the ships sail into and out of the oil and gas terminals, always accompanied by tugs. More than one in case there's a tug failure.

kylehotchkiss 5 hours ago||
When shipowners are willing to cut costs with sketchy moves like registering with a random landlocked African country, why should we believe they'll spend any time or effort reading/implementing NTSB guidelines? It isn't like there's some well respected international body like ITAO calling the shots
comeonbro 7 hours ago||
A label placed half an inch wrong on misleading affordance -> 200,000 ton bridge collapse, 6 deaths, tens of billions of dollars of economic damage

Instant classic destined for the engineering-disasters-drilled-into-1st-year-engineers canon (or are the other swiss cheese holes too confounding)

Where do you think it would fit on the list?

bragr 6 hours ago||
I guess this will still be bellow Therac-25 for CS and CE students, but above for EE, ME, and Civil Engineering.
ocdtrekkie 6 hours ago|||
The image brings to mind the Cisco ethernet boot infographic: https://www.cisco.com/c/en/us/support/docs/field-notices/636...
hexbin010 5 hours ago|||
I can't believe I've never seen this. I literally laughed out loud when I got to the image. Thank you! Absolute gold
protocolture 1 hour ago|||
I love this one.
dboreham 2 hours ago||
My rule for a couple decades: any failover procedure that only gets run when there's a failure, will not work.
mberning 2 hours ago||
This is a great example of why “small details” matter. How many times do you think an apprentice has been corrected about this? What percentage of the time does the apprentice say “yeah but it’s just a label”. Lots of things went wrong in this case, but if the person that put the label on that wire did it correctly then this whole catastrophe could have been avoided.
jojobas 7 hours ago||
"Contact" is a weird choice of words.
nocoiner 5 hours ago||
Yeah, when the word “allision” was right there!
crote 6 hours ago|||
Not really, because that's where that part of the investigation ends.

Pre-contact everything is about the ship and why it hit anything, post-contact everything is about the bridge and why it collapsed. The ship part of the investigation wouldn't look significantly different if the bridge had remained (mostly) intact, or if the ship had run aground inside the harbor instead.

ErroneousBosh 4 hours ago|||
Right? Like when I read that I thought we're talking a little paint-swapping.

No, we are not talking a little paint-swapping.

analog31 4 hours ago|||
Reminds me of "fetched up" describing what happened to the Exxon Valdez.
charles_f 6 hours ago||
Thought the same, bridge is fallen on its entire length, sounds like a way to undersell it. Such an opportunity to pass on clickbait is interesting in this day and age.
dhosek 6 hours ago||
I’m not sure that the NTSB is really in the clickbait business. But yes, contact does seem to really be underselling the event.
tonymet 4 hours ago||
The older I get , the more I trust people over rules.
1970-01-01 7 hours ago||
So there were two big failures: Electrician not doing work to code; inspector just checking the box during the final inspection.
nightpool 7 hours ago||
No, there was a larger failure: whoever designed the control system such that a single loose wire on a single terminal block (!) could take down the entire steering system for a 91,000 ton ship.
bragr 6 hours ago|||
There's a 3rd failure: the failure to install/upgrade dolphins that could deflect a modern containership, despite the identified need for such. That proposed project seems cheap in retrospect.
nightpool 6 hours ago||
Yes, 100%. Lots of failures across the board here. Especially with large ships and how many different nations they might be registered in, I can't imagine it's easy to have a lot of regulatory oversight into their construction, mechanical inspection or maintenance schedules. I'm curious how modern ports handle this problem, feels like it could cause a ton of issues beyond just catastrophic ones like this one.
DannyBee 5 hours ago|||
They didn't.

If you read the report they were misusing this pump to do fuel supply when it wasn't for that. And it was non redundant when fuel supply pumps are.

Its like someone repurposing a husky air compressor to power a pneumatic fire suppression system and then saying the issue is someone tripping over the cord and knocking it out.

DannyBee 5 hours ago|||
No. Lots more : It's because they were abusing a non-redundant pump to supply fuel to the generators. Which then failed, which ....

From the report:

> The low-voltage bus powered the low-voltage switchboard, which supplied power to vessel lighting and other equipment, including steering gear pumps, the fuel oil flushing pump and the main engine cooling water pumps. We found that the loss of power to the low-voltage bus led to a loss of lighting and machinery (the initial underway blackout), including the main engine cooling water pump and the steering gear pumps, resulting in a loss of propulsion and steering.

...

> The second safety concern was the operation of the flushing pump as a service pump for supplying fuel to online diesel generators. The online diesel generators running before the initial underway blackout (diesel generators 3 and 4) depended on the vessel’s flushing pump for pressurized fuel to keep running. The flushing pump, which relied on the low-voltage switchboard for power, was a pump designed for flushing fuel out of fuel piping for maintenance purposes; however, the pump was being utilized as the pump to supply pressurized fuel to diesel generators 3 and 4\. Unlike the supply and booster pumps, which were designed for the purpose of supplying fuel to diesel generators, the flushing pump lacked redundancy. Essentially, there was no secondary pump to take over if the flushing pump turned off or failed. Furthermore, unlike the supply and booster pumps, the flushing pump was not designed to restart automatically after a loss of power. As a result, the flushing pump did not restart after the initial underway blackout and stopped supplying pressurized fuel to the diesel generators 3 and 4, thus causing the second underway blackout (lowvoltage and high-voltage).

IncreasePosts 6 hours ago||
The terminal blocks could also have been designed to aid visual inspection.
ocdtrekkie 6 hours ago|
"and WAGO Corporation, the electrical component manufacturer"

Sucks to be any of the YouTubers influencers today telling everyone they should use WAGO connectors in all their walls.

Seriously though, impressive to trace the issue down this closely. I am at best an amateur DIY electrician, but I am always super careful about the quality of each connection.

Polizeiposaune 5 hours ago||
The WAGO connectors typically used in home wiring have a transparent plastic shell which lets you see whether the wire made it all the way through the spring clip. The ones shown in the NTSB video had an opaque shell around the spring clip.
ocdtrekkie 4 hours ago||
I think my attempt at humor butthurt a lot of WAGO fans. I used "seriously though" after in my actual... serious comment.
rootusrootus 6 hours ago||
I don't see anything in the report that suggests the connector failed. It sounds like the installer failed. Trust me, they can screw up twist connections too :)