chengkp75

When the propeller stops, the engine stops. When the propeller goes astern, the engine rotates in the other direction. The engine is directly bolted to the propeller shaft. Not sure what energy you are talking about. Energy to drive the turbocharger comes from the main engine's exhaust gas spinning a turbine which is shafted to a compressor, which compresses the combustion air for the main engine. So, when it starts, there is no energy from the exhaust (there isn't any exhaust), so the "auxiliary blowers" switch on and compress some air for the engine. As the exhaust gas builds up in volume and temperature, the blowers switch off, and the turbo spins on its own, driven by the exhaust.

No. Even at low speeds, where the turbocharger does not have enough energy to provide sufficient air to the engine, there are motor driven fans to provide that air.

From my understanding of the Corps of Engineers plan, they hope to clear the main span of the bridge from the channel first to allow what they are calling "one way", but which is really "one at a time" traffic into/out of the port. Then, when the spans are removed from the Dali, they will work to remove the Dali, and additional debris from the channel, and resume "two way" traffic, meaning ships can pass each other while under the bridge.

The navigable channel is basically the area under the "center" or largest span of the bridge. That span is 1200 feet, and you would want to probably clear the adjoining spans on either side, about another 800-1000 feet total. The remainder of the 1.6 mile (8600 feet) of the bridge is outside the navigable channel, and would not need to be cleared to resume vessel traffic, and lots of it hasn't collapsed.

The thing about container shipping and hazardous materials, is "reportable quantity". While the NTSB has stated that there are x many containers with hazardous materials in them, they are not saying how much, or what the materials are. Hazardous materials shipped in containers only need to be reported as "hazardous materials" when the amount shipped reaches the "reportable quantity", so there could be thousands of containers on the ship with vast numbers of hazardous chemicals that are, per container, under the reportable quantity, and no one other than the shipper (the company that actually filled the container to be shipped to a customer) knows what they are.

Didn't see your last question here. Yes, the main engine relies on motor driven fuel pumps, oil pumps, water pumps, air compressors (both for starting and for control). The engine itself does nothing but drive the propeller. But, generator engines are different, in that they basically have self-driven fuel, oil, water systems. But, then there are further "layers" of systems that interact as well. For example, the main engine has a "high temp" motor driven water pump and system that cools the engine directly (generator engine has engine driven high temp pump). These "high temp" cooling systems are cooled in turn by a "low temp" cooling system with motor driven pumps (common to both main engine and generators). The "low temp" cooling loop is then cooled by the "sea water" cooling system with further motor driven pumps.

I did some Reserve time on an Acme class minesweeper, but even then we had a complement of about 60. Navy manning levels have always left me speechless. The vast majority of ships I worked on in the Merchant Marine, and the Dali would be similar, would have a total engineering complement of 4 officers and 4 ratings. As noted in many reports, the Dali has a total crew complement of 21.

Personally, I would disagree with this, I would have my watch engineer on the phone relaying the status to the bridge, so that the Captain has data of what we are doing, in real time, so he can get a feel for when the problem may be resolved, as this can affect his decision making in real time. One company may have better equipment and experience with salvaging grounded ships, while another may have better equipment and experience with underwater salvage and wreck removal. But, yes, trying to get enough equipment and personnel on scene quickly and correctly in a short time is challenging.

And having multiple contractors working the site would be the norm, not a mistake. Just like a home renovation, there is a general contractor and subcontractors.

Hope this doesn't come across the wrong way, but let me ask you if you would pay for a bank of batteries and electric motors in your car, just in case the engine fails while you are on the highway? For the most part, the ship has several layers of redundancy: two generators on line while maneuvering (even though one could support the full load), another generator on standby to start immediately and come online in typically less than a minute, and finally an emergency generator that will start and come on line in less than 45 seconds. But, again, even with steering, a ship without propulsion is just a brick with a rudder. Think of steering your car using the back wheels, and how you would need to anticipate turning to keep the front end from clocking something. And, even if you restore electrical power, the main engine will have shut down on various safety interlocks, and requires multiple auxiliary systems that will need to be restarted and the interlocks reset. Unlike your car, the cooling water, lubricating oil, and fuel systems rely on external pumps driven by electric motors.

I will tend to disagree with the instructor, that in my opinion the best Captains I've sailed with will trust their Chief to be doing all possible, and passing required information to the bridge, and would not want to "get into the weeds" by getting on the phone to the engine room, but let the watch officer relay information, while the Captain retains the "big picture".

