Our cadets brought a couple of Bank line cadets onboard the Caltex tanker I was onboard in Durban.
The breakfast menu was printed on a standard menu card (A5?) . I think they started with the date. It was truly impressive the amount of food they put away.
I agree that for an apprenticeship you couldn’t beat the company for the experience they received.
One of our vessels, the New Zealand Pacific, was caught in the December storm in 1978 and she was built in the same yard as the Müchen, lost with all hands in the same storm.
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Luckily the weather at Port Said and Suez is normally hot and sunny and it is quite easy to board a ship via a ladder or gangway. Question remains why ms Ever Given increased speed from 7 to >13 knots during a few minutes after entering the canal at Suez … and then turned starboard/east ramming the canal bank/side. Only an idiot would do it. Sand storm? Then you don’t enter the canal and, if you are in the canal, you slow down and stop.
Heiwa.
There was no turning…….there was a hydrodynamic sheer.
There was no ramming…….there was a grounding.
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Ausmariner
Have you ever been to Suez and Port Said? 100’s of ships transit the canal every day at slow speed without hydrodynamic sheer and grounding as a result. Mystery is why ms Ever Given increased speed 100%, turned starboard and contacted the eastern canal side a few minutes after starting transit. I don’t think it was due to bickering pilots.
The ability of a ship to maintain course in wind is related to the ratio wind velocity / ship speed.
the world has moved forward since 1000teu ships…
Yes.
Mystery is why ms Ever Given increased speed 100%, turned starboard and contacted the eastern canal side a few minutes after starting transit. I don’t think it was due to bickering pilots.
Pretty straight forward really.
Initially, owing to wind force on the starboard quarter, the vessel was making leeway to port and rounding up to starboard. To counteract this the helmsman was using judicious applications of port helm which in effect tracked the pivot point towards the western batter. To extricate himself, the Pilot increased speed and drove himself back towards the centre of the channel. The increased SOG introduced two complicating elements……drift and bank effect. At this juncture, the wind was directly astern and became a minor factor in the vessel’s demise. The bridge team were incapable of addressing the generated hydrodynamics and did not identify the starboard drift. The vessel sheered at relatively high speed. Consequently, the vessel grounded.
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Perhaps also the squat should be brought into the equation especially with that double speed. The squat for confined waters is 2 x Cb x V^2/100 = 0.73 m with a Cb of 0.7 and V of 14 knots. Not a lot maybe but still if compared to the under keel clearance.
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Indeed Dutchie.
Particularly being mindful of how close she ran to the western batter. UKC would have been significantly reduced and squat significantly increased. Depending on initial trim, the squat by the bow may well have effected steerage and compounded the problem.
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We just had a quick reply from Heiwa accusing me of never being in the northern hemisphere, not accepting the explanation and alleging that the Suez Canal is too deep for a ship to ground.
It was quickly deleted for some reason.
The guy is a known nutcase. Ignore him is my advice.
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POWER was applied to increase steering effect. That’s a basic ship-handling technique in this situation specifically. But their error was in leaving the higher bell/increased speed on for too long. It is “intended” to be a power kick. It is specifically NOT done to increase speed. That is a fundamental concept well educated (trained) Pilots are taught and know all too well.
These SCA Pilots, given the size vessel they were handling, obviously missed that day in ship-handling class.
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Must admit , that i have been waiting for SQUAT input on this and other forums since 23rd of March and I am glad it has finaly been mentioned.
Folks talk eloquently about Bernoulli’s equation, but it acts not only horizontally (bank effects) but vertically as well and squat has seemed to me to be ignored issue in this and other threads.
Regarding Cb=0.7 pls note as follows:
source : DNV GL CONTAINER SHIP UPDATE No 01 2016 ( note it was 5 years ago)
quote:
■ For a homogenous container loading of 16t/TEU, the long and
narrow concept with 19 bays and 19 rows is again the preferred
concept. The highest block coeficient investigated here is - CB=0.72.
end quote
One may expect that Cb of 20 000+ TEU is even higher up to 0.75 although it requires peek into hydrostatic particulars /data of o given ship.
Some most user friendly and “popular” methods of squat calculation :
Barrass, Eryuzlu at al, Huuska/Guliev, Romisch , Yoshimura .Older ones are :Schijf and Sogreah which i have learned in 1980
Acc to Dr.Barrass- “Ship Design and Performance for Masters and Mates”
Chapter 17 Ship squat in open water and in confined channels-Squat formulae
13.4 x 13.4= 179.56 x 0.75=134.67/100= 1.35 m by the bow in open water
in confined waters x 2= 2,70 m by the bow ( this result is a bit exaggerated in comparison with Schijf and other methods) but at least on the safe side.
some squat facts :
Squat varies directly with breadth (doubling breadth doubles squat)
Squat varies by the square of speed (doubling speed quadruples squat).
Since one must assume , that old salts and practitioners with hands on experience are here i see no reason to elaborate on the trim by the bow effect on steering.
Now, regarding speed in such confined waters like Suez Canal and/or similar locations i will refer to the following publications (underlined in capture below)
All of the above underlined titles recommend the same as Nautical Institute Shiphandlers Guide in Chapter 7- Interaction- bank effect , squat.
quote:
end quote.
Hence increasing the EG’s speed under developing circumstances, irrespective of who had the con, was a final nail to her coffin.
In all formulas on squat and theoretical equations including Bernoulli’s, speed appears as V or V x V . But there are other significant equations, where speed features prominently.
