The 985-foot container ship, known as the Dali, left Baltimore about 12:30 a.m. Tuesday, bound for Sri Lanka. Clay Diamond, the executive director of the American Pilots’ Association, said the ship experienced a “full blackout” around 1:20 a.m., meaning it lost both engine power and electrical power to the ship’s control and communications systems.
The ship was traveling at 8 knots, a normal speed for the area that Diamond described as “ahead slow.” The ship never regained engine power, but Diamond said a diesel backup generator did kick in, restoring the electrical systems — the possible source of a puff of black smoke visible in video of the collision circulating on social media.
As I understand it, this is a fairly common and well-known option for collision protection on (newer) bridges, so do anyone know the specific reason why that protection was not selected for this bridge?Baluncore said:You do not have pillars, you have shallow water and rock around the towers.
Old bridge, old standards for (lot) smaller ships of old times?Filip Larsen said:As I understand it, this is a fairly common and well-known option for collision protection on (newer) bridges, so do anyone know the specific reason why that protection was not selected for this bridge?
There is of course an age aspect of that question, but it was constructed around 1972 so not all boats were small at that time, and establishing protective zones is something I would imagine can be added or augmented long after a bridge has been constructed so I would guess there are other more compelling reasons it was not done. I was thinking possibly candidate reasons could be cost (always a factor one way or the other), environmental impact (although that is a much newer concern, but one that is addressed quite often now when marine constructions are proposed in the area I live) or perhaps the tides in the bay would wreck havoc on any attempt to raise the seabed?Rive said:Old bridge, old standards for (lot) smaller ships of old times?
The two main supports of the Baltimore's Francis Scott Key Bridge, could have been retrofitted with collision protection, to bring it up to date. All other supports are in shallow water.Filip Larsen said:As I understand it, this is a fairly common and well-known option for collision protection on (newer) bridges, so do anyone know the specific reason why that protection was not selected for this bridge?
Agree. One thing is the malfunction of the ship (I'm still considering it likely related to human factor - not necessarily from the crew, though), other is the environment being unable to mitigate it.Filip Larsen said:I foresee this question quickly becoming relevant
It's a human made machine so ultimately human factor will be at play, even in a mechanical/electrical failure. But I tend to doubt it was an immediate cause, other than maybe procedural.Rive said:Agree. One thing is the malfunction of the ship (I'm still considering it likely related to human factor - not necessarily from the crew, though), other is the environment being unable to mitigate it.
A major reevaluation and overhaul of safety for harbors and bridges indeed seems likely.
I know it does not seem rational, but the volume of black smoke looked to me like a main engine restart, not one of the much smaller diesel generators being started.russ_watters said:The smoke is consistent with a diesel lighting-off, but which one? The (single) main engine re-starting or an auxiliary generator?
Are you saying that it's not a money problem? (Or that there's no parallel.) It would have been quite possible (albeit expensive) to avoid collisions with the bridge piers. OR, the decision could have been made to site a bridge elsewhere. That tragedy will go down in history and affect every subsequent major bridge installation. Those few seconds of video will play in the minds of all designers and investors and may /should change the culture. Normally, Investors Rule. (And the mayor of Amity)berkeman said:Please don't do that; it's very inappropriate.
Going too damn fast and without tugs (apparently). Money money money.PeroK said:I was thinking more how could a massive cargo ship collide with a bridge?
It is absolutely standard practice that once a ship leaving harbor is clear of the docks and under its own power in a clear channel, tugs leave the ship. That may change as part of the fallout of this investigation but nothing was done improperly in this case.sophiecentaur said:Going too damn fast and without tugs (apparently).
That's probably right. However, this experience should perhaps be taken as a lesson - as with the Space Shuttle. It took a long time for people to come clean about causes of those accidents.phinds said:but nothing was done improperly in this case.
For reference the main engine is 10x the size of the generators. Agree, it did seem like a lot of smoke.Baluncore said:I know it does not seem rational, but the volume of black smoke looked to me like a main engine restart, not one of the much smaller diesel generators being started.
Maybe but I doubt it unless they had engine but not (electronic) steering control. In reverse you lose steering control (due to loss of flow over the propeller).Baluncore said:When they lost steering, did they ring "Full astern" to reverse the main engine, and so slow the ship. That would explain the volume of black smoke.
Wouldn't the flow just be reversed? If not, my online games are messed up when I back up.russ_watters said:Maybe but I doubt it unless they had engine but not (electronic) steering control. In reverse you lose steering control (due to loss of flow over the propeller).
Did you mean loss of flow over the rudder?russ_watters said:In reverse you lose steering control (due to loss of flow over the propeller).
russ_watters said:For reference the main engine is 10x the size of the generators. Agree, it did seem like a lot of smoke.
Maybe but I doubt it unless they had engine but not (electronic) steering control. In reverse you lose steering control (due to loss of flow over the propeller).
Borg said:Wouldn't the flow just be reversed? If not, my online games are messed up when I back up.
Free-wheeling, or not free-wheeling?Baluncore said:Did you mean loss of flow over the rudder?
Just curious, can tugboats alter the course of a ship this massive once it's moving at 8 to 10 knots?tugs
Borg said:Wouldn't the flow just be reversed? If not, my online games are messed up when I back up.
Yes, the issue is loss of flow over the rudder due to the propeller being in front of it and also pushing the water opposite the motion of the ship. I'm not sure the numbers exactly but say the ship is moving 10kts and adds 10kts to the water, for 20kts over the rudder.Baluncore said:Did you mean loss of flow over the rudrudder
My one big bug bare with SS06 & 08 is the fact that the ships steer astern. This is totally unrealistic and does not happen in real life and big ships.
For a rudder to be effective it needs a flow of water over it. The prop is positioned infront of the rudder for this reason. When going astern there is minimal direct flow over the rudder which means a vessel would not readily steer.
What do you mean by free-wheeling?Bystander said:Free-wheeling, or not free-wheeling?
Unsure. Tugboats are designed to provide a large propulsive force at very low speed. How they would do at for them relatively high speed is tough to know. I suspect no.gmax137 said:Just curious, can tugboats alter the course of a ship this massive once it's moving at 8 to 10 knots?
I remember reading that for the biggest cargo ships it takes about a mile to go from cruising speed to full stop. Don't recall what it was in minutes, but I'm sure it's a few at least.russ_watters said:I'm not sure how long that takes.
I'm talking about ahead thrust to reverse thrust.phinds said:I remember reading that for the biggest cargo ships it takes about a mile to go from cruising speed to full stop. Don't recall what it was in minutes, but I'm sure it's a few at least.
Spinning as a result of water movement, a la, helicopter auto-rotation following power/engine loss.russ_watters said:What do you mean by free-wheeling?