Baltimore Francis Scott Key Bridge collapse - Page 1
Forum section: electronics / general

author: tom66
author_rank: Super Contributor
timestamp: March 26, 2024, 08:28:30 am
content: Looks like a major disaster, with many people in the water, after a ship collided with the bridge structure and the bridge collapsed.https://bbc.co.uk/news/live/world-us-canada-68663071Fortunately, fatalities are going to be lower just because of the time at night but multiple vehicles and at least a work crew have gone into the water, so almost certainly several will have died. It's not clear if anyone on board the ship was injured.Going to be an expensive day for the marine insurers. I thought bridges like this were designed to resist the collision of a ship? Is this a design fail? The bridge is, or was, roughly 50 years old, so it's within the range of time that you'd expect considerations like this to have been made.

author: rsjsouza
author_rank: Super Contributor
timestamp: March 26, 2024, 08:50:11 am
content: What an unfortunate event... The video of the collapse is very impressive - the bridge crumbles as if it was made of paper.Bridges that collapsed after collisions have happened before and I wouldn't be surprised if negligence or corruption related to its maintenance were critical factors in this case.

author: Whales
author_rank: Super Contributor
timestamp: March 26, 2024, 09:07:33 am
content: That brings up an interesting question: are those bridges designed to survive single-ship impacts like that? We'd hope so, but I wonder if it's actually a requirement.

author: guenthert
author_rank: Frequent Contributor
timestamp: March 26, 2024, 09:12:04 am
content: I'm pretty sure that with a massive enough ship sailing fast enough, one could take down any bridge. I'd think for that reason, there will be limits to what ship and how fast may approach such a bridge. Were those limits exceeded?

author: watchmaker
author_rank: Unknown
timestamp: March 26, 2024, 09:48:03 am
content: What a thing to wake to! We lived just outside Baltimore for 40 years. Sad for the victims, sad for the firemen (FIL led the response to a stadium escalator collapse). Some USN preposition ships there, port does handle mainly cars (that now screws things up). City/county/state cannot handle the loss of revenue and jobs.The Mates and Pilots school is also in Balmer ((hon) and this will a classic case study.Yeah enough mass at any speed will take down a structure with a direct hit. Which this appears to have been. Pilot lost his card unless he had a heart attack.Holy shit!

author: Ian.M
author_rank: Super Contributor
timestamp: March 26, 2024, 10:22:16 am
content: SeeNOAA chart 12281The main span's piers were in 30' - 35' of water (+ tidal range), and the channel is dredged to 50'. They were protected bydolphinseither side. To add enough extra dolphins to 'ship-proof' the bridge would be rather expensive, ballpark estimate on the high side of $100 000 000 USD, just for the dolphins and associated protection works, which is at least double the total annual revenue of the port authority, and a significant fraction of the city's budget which is already forecast to have a $180 000 000 annual deficit for the next decade.The insurers will pay out (eventually) for the cleanup and a depreciated cost for the bridge, and the city and port authority will have to pick up the rest of the tab unless they can get a federal grant. Ain't nobody going to be happy, as port fees and local taxes will have to go up.@Watchmaker,Even if the pilot had a medical issue, unless the ship was found to have suffered a critical systems failure, e.g. loss of both throttle and rudder control, Pilot lost his card FULL STOP, either due to responsibility for the incident or by being medically unfit. At this point (absent such a failure) the pilot and ships' bridge officers on watch are essentially unemployable in any similar role, probably for the rest of their lives. 'Take an oar and walk inland ...'

author: WatchfulEye
author_rank: Regular Contributor
timestamp: March 26, 2024, 10:36:24 am
content: Longer video here. Looks like it shows several episodes of complete electrical failure with the ship drifting.https://twitter.com/truth68201238/status/1772534441593737582

author: tom66
author_rank: Super Contributor
timestamp: March 26, 2024, 10:49:25 am
content: Yeah, that's terrible. Looks like the ship pilots would have been able to do nothing about that, and would have been aware of it the whole time... Makes you wonder if this is going to be down to whomever maintained that engine/power system last.

author: soldar
author_rank: Super Contributor
timestamp: March 26, 2024, 10:50:49 am
content: Quote from: Whales on March 26, 2024, 09:07:33 amI think this comment shows a lack of understanding of the scale and proportions of the entire thing. It is pretty much impossible to build that bridge in a way that it could withstand being hit by a mass of, say, 100,000 tons, 150,000 tons etc, going at speed. And it makes no sense, economic or otherwise.

author: vk6zgo
author_rank: Super Contributor
timestamp: March 26, 2024, 10:54:14 am
content: Quote from: Whales on March 26, 2024, 09:07:33 amThe Tasman bridge in Hobart was hit by a ship in 1975 & several spans collapsed, with the loss of 12 lives.The pillars on each side of the navigation channel were designed to take a ship impact, but the others where the ship hit weren't.The "Lake Illawarra" which brought it down was by today's standards, relatively modest in size.

author: iMo
author_rank: Super Contributor
timestamp: March 26, 2024, 11:18:01 am
content: From the video above - interesting how fast the ship changed its direction after the first power outage. I would expect the rudders of such a ship will stay in the "last good" direction after the outage.

author: jonpaul
author_rank: Super Contributor
timestamp: March 26, 2024, 11:21:33 am
content: Possible circidian effect on captian of ship at 01:30?Impact on commerce at the Baliomore port?JonPS: An old is dierect desendent of Francis Scott Key, composer of our National Anthem.

author: Circlotron
author_rank: Super Contributor
timestamp: March 26, 2024, 11:44:17 am
content: Quote from: vk6zgo on March 26, 2024, 10:54:14 amRemember it well.

author: watchmaker
author_rank: Unknown
timestamp: March 26, 2024, 11:54:46 am
content: Mykid (Structural PE) just told me there was a repair crew on the spans. Fuck. Coulda been her.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 26, 2024, 01:11:38 pm
content: Quote from: iMo on March 26, 2024, 11:18:01 amIs the ship steer by wire? I would expect that most ships are hydraulically steered and in any case, there would be redundant systems like on aircraft.

author: tom66
author_rank: Super Contributor
timestamp: March 26, 2024, 01:18:58 pm
content: Quote from: NiHaoMike on March 26, 2024, 01:11:38 pmI'm also wondering why they were so close to the bridge pier. I'd have thought you'd aim for the middle of the bridge and in the event of a power failure you'd just drift through the middle of the bridge. It looks like they were quite off course and then simultaneously lost power, a bit of a Swiss cheese event. I know very little about maritime navigation, but it does seem a bit odd that they even ended up in this position in the first place.

author: Andy Chee
author_rank: Super Contributor
timestamp: March 26, 2024, 01:35:14 pm
content: Quote from: NiHaoMike on March 26, 2024, 01:11:38 pmRemember that in order for the rudder to have any effect, the ship needs to be moving relative to the water, or in other words the ship’s propellers must be providing some thrust.If the ship is moving at zero speed relative to the water i.e. drifting with the current, the rudder does nothing.In aircraft terminology, if airspeed is zero the aircraft has stalled.

author: Ian.M
author_rank: Super Contributor
timestamp: March 26, 2024, 01:36:05 pm
content: The main span of the bridge was 1100 feet. MV Dali is approx 160 feet wide, and IRCPS ('COLREGs') Rule 9 states a vessel proceeding along the course of a narrow channel or fairway is obliged to keep "as near to the outer limit of the channel or fairway which lies on her starboard side as is safe and practicable.", so it would be normal practice under a bridge span wide enough for two vessels to pass, to aim for a point that's considerably off-center.The vessel would have been carrying considerable way, and in water much shallower than the beam, would require at least six ships lengths to stop from typical manoeuvring speeds, assuming full astern was available, and there was enough lateral searoom to accommodate the severe slew to one side that is typical of a single screw vessel going hard astern. If the engine failed, low speed steering would be compromised by the lack of forced water flow over the rudder.Re: WatchfulEye's video link: The observed thick smoke from the funnel implies the engines were rapidly commanded to full speed, and no pilot or watch officer in their right mind would go full ahead towards a near hazard in restricted waters. Its likely that the slew into the bridge pier was mostly due to going full astern with insufficient distance to stop. Dammed if you do, dammed if you don't.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 26, 2024, 01:59:26 pm
content: Quote from: Ian.M on March 26, 2024, 01:36:05 pmI wonder if that would get revised to aiming for the center as long as there's no traffic in the other direction, to give more room for error.

author: Ian.M
author_rank: Super Contributor
timestamp: March 26, 2024, 02:07:05 pm
content: No, but its common practice to put markers on a bridge span and have a harbour regulation that vessels shall pass between the markers, which effectively has the same result of excluding non-emergency navigation near the piers.

author: TimFox
author_rank: Super Contributor
timestamp: March 26, 2024, 03:11:22 pm
content: The last news report I heard on the radio (9:30 CDT on March 26) said that the container ship had suffered a total loss of propulsion.The ship notified authorities about the possibility of impact, who were able to reduce the number of people at risk on the bridge before the ship hit it.

author: guenthert
author_rank: Frequent Contributor
timestamp: March 26, 2024, 03:34:17 pm
content: Quote from: NiHaoMike on March 26, 2024, 01:59:26 pmFor the landlubbers: starboard is right side, the ship hit the left pylon.As far as change of rules is concerned, I could see a demand for ships exceeding a 'safe' size be required to be towed into port by tugs, rather than sailing under own power.

author: soldar
author_rank: Super Contributor
timestamp: March 26, 2024, 04:28:34 pm
content: I have sailed my own sailboat on the Chesapeake for quite a few years and know the area well although my main sailing was in the southern part of the Bay. Lots of stories and memories. I used to love sailing at night.There can be some strong tidal currents, more so on the southern part, much less so in Baltimore Harbor. I used to know the tides and currents pretty well and use them to my advantage.As a curiosity, those channels leading up to Baltimore Harbor are marked by "ranges"QuoteThe span of the bridge is wider but the width of the dredged channel is about 220m (700') so when the ship hit the bridge it was already outside the channel and had hit the bottom which probably slowed it down considerably.Remember the ship that got stuck in the Suez canal? Those large container ships are huge!If the dredged channel is 220 m wide you have 110 m in each direction and if the ship is about 50 m in beam then it only has 30 m clearance on each side. That is about 1/10th of the length of the ship.In the attached photo I have marked the edges and center of the channel and what width the ship would be taking.

author: TimFox
author_rank: Super Contributor
timestamp: March 26, 2024, 04:53:19 pm
content: Edited from an AP news item (11:24 AM CDT) with further details.BALTIMORE (AP) — A container ship lost power and rammed into a major bridge in Baltimore early Tuesday, causing the span to buckle into the river below and plunging a construction crew and several vehicles into the dangerously cold waters. Rescuers pulled out two people, but six others were missing.The ship’s crew issued a mayday call moments before the crash took down the Francis Scott Key Bridge, enabling authorities to limit vehicle traffic on the span, Maryland’s governor said.The ship struck one of the bridge’s supports, causing the structure to collapse like a toy. It tumbled into the water in a matter of seconds — a shocking spectacle that was captured on video and posted on social media. The vessel caught fire, and thick, black smoke billowed out of it.With the ship barreling toward the bridge at “a very, very rapid speed,” authorities had just enough time to stop cars from coming over the bridge, Maryland Gov. Wes Moore said.

author: David Hess
author_rank: Super Contributor
timestamp: March 26, 2024, 05:10:09 pm
content: Quote from: Ian.M on March 26, 2024, 10:22:16 amIt looked like the ship had power failure, and then power failure of the backup system if all of that smoke was from a backup diesel generator.https://twitter.com/CheeseEaterAnon/status/1772585380291784719

author: Ian.M
author_rank: Super Contributor
timestamp: March 26, 2024, 05:28:24 pm
content: I doubt that much smoke would come from a backup generator start. Usually you get a puff of white smoke from totally unburnt fuel till it fires, then the governor kicks in and throttles back to match the load so not much black smoke. OTOH if you suddenly throttle up a big diesel running at low speed under load to emergency full throttle, you will get *LOTS* of black smoke, especially if the engine isn't fully warmed up yet. Whether that was with the engine initially making RPM for 8.5 knots, or was immediately after an engine restart; and whether it was a desperate attempt to get flow over the rudder, or going full astern to take way off, will no doubt come out in the NTSB report.Meanwhile here's some preliminary analysis from ashipping industry expert:Quote from: guenthert on March 26, 2024, 03:34:17 pmNot from the ship's point of view. The ship was proceeding to seaward, but the video is looking landward, so left side pylon in the video is right (starboard) side as seen from of the ship. They'd only match if the video was from astern of the ship.Note that COLREGs rule 9 (part) "as near to the outer limit of the channel or fairway which lies on her starboard side as is safe and practicable." may not actually be to starboard of the channel centerline if no other vessel is approaching in the opposite direction. Depending on tidal/current and wind conditions, and the ship's manoeuvring characteristics, keeping port of the centerline to allow additional room to starboard may be prudent.

author: cosmicray
author_rank: Frequent Contributor
timestamp: March 26, 2024, 05:57:48 pm
content: The MV Dali was departing Baltimore, under it's own power, with two harbor pilots on board. Something happened to the power plant (still unclear) and the ship veered off course. Might have been the rudder, or might have been it got caught by the tide without any way to oppose it. There were 7 or 8 people on the bridge repairing potholes, and an unknown number of vehicles.This reminds me a little of the ship collision in 1980, with the (old) Sunshine Skyway Bridge (across the entrance to Tampa Bay). That accident occurred during a strong rain squall, and the ship had one harbor pilot on board. One (of two spans) collapsed during that accident.Prayers for everyone.

author: BrokenYugo
author_rank: Super Contributor
timestamp: March 26, 2024, 06:30:55 pm
content: My only question is how many months/years did this ship have this problem, or some actionable sign of an issue that should have been corrected but instead was allowed to snowball. Every disaster is a long chain or large pile of bad decisions, I'd be shocked if this was the first time it acted up.I'm sure it will come out in the report, it always does, too bad the people who need to read the reports apparently don't.

author: BILLPOD
author_rank: Frequent Contributor
timestamp: March 26, 2024, 07:02:55 pm
content: Does Boeing have a a ship building subsidiary

author: tom66
author_rank: Super Contributor
timestamp: March 26, 2024, 07:10:15 pm
content: Apparently the ship radioed a MAYDAY into the port authority and the bridge was closed to traffic before the collision. This can be seen in the footage, before the ship strikes there is a pronounced gap in traffic.That is fantastic on the part of the bridge operators, either quick thinking or a well rehearsed safety drill. Either way, they likely saved countless lives with this action. Sadly the construction crew stationed on the bridge didn't seem to be aware of the danger, or if they were, they didn't get out in time. You can see the trucks go down into the river when the collapse happens.

author: mariush
author_rank: Super Contributor
timestamp: March 26, 2024, 07:38:10 pm
content: Yeah... they tried but couldn't get the ship to stop or turn fast enoughThe guy in the video below says they black smoke is the engines running in emergency full reverse and he says the ship also dropped one anchor trying to stop the ship but the anchor was dragging along, and possibly that anchor contributed a bit to ship changing direction a bit but it was in theory a correct move in such scenarios

author: floobydust
author_rank: Super Contributor
timestamp: March 26, 2024, 07:42:41 pm
content: They'd stopped traffic on the bridge but the road crew was still there I guess.My heart goes out to the dead, crew fixing potholes at 1:30AM on the bridge. What a job to have.The MV Dali had prior problems and crashed once at an Antwerp dock, it's 9 years old. Who knows how well maintained these container ships are.The excessive stack smoke might be from the engine not fully supported (air pumps) when the backup generator is running?The Bow motor really needed to work but sure didn't.

