toucana Posted March 27 Share Posted March 27 (edited) According to the WSJ and NBC News reports, investigators are looking into the possibility that contaminated fuel may have contributed to the collision that caused the collapse of the 1.6 mile span of the Francis Scott Key bridge across the Patapsco River Baltimore just after 1.24 a.m Tuesday. https://www.nbcnews.com/news/us-news/rare-mayday-preceded-baltimore-bridge-collapse-couldnt-think-worse-sit-rcna145212 A 1000’ long cargo ship called the Dali broadcast a rare Mayday call shortly after leaving harbour to warn shore authorities that it had lost power and steering control, before slamming into a bridge support column 4m later. There was just enough time to close the bridge to vehicle traffic, but not enough time to evacuate a team of maintenance contractors who were out on the bridge filling in potholes - 6 of them are now presumed dead. Quote “The worst sound you ever hear on a ship is dead silence, because that means everything’s gone wrong,” said Salvatore Mercogliano, a maritime expert and historian. An engine conking out 3 miles out in the ocean is an aggravation and an economic problem, because you lose time,” said Henry Lipian, a retired Coast Guard lieutenant and founder of the Introtech accident reconstruction firm. “In a narrow channel at night, with a bridge in front of you, I couldn’t think of a worse situation to deal with.” A ship can drop anchor in an attempt to avert a collision, but given the Dali’s size, speed and distance from the bridge, such a move most likely wouldn’t have helped, said Morgan McManus, an instructor at SUNY Maritime College in New York who has worked on cargo ships and tankers. At 8 knots you need a couple thousand yards to do it,” McManus said. Officials have now recovered the black box data recorders from the Dali, the USA Army Corps of Engineers has been mobilised to clear the wreckage, and President Biden has said the bridge will be rebuilt at the expense of the Federal government at a cost of around $600m. Edited March 27 by toucana added 'have' line 1 Link to comment Share on other sites More sharing options...
exchemist Posted March 27 Share Posted March 27 (edited) 1 hour ago, toucana said: According to the WSJ and NBC News reports, investigators are looking into the possibility that contaminated fuel may have contributed to the collision that caused the collapse of the 1.6 mile span of the Francis Scott Key bridge across the Patapsco River Baltimore just after 1.24 a.m Tuesday. https://www.nbcnews.com/news/us-news/rare-mayday-preceded-baltimore-bridge-collapse-couldnt-think-worse-sit-rcna145212 A 1000’ long cargo ship called the Dali broadcast a rare Mayday call shortly after leaving harbour to warn shore authorities that it had lost power and steering control, before slamming into a bridge support column 4m later. There was just enough time to close the bridge to vehicle traffic, but not enough time to evacuate a team of maintenance contractors who were out on the bridge filling in potholes - 6 of them are now presumed dead. Officials have now recovered the black box data recorders from the Dali, the USA Army Corps of Engineers has been mobilised to clear the wreckage, and President Biden has said the bridge will be rebuilt at the expense of the Federal government at a cost of around $600m. What puzzles me is the loss of all power. There will have been a low speed main engine and a number of medium speed auxiliary generators. While they may all have used the same heavy fuel oil, it seems odd that all would have failed simultaneously due to fuel contamination, especially given there will have been several centrifugal separators on the fuel lines to the engines. Low speed engines are generally more tolerant to poor fuel than medium speed ones. Maybe loss of electrical power meant they could not control the main engine or the rudder. No doubt the facts will emerge fairly quickly though. Edited March 27 by exchemist Link to comment Share on other sites More sharing options...
