But I’m sure he gave you all the tugboats you wanted…
Who???
One of the more useful things that you as a seasoned and experienced pilot could add to the discussion is explaining to some the ship’s speed at dead slow ahead of a very large container ship. Without propeller wash over the rudder the action of the rudder quickly losses effectiveness as the speed bleeds off. Being a direct drive there is a minimum RPM that the engine will run at.
2 Likes
No worries Mr Hogsnort
The average speed of a larger Container Ship at dead slow is anything between 6 and 8 kts.
There were some awful examples that had dead slow at 9 to 11 but in all fairness they were normally smaller ships , 180 to 250m .
There are some innovative companies around that had some amazing low speeds like the MSC Zoe class who are 400m so basically a monster that could fire ahead at 23rpm and reduce to a minimum of 19 giving a speed of 3 kts , absolutely fantastic for us pilots as we could put them into a swing without even stopping the engine .
Normally as I said anything between 6 to 8 kts at 28rpm
1 Like
I reckon in still water I could keep control all the way down to 3 ISH KTS.
In a cross wind obviously depending on windspeed around 6 kts ( if higher you need tugs)
So if I think I am answering your question at 8 down to around 4 kts Dali should have had steering authority.
1 Like
As I said before I have piloted the Dali class and they are no big deal.
Hogsnort,
That is the other great advantage of a CLA escort tug. You can leave the VLCS/ULCS on DSAhead maintaining good steerage whilst laying back directly astern with the tug to control desired headway.
2 Likes
My reference to VLCS is towards the “Ever Forward” class of vessel which have regularly passed under the Key Bridge…….not the “Dali”.
1 Like
Mr 244 has answered my post succinctly. What I wanted to do was get people like yourself and 244 to explain exactly why a centre lead aft tug is required in some classes of ship. Especially if you start limiting the speed of the ship below a certain point. 23 RPM wow. I haven’t seen revs that low since getting a tow underway in an 83,000 tonne tanker towing a sister ship in the Indian Ocean. Steam turbine of course.
2 Likes
The Ever Forward didn’t get REAL far past the bridge.
Would You be so kind and indicate what thread you kave in mind as i have searched as per below with no good result. THX
Possible dumb Q here: Some of the cargo containers aboard are refrigerated. Does the ship have power and is refrigeration being utilized ?
It was actually post #378 in this thread.
2 Likes
THX .Well noted. 
04.04.24 addendum:
QUOTE after Maritime Sutra verbatim:
“This EEP apparently appears to be introduced after the recent Baltimore bridge collapse due to allision incident by MV Dali.” END QUOTE
Well , I am not going to argue but Sutra used “apparently” and I am not a linguist .
Has the EEP been introduced before Dali incident ?
or has it been introduced exactly at the time of the incident at 0130 lt
or about ??
or has it been introduced after the Dali incident??
The fact is it has been introduced after the Dali incident. What it means ??- it may mean nothing .
No point discussing speculations and yours BS is an opinion may be valid .I do not know. But coincidences happen and not all believe in coincidences.
Cheers.
Reading it was optional. Even though I have read up a little on this subject and have some access to one ship that will have this notation, I have not seen it in action.
My understanding is this arrangement will essentially do for bridge equip what central alarm and monitoring systems does for the engineering plant. So if you think of all the various bridge equipment as the pressure and temperature transmitters and level switches and an IBS central processing unit as the PLC - the field devices will communicate say serially to the processing unit which will have video display units. These would or could be configured as mimic screens showing the equipment and communication busses connecting them and alarm and status pages. Silence button(s) could silence any audible alarm or process message and they will be displayed on a list. Priorities can be assigned and all gets data logged/time stamped. If one is serious about sorting out this “mass of alarms” one has to consider this approach. Or not.
3 Likes
Sorry KP .
Did not know that.
Even with the biggest monsters having a tug or ,2 on the sides pulling back ,50 to 75, ,Percent will wipe the speed off sufficiently if you do it early enough.
It’s all about speed control.
Or should I say slow speed control.
It doesn’t matter how you do it
Me and Aus have debated the best ways to do it but in the end it does not matter,as long as you do it.
This of course has no relevance to the original subject
80t bollard pull (guessing they’re using MT) would put it in the same range as the majority of the Foss/Crowley/Bay Delta escorts on the US West Coast. Those tugs perform well in drills with loss of power/steering on tankers displacing 100,000+ tons.
2 Likes
If the breaker trips there could be problem with reffer container