author: tooki
author_rank: Super Contributor
timestamp: March 26, 2024, 09:08:05 pm
content: A friend of mine in Maryland texted me about this about an hour after it happened. Crazy.I used to commute across that bridge daily.

author: Bud
author_rank: Super Contributor
timestamp: March 26, 2024, 09:29:09 pm
content: The first thing that came to my mind watching the moment of collapse is the rightmost section of the bridge that also collapsed. Perhaps was not the best bridge design if the entire bridge collapsed because of one section was damaged.

author: guenthert
author_rank: Frequent Contributor
timestamp: March 26, 2024, 09:35:16 pm
content: Quote from: Ian.M on March 26, 2024, 05:28:24 pmAnd I was sure it was. I saw only the webcam video on youtube ("lifestream") and mistook the lights in background for the port. An aerial view clears things up:https://www.fox5dc.com/news/aerial-videos-photos-baltimore-francis-scott-key-bridge-collapseMy bad.

author: nctnico
author_rank: Super Contributor
timestamp: March 26, 2024, 09:51:51 pm
content: Quote from: soldar on March 26, 2024, 10:50:49 amStill, the bridge could have been constructed/designed in a way that only 1 or 2 sections collapse in case of a pylon getting damaged. Now all 4 sections of the bridge collapsed.

author: bdunham7
author_rank: Super Contributor
timestamp: March 26, 2024, 10:09:24 pm
content: Quote from: Ian.M on March 26, 2024, 05:28:24 pmThis ship has a low-speed direct-drive two-stroke engine that would have required a complete stoppage and reversal of the engine itself. AFAIK they typically will always be fully preheated with a boiler so it wouldn't be cold, but a full-power reversal/startup would certainly generate some pretty copious smoke. The heavy fuel they use doesn't help. Looking at that video I think you may be right in that reversing their single screw violently changed their direction, although I certainly wonder what the rudder issue was. I guess we'll wait for the reports to come out.

author: tom66
author_rank: Super Contributor
timestamp: March 26, 2024, 10:32:08 pm
content: Quote from: Bud on March 26, 2024, 09:29:09 pmQuote from: nctnico on March 26, 2024, 09:51:51 pmThis type of bridge is not redundant. A single lost section is catastrophic. This is common to most suspension and truss bridges of this scale. It is quite hard to imagine how you could build such redundancy into a bridge like this without fundamentally changing its design into something like a cantilever bridge which would require substantially more material.

author: bdunham7
author_rank: Super Contributor
timestamp: March 26, 2024, 10:41:35 pm
content: Quote from: soldar on March 26, 2024, 10:50:49 amIt's pretty common to have islands of large fill around the piers. The island can be mostly underwater as it is sufficient to have the ship run aground before it gets to the bridge itself.

author: EEVblog
author_rank: Unknown
timestamp: March 26, 2024, 10:45:14 pm
content: Thread from bridge designer Matt Durshhttps://twitter.com/MattDursh/status/1772605870599238112Quote

author: bdunham7
author_rank: Super Contributor
timestamp: March 26, 2024, 10:45:59 pm
content: Here's a photo of the bridge with the intended path in green and the actual path in red. Not particularly accurate, just a rough hand drawing. Quite the sharp turn and very unlucky.

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 26, 2024, 10:51:42 pm
content: Indeed, very unlucky.

author: coppice
author_rank: Super Contributor
timestamp: March 26, 2024, 10:52:16 pm
content: Quote from: bdunham7 on March 26, 2024, 10:41:35 pmAll the modern big bridges have those islands around the piers. They will certainly lead to a modest sized ship running aground in a fairly harmless way. Whether they are effective against a really big container ship is another matter.

author: EEVblog
author_rank: Unknown
timestamp: March 26, 2024, 10:54:07 pm
content: Quote from: tom66 on March 26, 2024, 07:10:15 pmYes, really fantastic effort here if that's the case.There wouldn't be any local "bridge operator" who could run out with witches hats and signs though right? Are there electronic signs they can just switch on warning people instantly? I pressume so.Very sad about the construction crew and anyone else caught up in this.EDIT: Yes, they have electonic signs.

author: Sal Ammoniac
author_rank: Super Contributor
timestamp: March 26, 2024, 11:07:47 pm
content: Quote from: soldar on March 26, 2024, 10:50:49 amThe San Francisco Bay Bridge was hit by a ship similar in size to the ship that hit the Key Bridge and the damage to the bridge was minimal. This was an ecological disaster due to the collision spilling 50,000 gallons of bunker oil into the bay, but no injuries on the bridge or on the ship.

author: soldar
author_rank: Super Contributor
timestamp: March 26, 2024, 11:11:13 pm
content: Quote from: nctnico on March 26, 2024, 09:51:51 pmThat makes no sense. It is a single bridge, designed and built as a whole. It is not three bridges.In any case. If the channel span falls it makes no difference: the channel is blocked and the vehicular deck above is blocked. The result is the same: both the maritime channel and the road above are unusable.This is a one in a billion occurrence. If the ship had lost power a minute earlier it would not have reached the bridge and if it had lost it a minute later it would have been past the bridge.In my estimation removing the wreck of the bridge is the most urgent task so that maritime traffic can be restored. We shall see how long that takes but I am generally quite impressed by how quick the feds deal with this kind of thing.Vehicular traffic still has a tunnel under the Bay a bit farther north and another bridge a bit to the south so, while inconvenient, it is not terribly bad.

author: tom66
author_rank: Super Contributor
timestamp: March 26, 2024, 11:12:08 pm
content: Quote from: EEVblog on March 26, 2024, 10:54:07 pmImagine being that one guy who blew past the 'STOP DO NOT ENTER' sign because "ehhh I can make it"...A system like this is installed in a tunnel in Sydney, not sure if anywhere else uses it for a bridge. Tunnels justify its use more often due to their greater risks (I imagine daylight vs dark tunnel makes it more difficult too).

author: EEVblog
author_rank: Unknown
timestamp: March 26, 2024, 11:16:00 pm
content: They had two minutes warning:https://www.bbc.com/news/live/world-us-canada-68663071Quote

author: EEVblog
author_rank: Unknown
timestamp: March 26, 2024, 11:19:54 pm
content: Quote from: tom66 on March 26, 2024, 11:12:08 pmThat has been activiated quite a few times in Sydney. Tall trucks getting stuck are not that uncommon, and you don't want cars piling up in the tunnel due to exhaust. IIRC they have a height detection system now and that water barrier activiates automatically if a tall truck tries to enter.Of course, worst case activiation would be a harbour tunnel leak.

author: soldar
author_rank: Super Contributor
timestamp: March 26, 2024, 11:32:30 pm
content: Quote from: Sal Ammoniac on March 26, 2024, 11:07:47 pmWell, yes, but... In this case they built the bridge the way they did and I assume they had their reasons. Probably cost was a major consideration. Probably today it might be done quite differently. To make a large enough island to protect the supports you might have had to widen the span of the bridge more than was considered economical or practical at the time of it's design.I mean, I tend to trust the people who designed it because they had the knowledge and information. I try not to second guess unless the flaws or faults are blatantly clear and obvious.At the time the engineers thought it was a reasonable compromise and the fact that it has gone for so many decades without this accident kind of supports their choice. It is a one in a million chance and if it did not happen this time the bridge would most likely have served its life without a similar thing happening.Engineers have to make choices with how to best use the budget they are given and after any accident there will be those who will say it could have been prevented if only they had spent more on this or that. It is just not economical to try to prevent everything that could possibly happen. Note also that the ship was already outside of the dredged channel and running aground (and slowing down).

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 26, 2024, 11:40:37 pm
content: Any info on how the steering system of the ship works? I'm surprised it doesn't have enough redundancy to prevent this, in particular a backup turbine (analogous to the RAT on an aircraft) powered by the momentum of the ship itself.

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 26, 2024, 11:48:36 pm
content: Quote from: NiHaoMike on March 26, 2024, 11:40:37 pmSo am I.

author: soldar
author_rank: Super Contributor
timestamp: March 27, 2024, 12:17:10 am
content: Quote from: NiHaoMike on March 26, 2024, 11:40:37 pmI guess it is most probably hydraulic and I think an emergency engine and pump would make more sense. I live next to a hospital and as soon as the electric power fails an emergency generator starts automatically. On a ship that size I would expect a standby system that guarantees the proper working of all essential functions. It may be that the ship did have them but they were not adequately maintained.I am always surprised by how emergency systems are not functional when needed. Like when there is a fire in a crowded place and the emergency exits are locked and people die.

author: cosmicray
author_rank: Frequent Contributor
timestamp: March 27, 2024, 12:33:51 am
content: Quote from: EEVblog on March 26, 2024, 10:45:14 pmThe Sunshine Skyway Bridge (entrance to Tampa Bay) came down in 1980. The FSK Bridge (that collapsed today) was built during the 1970s, so before the Skyway lessons were learned. The Sunshine Skyway Bridge (the current one) has dolphins surrounding the support columns. We live and we learn. The original Skyway Bridge lasted about ~25 years (originally there was a single span, then a second was added). The FSK Bridge survived for ~50 years. Properly taken care of, it might be still standing, other than for the vessel collision.I grew up around Tampa Bay. The original SSB scared me. The new one is much better, but it's still a long way down to the water.

author: cosmicray
author_rank: Frequent Contributor
timestamp: March 27, 2024, 12:40:33 am
content: Quote from: soldar on March 26, 2024, 11:11:13 pmUS Army Corp of Engineers has been tasked with restoring the shipping channel, which includes the removal of the wreckage. I'm assuming they will be working with the owner of the ship and the port of Baltimore, to have the ship carefully withdrawn from the accident location.Somewhere today it was mentioned that hazardous cargo that could cross the bridge, may not be allowable in the tunnel. So that is a complication that needs to be sorted out.

author: soldar
author_rank: Super Contributor
timestamp: March 27, 2024, 12:52:18 am
content: Quote from: cosmicray on March 27, 2024, 12:40:33 amI had not thought of hazmat but in the big scheme of things those vehicles can go around. Still, it the Key bridge being out of service will mean additional traffic on the other bridge and the tunnel and may lead to traffic jams, etc.I would think getting the ship out of the way is the easier part and removing the wreckage of the bridge is more complicated. Or maybe not. I suppose the first thing is to get everything out of the channel and not necessarily out of the water.I wonder how hard aground the ship is. I am reminded of the Evergrande ship that went aground in the Suez canal and they had quite a hard time getting it afloat again.As for the wreckage of the bridge, I suppose it can be cut up so it is easier to move. Still, quite a task.But clearing the channel and making it navigable again is, in my view, the most urgent task with great difference. Lots of ships are waiting to get out and to get in and waiting idle costs money.

author: EEVblog
author_rank: Unknown
timestamp: March 27, 2024, 01:18:17 am
content: Quote from: soldar on March 26, 2024, 11:32:30 pmThat would be my guess as well.Engineering is the art of practical compromise.

author: soldar
author_rank: Super Contributor
timestamp: March 27, 2024, 01:35:55 am
content: Quote from: EEVblog on March 27, 2024, 01:18:17 amAlso, safety is a relative and changing concept. In the late 19th century, in the age of sail, it was considered quite normal to lose a sailor or two on a long voyage. they climbed the rigging and accidents were common. If a sailor fell on deck he was probably dead or maimed for life. If he fell in the water the chances of recovering him were slim... even if they tried and many times they didn't because it might be considered too risky with little chance of recovering him.Up into the 1930s building bridges and other structures the risk of death was just considered part of the job. No safety equipment and no real accident prevention. It was a very different mentality.Today we build a tunnel and it is two tunnels plus one or two service tunnels, etc. And build with much greater safety in mind. The culture has changed. Electrical appliances and installations from 60, 80, 100 years ago were extremely dangerous by the standards of today.It is easy to see how the mentality of safety in general has changed in developed nations. Just go to some third world countries and you still see a mentality that any money or effort expended in safety and prevention is money and effort wasted.Safety costs money and it is good if you can pay for it. The richer we become the more safety we can afford. Which is good.

author: soldar
author_rank: Super Contributor
timestamp: March 27, 2024, 01:40:06 am
content: I notice an electric line running parallel to the bridge and the pylons are well protected by caissons. Still, they are in shallower water, farther away from the dredged channel. If they were hit by a ship that size I doubt they would survive.

author: BrianHG
author_rank: Super Contributor
timestamp: March 27, 2024, 01:49:54 am
content: Closeup view of crash. The ship appears to have it's power go off and on 3 times up to the crash...Areal reconnaissance the next day.

author: EEVblog
author_rank: Unknown
timestamp: March 27, 2024, 01:53:50 am
content: Quote from: soldar on March 27, 2024, 01:35:55 amBut there is still going to be practical compromise at some point, that six sigma does only get you so far.

author: fourfathom
author_rank: Super Contributor
timestamp: March 27, 2024, 06:12:26 am
content: Quote from: Sal Ammoniac on March 26, 2024, 11:07:47 pmThat was a mere side-swipe or glancing blow -- not a head-on crash. The Bay Bridge pylon gouged the side of the hull. Up close the Bay Bridge pylons are rugged-looking but I doubt that they could withstand a bad direct collision.

author: Jeroen3
author_rank: Super Contributor
timestamp: March 27, 2024, 07:02:10 am
content: The regs say the ship should have steering back within 45 seconds by emergency power.Looks like it takes more than a minute for power to recover.These ships have massive power plants. Looks like they have four ~4 MW generators. They're big, I worked on some.And depending on the amount of reefers they're running multiple generators are in parallel all the time. I'm not sure if they can run the main engine on emergency power alone, that is typically only to get one of the four others running.

author: EEVblog
author_rank: Unknown
timestamp: March 27, 2024, 07:38:26 am
content: In Tasmania they stop traffic when a large ship goes under:

author: EEVblog
author_rank: Unknown
timestamp: March 27, 2024, 07:40:50 am
content: Quote from: Jeroen3 on March 27, 2024, 07:02:10 amI heard on an interview with an expert on large ship navigation that the port thusters at full power can overload the generators and cause a complete loss of power.

author: tom66
author_rank: Super Contributor
timestamp: March 27, 2024, 08:36:34 am
content: Quote from: EEVblog on March 27, 2024, 07:40:50 amThat seems like poor design. Surely those thrusters should be electronically limited when on emergency power, or the circuit breaker to the thrusters should trip before killing the generator too. The last thing you need in a situation like this is losing electric power as well as steering, as it will disorient you at night.

author: Jeroen3
author_rank: Super Contributor
timestamp: March 27, 2024, 08:43:21 am
content: Quote from: EEVblog on March 27, 2024, 07:40:50 amYes, to operate thruster they will need more than 1 generator, often 3. Thrusters are awful for generators. They can take all the load in several seconds, and then also dump it. Wiki says the thruster is 3000 kW. That's challenging.

author: dietert1
author_rank: Super Contributor
timestamp: March 27, 2024, 11:46:43 am
content: Maybe the reason for the curve the ship took was trying to run it into the dolphins. It's terrible the ship passed all the dolphins and got stuck exactly at the bridge pillar. The pillar should have been in the "shadow" of the dolphins.Regards, Dieter

author: soldar
author_rank: Super Contributor
timestamp: March 27, 2024, 12:31:19 pm
content: Quote from: dietert1 on March 27, 2024, 11:46:43 amWhat? This makes no sense at all.There were no dolphins.The ship was out of control. If they had any control they would have gone under the bridge.