E = ( m x V x V) /2 and p= m x V - kinetic energy and momentum equation ( for 6th graders). The rule of the thumb derived from them, which should be known to those having the con is : less speed = less damage
And it goes without saying , that in above equations item V is the only one , those having the con can control. It is a vector which has two important and controlable attributes:
a) value
b) direction
Regarding item b) i believe Alias Kennebec_Captain has effectively deprived the commentators favouring “direction control” options for LOA 399 and B =59 m, with the formula for the swept path
SP = B + LOA * sin α, aided by the SCA RON picture of the crross section below:
and with the gradient 3:1 in the south the width at 15.7 m was even less.
I am quite sure , above calculations and drawings may not be applicable or are mere approximations, as the actual /true cross section of the Canal , the public eyes will never see .
Likewise we will never see the true bathymetry of the section , where the incident took place, we will never see the results of SCA Risk Assessment regarding safe passge of behemonths, whose dimensions reduced to zero all possible safety margins available for smaller units.
Last but not least the SCA dredging programs and their results may also remain shrouded in perpetual veil of mystery -just like their piramides.
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boats too big on a windy day for the suez,
heard that from an expert at the bar last night.
Actually heard that from 2 different people as soon as it happened (that work for ship owners) so it has clearly been a topic of discussion for a while.
Their worry is the SCA will create a maximum size limit.
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Considering the number of pilot fatalities, having a licensed deck officer at the ladder is essential. It wasn’t always that way, but it’s the best way forward.
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In the worked example the value V = 10 is in my opinion not correct. It seems you used knots instead of meters per second in the formula. The speed of a ship making 10 knots equals to 5.14 m/s. V squared is 26.47, the squat for confined waters is then 2 x 0.7 x 26.47/100 is 0.37 m and not 1.50 m. Correct me if I am wrong.
The outcome is not 100% correct as the H/T ratio must be between 1.1 and 1.4. The water depth H is 25 and the Ever Given’s draft T is 15.4. The ratio H/T is then 1.6 .
Alias Dutchie.
Reference is made to screen capture below:
Therefore pls remind me, lest I have forgotten, who is the author of above comment. ?
One can find it quite bizarre and amusing , that by using yourself simplified Barrass formula to highglight/signal the problem ,which has not been communicated/discussed yet in this forum , You have dismissed/igmored completely all the reservations/limitations, which You were so kind to highlight in the case, when somebody else used the same formula for the same purpose.
Isn’t it strange ? and it seems like discrimination .
Regarding H/T ratio stay assured , that some sources indicate the limits of the method for " open waters" as 1.1-1.2 and blockage factor as 0.06 and 0.3 for confined waters.(1<= B <=10).
So what??
The issue is not about precise accuracy of calculation but about directing readers/commentators attention to other then “bank effect” phenomenon , that could have a negative impact on manoeuvrability of said vessel, navigating within the confines of the canal ,with " alleged" by SCA cross section and dimentions, what possibly but not necessarily, could have contributed to her unfortunate grounding.
On the issue " correct me if i am wrong", I accept with regret Your invitation and declare that : yes You are VERY WRONG .
You are wrong not because You used m/s instead of knots but because most probably You have not excercised enough diligence to do even minimal research before voicing your " OPINION" .
I have enough humility to respect Your “opinion” but i do not necessarily have to agree with it
The same humility , spurred me to insert my input in this forum ,where careful reader will observe , that I rather quoted experts in the field, while keeping my opinions in carefull check.
Ending I would like to express my grattitude , that Your original and subsequent commment/input, allowed me to manifest my negligible existence/presence and participation in this forum.
Last but not least allow me for the note of caution, that all formulas in available literature should be used with caution and understanding as to their limitations and purpose, as well as with required input (metric or other) to avoid misunderstanding and mis or over-interpretation or simply wrong results.
Your little manipulations/adjustments regarding canal depth and original reported draft of EG has been noted.
In our particular case You used tulips , while I used smoked sausages . We can not be on the same page, without some other common denominator.
I am sorry that I seemed to have offended you in several ways, that was and is never my intention or my style of communicating on this forum. I think that it is contraproductieve to try to react to your comments and I will therefore refrain from that.
I rest my case.
Alias Dutchie.
Can not accept Your “I am sorry” as You have nothing to be sorry about as I am neither offended nor irritated but rather amused a little. That is all.
There is no case as well, as You have communicated an important issue in my subjective opinion and we both basically agree on that, but have applied different units for it’s measurement. You have used tulips and I have used sausages .
As far as I am concerned there is no drama in that. May be others will pick up your clue and elaborate, so all will learn sth in the process.
Therefore be so kind and cheer up and do not sound so gloomy. Cheers and have a wonderful rest of the day.
An interesting exchange.
I feel a little remiss in not mentioning squat in my response to Heiwa and was pleased that Dutchie raised it. Clearly, at the recorded SOG allied with the channel geometry and vessel positioning……squat by the bow was a significant factor.
During my Pilotage career, the Corporation engaged a firm to install a Dynamic Underkeel Clearance System owing to high entrance swell and limited UKC parameters. Depending on swell direction, areas of the channel could also become swell affected. The elements which were equated to calculated UKC were depth, draft, allowable bottom clearance, manoeuvring margin, squat and survey error allowance. The vessels were 300/50 with 10% UKC plus maximum transit speed of 8~9 knots. Channel was 180m wide and was not trapezoidal. Draft was around 15.5m
So, all the calculations were done and they needed to be validated/calibrated via real time RTK 3D measurement prior to acceptance and installation of the system.
The fascinating outcome was that the calculated and measured squat were in fact very close to each other. At 8 knots, if my memory serves me correctly, it was in the order of 0.9m by the bow.
A 15.7m/Cb=0.7/400m LOA/59m beam behemoth offset in the channel charging along at 13.5 knots is a different animal again.