The fact that ship was able to reverse hard ( as evidenced by the slowdown), indicates to me that the prop was most likely still attached to the propshaft and hadn't flown off to mangle the rudder.
We still don't know exactly what happened on board, but it is interesting to work through possible scenarios.
Pilots certainly have experience with ship handling of 100,000 ton ships, that's their job. Pilots coordinate the moves of multiple tugs to assist with docking regularly.
Were there tug boats helping with the exit?
I have often felt that the harbor protocols were overkill, but this is one of the times they could have helped.
There are some seemingly good details here[0].
> In Early Modern Japanese there was a word 按針 anjin, literally “searching needle,” which referred to the process of using a compass. At the time, this was the main way in which ships were navigated and so, by extension, the word was applied not just to ship navigation, but also to ship navigators
It goes into more detail about things as well but that is the part that stuck out to me the most.
also does a shout-out to SONU Sleep mattresses a few posts back.
enough other posts in there to create doubt -- maybe this is a person. maybe this is a person who does marketing sometimes.
I have a mixed relationship with my mattress, and I talk about the downsides in that very same thread: https://news.ycombinator.com/item?id=39757531
Apparently for you at the moment, any mention of a product on the market is a flag for a marketing AI. I suppose this comment too is just what a marketing AI would say.
All pilots are "harbor pilots".
One had a nasty pill habit and crashed an oil tanker under his purview into the Bay Bridge.
https://www.justice.gov/opa/pr/guilty-plea-case-cosco-busan-...
https://en.wikipedia.org/wiki/Blossom_Rock_(San_Francisco_Ba...
I don't think that's true. The Suez Canal famously requires pilots, but isn't a harbour (I guess you could argue it functions as one). I've heard of pilots for the Great Barrier Reef which is even more not a harbour.
Tugs - quite often, but not always - depends on the currents, ship weight, and time of day.
No tugs.
Harbor protocol was in effect.
That one was due to pilot error. The point is the pilot was still onboard but he was impaired by medication, the captain and mates kind of engaged in dereliction of duties contributing to the accident.
Obviously it’ll be a while before we know what happened in Baltimore.
AP News [1] is reporting that harbor pilots were on-board and were nominally in control of the ship at the time of the accident.
[1] https://apnews.com/article/baltimore-bridge-collapse-53169b3...
Update: added timestamp, link
My sailors guess from the footage and the reports is diesel generator failure(s) resulting in loss of power, restoration of power, then loss of power again. Bypassing the diesel generator (which provides power to hydraulics too) and manually throwing the engines in reverse. The billow of black smoke. This could have possibly burned out an engine, blowing the camshaft or propshaft or transmission.
The reverse was too late as the ship was already heading for the bridge pylon. Even at full reverse, you couldn't slow it down fast enough. Tragic.
Still, a diesel gen malfunction would render them useless unless one of them was a diesel mechanic as well (we sailors often have multiple credentials).
There is likely a pilot onboard until it leaves the Chesapeake, well past the CB Bridge-Tunnel.
When I worked on cruise ships, a pilot boarded a few miles out from the Sunshine Skyway going into Tampa.
The release was the decision of the pilot, who remaining in charge of the ship till the accident. If pilots are too liberal in their use of tugs, the ship owner becomes unhappy (because the ship owner ends up paying for them), and if they become unhappy enough, will stop using the port. I.e., pilots are under some pressure to keep the use of tugs to a minimum.
Note that it is probably the pilot who advised authorities to stop cars from entering the bridge minutes before the accident, which is why the only deaths were a team of 6 construction workers working on the bridge.
https://youtu.be/gafDs7sxJqg?si=hvLselyX9FQSczOH&t=98
MDoT == Maryland Department of Transportation. Note that the pilots in command of the ship were also employed by the Maryland state government.
https://en.wikipedia.org/wiki/MV_Dali
Propulsion Single shaft; fixed pitch propeller
Funny, I was starting a 2 stroke chainsaw a couple of years ago. I yanked the cord, it kicked back, pulling my arm back down but the saw started up and ran anyway. But it would not cut at all. I killed it and restarted it and noticed the chain going the other (right) way and it was now cutting fine. It has started in reverse the first time!
So to accomplish this for propulsion, you'd add a reverse polarity switch for your starter and you're good to go.
You don’t want to do it very long, because they don’t make oil pressure in reverse.
US energy policy has entered the chat.
As you start getting into more complex engines, where you have fuel injection, timed spark plugs, oil pumps, transmissions it becomes untenable, but not because a v6 can't run backwards but because you'd have to rebuild and time all the support systems.
[1] https://chiefengineerlog.com/2022/06/24/main-engine-fixed-pi...