toucana Posted March 27 Author Share Posted March 27 3 hours ago, exchemist said: What puzzles me is the loss of all power. There will have been a low speed main engine and a number of medium speed auxiliary generators. While they may all have used the same heavy fuel oil, it seems odd that all would have failed simultaneously due to fuel contamination, especially given there will have been several centrifugal separators on the fuel lines to the engines. Low speed engines are generally more tolerant to poor fuel than medium speed ones. Maybe loss of electrical power meant they could not control the main engine or the rudder. No doubt the facts will emerge fairly quickly though. There is some interesting reporting written by people with relevant maritime experience in the Telegraph: https://www.telegraph.co.uk/news/2024/03/27/baltimore-bridge-ship-captain-electrical-failure-pilot/ It seems that the auxiliary generators failed twice - the ships lights came back on, then went out again. Some eye-witnesses also reported seeing quantities of black smoke coming from the boat’s funnel after the initial loss of electrical power, which may have been a standby emergency generator kicking in. The crew perhaps lost control of the steering system with the rudder stuck in the starboard position - there was also a 10 knot wind on the port bow which would have pushed the ship to starboard, and into the pylon. Contamination of bunker fuel used in ships is most often associated with the presence of water which can encourage the growth of microbial biomass that can block filters, injectors, and damage marine engines. The use of biodiesel and low sulphur marine fuels can exacerbate this problem apparently. https://echamicrobiology.com/knowledge-hub/common-problems/marine-fuel-quality Link to comment Share on other sites More sharing options...
exchemist Posted March 27 Share Posted March 27 2 hours ago, toucana said: There is some interesting reporting written by people with relevant maritime experience in the Telegraph: https://www.telegraph.co.uk/news/2024/03/27/baltimore-bridge-ship-captain-electrical-failure-pilot/ It seems that the auxiliary generators failed twice - the ships lights came back on, then went out again. Some eye-witnesses also reported seeing quantities of black smoke coming from the boat’s funnel after the initial loss of electrical power, which may have been a standby emergency generator kicking in. The crew perhaps lost control of the steering system with the rudder stuck in the starboard position - there was also a 10 knot wind on the port bow which would have pushed the ship to starboard, and into the pylon. Contamination of bunker fuel used in ships is most often associated with the presence of water which can encourage the growth of microbial biomass that can block filters, injectors, and damage marine engines. The use of biodiesel and low sulphur marine fuels can exacerbate this problem apparently. https://echamicrobiology.com/knowledge-hub/common-problems/marine-fuel-quality Your link is about MDF. I wonder if the ship was burning that or RFO. (My comments about centrifugal separators relate to RFO.) I heard an interview with a bridge designers saying that if and when they rebuild it, it will probably be a cable stay bridge with piers set much wider apart, well out of the navigable channel. Link to comment Share on other sites More sharing options...
TheVat Posted March 27 Share Posted March 27 I heard somewhere that long continuous truss bridges like that will sometimes have their support columns centered on a small artificial island (e.g. a big pile of rock) to serve as a buffer against ship collisions. It's my understanding that nothing will really protect a support column from a container ship, unless it's actually islanded in that way. The ships are just too massive now, averaging much greater mass than in the 70s when construction began. 1 Link to comment Share on other sites More sharing options...
swansont Posted March 27 Share Posted March 27 8 minutes ago, TheVat said: I heard somewhere that long continuous truss bridges like that will sometimes have their support columns centered on a small artificial island (e.g. a big pile of rock) to serve as a buffer against ship collisions. It's my understanding that nothing will really protect a support column from a container ship, unless it's actually islanded in that way. The ships are just too massive now, averaging much greater mass than in the 70s when construction began. I was reading that the protective mini-islands are called dolphins https://en.m.wikipedia.org/wiki/Dolphin_(structure) 2 Link to comment Share on other sites More sharing options...
toucana Posted March 28 Author Share Posted March 28 1 hour ago, exchemist said: Your link is about MDF. I wonder if the ship was burning that or RFO. (My comments about centrifugal separators relate to RFO.) A newly created Wikipedia page about MV Dali offers some more information. https://en.wikipedia.org/wiki/MV_Dali Quote Dali is propelled by a single low-speed two-stroke crosshead diesel engine coupled to a fixed-pitch propeller. Her main engine, a 9-cylinder MAN-B&W 9S90ME-C9.2[11] unit manufactured by Hyundai Heavy Industries under license, is rated 41,480 kW (55,630 hp) at 82.5 rpm.[2] Her service speed is 22 knots (41 km/h; 25 mph).[5] For maneuvering in ports, Dali has a single 3,000 kW (4,000 hp) bow thruster. Electricity is generated onboard by two 3,840 kW (5,150 hp) and two 4,400 kW (5,900 hp) auxiliary diesel generators.[4] I’m not sure exactly what type of marine fuel that suggests ? The auxiliary electrical generating capacity is large, because ships of this type may need to cater for ‘reefers’ or refrigerated container units. Link to comment Share on other sites More sharing options...