author: bdunham7
author_rank: Super Contributor
timestamp: March 27, 2024, 02:11:31 pm
content: Quote from: soldar on March 27, 2024, 12:31:19 pmThere are, visible here in Bing maps and in my earlier photo. Oddly they aren't visible in Google maps satellite view.

author: ejeffrey
author_rank: Super Contributor
timestamp: March 27, 2024, 03:24:15 pm
content: Quote from: EEVblog on March 27, 2024, 01:18:17 amAlso the size of container ships has probably increased since the bridge was designed. It doesn't sound like the bridge was designed to take a large direct impact in any case but even if it was designed for a typical ship from the 60s and 70s, it might not have been enough. You try to plan ahead when you design a major civil engineering project but you can't necessarily plan for every thing that could happen in 50 years.

author: fourfathom
author_rank: Super Contributor
timestamp: March 27, 2024, 03:26:26 pm
content: Quote from: NiHaoMike on March 26, 2024, 11:40:37 pmOn any vessel with a rudder, there needs to be water flowing past the rudder for steerage. At low speeds, this flow is provided by the propeller. Once that flow diminishes the rudder becomes ineffective (especially with the relatively small rudders you find on large ships). And if you are trying to back up, a working propeller can no longer force water over the rudder, making steering even more difficult. In this case you get "prop walk" caused by the asymmetrical water flow around the propellor (the top side is close to the hull, the bottom side is not), and this pushes the stern sideways more than the rudder can compensate for. I believe we saw this in the video. Also, apparently they were dragging an anchor (ships anchors are generally too small to be of much use in this type of situation), and this also made any rudder steering control much less effective.Some ships have propellers on steerable pods, bow and stern, and/or bow and stern thrusters (mounted for sideways maneuvering thrust) but I understand that this ship only had one propeller (screw) and a rudder.

author: switchabl
author_rank: Frequent Contributor
timestamp: March 27, 2024, 05:31:59 pm
content: Quote from: fourfathom on March 27, 2024, 03:26:26 pmAs well as a single 3000 kW bow thruster according to Wikipedia.https://en.wikipedia.org/wiki/MV_Dali#DescriptionNot likely to have any relevant effect at 8 kts though.

author: fourfathom
author_rank: Super Contributor
timestamp: March 27, 2024, 06:14:10 pm
content: Quote from: switchabl on March 27, 2024, 05:31:59 pmI was not aware of the bow thruster -- should have checked first. Thanks!

author: tooki
author_rank: Super Contributor
timestamp: March 27, 2024, 06:22:19 pm
content: Quote from: EEVblog on March 26, 2024, 10:54:07 pmIn addition to the electronic signage, there is the toll booth area on the east approach (for both directions) that could have stopped westbound traffic. But additionally, due to the roadwork being done, there were apparently traffic flaggers present. I don’t know whether they were the ones who actually stopped traffic.

author: soldar
author_rank: Super Contributor
timestamp: March 27, 2024, 07:13:58 pm
content: Quote from: bdunham7 on March 27, 2024, 02:11:31 pmI believe they are intended more as navaids as they have lights and they are not really placed as dolphins and they are not massive enough to serve that purpose for any large ship.They would be useless for a ship that size. I suppose they could serve to stop small speedboats or such.

author: soldar
author_rank: Super Contributor
timestamp: March 27, 2024, 07:19:16 pm
content: Quote from: fourfathom on March 27, 2024, 03:26:26 pmThis YouTube channel shows time lapse videos of cruise ships arriving and departing Miami and... not a single tug.

author: tooki
author_rank: Super Contributor
timestamp: March 27, 2024, 07:39:32 pm
content: Quote from: ejeffrey on March 27, 2024, 03:24:15 pmNot “probably”. A better word is “dramatically”. The Dali is a roughly 10000-TEU ship. (TEU = twenty-foot equivalent units) That’s 4x the size of the biggest container ships in existence when the Key Bridge’s construction began in 1972. And a fraction of the size of the biggest ships today, which currently top out at 24,000 TEU!

author: nctnico
author_rank: Super Contributor
timestamp: March 27, 2024, 07:42:08 pm
content: Quote from: soldar on March 27, 2024, 07:19:16 pmI don't think that is a fair comparison. Cruise ships hop short distances from harbour to harbour including relatively small harbours. Freight ships OTOH travel much longer distances and are much more cost sensitive so it makes sense to equip a ship with the minimum necessary features. Keep in mind that what isn't on a ship, can't get broken

author: soldar
author_rank: Super Contributor
timestamp: March 27, 2024, 07:47:25 pm
content: Quote from: nctnico on March 27, 2024, 07:42:08 pmUm... I wasn't comparing anything. Only pointing out that thrusters exist and can be used usefully.

author: tom66
author_rank: Super Contributor
timestamp: March 27, 2024, 08:17:42 pm
content: Quote from: tooki on March 27, 2024, 07:39:32 pmI am curious how much of an improvement such container ships are. Ultimately the TEU-per-day figures are what matter for a port.I would presume the reason they exist is they have better fuel economy, and fuel is the biggest operating expense for a ship like this. Are they better in other ways, such as overall logistics capacity? Or, would it be better to have more smaller ships?If it is a case where these ships offer, for instance, 5% better fuel consumption per container-km, it could be argued that society is bearing the cost of these ships in other ways (Suez Canal blockage would not have been possible without the Ever Given for instance, 20kTEU capacity) and governments should be thinking carefully about this.

author: soldar
author_rank: Super Contributor
timestamp: March 27, 2024, 08:25:02 pm
content: Quote from: bdunham7 on March 27, 2024, 02:11:31 pmAlso visible in earlier Google Earth photos

author: bdunham7
author_rank: Super Contributor
timestamp: March 27, 2024, 08:31:48 pm
content: Quote from: soldar on March 27, 2024, 07:13:58 pmHmmm, small speedboats? The reinforced concrete part that is out of the water is over 5 meters in diameter and presumably there is much more below the water. They are placed over 50 meters from the main bridge piers. I'm pretty sure that would stop a medium, or even a large speedboat! But since the Dali bypassed them entirely, we'll never know for sure. I'm betting that if even a large cargo ship hit them at a shallow angle as they anticipated, it probably wouldn't reach the bridge piers. But without knowing the subsea profile around those, its hard to say.

author: floobydust
author_rank: Super Contributor
timestamp: March 27, 2024, 08:46:24 pm
content: Quote from: soldar on March 27, 2024, 01:35:55 amI say nope. Profit is priority #1. Engineering is not so important. Ref. Boeing.It's a toll bridge that makes a shit ton of money $56M last year. They even sell bonds. It's a big fat cash cow. I'm sure it's paid for itself a few times over its lifetime.Could they not afford tugboat escorts? Upgrades would not useful, no bridge can withstand a fully loaded container ship nailing it.

author: .RC.
author_rank: Frequent Contributor
timestamp: March 27, 2024, 11:32:20 pm
content: In a previous life I had a bit to do with cargo ships.The number that broke down or had inoperable things like bow thrusters was surprising. It is probably why they were mostly registered in some third world country.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: March 27, 2024, 11:52:39 pm
content: Quote from: tooki on March 27, 2024, 06:22:19 pmThe police stopped the traffic. This is well documented. (https://www.foxnews.com/video/6349808520112). Also there are no toll booths on this bridge (https://www.google.com/maps/place/Francis+Scott+Key+Bridge,+Maryland/@39.2298883,-76.5108951,319m/data=!3m1!1e3!4m6!3m5!1s0x89c80052ddeb3cad:0xf3fb8c8f100a3e9e!8m2!3d39.2323329!4d-76.5063164!16zL20vMDR2Njgw!5m1!1e4?entry=ttu)

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 28, 2024, 12:16:15 am
content: Quote from: floobydust on March 27, 2024, 08:46:24 pmThose cargo ships, as .RC. also confirms, are the epitome of favoring profits over anything else, being extremely polluting and transporting cheap goods all over the world that are of dubious quality and manufactured in dubious conditions for a bottom-low cost.So really, I don't know how we can even be surprised.

author: vk6zgo
author_rank: Super Contributor
timestamp: March 28, 2024, 12:20:38 am
content: Quote from: .RC. on March 27, 2024, 11:32:20 pmBack in the 1950s/60s the regulation of such things in Australian ports was very strict, to the point of harshness.Ships suspected of not meeting the safety standards, (usually back then, those registered in Panama), would undergo a "snap" inspection.If they didn't meet the requirements, they were asked nicely to fix things, & in the meantime they could not leave the port.The "Sheriff's Officer"*would nail (in reality, tape) a notice to the mast, officially arresting the ship.If they still didn't fix it, the fines started to apply.*Yes, Virginia, we do have Sheriff's, but they don't lead posses chasing "owlhoots", they are "Officers of the Court", who in turn have minions who do such things as arresting ships.

author: floobydust
author_rank: Super Contributor
timestamp: March 28, 2024, 12:22:22 am
content: Quote from: JustMeHere on March 27, 2024, 11:52:39 pm"All eight Maryland Transportation Authority (MDTA) facilities are all electronic (cashless). With All Electronic Tolling (AET), drivers do not stop or slow down to pay tolls. Instead, they are collected through E-ZPass, Pay-By-Plate, and Video Tolling...."source{mysteriously offline for a while now}I wonder if this disaster is out of the woods? The ship is stuck on top of the concrete pier, full 1.5M gal of fuel, has a history of structural damage from crashing into a dock years ago. Yeah good luck there. At least it's not on fire.It's said the ship had electrical problems for two dayswhile dockedand they're suspecting contaminated fuel as another problem.

author: Someone
author_rank: Super Contributor
timestamp: March 28, 2024, 12:47:24 am
content: Quote from: floobydust on March 28, 2024, 12:22:22 amYet/so-far.

author: johansen
author_rank: Super Contributor
timestamp: March 28, 2024, 01:41:12 am
content: Quote from: tom66 on March 27, 2024, 08:17:42 pmI don't think the ships are going to get much bigger than they are now, because at some point the lowest natural resonance frequency of the largest boats, which is already on the order of 1 second.. results in a problem where the waves can split the ship in half. bigger ship would require more steel which means your improvements in hull speed are offset by the ratio of dead to full load.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: March 28, 2024, 02:08:28 am
content: Quote from: johansen on March 28, 2024, 01:41:12 amThe size of the ships are limited by canal locks and the bridges it will encounter. The ship class is often incorporated into the name. Ex: Panamax 366m. 400m.appears to be the current size limit. These ships cannot enter the Panama Canal though .

author: JustMeHere
author_rank: Frequent Contributor
timestamp: March 28, 2024, 02:18:57 am
content: I don't think it's a question of cost vs safety. It's a question of mass. The more mass added to a bridge means the more additional mass that is needed to stop the bridge from collapsing under its own weight.At some point making the bridge stronger adds more weight to the point the bridge can't be made any stronger. (My university roommates were civil engineers, and I remember discussing this exact subject with them.)Space flight has the same limitation. Say it takes 2 kg of fuel to lift 1 kg of fuel. (Don't know the exact numbers, but I've heard 2-1 works.) This is why on orbit refueling is a big step to mankind moving past Earth.

author: coppercone2
author_rank: Super Contributor
timestamp: March 28, 2024, 02:40:50 am
content: this is why the nostromo had a self destruct on itI wonder if these ships will be robotic one day (or have a escape helicopter) and have a rapid scuttle command to sink them to save lives.

author: AlfBaz
author_rank: Super Contributor
timestamp: March 28, 2024, 02:40:57 am
content: It's been 20 plus years since I worked on ships that came into our local port so treat this info with a grain of salt.I have worked on, maintained and fault found all of the gear mentioned belowMost large vessels have three main alternators driven by 3 separate diesel engines. Each alternator is somewhere in the vicinity of 600kW and up and run on heavy fuel oil, the same as the main engine.This fuel at room temperature is a tar like substance and is heated to decrease its viscosity. It is then run through centrifugal separators to get rid of impurities prior to being fed to the enginesUnder normal electrical load conditions only one alternator powers the main switchboard.There are 2 methods of bringing a second or third main alternator on line. Automatically or manually. Both methods are the same just controlled by hand or actuators.The alternator to be brought on line is started, its governor is adjusted to bring the frequency of the alternators’ output up as close as possible as the one already on line.At this stage, fine adjustments are made to the speed to get the three phases in sync using either the three old school synchro lights or simply an analogue meter whose 12 o'clock position corresponds to phase alignment.As the needle or lights come around slowly to the synchronized position it is connected to the main bus.At this stage, depending on what you want to do the load sharing is adjusted by increasing or decreasing the governors whilst at the same time watching the frequency.For example if you want to bring an extra alternator online you would start the diesel, synchronize and connect it to the bus. Once connected you increase the governor speed which has the effect of increasing that generators load and decreasing the load on the existing one. If the line frequency starts getting too high then you decrease the speed of the alternator with the most load.Most of the ships at that time didn’t have autonomous load sharing, we did start to introduce these systems onto some vessels but that’s another story.Ships that had bow thrusters needed two geny’s on line. Namely to handle the start up current but consequently as a safety measure, should one trip off.All of the bow thrusters I had seen had variable pitch propellers and had to be at zero pitch before they could be started. Some were DOL others employed old school resistance starters with the latter method having massive inline resistance starters or slipring motors with resistors in their rotor circuits shorted out in stagesThey all have an emergency alternator that runs on normal diesel fuel that have a substantially lower kW rating and start automatically when power loss is detected on the main buss. These were also air start.When the emergency alternator is running only a small subset of essential equipment is powered and the main generators can't be switched onto the main bus until the emergency geny is oflineIn addition to emergency AC there are large banks of single cell batteries stacked up to create an emergency 24VDC supply for navigation, radios etc.Some vessels had more than one bank for DC supplie for other various systems. One example of this was for a vessel that had three internal gantry cranes used to move and store large 30 tonne slabs of steel with large electro magnets. A large bank of AGM batteries making up 110VDC were used in the event of loss of power to ensure a slab wouldn’t detach.In the steering flat where the top of the rudder comes into the ship, there would be a series of hydraulic rams actuated by a large pump and indeed had a backup. The port and starboard pumps. In fact there is very little equipment on a ship that doesn’t have 2 of everything.If that vessel had a bow thruster it would explain whyallthe deck lights turned on and off as with the emergency geny, only a few would have turned on but the bow thruster certainly couldNOTbe run off of it so they would have been attempting to put the main genys back online which presumably tripped when attempting to restart the bow thruster.Having worked on many overseas ships they were often poorly maintained with a lot of safety stuff spragged out. Many times when surveyors were called onboard to inspect dodgy vessels, they would be laid up and barred from going to sea until rudimentary safety gear was repaired.Speculating here, but if they were attempting to restart the bow thruster any number of issues would certainly cause the generators to trip offedit: typo bow thruster can not be run from emergency generator

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 28, 2024, 04:51:38 am
content: Given all the difficulty of having to match phases, wouldn't HVDC make more sense nowadays? And/or just stick to hydraulics for the big mechanical stuff?

author: AlfBaz
author_rank: Super Contributor
timestamp: March 28, 2024, 06:00:25 am
content: Most ships don't carry an electrician any more let alone EE's. So having complex systems out in the middle of the ocean needs simpler systems which facilitate farming style bodges.I recollect one vessel coming into port where the ctrl system wouldn't, for some reason or another, allow some motor contactor to energize. I opened the front enclosure door and a lump of timber fell out as they'd jammed it in there to keep some pump motor running till they got to shore

author: tooki
author_rank: Super Contributor
timestamp: March 28, 2024, 07:44:41 am
content: Quote from: JustMeHere on March 27, 2024, 11:52:39 pmI don’t do Fox News, sorry.The various sources I saw didn’t specify exactly who was actually by the bridge directing traffic, but the construction company had stated they had traffic control staff there.As for the toll plaza: hah, serves me right for using, um, another map app! (See attached screenshot.) Well that and the fact that I haven’t driven through there in probably a decade at least.