For example, a transmission would expect the engine to always run in the same direction, but given correct fuel and ignition timings, it doesn't really matter which way the crankshaft is turning while things are running.
The center prop (that only goes forward) is the one directly behind the rudder, so the theory is partly that they lost some steering advantage when they lost the center prop.
In general it depends on the rudders and the boat.
Longer keeled boats don't respond well in reverse at all but more modern boats (like mine, 1990) will do better but will still need some way to have steerage. I can certainly manouver around the marina in reverse, it's just harder than forwards and I need to be going a bit faster to get the control.
I have no idea about container ship sized boats, though I'd imagine a bow thruster of steerable prop might not be practical at that scale.
Modern flat boats (like the 2017 Dufour I learned on) are highly manouverable at slow speed, we practiced spinning the boat on the spot by using prop wash over the rudder forwards then ticking over in reverse. Could turn the boat in not much more space than the boat length, but may not track as well, may slam more, and make more leeway.
I have to protest here. Reversing and using the rudder on a 40ft boat works perfectly fine. I've done it on multiple sailing boats. You need to hold tight so that the rudder wont slap you if using a stick.
EDIT: also planning ahead is important, because if I do it right the prop walk in reverse can be used advantageously.
Also, with the BI-40's barn door rudder it'll slap you through the wheel if you're not careful. Almost broke my leg that way, not a lesson to forget.
It happens something that I really can't explain, but I guess it is weight related. Or maybe area. Dunno.
Also, the bow seems to catch the wind really hard so you can get spun around if it's blowing and you head off the wind too much without enough way on. Leave room, plan ahead, have a backup plan, etc.
The rudder is a wing, it's just vertically oriented and underwater.
The rudder is capable of stalling, just like any wing. The rudder only produces lift related to the flow of water over the rudder. The lift produced by the rudder is what is experienced as turning force. The tiller or wheel changes the angle of attack.
I used to helm a racing sailboat with a high aspect (long & narrow) rudder. It could provide a lot of turning force but stalled easily. It didn't work as well under power as it did under sail; I suspect this was due to the turbulent flow off of the propeller, which was forward of the rudder.
On the Dali, the rudder should have been providing some turning force due to the 7+ knot flow of water over the rudder. Full reverse propeller might have impacted that; I can't comment because I've never helmed a ship that large.
Additionally, a single-propeller vessel like the Dali, will have "prop walk" - asymmetric thrust that pushes the stern of the craft one way or the other while the propeller is rotating.
It sort of makes high-level sense that a lifting bias could in theory work as a counteraction to propwalk. But the terminology is a bit confusing because aerodynamic lift is a byproduct of air being a compressible medium, whereas water is not. Maybe lift means something different when we're talking about water?
At any rate in scenarios where the prop is not engaged, which in a sailboat is most of them, I don't think I've ever noticed a tendency for heading to track predominantly one way or the other, in circumstances where it seems that would be very pronounced and hard to miss, like extended running downwind. Is the lifting body rudder mainly a performance boat thing? Or perhaps am I just so used to trimming this bias out that I don't recognize where it's coming from?
But water and air are both fluids and the same aerodynamic/hydrodynamic rules apply.
A rudder on a boat or airplane is symmetrical in cross section; the chord on both sides is equal. Wings and hydrofoils are asymmetrical; usually the “top” has a deeper chord than the “bottom”. But rudders are a still a kind of wing in that they generate a useful force by redirecting a fluid and thereby inducing a pressure differential. The pressure differential between the two sides is what causes lift - vertically with wings/foils and horizontally with rudders. If you think about it, this makes perfect sense – it would be silly to think that rudders and ailerons and elevators obey different laws than wings. In fact, one of the first things you learn as a racing sailor is that the sails themselves are wings - they’re not “parachutes” as commonly believed.
Anyway, my point was that you can stall a rudder just like an airplane can stall its wings- if the angle of attack is too high.
Stalling, the rudder, most commonly occurs during a round up, if you’re familiar with sailing with spinnakers. The rudder in that case is no longer able to generate enough lift (turning force) To counter the turning force, imparted by the force on the spinnaker forward of the center of mass of the boat, and the boat turns uncontrollably.
I am just speculating, but if the rudder became very misaligned compared to the direction of the ship, then when power was restored, the rudder might not be able to establish laminar flow and therefore would be stalled and unable to provide turning force.
A https://en.wikipedia.org/wiki/Hydrofoil is a wing that produces lift in water.
Though note: compressibility is not the same as "exerting pressure". A hydrofoil or marine propeller works on pressure differences, even though the fluid is effectively incompressible.