exchemist Posted March 28 Share Posted March 28 6 hours ago, toucana said: A newly created Wikipedia page about MV Dali offers some more information. https://en.wikipedia.org/wiki/MV_Dali I’m not sure exactly what type of marine fuel that suggests ? The auxiliary electrical generating capacity is large, because ships of this type may need to cater for ‘reefers’ or refrigerated container units. Main engine will be RFO for sure. It’s a big one: 9 cylinders of 90cm bore. (The C will I think stand for container ship, normally meaning higher rpm and shorter stroke than, say, the variant for tankers.) However I have just remembered it used to be the practice in some areas to switch to MDF in coastal movements, to comply with local emissions regulations. So what you posted about MDF could be relevant. Link to comment Share on other sites More sharing options...
TheVat Posted March 28 Share Posted March 28 I found the Dali's electrical problems kind of surreal. (too soon?) Link to comment Share on other sites More sharing options...
geordief Posted March 28 Share Posted March 28 32 minutes ago, TheVat said: I found the Dali's electrical problems kind of surreal. (too soon?) think so. Link to comment Share on other sites More sharing options...
Airbrush Posted March 28 Share Posted March 28 (edited) What caused the bridge disaster? The fact that a SINGLE support was so vulnerable to large container ships. After giant container ships started going under that bridge, they should have built up a concrete island around the single support so that if a ship crashes into the support, it will crash into concrete surrounding the single support. Pile up concrete blocks all around the single support, and pour concrete on top of it so there is a smooth, gentle slope, that will stop the giant ship before it can reach that single support. Thank you. 16 hours ago, TheVat said: I heard somewhere that long continuous truss bridges like that will sometimes have their support columns centered on a small artificial island (e.g. a big pile of rock) to serve as a buffer against ship collisions. It's my understanding that nothing will really protect a support column from a container ship, unless it's actually islanded in that way. The ships are just too massive now, averaging much greater mass than in the 70s when construction began. Great, you noticed the structural deficiency. No mention in ANY news about this that I've heard. I posted before I read what you wrote. Thank you. Edited March 28 by Airbrush Link to comment Share on other sites More sharing options...
TheVat Posted March 28 Share Posted March 28 4 hours ago, Airbrush said: Great, you noticed the structural deficiency. No mention in ANY news about this that I've heard. I posted before I read what you wrote. Thank you. IIRC, WaPo mentioned it. Their coverage was extensive, since DC is close to Baltimore. @swansont posted a wiki article that provided a clear description of dolphins (structural). Dolphins are also used to protect structures from possible impact by ships, in a similar fashion to fenders.[2] A notable example of dolphins used to protect a bridge is the Sunshine Skyway Bridge across the mouth of Tampa Bay. In 1980, the MV Summit Venture hit a pier on one of the bridge's two, two-lane spans causing a 1,200-foot (370 m) section of the bridge to fall into the water, resulting in 35 deaths. When a replacement span was designed, a top priority was to prevent ships from colliding with the new bridge.[3] The new bridge is protected by 36 dolphins: four large dolphins protecting the two main pylons supporting the cable-stayed main span plus 32 smaller dolphins protecting bridge piers for 1⁄4 mi (1⁄2 km) to either side of the main span.[3] The cost of the dolphins was $41 million (approximately $90 million in 2017 dollars).[3] Link to comment Share on other sites More sharing options...
swansont Posted March 28 Share Posted March 28 6 hours ago, Airbrush said: Great, you noticed the structural deficiency. I’m not sure deficiency is the right word. Ships were smaller when the Key bridge was built in 1977. https://commercial.allianz.com/news-and-insights/expert-risk-articles/shipping-safety-22-losses.html “Container-carrying capacity has increased by around 1,500% since 1968 and has almost doubled over the past decade [referenced to 2022]. Ever larger vessels are on order.” The Dali’s capacity is almost 10000 teu, almost triple the biggest ship when the bridge was designed. Link to comment Share on other sites More sharing options...