author: tooki
author_rank: Super Contributor
timestamp: March 28, 2024, 07:49:21 am
content: Quote from: Someone on March 28, 2024, 12:47:24 amWhy would you expect this to happen, given that no indications so far point towards anything even distantly fire-related. The Dali is now at rest, and ships at rest don’t normally just burst into flame.The two sources of smoke initially reported by some have since been explained: the black smoke is from the engines, and the “smoke” at the point of impact is concrete dust, isn’t it?

author: SeanB
author_rank: Super Contributor
timestamp: March 28, 2024, 08:03:18 am
content: Also to point out that those shipboard lights are high pressure sodium lights, which take 3 minutes to restrike when the power is interrupted. Cheap iron core and superimposed pulse starters will not strike a hot tube, until it has cooled down a little, when it will restrike, in about 3 minutes. I would also say the ship owners would also not buy dual tube lamps, where they have 2 arc tubes in parallel in the glass envelope, and which will, if there is a single power dip, have the other tube light up and run, as these cost double the price of the cheap Chinese Ya Ming lamps they likely buy by the case lot. The lights going out is a good indication of power loss, but the relight shows the hot restrike time, and they all coming on nearly at the same time says they were all from the same batch, and all had similar running hours on them, as the restrike time varies greatly with age, and from batch to batch. The only way to have hot restrike is to buy more expensive ballasts that can provide the 5kV plus needed to strike the tube, which needs the wiring to be insulated to the socket, and the socket to be rated for 5kV without flashing over, plus the tubes need a different E40 base design with a wider glass insulator.No LED lights, the power supplies fail badly, even those designed for rough service use, and do not mix well with salt water ingress, while the magnetic will carry on till the core rots away. Also easy to relamp, as all you need to carry up in a small sling bag is a spare lamp, a new ignitor, a can of WD40 for the rusted fasteners, and some pliers and screwdrivers to open the fixture, which mostly use simple spring clips to allow tool less lamp changes. LED you have to use a rope and pulley to first lower the old one down, and then pull the new one up, and need 2 people up there, and 2 on deck, to do this. Lamp just needs one person and possibly a deck watcher for the crew of 3, doing 3 at a time in an area. Plus also 5 minutes per lamp, excluding the climb, and power does not have to be cut either.

author: Someone
author_rank: Super Contributor
timestamp: March 28, 2024, 08:42:11 am
content: Quote from: tooki on March 28, 2024, 07:49:21 amMostly in jest, but grounded ships have subsequently caught fire in the past so its not implausible.

author: Circlotron
author_rank: Super Contributor
timestamp: March 28, 2024, 11:50:08 am
content: Quote from: tooki on March 27, 2024, 07:39:32 pmThat's twelve thousand large truck's worth! Yowsers!

author: floobydust
author_rank: Super Contributor
timestamp: March 28, 2024, 06:45:15 pm
content: Quote from: tooki on March 28, 2024, 07:49:21 amCargo manifest shows 56 containers of hazardous (764 tons) mostly corrosives, flammables, "Class 9 including lithium-ion batteries" according to the NTSB Media Briefing 2.Containers are flattened, crushed. Some in the water, some are leaking. There's around 4,700 on the ship.It's not a static situation, tides up and down and things have to be moved, torched cut as they clean up the mess.I would say there is a fire risk- but putting it out is the impossibility if one starts. The bow has a huge hole in it.

author: tooki
author_rank: Super Contributor
timestamp: March 28, 2024, 06:57:44 pm
content: Quote from: Someone on March 28, 2024, 08:42:11 amI said ships do notnormallycatch fire, not that it's impossible.And it's not grounded, mind you. The ship is afloat.

author: tooki
author_rank: Super Contributor
timestamp: March 28, 2024, 06:58:53 pm
content: Quote from: floobydust on March 28, 2024, 06:45:15 pmDefinitely not impossible. But no reason to assume it's a likely outcome.

author: coppercone2
author_rank: Super Contributor
timestamp: March 28, 2024, 07:08:37 pm
content: a container full of massagers might turn on and cause the entire situation to shake apart

author: Sal Ammoniac
author_rank: Super Contributor
timestamp: March 28, 2024, 07:24:48 pm
content: Quote from: AlfBaz on March 28, 2024, 02:40:57 amOne theory that I've seen, that sounds plausible, is that contaminated fuel clogged the fuel filters for the generators, causing the generators to stop. Perhaps the ship didn't have centrifugal separators, or the separators didn't filter out enough impurities to prevent clogging the filters.The bunker oil used as fuel on ships like this one is the dregs of the petroleum refining process and often contains gunk that may be problematic.All of this should be easy enough to figure out as the ship is still intact and presumably there's data logging that will point to the cause of the problem.

author: tooki
author_rank: Super Contributor
timestamp: March 28, 2024, 07:44:26 pm
content: Quote from: Sal Ammoniac on March 28, 2024, 07:24:48 pmYep. The NTSB has already taken the data recorder. However, we may end up disappointed with what it contains, or rather doesn't.This is what theNYT reported:Quote

author: tom66
author_rank: Super Contributor
timestamp: March 28, 2024, 09:14:06 pm
content: It should be easy enough to examine parts of the engines, generators, fuel and fuel system to determine the likely fault. Chances are, if they powered the ship up in this configuration they'd be able to replicate the fault too, if it's related to a problem that exists there rather than crew misoperation.It sounds like from another NTSB report that the data recorders are only operational when the main ship power is running, so they likely only recorded data when things were operating correctly. The audio recorders, however, do operate off backup batteries, and so they've retrieved the audio from the ship's bridge for the duration of the incident.

author: Someone
author_rank: Super Contributor
timestamp: March 28, 2024, 10:55:05 pm
content: Quote from: tooki on March 28, 2024, 06:57:44 pmEqually I'm not saying it will catch on fire in the future for certain. yet/so-far both leave either possibility for the future and literally mean "up to the current time".As to grounded, if it cant move as its tangled in things sitting on the riverbed, that mass/agglomeration of which the ship is a part is grounded.Wikipedia references bringing the goods:https://maritime-executive.com/article/bridge-s-weight-is-pinning-container-ship-dali-to-the-bottomQuote

author: Andy Chee
author_rank: Super Contributor
timestamp: March 28, 2024, 11:40:36 pm
content: Quote from: tooki on March 28, 2024, 06:57:44 pmNot with the weight of a broken bridge span sitting on the deck of the bow!I’ll be fascinated with the salvage operation. Much like the refloating of Costa Concordia, they’ll have to be careful about weight and buoyancy shifts.

author: coppercone2
author_rank: Super Contributor
timestamp: March 29, 2024, 01:17:22 am
content: let people claim containers as salvage and it will be gone in 3 daysHowever the value of a good failure analysis could benefit us for the next 100 years if they figure out every detail and determine how to make improvements

author: Andy Chee
author_rank: Super Contributor
timestamp: March 29, 2024, 01:49:10 am
content: Once enough debris has been manually cleared from the ship’s bow, the ship refloated and towed away, the remaining bridge span elements, both above and below water, will probably be broken down into smaller pieces by demolition explosives.The bridge is way too big to cut apart with plasma torches or oxygen lances.The ship itself is also probably destined for scrap metal yard.

author: floobydust
author_rank: Super Contributor
timestamp: March 29, 2024, 01:54:02 am
content: Keep the ship for collateral - some 1851 law which was cited by the Titanic’s owner in a Supreme Court case 1912, could limit the payout.Titanic law could help ship owner limit liability in Baltimore bridge collapseEstimates are $2B to repair/replace the bridge, $0.1B to free the ship and clean up the mess. Biden is talking like the Feds will give the money, but I have to ask why the US taxpayer is ultimately on the hook, as well as the many years of cranked up toll pricing we know will result. OUCH.

author: Andy Chee
author_rank: Super Contributor
timestamp: March 29, 2024, 02:06:07 am
content: Quote from: floobydust on March 29, 2024, 01:54:02 amRecouping the costs from the “at fault” parties, will probably take a long time in courts, longer than if the US government financed the rebuilding from the start.The US government can always recoup the costs later.

author: xrunner
author_rank: Super Contributor
timestamp: March 29, 2024, 02:06:26 am
content: Oh yea Money Money Money (I'm humming the song from Dark Side of the Moon in my head at the moment). Of course we have lessons learned from the collapsed bridge, so they'll design the new one to withstand such a crash better. Maybe more lanes? How about restaurants and shopping areas at the entrances. The list goes on ...

author: coppercone2
author_rank: Super Contributor
timestamp: March 29, 2024, 02:45:24 am
content: Quote from: xrunner on March 29, 2024, 02:06:26 amI think you should put them on the bridge. Like the original london bridge.I think you are going here with your idea.You could buy all sorts of services on it. From the late seventeenth century there was a greater variety of trades, including metalworkers such as pinmakers and needle makers, sellers of durable goods such as trunks and brushes, booksellers and stationers.How about a drive through chapel?

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 29, 2024, 03:02:11 am
content: Quote from: coppercone2 on March 29, 2024, 01:17:22 amI know it's just tongue-in-cheek, but just for the sake of the idea, how would people salvage all this in 3 days right in the middle of the river with no bridge?

author: themadhippy
author_rank: Super Contributor
timestamp: March 29, 2024, 03:40:52 am
content: Quotecanoes

author: floobydust
author_rank: Super Contributor
timestamp: March 29, 2024, 03:58:36 am
content: Given $xx million to get this ship out of the way, how are we doing it? FASTUse Thug Technology® - wait for high tide, maybe a Supermoon - startup the ship's engine and nail it in reverse!Use TNT and blow up that pier!I could borrow my uncle's tugboat, maybe call up his friends and get their tugs pushin' too.Remember the Suez Canal incident March 2021?Ever Givenran aground. It's over 2x GT as big as theMV Dali(but similar engine power, odd). Call upSMIT Salvagehas a huge crane and tugs.Bloomberg storyThe Francis Scott Key bridge alsogot nailed in 1980by (smaller) container ship named the Blue Nagoya. Good to know nothing was changed.

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 29, 2024, 04:10:59 am
content: Quote from: themadhippy on March 29, 2024, 03:40:52 amYes.(Just for some figures, a 400m container ship holds an average of 20,000 TEU (https://en.wikipedia.org/wiki/Twenty-foot_equivalent_unit), it's hard to give an equivalent weight of course, but it's usually about 20T per TEU.So, that's about 400,000T for the whole ship. And, of course, in containers piled up on several layers.All that in 3 days on some canoes.)

author: mfro
author_rank: Regular Contributor
timestamp: March 29, 2024, 07:17:05 am
content: Stick a $10000 tag on each container and they will be gone by tomorrow.

author: coppercone2
author_rank: Super Contributor
timestamp: March 29, 2024, 08:06:40 am
content: I think they would form a fleet of various boats from all over the place in american east coast to take it on anything they can

author: Jeroen3
author_rank: Super Contributor
timestamp: March 29, 2024, 08:21:12 am
content: Quote from: NiHaoMike on March 28, 2024, 04:51:38 amYes and no. Matching phases is easy, we're doing for decades. The gear is there, you can buy DEIF, Woodward, Deep Sea controllers for it. Standard gear. DC is not standard. It requires inverters, and those are complicated and dangerous. They require complex control theory and software. Where you can manually keep spinning copper in check if you have to.However it is attempted. DC busses or having a few drives on DC bus is attempted at some ships. I know of a large ferry and some youghts but inverters do not play not nice with good old spinning copper and iron. Plagued with problems and breakdowns.Inverters can do things generators cannot keep up with, not engine wise, not control wise and not due to reactances, complicated physiscs.

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 29, 2024, 09:01:49 am
content: Quote from: coppercone2 on March 29, 2024, 08:06:40 amThere are things that are physically difficult. Various boards all over the place? That would be a major safety hazard, that's just insane.And you can't lift those containers like that, they are all tightly placed next to one another and on top of one another. That needs major means to do it effectively and safely.

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 29, 2024, 09:04:11 am
content: Speaking of figures, if I didn't mess up my calculations, at the speed the ship was estimated to move when it hit the pillar and with its estimated mass, the energy must have been something the equivalent of the explosion of between 500kg and 1t TNT. Just to get an idea.

author: jpanhalt
author_rank: Super Contributor
timestamp: March 29, 2024, 10:17:55 am
content: Sunrise in Baltimore: 6:55 AM:QuoteInspired by FSK and quoted in part.

author: xrunner
author_rank: Super Contributor
timestamp: March 29, 2024, 10:58:46 am
content: Quote from: themadhippy on March 29, 2024, 03:40:52 amDidn't the ancient Egyptians move multi-ton obelisks on simple wooden boats?

author: langwadt
author_rank: Super Contributor
timestamp: March 29, 2024, 11:31:30 am
content: Quote from: Sal Ammoniac on March 28, 2024, 07:24:48 pmcoastal areas and ports are sulfur emission controlled areas, so there they run bunker A which is basically diesel

author: switchabl
author_rank: Frequent Contributor
timestamp: March 29, 2024, 12:14:41 pm
content: Quote from: floobydust on March 29, 2024, 01:54:02 amThe article makes it sound a bit like it is some loophole in an old, forgotten law. But in fact the principle of limited liability has been a central element of maritime codes internationally for centuries and it comes up in almost all major shipping accidents.Now, many people do think that this doesn't really make sense anymore in a world where LLCs and huge insurance companies exist and shipping isn't nearly as dangerous as it used to be. But any attempt to change this unilaterally might prove hard to enforce. E.g. the owner of the MV Dali is based in Singapore which is a member of the International Convention on Limitation of Liability for Maritime Claims.

author: Sal Ammoniac
author_rank: Super Contributor
timestamp: March 29, 2024, 03:00:22 pm
content: Quote from: langwadt on March 29, 2024, 11:31:30 amSometimes they run cleaner fuel when in port and switch to the dirty stuff when at sea.Even the lowest grade bunker fuel is lower in sulfur than it used to be. In fact, that change has contributed to global warming because higher sulfur emissions tended to mitigate warming.

author: langwadt
author_rank: Super Contributor
timestamp: March 29, 2024, 03:11:42 pm
content: Quote from: Sal Ammoniac on March 29, 2024, 03:00:22 pmyep, and if they are going to shut down the engines. Don't want things to cool down with the thick fuel that needs to be hotQuote from: Sal Ammoniac on March 29, 2024, 03:00:22 pmyes, the global limit was lowered to 0.5% from (afair) 3.5% in 2020, I think in ports and coastal areas it is ~0.1%

author: coppice
author_rank: Super Contributor
timestamp: March 29, 2024, 03:16:18 pm
content: Quote from: Sal Ammoniac on March 29, 2024, 03:00:22 pmThe response to this seems to be that we now need to throw more crap into the atmosphere to replace the crap we've just removed. Welcome to clown world.

author: xrunner
author_rank: Super Contributor
timestamp: March 29, 2024, 04:27:50 pm
content: The largest crane on the Eastern seabord has arrived at the bridge. That may well be, but it doesn't seem large next to the wreckage.