An interesting note is that well-designed sailboats are designed to round up in the case where the headsail gets overpowered. As the sail gets overpowered, the boat will naturally try to turn away from the wind and also will heel further. The heeling of the boat will cause the headsail to lose lift and spill air before the main sail does, and the keel, which normally generates lift and drag to counter sideslip, combined with the now-more-powered mainsail, Generate a strong leeward yawing force aft of the center of mass which causes the boat to turn sharply into the wind. Rounding up only happens when you are losing control of the boat so turning into the wind ends up putting you in a safe mode where you can recover. There are a few boats out there where the keel is too far forward and/or the main spills air before the headsail; these boats round down in uncontrolled situations and can jibe unexpectedly – very dangerous.
This is not correct.
this is a stupid argument from all users , comparing a 40ft sailboat to other 40ft sailboats is like making a broad assumption about cars when comparing a dragster to an SUV simply because they have a similar singular aspect.
ANY sailboat, regardless of size, can have poor reversing performance just simply due to its hull shape and rudder plan. Some boats famously cannot reverse with authority due to the turbulence created between the parts. Some boats use feathering propellers which collapse inwards when reverse is applied in order to make a more efficient sailing experience, which effectively makes propulsion reversing useless.
There is NO generalized '40 foot sailboat' in existence. They all act different, and there are some that are perfectly capable of doing what other 40 foot plans might consider IMPOSSIBLE.
I would expect anyone piloting such a ship in a harbor/under bridges. We requite airline pilots to train for many unlikely plane failures because the alternative is letting planes crash that we could have saved with better training.
Friends of mine are pilots on the Thames (London) and I seem to recall one of them telling me it was over 10 years training before you could bring a big boat in. Pretty fascinating really - they figure out all the tides and weather and plan the route. On the day they board along with a sensor system that sits in the bridge and gives the position to a high level of accuracy.
The crew would have know for several minutes that the collision was imminent. These things happen slowly, it wasn't like the bridge suddenly jumped out of the water unexpectedly in front of them. The tragedy is that the crew had no options to avoid the disaster.
I think you are missing the point.
Clearly I am speculating, but I don't think any more experience would have helped in this event.
Why ? I think what happened today was almost entirely down to not being able to fight the basic Laws of Physics.
Its a well known fact that enormous ships take an equally enormous amount of time and distance to reflect the actions of the captain. You make an input and you see the result a bunch of time and distance later.
Time and distance were, sadly, not on the captain's side today. Physics took care of the rest.
I would hope, given the economic and humanitarian consequences of a crash, that we have simulators for this
And I assume there will lawsuits to recover costs as this caused economic damage and risk to life (8 people unaccounted for at current time).
Not to mention that one can scarcely find a "bluer" area than Baltimore -- I would assume that the most proudly right-wing politicians would be more than happy to let Baltimore suffer to score points with their polarized supporters. I hope it doesn't come to that, but they tried to block Hurricane Sandy relief, despite every hurricane in the South being an automatic 'non-partisan' emergency.
This is what he said. I would expect Congress to play along too -- just how unpopular would it be to abandon Baltimore??
1/8 red house seats. The other 7 very comfortably blue.
The rest of the state doesn't seem like it matters much to the only results they'd care about - seats and EC votes.
Edit: not that Republicans are any better.
You underestimate how much vitriol is coming from the Right about Democratic-leaning cities. Baltimore is 60% Black and voted 87% for Biden in 2020. Baltimore isn't on the top of the list of cities they like to claim are failures, but just wait.
My dad is deep in the Right-wing media econsystem and he is convinced that the downtowns of Portland and San Francisco have been burned to the ground and the entire region is a lawless anarchy.
I mean I'm from the Baltimore area and.. well.. I mean some of us would consider that town somewhat abandoned already, think Detroit. It has some pretty rough parts. With the main triggering event being 60s/70s loss of steel industry (Bethlehem Steel). Of all the big east coast cities (Boston, DC, NYC, Philly, Baltimore) I would say Baltimore is the most abandoned already.
As someone else posted above, Baltimore is a massively important US seaport, that moves tons and tons of goods.
Even the most pro-business Republican realizes that a lot of industries are going to get hurt, and in places far away from Baltimore, if they can't move freight through there.
But a loaded container ship at 8 knots is not going to be stopped by anything remotely feasible.
Container ships weigh between 50,000 and 220,000 tons. A US aircraft carrier weighs 100,000 tons.
If they're designed to stop a bulk carrier then presumably they can stop a container ship.
deadweight tonnage of 33,912, gross tonnage of 19,735, and a net tonnage of 13,948.
The one that took down this bridge:
https://en.wikipedia.org/wiki/MV_Dali
Her registered gross and net tonnages are 91,128 and 52,150, respectively, and her deadweight tonnage is 116,851
Many times larger.
