John - ships rudder deflects wash from the propeller - Steering is only effective when there is water flowing over the rudder. Water flow over the rudder is gained in three ways: 1) The boat moving through the water 2) From the propeller (propwash) most effective! 3) When a stream of water is running over the rudder such as tide For example - Submarines have their rudders above and below the propeller - for stealth and hydrodynamics. .
One more thing that is going to rear it's ugly head, is that some of the containers - not just on the Dali, but in the port of Baltimore, are refrigerated. They have to move whether the port is open or not. There may well have to be a major effort made to ship those containers by rail or truck to another port. Fast.
I assume that's already underway. As an example of the magnitude, 80 containers of oranges had just been offloaded from the Dali alone.
Here is a Buick that I am sure he had to change his underwear at the Tampa Bay Skyway Bridge in 1980, my friends grandmothers neighbor. Fernando
I read that the shipping channel into Tampa is about as difficult as they get. I knew a person who was trying to get his 500 - ton license, and they made him simulate the approach to Tampa. He later said (after the skyway came down) that he was surprised that it took as long as it did before a ship hit it. BTW: He passed the test and is or was running a ferry between Boston proper and Logan Airport.
This post surely deserves an award for the most outstanding linking of Buick content to a news story with zero apparent Buick content!
I think the capt did all that could had been done....the tugs help the vessel get into the main channel, vessel was moving at about 8 knots......not much judt enough to maintain course with current flow. Yes the rudder at those speeds doesn't fo much with the water from the props passing over it............. They called for mayday right away, got the traffic dang near all cleared off, had dropped the port anchor to help swing it. Had full reverse once power came back on. Bow thrusters wouldn't do much when the vessel us moving at those speeds and most likely with power out they were out too. Stopping this thing would be like your 1/2 truck tring to stop a fully loaded semi trailer going down hill at speed........... And it looks like the port motor came back online 1st giving the way the vessel kicked just leading up to the actual striking. And keep in mind with that much forward drive from the weight when the hit reverse and powered up the amount of cavitation would had been great.........think of it like slowly sliding down a hill on ice......grabbing reverse and flooring it...........without traction all the wheel speed won't matter. Props are not good at grabbing water in reverse......
I did hear a little bit of MDOT police radio traffic & an officer was going to go alert the construction crew when the bridge came down so seemingly they didn't have communications. Obviously an unusual event but hopefully in the future... It's also apparently been a concern since around when the bridge was built that this could happen & that the bridge couldn't withstand such an event.
Very few thing could withstand getting stuck by an object with over 100,000 tons of weight moving at say only 10mph
I personally have over 50 train Engineers(Ohio wreck) ship captains(Baltimore) and Immigration specialists on my Facebook page... I guess our times have went from people with opinions,to Influencers and keyboard specialists... I can't wait to bring up something like a new formed wart on my finger or bunion so I can get these specialists to diagnose my issue..
EXCEPT, the captain issued a MAYDAY warning of his loss of power and steerage, if it was deliberate, a terrorist doesn’t do that or have second thoughts “Oh, I changed my mind”
IMHO, it was just lousy circumstances, lost power, and a bridge supported by tooth picks. Ships slam into abutments quite often, no issues. Heck, I was surprised when the planes slammed into the twin towers, that they held up from the impact, ESPECIALLY near the top of the towers.
New York's Tappan Zee bridge was replaced primarily because the original bridge had been designed prior to the era when large bridges would not collapse due to a single-point failure. Road traffic over the Tappan Zee is such that dozens - perhaps hundreds, of vehicles would go into the water if the bridge were to collapse. The new bridge can withstand a hit from a ship without a total failure.
Bens99gtp - Port motor? I believe it has a single engine for propulsion. Where there tugs in the water nearby? Just for the turn - makes more sense. I still think they should have escorted the big girl out of the harbor past the bridge. Even with full reverse it would take over a mile to stop, based on large military ships. I can't imagine a civilian crew practicing an emergency stop in real life. I agree it's sad that folks take a tragedy and turn it into a meme, joke, or political attack. I worked as a naval engineer for 30 years, so I have a little knowledge - just enough to be dangerous!
It's interesting that the ship was being tugged out of port, but the tugs released it as soon as it entered the channel. In the perfection of hindsight, keeping the tugs on the vessels until they cleared the bridge would have been a good idea.
As I stated previously - I'm far from an expert on large boats, but I can do research; The Dali (Named for Salvatore Dali) has four diesel engines. One is for propulsion; the other three are for generating electricity. I assume that the single bow thruster is electrically powered, so if the generator went out, so would the bow thruster. Edit: I have found that the hydraulic pump that provides power to the Dali's rudder is also electrically powered. When the electricity went out, there would be no effective way to steer the ship even if the main engine was running. Since the main engine must be stopped and then restarted - spinning in the opposite direction - to reverse the propeller, it would take some time to get the ship into backup mode.