author: delfinom
author_rank: Regular Contributor
timestamp: March 29, 2024, 05:49:06 pm
content: Quote from: xrunner on March 29, 2024, 04:27:50 pm* Largest water borne crane the army corps of engineers has access toAlso the photo is not even correct, they took a photo of another crane that got moved closer to the wreck.This is the crane that's called in:https://www.donjon.com/ches1000.htm

author: Sal Ammoniac
author_rank: Super Contributor
timestamp: March 29, 2024, 06:14:31 pm
content: That crane looks precarious. It's hard enough working with big cranes near the limit of their load capacity on solid ground--doing it on a floating barge adds another element of difficulty.

author: floobydust
author_rank: Super Contributor
timestamp: March 29, 2024, 07:35:02 pm
content: Is this an example of decaying infrastructure or misplaced pride?That crane barge built in 1972, max. 1,000 short tons (within 63ft), Donjon's stuff is all very old but with upgrades apparently.It looks not enough to deal with the mangled steel trusses, and having to cut it up into nice little pieces will take a long time.Just phone up a professional salvage company that has real cranes and foot the bill. The port needs to be open ASAP."U.S. Army Corps of Engineers (USACE) is deploying more than 1,100 personnel to Baltimore..."It's going to be impressive, they don't mess around- but you still need good tools for the job.

author: mariush
author_rank: Super Contributor
timestamp: March 29, 2024, 07:51:39 pm
content: I was wondering how feasible would be inflate some thick things with air or something and tie the to the metal of the bridge and then cut small segments of that bridge and drag the segments to the river sides while they float.Maybe even something like filling shipping containers with ping pong balls or something and welding them shut... cheap flotation devices with mounting points at the corners to attach to the bridge.I'm thinking the surface of the bridge would be the hardest to lift out the water and remove it, I imagine they'd have to cut strips and lift it with the crane.I guess river's too deep for a boat like this to work :

author: coppercone2
author_rank: Super Contributor
timestamp: March 29, 2024, 07:56:22 pm
content: Quote from: floobydust on March 29, 2024, 07:35:02 pmthey need to make better boats because fuck the cost going on the tax payer. You can probobly make a better bridge but someone is just gonna make a bigger boat. Its way cheaper to make the boat and it effects way less people if they improve the boat rather then improving the bridge.Why should we have to build crazy bridges, when there is a over seas non American manufacturer that probably caused this problem by putting copper clad wire in a generator to keep his costs down?Like we are gonna end up eating off brand ramen to protect the right of Marsk to use alibaba inverters and crap like that. I don't think the infrastructure is failing.

author: langwadt
author_rank: Super Contributor
timestamp: March 29, 2024, 08:16:22 pm
content: Quote from: coppercone2 on March 29, 2024, 07:56:22 pmwhat a weird nonsensical rant..

author: coppercone2
author_rank: Super Contributor
timestamp: March 29, 2024, 08:22:29 pm
content: whats decaying about the infrastructure? It was a fine bridge. Probably would have passed inspection for 50 years more. It is the ship that was having problems even by its service history. A boeingesque problem?

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 29, 2024, 08:41:07 pm
content: Worse than Boeing, IMO, although (usually) less of a problem as there are no passengers.The reliability and maintenance of those cargo ships are disastrous, from what I've heard.

author: David Hess
author_rank: Super Contributor
timestamp: March 29, 2024, 08:49:38 pm
content: Quote from: coppercone2 on March 29, 2024, 08:22:29 pmThe ship has been in service for a while, so a maintenance problem is more likely than a design or manufacturing problem. It could have been contaminated fuel so we will have to wait for the investigation and report.

author: soldar
author_rank: Super Contributor
timestamp: March 29, 2024, 10:05:01 pm
content: Quote from: langwadt on March 29, 2024, 08:16:22 pmEspecially when pretty much everybody agrees America's infrastructure is in bad state of decay and in serious need of update, repair, improvement and maintenance.A search forAmerica, infrastructure, decaybrings up dozens of pages, including the White House.https://www.businessinsider.com/asce-gives-us-infrastructure-a-d-2017-3https://www.csis.org/analysis/united-states-broken-infrastructure-national-security-threathttps://www.whitehouse.gov/cea/written-materials/2021/11/15/the-time-is-now-to-modernize-u-s-infrastructure/And, in any case, the prevention of accidents, in general, is a multitude of layers, of redundancy.That bridge today would be built with a breakwater and other better measures that it had when it was built fifty years ago.Accidents happen. They happen in American built ships. They happen in American navy ships. They happen.Blaming the whole thing on a foreign built component is misplaced.

author: tom66
author_rank: Super Contributor
timestamp: March 29, 2024, 10:48:38 pm
content: Given the last disaster of similar scale in the USA was almost 50 years ago, it could be argued that a one-in-50 year event is not worth spending billions of dollars on (across all possible bridges on entry to ports in the USA).Whilst tragic that six lives were lost, it is clear that the port authority and bridge operator had reasonable mitigation for this type of disaster by being able to close the bridge to traffic quickly. The cost is mostly economic, and even if it costs $2 billion to rebuild this bridge, it would probably not be worth spending, for instance, a further $2 billion on reinforcing remaining bridges.I would like to see maritime law changed to make the insurers liable for these costs, though. It's not okay that the federal government has to pick up the tab for incompetent maintenance, or contaminated fuel.Edit: corrected amount, brain fart

author: soldar
author_rank: Super Contributor
timestamp: March 29, 2024, 11:01:26 pm
content: Quote from: tom66 on March 29, 2024, 10:48:38 pmWhere do you get the idea that the insurers are not liable?Quote

author: tom66
author_rank: Super Contributor
timestamp: March 29, 2024, 11:19:44 pm
content: Quote from: soldar on March 29, 2024, 11:01:26 pmThe post above by @floobydust suggests they might be on the hook for a maximum of the ship's value + cost of cargo transport. So probably north of $100mn, but well short of the cost of one replacement bridge.

author: floobydust
author_rank: Super Contributor
timestamp: March 29, 2024, 11:49:14 pm
content: Quote from: coppercone2 on March 29, 2024, 08:22:29 pmI meant the infrastructure to deal with modern shipping accidents - such as newer, VLCC tankers, big container ships, scuttling or on fire etc.It's all fine letting these ships in/out of ports and on your waters, but at the same time you need to invest in the equipment to deal with their calamity, and not be caught with your pants down.Coast Guard, U.S. Army Corps of Engineers (USACE) etc. doesn't have the equipment and it looks like neither do American salvage companies. We'll see how that crane barge from New Jersey does.edit: It's the largest crane in the Eastern Seaboard.edit 2: I was right, nobody makes a crane like this for general purpose unless..."The crane originally was built as the Sun 800 in 1972 to help construct the Hughes Glomar Explorer, a deep-sea vessel used by the CIA in a secret mission called "Project AZORIAN" to recover a Soviet nuclear submarine that sank in the Pacific Ocean during the Cold War {1968}, according to the Engineering News-Record."

author: soldar
author_rank: Super Contributor
timestamp: March 30, 2024, 12:18:35 am
content: Quote from: tom66 on March 29, 2024, 11:19:44 pmRegardless of the liability, I would advise not legislating in the heat of the moment and pondering things very carefully. Legislating too quick makes for bad laws.All countries, including the USA, have many ways of limiting liability because it is considered to result in a benefit to society in the big picture. Limited liability corporations, bankruptcy laws, etc. might seem unjust in specific cases but they benefit society as a whole.Governments already pay for infrastructure out of taxes because it results in economic activity and development and well being.If the government required every business to have unlimited insurance coverage then many businesses would have to shut down because it would not be affordable.I do not know but maybe if the USA required too much insurance or other requirements for ships and other forms of freight then that would result in much higher shipping costs or even in some ships or companies just refusing to go there.It may well be that the USA considers the cost of rebuilding a bridge every few years more affordable than putting very onerous requirements on ships.Legislating in the heat of the aftermath often makes bad law and has unwanted consequences.Laws have to be considered and crafted very carefully and even then they often backfire.The Jones Act requires vessels transporting freight within American ports to be American built and crewed. The ostensible purpose was to protect the American shipbuilding industry. In fact it totally backfired.https://www.cato.org/publications/policy-analysis/jones-act-burden-america-can-no-longer-bearI would advise to tread slowly and carefully and consider changes with great care.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: March 31, 2024, 04:00:16 am
content: Check out this video on how those engines work.So the smoke is not likely the ship being "slammed" into reverse. You just can't do that with these engines. You basically have to stop the engine and restart it, and that takes a long time.

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 31, 2024, 05:32:35 am
content: Some analysis:

author: guenthert
author_rank: Frequent Contributor
timestamp: March 31, 2024, 08:05:40 am
content: Quote from: soldar on March 30, 2024, 12:18:35 amThe monetary cost perhaps, but the loss of live (even if just minuscule when compared to car traffic) won't be very popular.

author: EEVblog
author_rank: Unknown
timestamp: April 01, 2024, 02:26:58 am
content: Wow, the response time of the pilot on board was incredible.30 second after losing power the first time he was calling to get the bridge closed, and it was within 2 1/2 minutes.https://twitter.com/cfishman/status/1773733488295882896

author: langwadt
author_rank: Super Contributor
timestamp: April 01, 2024, 02:31:04 am
content: Quote from: EEVblog on April 01, 2024, 02:26:58 amafiau the only reason they actually managed to close the bridge so fast was that police was already there because of the work being done on the bridge

author: SiliconWizard
author_rank: Super Contributor
timestamp: April 01, 2024, 03:16:20 am
content: Quote from: langwadt on April 01, 2024, 02:31:04 amYes.

author: soldar
author_rank: Super Contributor
timestamp: April 01, 2024, 08:20:59 am
content: This kind of accidents happen with certain regularity for one reason or another.https://www.independent.co.uk/news/world/americas/oklahoma-highway-barge-bridge-closure-baltimore-b2521319.htmlBarge hits bridge in Oklahoma just days after Baltimore tragedyState patrol troopers closed US Highway 59 about 1:25 pm after receiving word of the incident and diverted traffic from the area

author: AlfBaz
author_rank: Super Contributor
timestamp: April 02, 2024, 09:25:35 pm
content: Quote from: langwadt on March 29, 2024, 11:31:30 am*********************************************************Quote from: langwadt on March 29, 2024, 03:11:42 pmContaminated fuel causing this issue is highly unlikely. If it were, the ship would of stayed blacked out. The fact that power was reenergised in short times indicates an electrical faultMain engines are always stopped in port, ALWAYSMain Engines are designed to run on heavy fuel oil (HFO) you can't change fuel on the fly and the cost of running a vessel on anything approaching diesel would be prohibitively expensive and need a completely different engine.Then there' the matter of being able to carry the volume of any fuel other than HFO to be able to make the voyage.The fuel oil tanks are at capacity when setting off.If it were feasible to change the fuel type you would need the ship to drop anchor and change out major engine components.Simply throwing a valve from one fuel to another is not what would happen you would have to clean out the cylinder liners and the scum deposits internally would require waiting for the main engine to cool down, remove heads and possibly liners and pistons and having people climb into the scrubbers to clean them out.You have to remember that fuel ignition is caused by compressing the fuel air mixture, causing it to heat up and the fire. There is no "spark plug" that determines when it fires.The firing point is determined by the stroke of the piston and bore diameter.Not to mention the different operating temperatures caused by using different types of fuels. This alone would require fundamental mechanical engineering properties of the engine to change as heat exchangers would need to be different based the different heat generated from different fuelsAs for who's fault this is, I would be looking at the port authority who allowed a vessel to navigate past what is an intrinsically flimsy bridge to move through this area without tug boats. Sure bow thrusters are installed to mitigate tug cost but it is electrical equipment which is prone to fail without notice and to not have a backup for this the outcome could be predicted by anyone who has the slightest idea of what hazard analysis is.Given the power generation is at the back of the ship and bow thrusters are at the front of it and the typical length of a ship is 300-400m, voltage drop on startup is huge.I have seen some vessels employ large transformers to increase the generated 415 3 phase voltage to 3.3kV to reduce the cable size feeding the bow thruster motors but I am not entirely sure this is standard practice.Haven't seen any concrete evidence this vessel even has a bow thruster. If it doesn't then certainly a port authority issue for not using tug boats to manoeuvrer the ship out of the harbour.Lets also not forget that when pilots are on board they're captaining the ship so the responsibility is on them not the master

author: langwadt
author_rank: Super Contributor
timestamp: April 02, 2024, 11:33:44 pm
content: Quote from: AlfBaz on April 02, 2024, 09:25:35 pmthey a change over to the cleaner fuel (Marine Diesel Oil) in coastal areas, changing from hot HFO to cold MDO it takes a while and of course has to be timed to use as little MDO as possible

author: ZigmundRat
author_rank: Regular Contributor
timestamp: April 03, 2024, 12:39:01 am
content: Some further side scan sonar imagery gives an idea of what the underwater cleanup crews are facing. Looks a mess.https://www.msn.com/en-us/news/us/new-underwater-images-at-site-of-baltimore-s-deadly-bridge-collapse-first-vessel-uses-temp-channel/vi-BB1kWX63

author: floobydust
author_rank: Super Contributor
timestamp: April 03, 2024, 10:08:00 pm
content: I wonder if the ship's engines work or were they damaged when the smoke was going on? It's a huge engine 3 stories 82 RPM typ.They plan to unload that ship. "Coast Guard Rear Adm. Shannon Gilreath said... planning to remove undamaged containers off the ship but has been held up by weather..."edit: oh, the ship is grounded, water too shallow where it sits.

author: soldar
author_rank: Super Contributor
timestamp: April 04, 2024, 08:53:43 am
content: Well, the shiphasto be grounded because it left the dredged channel and so unloading the containers helps with getting the ship afloat again .. and with getting the containers on their way.

author: RJSV
author_rank: Super Contributor
timestamp: April 04, 2024, 06:35:27 pm
content: I've heard cost figures, in the past (...>> 20 years ago) that one container generally has goods valued at some 1 million dollar, of course in rough terms.Some percentage, in the case here, are going to be expensive logistical crises, especially when causing long wait times. Consider a manufacturing line, that has to wait for container of 4 dollar parts, like a door handle for automotive factory line.Do you wait, some weeks or months, to finally receive shipment, or, as purchasing agent, just contract out a duplicate order? One alternative leaves (you) with an Xtra 'million' dollars worth of extra stock.i

author: guenthert
author_rank: Frequent Contributor
timestamp: April 05, 2024, 08:55:29 am
content: Quote from: RJSV on April 04, 2024, 06:35:27 pmI'm sure the value varies wildly. Given that end customers pay just in the order of $2k for a container to be shipped across the Atlantic, you can expect the value to be a multiple of that. If you're lucky, you fetch the container some multi-millionaire shipped his art collection with or the one used to smuggle cocaine, but you're more likely to fetch the one full of cheap Chinese made cloth hangers.

author: Ice-Tea
author_rank: Super Contributor
timestamp: April 05, 2024, 09:37:49 am
content: Quote from: AlfBaz on April 02, 2024, 09:25:35 pmI'm not entirely sure I completely understand what you're arguing here, but you can't run HFO in pretty much any port or coastal zone. A changeover to DO is always performed. You're right that it isn't on the fly, it does take some time, but the procedure is pretty standard. In addition, you don't want HFO in the tubes, pumps and injectors when you shut her down. There's tracing steam on pretty much all lines but starting up the engine with HFO is always a PITA regardless.QuoteEh, no. You heat up and compress the air (without fuel) and then inject fuel in the hot air. These are diesel engines, not petrol.QuoteNot at all. The heaters have a regulation loop based on the measured viscosity of the fuel. As a result, HFO will be heated to 120°C or so and DO to 30°C by the same machinery.QuoteComes down to cost, obviously, but even then it is somewhay debatable if tugs would have been able to do much.QuoteAside from every bit of documentation out there and, well, common sense?

