OT: Baltimore bridge replacment

The reports I have seen only said an electrical problem. No mention of problems with the engines while in port.

Tugs doing escort duty at Baltimore cost $1,700 per tug per hour, and the ship reached the bridge just over an hour after undocking. Wire hawsers cost an additional $1,900 to attach and a further $1,900 to detach. Who is going to pay for this 'insurance' given that the pilots would have needed to have assurances that the ship was seaworthy before allowing it to undock?

But clearly an electrical problem can see the ship hit and demolish that bridge pylon.

Much cheaper than it will cost now.

Fat lot of good those 'assurances' turned out to be.

Of course the shipping company pays for the costs when the port requires them to do that when there is a real possibility that the fault has not been fixed and the consequences are so expensive if it turns out that it had not been properly fixed.

Had there been doubt, the port would have been negligent to allow an unseaworthy ship to set sail. Doing so would be to risk it being lost at sea. You are applying 20/20 hindsight in saying that any additional precautions should have been taken.

Of course there is always some doubt about whether a fault has been fixed or is intermittent.

That's wrong too when the fault is just a nuisance if it recurs.

Bullshit when the fault just causes a temporary loss of engine power.

No hindsight involved in a recognition that faults can be intermittent and that if the fault returns when passing that bridge, it can see the bridge collapsed and put the port out of action at vast expense for a long time.

There were two tugs, to pull the vessel safely away from the dock. They stayed at the side of the vessel, until it was making the straight run towards the bridge. Then, they departed to the side of the vessel (steered away from it). This was presumably done, to avoid an incident like the dock strike that the DALI was involved in before. Their job was dock departure control.

Those two tugs would not likely have the power to escort the ship safely through the channel, the way the vessel could do on its own. The tugs were more functioning like bow or stern thrusters, to safely leave the dock.

When the mayday came in, the (small) tugs fired up engines and tried to catch up with the ship, but they were too late. And likely no match for a braking operation. There is a picture of a tug stationed near the bow of the ship. That one looks like a harbor tug and not an ocean going one (used to haul oil drill rigs or the like).

MV Dali

Singapore Installed power

Propulsion 1 fixed pitch B-1-3000 thruster Speed 22 knots (41 km/h; 25 mph)

"In this ship the engine turns at just 82 RPM, matching the optimal rotational speed of the propeller, so no reduction gear is needed.

There is also no reversing gear so, to generate reverse thrust, the engine is stopped and restarted turning the opposite direction."

Hmmm. That's a handy feature.

Her service speed is 22 knots.

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) two 4,400 kW (5,900 hp) [auxiliary diesel generators] "

Then it's left to your imagination, to figure out whether a pair is for engine maintenance and steerage, and a pair is for general ship power. The auxiliary power is roughly equal to eight of our train locomotives (the diesel-electric ones).

How is the output power modulated ? The prop pitch is fixed. It seems to be direct drive.

Paul

Paul snipped-for-privacy@needed.invalid wrote

But were quite adequate to ensure that if the fault did manifest again, that the ship would not take out the bridge pilon.

But could obviously do the same thing to avoid the ship taking out the bridge pilon if the fault recurred.

So they clearly knew that they were quite capable of doing something useful if they could have got to the ship in time.

But wouldnt have been if they had tracked the ship until it was past the bridge and was no longer any threat to the bridge if the fault recurred.

But perfectly capable of acting as a thruster to avoid the ship hitting the pilon because that is what they did when moving it away from the dock and turning it around so that it could move out of the port.

Dont need one of those to stop the ship hitting the pilon

I believe that the auxiliary engines just provide power to an electrical bus, which supplies power to whatever needs it. This would include a hydraulic system which powers everything mechanical, including the fuel pumps and the steering gear. No auxiliary engines, or no bus power, no engine or any control. Power control would presumably be by modulation of the fuel delivery.

Having once owned a two-stroke engined car, I had a vision of mixing vast quantities of lubricating oil with the engine fuel, although I don't know whether a 2-stroke diesel needs lubricating oil added, or does the diesel do it's own lubricating?

There are lots of Youtube videos available of large engines starting up.

The ship was named after Salvador Dali. I winder what he would think of this mess?

It's pretty standard on big ships like this, imagine the cost etc. of a gearbox to handle 55000hp.

In message <Iz%MN.106894$ snipped-for-privacy@fx16.iad, at 20:45:27 on Wed, 27 Mar 2024, Sam Plusnet snipped-for-privacy@home.com remarked:

A vox-pop I saw once, and only once, from a port worker said the boat had too many refrigerated containers on board and they kept tripping the vessel's electrical power.

Via a fuel injection throttle

At 3:51 into this video

At the other end of the scale, some British three wheel cars in the 1960s needed the same. Stop the engine, switch to another set of points, and start in reverse.

My hybrid car can only reverse on electric; no reverse gear on the engine.

My British three wheel car had a three speeds AND reverse! Luxury.

The rules at the time allowed cars without a reverse gear to be driven on a motorbike licence.

Oh yes, I remember one of our neighbours had one of those, a Bond Minicar with the engine mounted on the single, steering, front wheel.

The Bond Minicar did not reverse the rotation of the engine and nor did it have a reverse gear - the entire front wheen, with the engine sitting on it, could be turned right around to face backwards to reverse the car.

That doesn't quite fit with my memory of a school colleague's example. The eng "... had no reverse gear. However, this was a minimal inconvenience, because the engine, gearbox and front wheel were mounted as a single unit and could be turned by the steering wheel up to 90 degrees either side of the straight-ahead position, enabling the car to turn within its own length.

"A method of reversing the car was offered on later models via a reversible Dynastart unit. The Dynastart unit, which doubled as both starter motor and dynamo on these models incorporated a built-in reversing solenoid switch. After stopping the engine and operating this switch the Dynastart, and consequently the engine, would rotate in the opposite direction."

But I also recall it was quite easy to just lift up the car and turn it the way you wanted it!

I also vaguely remember a motorbike-type kick start under the bonnet if the battery was flat?

nib

Even cleverer! :-)

Yes, I was thinking of the Invacar.