There are a lot of people talking about this who don't know what they're talking about because they've never set foot on a boat, let alone captained one. Here's a very interesting breakdown of the incident from a professional captain. The ship broadcast a Mayday call before the crash and AIS data seem to imply that they ran the engines in reverse as the ship drifted off course. It looks a lot like a failure in the steering system which is all fly-by-wire computer controlled these days.
He also describes the equipment on board - for example, a black box data recorder like airlines have. I hadn't known that commercial ships have those, but do now.
The video does not discuss what I am hearing other places, that there was a power outage on the ship, lasting around a minute. Power came back on, but then failed again. The ship is Singapore flagged, and Singapore has a reputation for strict enforcement of nautical regulations.
My suspicion is that this was a single point of failure, or a situation where redundant systems both failed at the same time.
UPDATE 26 MARCH 2024 16:50: It's confirmed, the MV Dali lost power for a considerable time before impact, and when power was restored both ran the engine in full reverse as well as dropped the port side anchor.
UPDATE 26 MARCH 2024 17:03: There is a lot of buzz supposedly from Port of Baltimore personnel that the Dali had repeated power outages at dock during the two says before setting sail. This is unconfirmed, but interesting.
For sure the ship lost power, as you can see in the second video. When power came back on and the engine ran hard reverse, the "prop walk" kicked the stern to port, taking the ship's heading starboard towards the bridge. Dali is single screw, so prop walk is a real thing here.
8 comments:
I garnered much of what is reported here upon first viewing of the video, this morning. I spent a lot of time on the bridge of my old destroyer (DD715), and paid attention to how the bridge officers handled that ship.
Single-screw propulsion has been all the rage for over 50 years, in the both the Navy and commercial shipping. But my of ship had twin screws, and danged if we couldn't steer, quite nicely, by properly varying the speeds and directions of those screws.
Emergency handling? With twin screws, you can perform an "Anderson turn". One screw ahead full, and one screw back full, pivots the ship in one spot. We used that maneuver to "come about sharply" to recover a crewman who washed overboard in a bad storm.
To shorten this a bit, the MV Dali had no real chance of avoiding the collision, given the ship's design.
They did call a Mayday and according to reports the bridge dropped their emergency gates stopping traffic. Since it was the middle of the night vehicles on the bridge all cleared. The missing people are being reported as maintenance workers doing road surface repairs.
This is only a couple of exits up from where my in-laws lived and I have traveled over that bridge many times. In addition to the loss of life, this is going to snarl the port and create a bottleneck for commuters for months or years.
One of the ignorant CNN commentators had a familiar sounding name....Andrew McCabe. Senior Law Enforcement Analyst. Now where have I heard of him????
Tacitus
I happened to be awake at 02:00 (approx) and saw the report hit the news stream - I saw the SteramTime LIVE feed shortly after 3:00 (MT) and ran it back about 20 times to see if any cars cleared the bridge before the collapse. I saw none and breathed a sigh of relief, not realizing that there were maintenance workers fixing the deck of the roadway. I saw the power outage, figured out the steering would go, and sure enough it slammed into the pylon for the main suspension portion of the bridge and it fell in accordance with the tensions on the bridge structure (I have had Mechanical Engineering, among other disciplines) and saw the carnage.
In the light of day, I saw the damage that a 900-foot long relatively lightly loaded container ship doing less than 2 knots can do to a concrete pylon - the ship pulverized one of the four "legs" and the rest is history.
What I want to know is, WHY is the FedGov paying one thin dime for the repair of the bridge? Where is Lloyds or the ship's owners for the money necessary to pay for repairs, damages, claims on the shipper, etc.?? We (the USA) can't afford anything like this, repairs and lawsuits will be in the BILLIONS of dollar ranges!! This pisses me off.
The thing that bugs me about this is that the blame is laid on the power failure. Trouble is, the ship was ALREADY in a SOLID starboard turn BEFORE the power went out. If the ship was in the main channel, coming up on the bridge, then WHY was the helmsman executing that kind of turn??? At that juncture, you're turns are a matter of a couple of degrees, port or starboard, just to keep the ship lined up. Not something that's going to swing the stern of the ship by as much as it was being swung in the video prior to the lights going out...
It's a lot easier for most to embrace a baseless conspiracy notion than to try and learn exactly what technology is involved and how many people are involved in piloting such a ship in and out of a major harbor.
It's been nice to see the voices of reason slowly overpower the conspiracy nuts. From an industry perspective, it's a pretty straightforward incident, and while not predictable, obviously, it wasn't hard to see what happened, roughly, anyhow.
Peteforester, to answer your question, coming out of a turn, the quartermaster will use the rudder to adjust his rate of turn, but it's truly rare to 'meet her,' to come to a steady heading and stay there, without having to shift the rudder more than twice to check a swing. It's also not unusual to quickly kick the rudder over 10-15 degrees and back without stopping in between at maneuvering speed, to check the momentum or stop a swing off course if a ship is acting squirrely on the helm. The quartermaster is expected to keep the ship within 1/2 degree of the pilot's orders, which is hard. A 'mind your helm, quartermaster' is deeply shaming, equivalent of a GFY for land people.
Between that and the prop walk effect when the pilot ordered them to restart the engine in reverse while moving ahead, the turning effect isn't raising eyebrows inside the industry, anyhow. BUT, that will come out in the voyage data recordings, at least while the power is on and the VDR is being fed data, we'll be able to see.
As to the twin engine idea, it's just too damn expensive. The US has a couple of twin-screw tankers in Alaska service, and the world's only diesel-electric twin screw tanker, which bankrupted the builder and drove them out of business. Sadly, that was my former employer, so I got to watch it happen.
You really have to know/understand all the forces acting on a ship underway. The current, the set and drift, the wind, the action of the rudder and as mentioned, propwalk. Going in reverse in a single screw ship magnifies prop walk but the pilots had command of that ship until command was lost with the power outage. They should have been able to see at a glance if their unpowered but underway course would carry them safely under the bridge or not and if it would have and THEN caused them to run aground then the pilots were at fault for reversing engines and causing the bow to swing to starboard followed by the rest of the ship.
I don't know though. I wasn't there. I know they lost power once and then again a minute later. I know brownouts can be fatal to electronics and restoral of power in a brownout can be fatal to electronics. Everything on ships is electronic from engine controls to rudder controls. Hell, any warning coming off the ship probably came from the pilot's handheld radios they use to talk to the pilot boats, tugs and port control.
Ships lose power all the time. One of the strangest things is to be steaming along in a diesel engine ship, lose all electrical power and just keep steaming along at 12 knots because the propulsion system doesn't require any electrical power.
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