author: Kleinstein
author_rank: Super Contributor
timestamp: April 05, 2024, 09:58:33 am
content: A fuel problem is well possible to cause the engine to fail / stall. It could be as simple as an air bulble or a clogged filter that has a switch over to an alternate filter to allow cleaning on the fly.The smoke plume is likely from restarting the engine. From the analysis (the speed of the ship did drop from that point on) this was with reverse direction, trying to slow down the vessel. This may have been the final large mistake, as this also caused the ship to turn and really get the wrong direction. With just the engine stoped, chances are they could have still passed the bridge, even with lost control over the rudder.Using tugs may not be much safer: with such a large ship the tugs have limited control, once the ship has any useful speed. With tugs a broken line could as well cause a similar desaster if this happens at the wrong time and with some wind.For improved safty it would be more having better backup for steering, so that a loss of control is less likely for the large vessels.

author: m k
author_rank: Super Contributor
timestamp: April 05, 2024, 12:50:09 pm
content: Quote from: Ice-Tea on April 05, 2024, 09:37:49 amSulzer?

author: langwadt
author_rank: Super Contributor
timestamp: April 05, 2024, 01:00:22 pm
content: Quote from: m k on April 05, 2024, 12:50:09 pmMAN B&W

author: David Hess
author_rank: Super Contributor
timestamp: April 05, 2024, 06:03:14 pm
content: Quote from: Kleinstein on April 05, 2024, 09:58:33 amApparently depending on the tide, there is a significant cross-current at that point in the shipping channel, so without steerage they were doomed.QuoteTugs are basically useless for handling an emergency like this, unless they want to be part of the emergency. The bow thruster is also useless for something like this.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: April 05, 2024, 06:39:48 pm
content: Quote from: Kleinstein on April 05, 2024, 09:58:33 amWatch the engine video that has been posted. It takes about 10 minutes to reverse a marine engine.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: April 05, 2024, 06:45:22 pm
content: Quote from: AlfBaz on April 02, 2024, 09:25:35 pmAgree. With low engine speed, electrical blowers will be feeding most of the air into the engines.If the engine is directly connected to the shaft then there's no way it can stay at the dock with the engine running. I guess it could, but not a good idea.

author: DiodeDipShit
author_rank: Regular Contributor
timestamp: April 05, 2024, 07:44:15 pm
content: Bound to happen, a very slight base, no surrounding bumpers .....

author: soldar
author_rank: Super Contributor
timestamp: May 08, 2024, 10:24:23 am
content: How Bridge Engineers Design Against Ship Collisions

author: floobydust
author_rank: Super Contributor
timestamp: May 09, 2024, 12:09:16 am
content: The demolition plan is to free up the cargo ship using explosives, to get the big bridge span piece off the top of the ship. The ship's crew gets to stay on board.Regarding the Dali engine exhaust smoke, I did find this. It was a valid engine room command back in the day of steamboats in the Civil War.Some of my projects could use one of these lol. Stop Making Smoke!

author: floobydust
author_rank: Super Contributor
timestamp: May 14, 2024, 11:08:35 pm
content: NTSB Marine InvestigationPreliminary ReportMay 14, 2024 is out, with good info on what happened (but not the cause).I thought it strange the LV transformer TR1 primary and secondary breakers tripped at the same time. Redundant system but was brought up a bit uh odd and too late.

author: SiliconWizard
author_rank: Super Contributor
timestamp: May 14, 2024, 11:21:54 pm
content: Interesting read.

author: tom66
author_rank: Super Contributor
timestamp: May 14, 2024, 11:24:50 pm
content: "The road maintenance inspector had been walking the length of the bridgewhen the ship struck it. He ran north and made it to the nearest surviving span beforethe rest of the bridge collapsed."Hell of a story. I'd buy a lottery ticket if I were him.

author: NiHaoMike
author_rank: Super Contributor
timestamp: May 15, 2024, 04:06:21 am
content: I find it hard to believe it would be designed such that a single transformer would be a single point of failure for all 3 steering pumps. Had one of the steering pumps been mechanically driven from the propeller shaft (including turning at a reduced rate from the momentum of the ship after the engine shut down), might it have side scraped the bridge or missed it altogether instead of a head on collision?

author: SiliconWizard
author_rank: Super Contributor
timestamp: May 15, 2024, 05:38:38 am
content: The trajectory was very unfortunate. They headed up straight to the pier and avoided (by not much) the dolphin that was supposed to be a first protection. (Not sure the dolphins for this bridge would have done much for a ship this size, but who knows, maybe that would have been enough to at least change its trajectory a bit.)

author: coppercone2
author_rank: Super Contributor
timestamp: May 15, 2024, 06:42:44 am
content: Quote from: NiHaoMike on May 15, 2024, 04:06:21 ami swear try to get that installed at a engineering job, the only things thats gonna churn mechanically is your stomach.you will get the randomly generated risk matrix with no defined units for the axis (I only figured out their actually related to cost and seniority level)

author: Ice-Tea
author_rank: Super Contributor
timestamp: May 15, 2024, 10:03:31 am
content: Quote from: NiHaoMike on May 15, 2024, 04:06:21 amThereisa second set of trafos and they actually managed to get those online. In addition, the EG powered up and remained active which seems to have allowed one of the steering gear pumps to remain active throughoput subsequent blackouts. Not mentioned in the report but it seems teh EG was a bit slow in coming online maybe.Efficiency of a rudder at low speeds is poor, though, without a propeller to "force" things a bit.

author: coppice
author_rank: Super Contributor
timestamp: May 16, 2024, 12:27:02 pm
content: Quote from: NiHaoMike on May 15, 2024, 04:06:21 amPeople aren't very good at spot the SPOF at the best of times. When there is a cost saving they suddenly get much worse. I once worked with some FEMA (Failure mode and effect analysis) people who usually worked for the nuclear power industry, and was horrified how easily they glossed over potential problems in the systems they were looking at for us. Nobody was pressuring them to dumb down their analysis. Quite the opposite. They were tasked to be as thorough as possible. It was just their modus operandi.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: May 16, 2024, 12:53:46 pm
content: I would think not only about engineering problems, but also that there are people who blow up bridges and pipes in other countries...

author: Kleinstein
author_rank: Super Contributor
timestamp: May 16, 2024, 06:10:24 pm
content: Spotting tricky accident scenarios is tricky. It is quite common to have external effects (e.g. thunderstorm, extreme temperature, high wind) to stress the system an multiple points. Suddenly multiple failures at different point get more likely than normally though.It is a bit odd design with the main motor shutting down even with a rather short interruption of the generators or just a breaker to trip, which likely can be for multiple reasons, not just overcurrent. They should have tested the effect of power interruption on stearing. It is not that there was something really unusual failing and the emergency generator was only a little late to start. To me this open the question why the design was accepted at all.

author: dietert1
author_rank: Super Contributor
timestamp: May 16, 2024, 07:19:25 pm
content: There are many non-redundant parts like the main engine, the rudder, the HV power bus, the LV power bus. Also the rudder depends on the main engine and everything depends on the electrical power buses. Seems the HVR and LVR switches that pretend redundancy were useless.The report explains that the bow thruster is connected to the HV bus, but don't mention it later. Did DGR3 and DGR4 trip when the thruster was turned on?Regards, Dieter

author: Kleinstein
author_rank: Super Contributor
timestamp: May 16, 2024, 10:36:31 pm
content: AFAIK the bow thrusters are only effective at very low speed, like when departing from the dock. At the relatively high speed the thrusters should not be really effective. So chances are the thrusters were never started in the accident.At least the plan shows a way to split the HV and LV bus in a left and right part to use. So they should be able to use only half the buses, but than with a fixed combination of genrators and transformer.For me the surprising point is that the loss of the main engine caused the vessel to turn so fast that they could not counteract with the rudder driven by the emergency generator. The electrical outage was the trigger, but it looks there was more wrong than just the electric.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: May 16, 2024, 11:20:37 pm
content: Such massive vessel could not independently change its trajectory. Even if it is allowed to drift, it will continue to move on the same course. Keep moving in a straight line.In order for the course to change, it is necessary to apply force. It's just ordinary physics.The conclusion suggests itself: technical malfunctions do not matter, since there was an incorrect select for the trajectory of movement.At least in the adjacent section of the fairway.

author: Andy Chee
author_rank: Super Contributor
timestamp: May 17, 2024, 01:58:55 am
content: Quote from: S. Petrukhin on May 16, 2024, 11:20:37 pmWater currents are often NOT straight.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: May 17, 2024, 04:15:57 am
content: Quote from: Andy Chee on May 17, 2024, 01:58:55 amYeah. There are two rivers involved in this.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: May 17, 2024, 04:31:07 am
content: Quote from: Andy Chee on May 17, 2024, 01:58:55 amA significant remark... I thought there a bay and no tangible currents.

author: dietert1
author_rank: Super Contributor
timestamp: May 17, 2024, 06:13:20 am
content: Quote from: Kleinstein on May 16, 2024, 10:36:31 pmYes exactly: They were in a harbour and slow. When space is limited, a tail rudder is of little use anyway. Before changing course by turning the ship around its vertical axis the rudder drags the ship exactly to the wrong side. I was wondering whether a 7 kW bow thruster running for some minutes could have avoided the collision or modified the impact enough to save the bridge.Regards, Dieter

author: Ice-Tea
author_rank: Super Contributor
timestamp: May 17, 2024, 06:39:10 am
content: Quote from: Kleinstein on May 16, 2024, 06:10:24 pmIt's impossible to countereveryeventuallity. If you have a blackout on a ship like this when manouvring its pretty much a given you're goig to havesomeegg on your face. Adding more layers of redunancy may even be counter-productive (more shit that can break). There's even an argument to be made that thatalreadyplayed a role here. Seems they switched to the other set of trafos the day before which then failed. If they had only had the single set of trafos they had been using before, this would not have happened.Quote from: Kleinstein on May 16, 2024, 10:36:31 pmIn addition, they run on electricity. Lots of it. Like, lots. Not something you're going to run in a blackout (obviously) or when just recovering from it.Quote from: dietert1 on May 17, 2024, 06:13:20 amYou're off by an order of magnitude. They had a 3MW bow truster.

author: dietert1
author_rank: Super Contributor
timestamp: May 17, 2024, 06:54:58 am
content: Even better. They could have tried, i mean they had nothing else. Probably at time they were half asleep and thought they can do nothing.

author: Ice-Tea
author_rank: Super Contributor
timestamp: May 17, 2024, 07:03:28 am
content: Not really. Again, the bow truster needs electricity. Which they had not.

author: dietert1
author_rank: Super Contributor
timestamp: May 17, 2024, 07:41:55 am
content: If you read the report, that's just not true. The diesels on the HV bus were running and the LV bus was operative, too, except a short period. At the time of the crash the ship had illumination.

author: Kleinstein
author_rank: Super Contributor
timestamp: May 17, 2024, 07:51:37 am
content: The balckout was from the brakers at the transformer tripping. From the reports the genrators were still running OK and thus the high voltage supply electricity from which the bow thruster would run still active. The problem with the bow thrusters is more that they are for really low speed, like < 1 knot and they loose effect when going much faster. When they lost power the ship was running at some 8 knots and thus not that slow any-more.Similar the tug boats would have to litte power to make a real difference at that speed. The habor tugs are made for low speed. So keeping the tugs would also require the ships to go slower.Quote from: S. Petrukhin on May 16, 2024, 11:20:37 pmThe propeller from the main propulsion not only provides the main propulsen, but as an unwanted side effect also a sideways force. When going straight under power the rudder (or a asymmetric hull shape ) has to compensate for this. When the motor (und thus the propeller) stopps, chances are that the propeller slows down the ship a little and produces an opposite side force too.So the main engine stop not just slows down the ship, but also makes the ship turn. To keep the ship straight after the power loss they need a correction by the rudder.My point is that this is not a surprising effect and the emergency generator should get steering back fast and powerfull enough to not get such a large excursion from the normal course.In addition there was also some (though not very strong) wind pushing the vessel to the side it finally went. The the propulsion is lost the rudder gets less effective and thus additional correction needed.Even in just a "bay" there can be quite some tidal currents. With the shipping channel and relatively shallow otherwise I would not expect the currents to be much sideway though. At least the pilots should have known (such local knowledge is the main reason for habor pilots) and we would have heard about this.

author: soldar
author_rank: Super Contributor
timestamp: May 17, 2024, 08:45:35 am
content: Quote from: dietert1 on May 17, 2024, 06:54:58 amI take this as a throwaway comment without intention of substance but all indications are that the crew, including the pilot, acted very well, very professionally. Nobody was "half asleep". They acted fast and correctly.https://www.washingtonpost.com/dc-md-va/2024/03/26/pilot-anchor-turn-baltimore-bridge-collapse/Pilot on board the Dali tried to slow ship before it struck Key BridgeThe specially trained pilot ordered the rudder turned hard to the left and an anchor drop to steady the ship and slow it down, an industry official said

author: Ice-Tea
author_rank: Super Contributor
timestamp: May 17, 2024, 08:48:37 am
content: Quote from: Kleinstein on May 17, 2024, 07:51:37 amYes, but there was no means to activate the truster as the LV bus was down (and thus navigation). When the EG kicked in there was a small window where theycouldhave used the bow truster but following a blackout of (at that time) unknow origin you don't exactly wan't to dump a 3MW load on the HV bus (aside from it being, as you mentioned, probably being of little use at higher speeds). At the very minimum the bridge would have had to contact the ER and those fellows were kinda busy. It would also have been a shortlived triumph as shortly after that a second blackout occured, this time tanking the DGs and thus the HV bus (which is kinda weird, there doesn't seem to be an actual reason for them to go down).TBH, it looks like pretty much everyone did what they could do with the time and lack of hindsight offered to them.

author: soldar
author_rank: Super Contributor
timestamp: May 17, 2024, 08:55:29 am
content: Quote from: S. Petrukhin on May 16, 2024, 11:20:37 pmYou have no idea about the complexity of this. In the Bay there are river and tidal currents. A vessel is subject to a multitude of forces. The rudder, the prop, the proximity to the bottom and the irregular shape of the bottom, the currents, the wind, etc. You have no idea how complex it is.

author: dietert1
author_rank: Super Contributor
timestamp: May 17, 2024, 05:40:17 pm
content: I found this info on thrusters:https://www.marineinsight.com/tech/bow-thrusters-construction-and-working/They say:"Bow thrusters are generally used to maneuver the ship near coastal waters and channels or when entering or leaving a port during bad currents or adverse winds.Bow thrusters help tugboats berth the ship to avoid unnecessary time and, eventually, money wastage because the vessel stayed less in the ports. The presence of bow thrusters on a vessel eradicates the need for two tugs while leaving and entering the port, thus saving more money."So i don't understand what is meant by a bow thruster being ineffective. Where does this idea come from?I estimated a bow side-shift of about 27 m after running a 4 MW thruster for 180 seconds.It's a fact that the hazard occurred after midnight when everybody needs a rest.The question i asked will be asked anyway. There will be enormous legal fights about this. They caused a tremendous hazard and killed six people.Regards, Dieter

author: soldar
author_rank: Super Contributor
timestamp: May 17, 2024, 11:59:43 pm
content: You are out of your depth here.