My guess, and it is a total guess, is that the protection on the bridge was nowhere near sufficient for a ship of that tonnage.
I’m assuming it was built to whatever the correct standard was when constructed in the 70s. I’m also assuming the ship weighed far more, or perhaps traveled noticeably faster, than the cargo ships going into the port back then.
Basically I’m guessing it needed an upgrade in its protective barriers but it wasn’t recognized or hadn’t happed if it was.
Wouldn't the ship's insurance be the one paying here?
This
> Similar to a car that hits ice, wheels have arbitrary alignment when they reengage road, when power starts being delivered again, car swerves towards concrete barrier even with brakes. Driver with limited crash experience is mostly just panicking and stomping.
is almost certainly not the case on a large ship. The rudder is rotated hydraulically. Loss of power simply causes the rudder to stop moving, it's effectively "stuck". Some ships have manual override using a massive wrench, but it takes hours to move the rudder meaningfully in that situation.
As for this:
> How many pilots, trained or not, really have any experience with a 100,000 ton ship in a crash situation with responses where seconds matter?
Probably way more than you think. This is a significant reason why they seem so calm when they show up on the bridge. They just hopped from a relatively tiny pilot boat or tug onto a massive ship, possibly with significant sea state. This can be some Indiana Jones level crazy.
https://www.youtube.com/watch?v=18VF8WXWfZw
https://youtu.be/C8ER9Ladqg4?si=Ijwhu90iJi8WPAas&t=226
Pilots are very seasoned mariners who have seen multiple losses of power, and pretty much everything.
Now, back to point 1: bridge team. I have seen a captain the crew trusts execute flawless maneuvers even in exigent circumstances. I have seen a captain the same crew doesn't trust fail repeatedly at everyday things.
We don't have the whole story yet. What happened on the bridge? What happened in the plant? Why did power drop? Did they flood an online generator with diesel oil? I ask because I've seen that happen. Did they blow an exhaust manifold? Seen that. Did they trip the plant by getting preparatory checklist work backward? Seen that. Did they go all back full immediately? Possible that they couldn't ring the order if they dropped power. Was there panic on the bridge (bad sign) or was there grim fortitude to process checklists that would never help (better sign). In any case, no doubt the captain is done. Probably happy to never drive a ship again after that, tbh.
I've just always be impressed by the amount of energy that boats impart when they collide with anything. Like in this case, the entire bridge was brought down by a collision at under 8knots. Obviously that ship had orders of magnitude greater mass than the little pilot boat, but presumably you want to avoid even dinging up the larger ship, and so that's an orders of magnitude smaller goal as well.
Back to the pilot boat: Steering one in heavy seas when trying to deliver or recover a pilot is clearly a difficult art. But at least in the videos shown, there doesn’t seem to be much of an impact between the vessels. I am sure that is in part due to the skill of the steersman. Besides, I am sure the pilot boat will have permanently mounted fenders all around.
Or even if so was it just too late when it all went down and it wouldn’t have made a meaningful difference?
Catastrophic engine failure (1:24) causing wide scale power loss.
No rudder control, rudder drift, and ship alignment drift (1:24-1:25:30)
Power restored and ship reengages prop with bad ship/ruddder alignment (1:25). However, ship is now pushing itself into a further bad turn. Pilot likely stomps the brakes realizing misalignment. Obviously 2-3 minutes is not enough to stop 100,000 tons at 8.5 kts, since it only got to 7.5 kts before crashing. Power loss may have caused total rudder loss.
Similar to a car that hits ice, wheels have arbitrary alignment when they reengage road, when power starts being delivered again, car swerves towards concrete barrier even with brakes. Driver with limited crash experience is mostly just panicking and stomping.
How many pilots, trained or not, really have any experience with a 100,000 ton ship in a crash situation with responses where seconds matter?
Edit: Also, economic disaster for Baltimore.
> (Wiki) The Port of Baltimore generates $3 billion in annual wages and salary, as well as supporting 14,630 direct jobs and 108,000 jobs connected to port work. In 2014, the port generated more than $300 million in taxes. 1st in automobiles, light trucks, farm and construction machinery, imported forest products, aluminum, and sugar. 2nd in coal exports.
Edit2: Bloomberg has an economic look including info on autos. ~$500 million in March 2024 so far. Honda, Mercedes, Subaru likely worst hit. https://pbs.twimg.com/media/GJmvXiCWkAAgDcE?format=png&name=...
3,600 commercial trucks / day. Hazardous material transport has a 30 mile detour. Baltimore had $350 million of insurance. However, Brent Spence Bridge is noted for cost comparison at $3.6 billion and 1/5 the length.
Baltimore StreamTime also has live view with ongoing discussion. https://www.youtube.com/watch?v=83a7h3kkgPg