Dali Timeline from Data Recorder in Striking Francis Scott Key Bridge in Baltimore, March 26, 2024

Ex machinist mate of a Ohio class sub here. When you lose hydraulic power, the pressure in the rudder control cylinder will start trying to equalize. This could push our pull the rudder a few degrees in a certain direction. Also, the hydraulic control pilot valve would have stopped where ever the last position it was when the hydraulic accumulators went dry. It's possible the helmsman was inputting a little right rudder to hold heading when the power went out, because you can't hold a heading without steering back and forth from left and right. In the Navy, they have us +/- 5 degrees of rudder to hold heading without having to ask permission. The slower you go, the greater change in rudder is required to hold a heading. So for all we know, the rudder could of been stuck at Right 5 to 10 degrees there whole time there power is out. Which would help explain the veering into the bridge.

As a Traffic officer who's had to put on many a emergency rolling roadblock. I don't think many appreciate just how much of a miracle it is that officers can get the road fully stopped so quickly saving many many lives. Getting a RRB on this quickly is unheard of. Normally it takes a good few mins even if units are in the right position at the time. While i fully appreciate we lost a number of road workers which is a tragedy, things could of been so so much worse without this miracle taking place. Thoughts are with everyone effected by this whole event.

Sal. Retired Chief Engineer here. 30+ yrs as Chief Engineer on Slow Speed diesels such as this vessel. You have done a great job, but a couple of points to clarify. 1 - The ship's electrical systems are laid out such that there is a "Main Distribution Buss" and an "Emergency Buss". These two are NORMALLY 'TIED' together via the 'Buss Tie Breaker' and fed from the ships' main generators (DALI has Four). They can all be brought online to supply power. Usually one will carry the load unless there is a lot of refrigerated containers on board. When the bow thruster is running, two or three generators would be online to supply the Bow thruster which is typically an electric motor 1,000~2,500 HP. The Emergency buss is ALWAYS powered. In the event of loss of power, the Emergency Diesel Generator (EDG) starts, and the breaker connecting the two electrical busses (Buss-Tie Breaker) opens, then the breaker connecting the EDG to the electrical buss is allowed to close and power the emergency buss. There are only a handful of equipment that are on the Emergency Buss, ONE of the steering gear motors would be on this. The Deck lights are not on the emergency buss. So when you see the deck lights come on and off, that is a Main Generator. The large light on the bow that seems to come on at a different time is likely a High Pressure Sodium light and they usually take a while to 'warm up' before putting out any light. 2 - The black smoke is likely from the Main Engine (M/E). The M/E is a 9-cylinder two-cycle diesel engine that develops 55,630HP @ 82.3 RPM. The pistons are 0.90 meters in diameter and typically weigh around 7-tons each. If they were doing 8knots ahead and requested a 'crash astern' engine command, the automation of the engine has a separate program that will introduce more 'start air' than normal, for a longer time. 'Start Air' is high pressure air that is introduced into the engine in the same sequence as firing order to turn the engine (kinda like a push start) in the proper direction before fuel is introduced. Once fuel starts pouring into the engine in the reverse direction, the engine is initially starved for combustion air as the three turbochargers on the engine (that weigh as much as a Volkswagen Golf) take a bit of time to spool up to speed. 3 - I was an Engineering Officer, not a Deck Officer (Mates), but the mates used to remark about how the astern bells would affect the stern by 'walking' the stern one way or the other depending on how the blades on the 65-ton propeller bit into the water. Much more than the ahead bells because the propellers are optimized for pushing the vessel in teh ahead direction. Hope this helps clarify some of your questions. 4 - The rudder is controlled hydraulically and without power, would stay in the last position before loosing power.

15 years professional dog walker and 4 years shopping cart retriever and 6 months door dasher here. This is an excellent breakdown, could not have done any better myself.

Boy, 30 minutes with you is well spent, Sal! I feel like I've gone to seamanship school! Thank you for these videos.

I retired at the end of 2022 after working for 50 years at most every Port of Baltimore facility. Back in the mid 70's when the Key Bridge was built no one imagined a container ship of this size. When I started, ships with cars were still bulk carriers using the ships cranes to lift the cars from the holds to land them pierside! Now they are all RoRo vessels. I don't think the architects of the bridge could imagine the size of these behemoths now.

I have very little knowledge of the maritime world. But, I’m a Maryland resident and I have really come to value channels such as this as we try to come to grips with this tragedy. Thank you, Sal, for providing so much sensible and insightful analysis.