author: Andy Chee
author_rank: Super Contributor
timestamp: May 18, 2024, 12:48:15 am
content: A bit of trivia:Looks like Google Streetview has stopped "travel" over the Francis Scott, despite being intact in cyberspace!https://maps.app.goo.gl/EQ9Q9w5jR4qMU5KS7

author: Andy Chee
author_rank: Super Contributor
timestamp: May 18, 2024, 01:05:55 am
content: Quote from: dietert1 on May 17, 2024, 05:40:17 pmNo power.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: May 18, 2024, 04:43:55 am
content: Quote from: Kleinstein on May 16, 2024, 06:10:24 pmThe engine will stall if the blowers are not running. The engine cannot breathe on it's own at low power.

author: ArdWar
author_rank: Frequent Contributor
timestamp: May 18, 2024, 06:59:56 am
content: Two stroke diesel can't breathe on its own at all. If its scavenge air blowers stop the engine stops, period. The blowers are integral part of the engine operation cycle, unlike 4 stroke engine.However at most operating range other than very low load (<25%) its exhaust should be enough to self sustain the turbocharger without needing auxiliary powered blower.

author: dietert1
author_rank: Super Contributor
timestamp: May 18, 2024, 07:20:19 am
content: Quote from: Andy Chee on May 18, 2024, 01:05:55 amRead preliminary report. From first electrical problem to crash were about 5 minutes with two outages of about 1 minute each. That's why i assumed 3 minutes = 180 seconds.

author: Ice-Tea
author_rank: Super Contributor
timestamp: May 18, 2024, 09:28:23 am
content: Quote from: dietert1 on May 18, 2024, 07:20:19 am* You don't use a bow truster at that speed. Good chance the controls are labelled to avoid some clown to try that anyways.* You don't launch a 3MW load on an electrical net that is already troubled. In other words: the occurance of the second blackout was unexpected and unlikely but you would increase the chances of it occuring by an order of magnitude by launching the bow truster.* After the second blackout, power was restored but only DG2 was running. Launching the bow truster at that time would have caused aguaranteedfresh blackout.There are very few things you can do on board such a ship that would cause a blackout undernormalconditions. Running the bow truster with an unprepared ER is one of them.

author: soldar
author_rank: Super Contributor
timestamp: May 18, 2024, 10:07:49 am
content: Quote from: Ice-Tea on May 18, 2024, 09:28:23 amFurthermore, from the plan shown in the preliminary report, it seems the Dali started veering to starboard only after the second power failure.The report says:QuoteThe discrepancy between the ship's heading and COG, Course Over Ground, indicates the effects of currents and winds which are very changing in that area.We will have to wait to find out why the electric power failures but it seems to me the crew were first class and acted decisively, promptly and professionally.Anyone who thinks they know how to do better just does not understand the magnitude and complexity of the problem.It seems the ship had been running on trafo #2 for months without problem and due to a mistake made by a crew member while in port they decided to run on trafo #1. It could be unrelated but there is a good chance this is the root of the problem and what triggered the whole incident. It will be interesting to see what comes out later.

author: dietert1
author_rank: Super Contributor
timestamp: May 18, 2024, 10:47:25 am
content: They write the circuit breakers of the two generators 3 and 4 tripped when the second blackout happened. They don't say the generators stopped. I understood they had three HV generators and the LV emergency generator running. If necessary they could have used the fourth generator, too.About not using a bow thruster at slow speed: We should not substitute reasoning by calling other people names.Regards, Dieter

author: Ice-Tea
author_rank: Super Contributor
timestamp: May 18, 2024, 11:36:16 am
content: The clown remark was aimed at a hypothetical deck officer that would need a reminder not to use the bow truster above a few kn, not you.Once again, you don't launch the bow prop if the ER is unprepared or, worse, recovering from a blackout. That is how youcreateaccidents, not how you avoid them.Note also that the NTSB report doesn't even mention the availability of the bow truster. It would seem that for them, it's not even a topic as there is no expectation or desire to have that as an option.When the breakers for DG3 and DG4 tripped there was areasonfor that. They may have been overloaded (in which case adding a huge additional load on the bus is kinda bad) or the DGs themselves may have experienced propblems causing speed and thus bus frequency to drop (which would make them too unreliable to put back on the bus).And no, they could not have quickly started DG1. That one was not in standby.And even if by some miracle there was a minor window in time where they could have reliably used a magic truster that works at higher speeds, then this would have been known in the ECR, not on the bridge.

author: NiHaoMike
author_rank: Super Contributor
timestamp: May 18, 2024, 02:30:05 pm
content: What other large loads are there on the HV bus besides the bow thruster? Seems like it would have made more sense to have the bow thruster be hydraulic and use HVDC for the electrical system.

author: Ice-Tea
author_rank: Super Contributor
timestamp: May 18, 2024, 03:25:48 pm
content: Probly only power distribution to reefers.

author: coppercone2
author_rank: Super Contributor
timestamp: May 19, 2024, 06:00:39 am
content: I mean can't a black out be caused by anything like sticky breakers and some short that burned itself out? if that is the case then so long it mostly cleared itself you can try to run the thing full power right away. there is a chance the trouble is at that point completely isolated (vaporized wire somewhere)there is always a chance like a small breaker will fail, the load will be vaporized, the big breaker will trip. but after that its irrelevant like nothing was ever there.... the problem is isolated and you can run the circuit at its 100% capacity or even more since that load is gonei mean its a shady condition and you wanna get that checked out right away but if your gonna crash you might as well try

author: mendip_discovery
author_rank: Super Contributor
timestamp: May 19, 2024, 06:55:16 am
content: From the chats I have had with a friend who spent most his life fixing big boats. He would always complain about the lack of spending, if there was a problem they would work around it until it was a big problem or they could dock somewhere where the labour was cheap enough, a bit like not going to the main dealer for a service but using a local independent.I did lol at a bbc news article the other day that had the headline Boat Crew still Stuck on board. They were planning a long trip anyway but I think it was a slow news day and a reporter needed to up their word count.

author: Ice-Tea
author_rank: Super Contributor
timestamp: May 19, 2024, 07:01:18 am
content: Quote from: coppercone2 on May 19, 2024, 06:00:39 am* There probably wasn't enough power after the first blackout* There was no reason to even try after the first (heading)* There surely wasn't enough power after the second blackout* Restoring propulsion would have been orders of magnitude more effective, so why waste time and effort on that.

author: AVGresponding
author_rank: Super Contributor
timestamp: May 19, 2024, 07:04:16 am
content: Quote from: NiHaoMike on May 18, 2024, 02:30:05 pmAnd how would you power the hydraulic pump that drives your hypothetical hydraulic bow thruster?

author: NiHaoMike
author_rank: Super Contributor
timestamp: May 19, 2024, 09:28:00 pm
content: Quote from: AVGresponding on May 19, 2024, 07:04:16 amMechanically from the auxiliary engines.

author: ArdWar
author_rank: Frequent Contributor
timestamp: May 20, 2024, 12:33:56 am
content: Mechanically driven "Z-drive" bow thrusters are pretty common. Its just that it's uncommon for this kind and size of vessel since it requires placing a diesel engine at a remote location, which also requires engineer to attend during operation. Hardly any safer, and importantly more $$$ to operate.Hydraulic driven bow thruster (actual hydrostatic drive, with pump-motor pair) also exist(ed). It just that it's probably not exactly what you want since the hydraulic line is only used to bridge the small gap between thruster hub and ship hull. You still need a diesel engine or electric motor close by to run the pump which doesn't exactly simplify things from how it is currently done.

author: Ice-Tea
author_rank: Super Contributor
timestamp: May 20, 2024, 12:37:23 pm
content: Chief Makoi on the NTSB report:

author: NiHaoMike
author_rank: Super Contributor
timestamp: June 30, 2024, 12:09:54 am
content: If that does indeed turn out to be the cause, that would be the most costly connector failure in history.

author: coppercone2
author_rank: Super Contributor
timestamp: June 30, 2024, 12:24:56 am
content: Ah the highly regarded wago style connector.People really hold them in high regard

author: floobydust
author_rank: Super Contributor
timestamp: June 30, 2024, 01:23:25 am
content: I've spec'd and used the Wago spring clamp terminal blocks to 40A (PCB) and they are excellent. They are typically used with wire ferrules. Used on locomotives because temp cycles and vibration cause screw-type terminal blocks to loosen with age. Unpopular in North America though, compared to Europe.If a bonehead twists the screwdriver (instead of just pushing it in) to open the clamp, or uses the wrong size screwdriver, or pry's, it can wreck the terminal block inside by deforming the spring.I would suspect that is what happened, improper assembly.When panels are being built, we have a "tug'n tighten" requirement that you tug on all wires after assembly. I've had a few electricians with weak hands leave screw-terminal wiring really loose (just like idiot crimp-connecting) and the wire pulls out.If I find a few loose connections, I flip out and demand everything gets re-tightened or re-crimped.Out in the field, I have encountered control panels full of loose wires and spent 1/2 hour redoing all, which gets rid of many problems.Other brands of spring clamp I've tried are crap. Hear that Weidmuller lol.

author: coppercone2
author_rank: Super Contributor
timestamp: June 30, 2024, 02:31:36 am
content: some people on the forum were saying that it turns out the dumb american wire nut has a kind of welding action going on akin to wire wrapping which improves its reliability compared to wago connectors if used properly. The ones with the metal spiral insideTwo wires being pushed into each other by a spring that digs into them and also compresses them actually seems pretty advanced to me, if you think about it. There is no piece of sheet metal in the circuit, like wago.Unlike crimps, you have very high point pressure (great contact) in a structure thats not been yielded. It is in the spring region the whole time and it does not desperately want to relax. A crimp exceedes the yield pressure of the metal to form. A wago is also in the spring region but it does not have that sharp edge (possible cold weld) wrapped around the wire...

author: SiliconWizard
author_rank: Super Contributor
timestamp: June 30, 2024, 03:03:26 am
content: At this point anyway, the most likely culprit looks like a maintenance issue (maintenance badly executed). Which is quite often the culprit in aviation accidents as well.

author: floobydust
author_rank: Super Contributor
timestamp: June 30, 2024, 04:10:46 am
content: It's weird the ship is 9 years old and a DIN-rail terminal block fails now?Switchboards made by Hyundai but using Wago?Even if this is root-cause, the power system is redundant and switching to the backup appears to have been also bungled.

author: nctnico
author_rank: Super Contributor
timestamp: June 30, 2024, 09:48:25 am
content: Quote from: floobydust on June 30, 2024, 01:23:25 amIf you read carefully, you'll read that the NTSB removed a terminalsimilarto Wago. They don't specify which brand it actually is.

author: nctnico
author_rank: Super Contributor
timestamp: June 30, 2024, 09:54:02 am
content: Quote from: coppercone2 on June 30, 2024, 02:31:36 amNot welding. But like wire-wrapping, you do get a very large, gas-tight contact surface when using a wire nut which has a coil made from rectangular wire. But you'll need to buy/use high quality wire nuts. Not the fake crap you find at home improvement stores.Then again, wire nuts are not practical for wiring up control / distribution panels.

author: AVGresponding
author_rank: Super Contributor
timestamp: June 30, 2024, 10:50:31 am
content: Quote from: nctnico on June 30, 2024, 09:54:02 amYou also need to be skilled in their use, which introduces the human fail factor at a low bar; harder to muck up a spring connectorQuote from: floobydust on June 30, 2024, 01:23:25 amHence the mandating of torque screwdrivers in electrical installation in the UK (yeah, very few sparks use them, I'm usually the only one on site)

author: David Hess
author_rank: Super Contributor
timestamp: June 30, 2024, 02:23:51 pm
content: Older industrial equipment which must operate in a difficult environment with vibration often used barrier strips with wires terminated with spade or ring terminals. I am not sure how they prevent the screws from backing out, but it seems to rarely happen and they should be checked periodically.

author: floobydust
author_rank: Super Contributor
timestamp: June 30, 2024, 03:27:47 pm
content: Quote from: nctnico on June 30, 2024, 09:48:25 amI did read theNTSB updatea few times.Photo caption:"Exemplar terminal block identical to model removed from ship. (Source: WAGO)"

author: tom66
author_rank: Super Contributor
timestamp: June 30, 2024, 03:36:05 pm
content: Is this possibly the most consequential failure of a single conductor ever?One conductor causes the death of six roadworkers and the destruction of a bridge which will cost the best part of $2bn to rebuild, in addition to the economic loss to the region.Makes you think how many other ticking timebombs there are like this in systems - just waiting for the Swiss cheese to line up.It's got to be up there with something like Swissair 111 where it's thought that a faulty connection in the in-flight entertainment system led to a rapidly spreading fire which eventually disabled flight controls and caused the plane to nosedive, killing all 229 passengers on board.

author: floobydust
author_rank: Super Contributor
timestamp: June 30, 2024, 05:12:11 pm
content: Major disasters I find are caused by at least two or more faults.Swissair 111 second failure was the plastic air ducts did sorta meet the vertical flame tests but not in reality. I saw it, it was super creepy - glowing orange hot plastic, sitting there and after 10 seconds foof it would self-ignite and start burning. Aftermath I thought they updated the test standard to include a 30 second wait for self-ignition to not happen or something. I also recall the ducts already being replaced in aircraft because of this, before the place crach - it was already a known safety problem.Quote from: David Hess on June 30, 2024, 02:23:51 pmOn screw terminals, sometimes initial torque is low. All day long you turn a screwdriver as your job, and after a while you get tired, carpal tunnel etc. and things are not tightened much.It's the potpourri of metals involved. Steel, copper, aluminum and then their plating - nickel, zinc, chromium etc. DIN-rail terminal blocks are made to a price point and some are very cheap. In a marine environment I have no experience what works well in the humidity and salt. There are no lock-washers in these terminal blocks.With time, I have seen many connection screws go loose, then they heat up and things melt. That's why the spring-cage has an advantage.Considering this is multi-billion $ incident, I could see everyone getting sued, terminal block manufacturer as well.

author: tom66
author_rank: Super Contributor
timestamp: June 30, 2024, 05:58:03 pm
content: I do foresee Wago (or realistically their insurers) picking up some of the bill here. And then every datasheet will come with a one-page sheet detailing how they accept no liability in the future unless the connector is regularly tested, which no one will realistically do. All the lawyers will laugh on their way back to the bank and nothing actually gets better.Remember how Securitas, the company that provided the security guard being paid $15 an hour at the Miami apartment block, settled for over $500mn because they were deemed partially negligent for the incident and resulting deaths. Their security guard was supposed to be able to recognise the signs of a building collapse and take appropriate action. Yeah, in the 10 or so minutes from the first signs of danger to the building collapsing, I think most here would fail to appreciate the severity unless they held a structural engineering degree. The actual company that deficiently built the apartment block is long gone so you can't sue them. Doesn't seem reasonable but that's how these things go.

author: nctnico
author_rank: Super Contributor
timestamp: June 30, 2024, 09:55:50 pm
content: Quote from: floobydust on June 30, 2024, 03:27:47 pmBut that doesn't say it is the same manufacturer. Products from Wago (and Phoenix) are widely cloned so an 'identical model' says nothing about the actual manufacturer. If the NTSB had determined the terminal block they removed from the ship is made by Wago, they had written that the terminal block they removed from the ship was made by Wago. But that is not what they wrote at all. Notice the word 'Exemplar'.

