Very sad breaking news out of Baltimore…..yet another allision. M.V. “Dali”

If the breaker trips there could be problem with reffer container

Good day .

May i chip in hoping i am not transgressing the Pilots conversation. Feel a bit uncomfortable using my elbows among individuals who are well beyond my league as far as practical experiences are concerned in ship maneuvering.

As I understand the Pilots claim ACL would be most effective in the Dali scenario. They are absolutely right as far as simple physics is concerned. One does not need to be a rocket scientist to figure that out although I may be wrong of course.

So we have a force F, lets say 80 Mt ( a tug) and we know , that in the case of a vessel moving forward /ahead, the " pivot point" tends to shift it’s location forward as well . Different theoretical sources argue vehemently and with passion, where the pivot point finally rests, while the speed forward increases but it is not relevant here. Lets assume it is somewhere just behind the forecastle .

The ACL when the force " F " is applied offers the longest distance/arm , lets call it “R” from the pivot point, hence applying force F at ACL point one achieves the biggest available "Moment of force “F” " MF= F x R in relation to pivot point , what is simple as pie.

Hence if R1 > R2 , then MF1> MF2 with F being constant and if R is reduced to almost “zero” the required MF is reduced to zero as well . And when one looks at the ship imagining it as a “forklift” then it sounds/looks like “eureka”.

Stopping ability from ACL does not need any comment.

I think I am done here trusting that Pilots may now unleash all hell on me for debunking the WooDoo stuff so unceremoniously .

Forgot about the source : what could it be ??? but my good old bible reminding me of my youth and crazy days in WAF with no tugs and shitting my pants regularly .
image

Cheers.
Have forgotten to say , that in former East Germany there is an institute i believe in Rostock , where the pivot point theory is seriously challenged but with such confusing “math and physics” , that each time i try to crack their code my head explodes and i need a drink . Too old for this shit.

…and for sure change the dang pitch so those of us “of a certain age” can hear the dang thing and have a reasonable chance of locating the source!

(But running to a central alarm panel would be VERY helpful)

spowiednick,

This is a discussion for a separate thread although one thing I will say is that I can practically display to you that the peripatetic pivot point or centre of lateral resistance can actually be made to move outside the shipshape.

1 Like

Well Sir . With "peripatetic " thing or without ,You do not need to convince me that judging by all You have said here in this or other topics and I read it with great interest and passion to learn , that You are a pro.
I have no doubts about it .
And Your lecture here will be most welcome . :joy:
Cheers and have a wonderful evening and night

1 Like

Forgot to add, that in the heat of the moment "when the lights went off " the bridge team on Dali was more concerned with "peristatic " thing then with “peripatetic” .Just speculating .

Comment from Steam man

Dali size containership steering system. How it’s designed to not hit Francis Scott key bridge (youtube.com)

Damn Yankee makes sense

1 Like

Breaking News!!!
23 hours ago — The container ship MS Dali which collided with the Francis Scott Key Bridge at Easter had an engine control system from Kongsberg Maritime.
Source: Teknisk Ukeblad (In Norwegian, behind paywall)

There you have it. Norwegians must somehow be to blame.

PS> Don’t know to what extent the M/V Dali was equipped, but here is a link to Kongsberg’s system for container ships:

1 Like

The official site for updates.

https://www.keybridgeresponse2024.com/

1 Like

Hello all
Lots of good info on this subject including details of the main/principal equipment. Anybody has any thoughts on why she went off course?

Is it possible that the Bridge informs the engine room that they are finished with the bow thruster (BT) and when crew opens the breaker the vessel blacks out. We know the vessel is equipped with 4 generators of approximately 4 MW each. Not sure if the alternators on these diesels are 3.3kV, 6kV or even 11kV rather than the standard 440V on merchant vessels. Reasonably sure the BT is high tension. If the main switchboard is high tension, the BT main breaker will be on this SWBD. SWBDs most likely will have arc flash protection as well. Does this blackout damage the steering gear?Possible. At 7-8 kts, rudder should should be more than responsive. When the Bridge realizes the vessel is not responding to steering (assuming they started the pumps … these pumps are usually not on the sequential start program after blackout), they call the engine room for the BT. Meanwhile power is back and main engine is started astern on maybe half or even full astern (evident with smoke), but not able to steer. Crew goes to close the BT breaker and the second blackout.
Maybe a believable scenario. Going off course is really a mystery.
BTW, I think the EDG came on-line within the statutory (IMO) 45 seconds. The exhaust for the EDG will not be on the main funnel, but rather directly led out of the space that will have direct access from the main deck and completely separated from the engine room.

Also split switchboards are not common on commercial vessels as opposed to DP vessels.

On MAN ME (electronic) engines, ‘super DEAD SLOW’ is possible by controlling the 3 to 4 injectors on each cylinder independently. They will fire/inject in sequence every revolution to maintain thermal balance in the cylinders. Wonder if the DALI was equipped with this functionality. About 12 rpm (4-5 kts) possible.

Thanks.

Not really. No engine/rudder, and pressure from the bank turned her the other way. With nothing available to correct it, she just kept on going.

4 Likes

yea - my only issue with the bank cushion is if they were feeling that - they helmsman may have been carrying left rudder when all went dark -

I am more thinking - the ship was in the process of trying to get back to dead middle of the channel to line up for the bridge and had a bit of right rudder on when all went dark

but all of that is nothing but guesses - time will tell

1 Like

True, unless he happened to be midship when the lights went out.

Like you said, we’re all just guessing.

It will be interesting to see what the VDR has. It should eliminate some of the questions. The engine room data should tell the rest of the story

1 Like

I said early on that I believed there was some right rudder on when the ship went black and we see the ship slowly swinging right while it was dark then power restored. Once the main was restarted astern comes the inevitable greater swing right as the prop walks the stern to port. Probably the toughest decision to make for the pilot…to either do what he did or throw the rudder hard to port and give a full ahead order. This is why having an escort tug could have prevented the strike and we know now they will be required for any ships transiting beneath highway bridges everywhere in the US as they already are in almost all other nations.

4 Likes

Thanks for confirming that I was not dreaming when I posted about this earlier :+1:

It was a one off call for MSC Zoe we were not her usual UK port and I quoted a higher rpm than 12 as 12 simply does not seem possible but thinking back it was 12 which would give a STW of 2.5 kts . Incredible really.

I can also confirm that The Dali did not have this system, or at least her sisters that I piloted didn’t.
The Zoe was the only ship I ever saw with this system, hopefully there are many more now

That is an amazing system. It was always terrifying to be going at a speed you didn’t want all in the name of efficiency.

One of the feed back systems would be to the autopilot the other to the helm indicator. We lost the helm indicator entering Melbourne on a thankfully small container ship. The helmsman didn’t know where the rudder was so couldn’t steer. We switched to the autopilot and continued to the berth.

3 Likes

Some blooming quick thinking there.

Must say I never thought of that happening