Former Ocean Master here. This was a terrible accident, but Sal is doing great work with comprehensive commentary. Thanks Sal.

So great that you're spreading the word about other worthwhile YouTubers, Sal! 😎✌️

Sal, you do realize that you are for many of us our source of factual news on this event, yes? We have come to understand that typical media outlets seem to sensationalize what is actually going on. Thank you for a rigorous explanation of the events and your questions and concerns as opposed to stating them as facts. Keep these coming, thank you so much for what you do here!

I really really appreciate how you cite your sources in the video, and how generous you are in pointing and linking to related videos. Not everyone does this, but it's so important!

You're a class act for using your growing channel to boost other great channels. A rising tide...all boats...etc.

Great report again. Having ran large tugs before I can tell you that it is not as easy of a job as it looks. I've never ran a tug in Baltimore, but I would never want to be attached to a ship this size going 8.5 knots. The tug I was running one day was a 7,000 BHP rated with 3 directional props. I was helping dock a container ship that is about this same size one day in a very high wind. It was about all we could do to hold the ship off of the dock and the bumpers that were in the water at the dock. The wind was straight on to the side of the ship with its containers all stacked to the top, so a lot of area for the wind to catch. The wind speed increased all of the sudden with the ship about 40 meters off of the dock, and boy could we feel it as the ship started to pull harder. I increased to full power on all 3 props with a fear that the tow line would snap and kill someone, so I got everyone off of the deck. We stood low in the wheelhouse. With all of this, the ship closed into the dock, but thankfully the bumpers in the water took most of the pressure and the dock or the cranes were not damaged. The bumpers however were toast and needed to be replaced when the ship departed. With this ship moving at 8.5 knots, the only thing a tug could have done it it was there would have been to push on the starboard bow of the Dali to perhaps hold it off of the bridge piling. Lets be real however, under full power forward, these powerful tug don't go very fast and it would have been hard to get it up to speed an into place with enough lateral power to move the bow over. The propellers on a tug boat are engineered to provide force, not speed. At the end of the day from what I see, they lost power at the worst possible time. when it happened odds are the engine room crew didn't know exactly where the Dali was in relation to the bridge and the approaching danger, but I assure you the phone rang down there and they were told. It looks like they lost power somehow, either the generator shut down for some reason or it was an overload trip. Often on ships like this if they have a lot of refrigerated containers plugged in, they will have 2 generators running in parallel to supply enough power. These refrigerated containers always require a lot of electricity when first leaving the dock since while on the dock they were often left unplugged for a while; so they're all working to stabilize the temperature in them. If that parallel generator tripped out for some reason, then the other generator would have also tripped off from overload. On these big ships, vital things on the main engine are ran with electric motors, not driven by the main engine itself like a highway truck. So losing power would also drop out the lube oil pump, and water pumps which then would have triggered a main engine shut down so the oil pressure accumulator can provide oil to the engine while it is slowing down. As your video points out, re-starting this main engine is not like hoping into your Ford F-150 and turning the key.   From watching the dock camera in real time it looks to me that the engine room crew was all over this in as quick of a manner as they could. Once power came back up from the emergency generator or a main generator, they started the main engine start process, and it looks like something then tripped it out again. But once they got the main generator started and isolated to provide power to the ship only, they got the main engine started and the black smoke you see was the bridge pouring on the power in reverse to try and stop the ship. At this speed and slower, especially in the reverse direction, the rudder does not respond that well since less water is moving over it than out on the open ocean at 18 knots. All this time, the ship was moving. It did slow quite a bit, but not enough.... Kablamo! Very sad deal. I give aplomb for the bridge getting that MayDay call off so they could close the bridge to traffic. Even at 1:30 AM, that bridge is well traveled. While some were unfortunate, that MayDay call probable saved a lot of lives.

This channel is an absolute gem. Thanks Sal.

Sal is one the most IMPORTANT YouTubers of our time!! He is also an absolute BEAST at what he does!! 👍

I saw you on the news and told my son - hey! that's Sal! Well deserved. I can not tell you how much you give us all with your knowledge and how much better off we are for it. Thank you.

My father is a Retired Chesapeake Bay Pilot, and he is heartbroken.

Thank you for this video. The incident has caused a huge amount of BS on social media from folks that are clueless. Now, thanks to you I can share this informative video with others. Thank you again.

Your channel is superb. Clear, rational, easy to grasp if you have a basic head on your shoulders.

As a Filipino American, I am happy to see Chief Makoi educate us about operating ships in the engineering room. Great job to you and everyone involved in this video. I’ve been following your channel ever since the Oceangate disaster.