exchemist Posted April 7 Share Posted April 7 I have just watched an interesting video made by a Marine Chief Engineer, on this incident: He is not privy to any inside information but he can make certain deductions from looking at the footage of the incident. They key points I got from this were that: (i) the emergency generator did not restore power within the 45seconds mandated by SOLAS rules. It came on but after about a minute, too slow, why? and (ii) there was black smoke from the funnel after the restoration of power after the blackout. He does not believe they would have had time to restart the main engine, which would have shut down when electric power to run its fuel pumps etc was lost. So it cannot have been from the main engine. It must therefore have been from trying to restart the main generators. But these are indeed supposed to run on MDF when manoeuvring close to port, which should not produce black smoke, even during start-up. So the finger of suspicion points to the fuel fed to the main generators. Possibly there was something badly wrong with the MDF or possibly they were incorrectly trying to run the gensets on RFO too soon and something went wrong with the switchover from MDF to RFO. The ship should have been able to operate its rudder even on only the emergency backup genset, but without the propeller, the turning effect from the rudder would have been very limited. He did make the comment at the end, just in passing, that if the port regulations had required tug assistance until out from the bridge channel then the outcome would have been different. That thought had occurred to me too. Expecting these large ships to get out on their own, with the tidal current in the river estuary......well.....I don't know. Link to comment Share on other sites More sharing options...
dimreepr Posted April 8 Share Posted April 8 15 hours ago, exchemist said: I have just watched an interesting video made by a Marine Chief Engineer, on this incident: He is not privy to any inside information but he can make certain deductions from looking at the footage of the incident. They key points I got from this were that: (i) the emergency generator did not restore power within the 45seconds mandated by SOLAS rules. It came on but after about a minute, too slow, why? and (ii) there was black smoke from the funnel after the restoration of power after the blackout. He does not believe they would have had time to restart the main engine, which would have shut down when electric power to run its fuel pumps etc was lost. So it cannot have been from the main engine. It must therefore have been from trying to restart the main generators. But these are indeed supposed to run on MDF when manoeuvring close to port, which should not produce black smoke, even during start-up. So the finger of suspicion points to the fuel fed to the main generators. Possibly there was something badly wrong with the MDF or possibly they were incorrectly trying to run the gensets on RFO too soon and something went wrong with the switchover from MDF to RFO. The ship should have been able to operate its rudder even on only the emergency backup genset, but without the propeller, the turning effect from the rudder would have been very limited. He did make the comment at the end, just in passing, that if the port regulations had required tug assistance until out from the bridge channel then the outcome would have been different. That thought had occurred to me too. Expecting these large ships to get out on their own, with the tidal current in the river estuary......well.....I don't know. I wondered about the ankers too, but I guess even a failsafe anker drop would have little effect in this case. Link to comment Share on other sites More sharing options...
swansont Posted April 8 Share Posted April 8 Another cargo vessel lost power near a bridge but was being escorted by tugs. https://abc7chicago.com/verrazzano-narrows-bridge-new-york-apl-qingdao-cargo-ship-loses-power/14634032/# “The U.S. Coast Guard confirmed the container ship "had experienced a loss of propulsion" Friday night as it traversed a waterway in New York Harbor.” I’m guessing this happens relatively often but we just weren’t aware because near-misses usually don’t make the news Link to comment Share on other sites More sharing options...
swansont Posted April 19 Share Posted April 19 On 4/8/2024 at 10:58 AM, swansont said: I’m guessing this happens relatively often but we just weren’t aware because near-misses usually don’t make the news “From 1960 to 2015, there were 35 major bridge collapses worldwide due to ship or barge collision, with a total of 342 people killed” https://apnews.com/article/bridge-collapses-barges-list-1f2d6261d523ddc625aaaf3b32c626bc# Link to comment Share on other sites More sharing options...
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