author: Someone
author_rank: Super Contributor
timestamp: June 30, 2024, 10:36:34 pm
content: Quote from: tom66 on June 30, 2024, 05:58:03 pmMost volume product data sheets already have something along the lines of that: "not authorized for use in safety-critical applications" etc

author: johansen
author_rank: Super Contributor
timestamp: July 02, 2024, 01:21:11 am
content: Quote from: David Hess on June 30, 2024, 02:23:51 pmI don't see the screws fail when torqued correctly, except on the aluminum lugs on modern electrical panels and aluminum wire. those burn up all the time (and as a friend says, i don't use a torque wrench and i don't know any electricians who do)stranded wire crimped into anything, can slowly corrode in a manner in which every single strand becomes insulated from each other, and over time the wire becomes higher and higher resistance.i've found these types of failures across a wide variety of equipment:several almost open circuit ring terminals in a 1983 era 50kw generator with all of 300-400 hours of run time on it. the battery cable which is probably 19 groups of ~12 gauge stranded wire, also failed when only 1 group of those 19 strands carried all the current and melted 8 inches of the outer jacket, which had it been bundled with other wires, easily could have resulted in a fire if it had shorted out against something.the factory oem battery cable crimp on my 1996 toyota. i heated it with plumbers tinning flux and wicked solder into the crimp. it was a very nice looking brass or bronze terminal with a factory, very tight crimp, nearly 1 inch long, on a 1 gauge ish wire. after fixing it, engine turned over a little faster and the ring terminal did not get HOT during cranking.trusting a spring clip on a stranded wire is insane in my opinion.trusting a solid wire with a spring clip on a ship subject to heavy vibration, is as retarded as trusting backstabbed american outlets..

author: David Hess
author_rank: Super Contributor
timestamp: July 02, 2024, 01:40:55 am
content: Quote from: johansen on July 02, 2024, 01:21:11 amIf that happens, then it was not properly crimped. Crimping pressure is suppose to weld the wires to the inside of the terminal, and with a gas tight weld, corrosion cannot get between the surfaces. I tend to solder after crimping although wicking creates other problems.QuoteI had to splice and extend my battery harness after the side terminals on the original starter battery corroded. There was not much room, so I used bus bar wire to wrap the stranded cables together for about an inch of overlap and then soldered them. I replaced the side terminals with bronze/brass top marine terminals. I should solder the stranded battery cables where the terminals clamp, but have not done that yet.QuoteYea, I am amazed the American style spring clips do not cause more fires. I tend to use the screw terminals.

author: johansen
author_rank: Super Contributor
timestamp: July 02, 2024, 02:05:42 am
content: Quote from: David Hess on July 02, 2024, 01:40:55 amhttps://www.amazon.com/Ferrule-Crimping-Tool-Kit-0-08-10mm%C2%B2/dp/B07PJK2VNT/ever seen these things in professional equipment? aint going to get a gas tight crimp with them...

author: David Hess
author_rank: Super Contributor
timestamp: July 02, 2024, 04:54:00 am
content: Quote from: johansen on July 02, 2024, 02:05:42 amLouis Rossmann did a video which mentioned defective crimp connectors from Chinese vendors on Amazon:https://youtu.be/7trdHLtsFKM?si=Wed39PLgyylyreTP

author: tooki
author_rank: Super Contributor
timestamp: July 05, 2024, 05:47:24 am
content: Quote from: johansen on July 02, 2024, 02:05:42 amWhat “these things” do you mean? No-name ferrules and a no-name crimper, or ferrules in general? Because yes, you see ferrules in professional equipment all the time. And yes, you get a gastight crimp with the correct tool.

author: coppercone2
author_rank: Super Contributor
timestamp: July 05, 2024, 10:34:06 am
content: I see people buy no name wago at work because "why is it so expensive?!?!!"if you do the test its pretty easy to find what happens. if you do the paper clip test, their stuff breaks with 1/2 of the bends. and thats just the easy one to find. its probobly built from shitty pot brass rolled into sheets and shitty plated. the battery contacts nickel for instance, 2 bends. the name brand 8$ piece of "its a ripoff" survived 4-5 back and forth bendswhen I am around engineers in a building sometimes I feel very thankful they strictly forbid anyone doing anything with the outlets or lights LOL. i can do python so i am smarter then the interconnect people's over priced stuff, it looks the same!!!some hot shot always thinks their hot shit because they THINK they figured out a way to save a dollar.if you cast it inproperly it absorbs air like seltzer water and becomes shitty copper. thats not even if you have pot copper. *mind blown*and the amount of shit I have seen go wrong with a plating bath makes me think that the prices we see right now for interconnects are VALUE prices. its so god damn touchy to get itright. You need constant vigilance with all those processes. it costs money. its not magically gonna get cheaper.Spend a few hours reading about the physics of plating and you WILL be humbled.With all the scandals right now in the airline industry and others with counterfeit parts, and the huge amount of creative fraud going on with wire (i.e. copper clad copper wire, dirty electroplated copper that has 30% conductivity of the element), would you really be surprised if the technicians and builders did their job right, used the right torque, and it turns out it was like porous & contaminated metal that yielded at an unusually low pressure?? if they can get counterfeit titanium into a air liner, how easy is it to get bogus wagos or crimps into some ship ?? no one even makes a fuss about ships usually. their super low key. Its a simple device but a spring has to be exactly correct to work properly for the expected life time!!!!!

author: floobydust
author_rank: Super Contributor
timestamp: July 05, 2024, 07:10:45 pm
content: The ship's environment is high humidity and salt air, so plating would be very important. Few manufacturers test for this. You would think this rules out the cheap stuff...I had specified Phoenix ContactUK5-HESIUSD $9.56 ea. when complaints started coming in, they would jam and the handle break off. When I dug in I found manufacturing had been moved over to china and the moulds, tolerances, plastics etc. had changed. Small but noticeable differences and the end product not great nor being fixed after I complained.Now, had the made-in-Germany pricing changed? No, not at all. You offshore to china and a get minimum 10-20x savings. This is the new business model- offshore and reap profits.AliexpressPhoenix Contact Storelol pic related springs come pre-salted and oxidized!Not to blame the terminal block, but we don't know COO for the possible original Wago280-681Oops one problem with china is they copy the IP that you gave them, stupid naive Westerner.Wonke Electric Co.or similarAliexpress cheap parts,note the spring is basically shit and hidden though in the cage, tolerances pretty loose. Unknown plating and metals.Would you use these on a big job?$0.50 each compared toDigiKeyasking USD $2.81/100-lot (CAD $4.06) for the Wago 280-681 !I'm saying the temptation to save money is huge, on these terminal blocks. 100's are used in these panels. Seems odd Hyundai? used Wago in these panels.

author: coppercone2
author_rank: Super Contributor
timestamp: July 05, 2024, 08:27:07 pm
content: shit plating + vibration = flakingflaking + corrosion = failure

author: tooki
author_rank: Super Contributor
timestamp: July 05, 2024, 08:42:23 pm
content: Quote from: floobydust on July 05, 2024, 07:10:45 pmAre you absolutely certain it was moved to China? The Phoenix Contact website right now says those are manufactured in Turkey, so if you are correct about it having moved to China, then they actually moved it back!Quote from: floobydust on July 05, 2024, 07:10:45 pmYou know that's not Phoenix Contact selling there, right? If it's genuine Phoenix Contact product, it's just a reseller.Quote from: floobydust on July 05, 2024, 07:10:45 pmWago products areextremelyexpensive on Digikey. Coincidentally, I actually just placed a big order today directly from Wago. (I also ordered another couple hundred bucks or so of Phoenix Contact stuff from Digikey and Mouser today.)My employer has an extremely good discount at Wago, so we would pay under USD $0.70 each for 280-681, in a box of 100. List price here is about $1.75 per piece. Given the discounts Wago will give when ordering directly, the $0.50 for a knockoff is extremely unattractive. That tracks with the pricing for AliExpress terminal blocks in general -- they are no bargain, often costing exactly the same as original Wago, Phoenix, or Weidmüller.

author: coppercone2
author_rank: Super Contributor
timestamp: July 05, 2024, 09:19:23 pm
content: but you fail to take into account the cheap ass maintence that can be done with small amounts of counterfeit parts for massive profitif they have like stock rooms for all the parts, then sure, its probobly low incentive. if someone just buys a ship and gets a parts list ANYTHING can happen.I assume its a service you can buy from who ever, just like calling the electrician from the yellow pages.i.e. would you think a manager might not try to hire cheaper people if they feel they can get away with it. Like the light bulb guys vs the engine room guys. But sometimes they trespass on each others turf to get the job done and then you can get bad parts running for years before their even looked at by the other crewyou get the cheap guy that are still damn expenisve to do some "non critical work". It turns out there is something they gotta do where they did not think to get the job done. Then your left with either letting them try it, or getting a mad expensive service call to the right guys. Then you possibly just cost money on your gamble. Some people will just say "hey go try it". Especially if he thinks he knows what it is and he happens to have a part that might work in his truck and its friday before a vacation.I would hope ships are better then this with some more established rules, but it seems like it can happen. Especially if their doing maintence all around the world! the navy can't even get their ships maintence in order and they got the fattest government budget ever and oversight like you would not believe (fat leonard scandal)if they HAD to go to a particular port for maintence, with a certified company thats like life time involved with the ship, thats good. but you know the maintence may happen near the cape of africa with god knows who. And the ships gonna be loaded with bananas and Australian fancy ass meat, so they will have a gun to the maintence guys head to finish ahead of schedule. Their like truckers, dead line is EVERYTHING. If it was carrying minerals or some shit OK it might get done right but not if its loaded with millions of dollars of perishable goods.

author: floobydust
author_rank: Super Contributor
timestamp: July 05, 2024, 10:05:54 pm
content: Quote from: tooki on July 05, 2024, 08:42:23 pmThat was the COO paperwork where they are made, it could have moved after the pandemic lockdowns rattled manufacturers over there to leave, or the website is inaccurate.Quote from: tooki on July 05, 2024, 08:42:23 pmYes, I wasn't taking any of the cheap stuff seriously. No brand name or model number, trademark, copyright etc. is sacred unless youregister it therebefore someone else. But the visible oxide is terrible in that pic. ICK.Quote from: tooki on July 05, 2024, 08:42:23 pmI find the German terminal block companies - Phoenix Contact, Wago, Weidmüller are all the same, you go through their rep, their distributors, their dealers etc. in some antique sales ecosystem they have. I wasn't doing the high volume purchasing but it was not direct, ist es verboten- only through distributors. Maybe different in your country?Purchased through distributors in North America, the prices are similar and overinflated. Weidmüller was several k pieces a year but I don't know who/how we bought them from. There are always parasite middlemen I find adding some fat.These are dollar parts used in critical infrastructure. Price only was an issue if bidding on lump sum for the panels, most of the cost is labour.I think it more likely human factors such as bad wiring assembly or damage of the terminal block would be the Mavi issue, as a guess.Even the ferrule crimp tool, I got in shit for buying the Phoenix Contact 6-point one but the corporate standard was the 4-point ferrule crimper. Who knows why or what, and what works with the Wago's. There seem to be undocumented practices as well. Ferrule tube thickness was also a concern of mine, less copper lower price but how's the crimp?

author: johansen
author_rank: Super Contributor
timestamp: July 05, 2024, 10:13:14 pm
content: I cant comment with regard to oil tankers and container ships.But i can tell you that smaller fishing vessels.. they wont even bother fixing a 2 inch pipe pissing 100 gallons a minute of seawater into the bilge. Its not a big enough leak to spend any man hours at sea fixing, when there is money to be made.Arguing over whether or not it was a genuine wago part?The ships are run until they fail, same as cheap cars. People drive them until they break down, preventative maintenance? What's that?

author: tooki
author_rank: Super Contributor
timestamp: July 06, 2024, 08:27:56 am
content: Quote from: floobydust on July 05, 2024, 10:05:54 pmGenerally speaking, companies have been shifting away from the old model of middlemen and official distributors, towards selling directly to their customers. (Not just industrial products, it’s the same with consumer goods.)Switzerland used to be absolutely dominated by “official distributors”. Nearly every major brand had some local company as the sole importer. Over the years, more and more of the big brands they imported ended up just buying the respective distributor and turning it into the local subsidiary, or simply ending the distribution contract and establishing a new subsidiary.We certainly aren’t high volume by any stretch of the imagination, but both Wago and Phoenix are happy to sell to us, and I think they will sell to anyone (at minimum, to companies). The big difference I see between the two is that while Wago gives bigger discounts, they generally won’t split packages, so I had to buy way more terminal blocks and accessories than I actually needed, since I have to buy the boxes of 25, 50, or 100. Phoenix has a lot more products you can buy by the piece, but the discounts are more modest. So I buy in bulk directly, but small quantities I get from distributors.Quote from: floobydust on July 05, 2024, 10:05:54 pmProbably. That’s why the industry has been moving steadily to technologies that reduce human labor and error. First from screw to tool-required cage clamp, then to basic push-in, then push-in with plastic button opening, then versions with levers, and now Phoenix’s latest has the clamping mechanism pre-stressed like an armed mousetrap, so even stranded wire without a ferrule can be inserted with no tool at all. The wire hitting the base triggers the mechanism and it snaps shut.Quote from: floobydust on July 05, 2024, 10:05:54 pmFerrules are pretty standardized, at least from all the brand-name manufacturers. With that said, just to cover my ass, I did buy a Phoenix ferrule crimper and ferrules, sinceas a systemthey have UL certification. (I.e. the certification is valid only when those products are used together.) I needed the crimper anyway, so buying a few “certified” ferrules to go with it was no big deal.But if you look at the specs of the ferrules (which include dimensions), it’s all the same. They just follow the old DIN standards that originally defined these things.I certainly would not buy no-name ferrules from AliExpress, since their quality is truly unknown. FWIW, I buy mostly Vogt (extremely good prices on these from Reichelt.com, by the way), with some Phoenix and Wago. (I have one set that is Knipex branded, but I’m fairly confident that Vogt is the actual manufacturer of those.)As for the crimp shape: this is a bit of a sore spot for me, as someone who is a bit of a perfectionist and likes to have the best solution for a given situation. Clearly the existence of multiple shapes has some reason. Otherwise we wouldn’t bother having hex, square, true round, and trapezoid for small wires, and hex, trapezoid, and rectangular-ish for big ones. (And there are likely more I didn’t think of.) Yet whenever I have asked the manufacturers for guidance on when to choose which shape, they all insist it makes no difference. (If you know and are able to share, I’d love to know what the reason is that your employer had settled on the hex crimp.)My conclusion so far has been that the only reason to choose one over another is to better match the opening the crimped ferrule will eventually go into.In the end, the only reason I ordered the square crimper was because the trapezoid crimps are slightly wider than square ones, and one size of trapezoid crimp won’t fit into the small (3.5mm wide) terminal blocks, whereas the same size ferrule and wire with a square crimp will do so comfortably. My reasoning was that a square crimp will have more contact area in the fundamentally square spring clamp than a hex crimp. I’ll probably eventually add a hex ferrule crimper for screw terminals with round wire holes (which is what every single user-mounted Swiss mains plug uses inside), too.In a way I wish someone would make a “mil-spec” ferrule crimper using indent crimper technology and precision. I mean, with my AFM8 indent crimper, I can crimp a ferrule for 4mm2 onto 0.25mm2 (24AWG) wire securely! But of course it’s not fully automatic (in that you have to set the indent depth manually), and in reality you’d need to change the crimp shape, since indents alone would be terrible for this application. (Too little contact area with the strands.) But it’s just a curious exercise in tool precision.(The lack of manufacturer guidance is similar to when choosing soldering fluxes: ChipQuik has something like 2 dozen different fluxes, many of which have practically identical descriptions, so you have no way to know why you should choose one over another, among the group with similar descriptions. Same thing with MG Chemicals solder wick: multiple versions with identical descriptions. I actually wrote ChipQuik, but of course got no reply at all.)