What were the reduced speeds? So, what would cause rolling if you were in "calm seas". Is there something wrong on the ship that moves from side to side making the ship roll?

As noted, stabilizers have no effect whatsoever on pitching. Secondly, stabilizers are not designed to, nor will they stop rolling. Their purpose is to slow the "roll period" (the time it takes the ship to go from listing to port to listing to starboard) to a comfortable period. In fact, stabilizers have to have the ship rolling to a degree before they start to work. And, finally, as noted, stabilizer effect is proportional to speed through the water, not necessarily speed over the ground the ship is making. A following sea and current can greatly reduce the stabilizer's effectiveness, since both the water and the stabilizer are moving in the same direction.

Of course, without propulsion, the ship will react to wind, but I don't know what the weather was at that time. I think that dropping the port anchor caused the ship to veer to starboard, and into the abutment. But, even without the final veer into the support pillar, I think the ship would have been too high for the bridge structure at that point, so instead of hitting the support, it would have struck the bridge truss structure, but given the type of bridge it was, this would have had the same effect.

Correct. The lashings would be removed, the windlass clutch released, and the anchor "hanging" on the brake, and the Bosun and a Seaman standing by. Spin the brake handle, and gravity does the rest, in a cloud of dried mud and rust.

Just remember that until the last few moments, the ship was in the shipping channel. Also, like most cruisers, and one poster on this thread, I believe, perspective is deceiving, as it looks like the ships are almost touching the bridges as they go under, so how well a person could determine that a ship was too close to the bridge abutment is up in the air.

How does he know that there isn't an incident commander? What is his clearance to know this information? I sure don't know whether there is or not, but given past experiences, I know there will be one. His comments about "dragging" the bridge out of the channel is just rubbish. That is a certain way to leave potentially damaging debris behind. Likewise his comments about "blowing up" the bridge. He's showing his unfamiliarity with modern salvage operations, where the bridge will not be "blown up", but will be cut up by divers using thermite charges which will work like cutting torches, but with the safety of the divers not being there working the torches. Also, anything dealing with the bridge repair outside the channel (i.e. the area of the main span of the bridge) will be as he correctly notes is the jurisdiction of MDOT, but it is by far a secondary concern, and not in the slightest a concern with regards to opening the channel.

This is an urban myth, port dockage fees are generally for a 24 hour spot.

I don't know of any way of stowing an anchor where it cannot be dropped without power, gravity is a wonderful thing. And, typically, both anchors are prepped for release as soon as the ship leaves the dock.

At double occupancy typically the cruise fares cover all the overhead. Onboard spending provides the profits

The Chesapeake Bay Bridge, further down the bay, that ships would also have to pass under, is only 186 feet high, or the same as the Key bridge, so raising the Key bridge would do nothing.

The Patapsco river at the point where the Key bridge is, is 1.6 miles wide, whereas the Whitman bridge's longest span is 2000 feet. Since the Key bridge's longest span (what collapsed) is only 1200 feet, that means there are 1.4 miles of pilings in the river supporting the bridge spans between the shipping channel and shore. And, in fact, the clearance below the main span of the Key bridge is 185 feet, while the clearance under the Whitman bridge is only 150 feet. While the Whitman bridges total length of 2.2 miles is longer than the Key bridge, as noted, all but 2000 feet is over land, while all of the Key bridges 1.6 miles is over water. While there are suspension bridges that have spans much greater than either the Key or Whitman bridges, the problem comes with whether the land under where you want to place the support piers can withstand the weight and suspension forces of the bridge. Chesapeake Bay is alluvial, and I'm not sure how far down bedrock is, that would be needed to support a bridge with over a mile of span.

Let's see, first we have to tear up the dock to reinforce it to carry the weight of these cranes, and add the rail tracks they roll on (in the mean time tearing down the passenger terminal to run the rails and have space to run the cranes up and down the dock). Then you need specialist cranes to dismantle these cranes where they are (and I don't know of any just laying around spare and unused), transport them by water (so that means the idled Baltimore cranes can't be used since the channel is blocked), and then have the specialist cranes reassemble them at the new dock. Might be done in 1-2 years.

The vast majority of container ships are not self-unloading, meaning they have no cranes onboard, and rely on shore cranes to load/unload. Haven't seen too many container cranes around passenger terminals. Seen anything like this around passenger terminals?:

Yes, all of these container ships will be lining up to dock at a passenger terminal to unload their containers down the boarding ramps, and store the containers in the baggage area of the terminal.