Viking Sky position, adrift off Norway Coast and evacuating Passengers & Crew

[Clay Clayton]

40 minutes ago, chengkp75 said:

This, coupled with the restoration of power within a couple of hours is how you can have a multiple engine, multiple propeller failure.

 

Chengkp75

Thanks for your educated speculation!  It’s the first that has made any sense to this poor dumb architect.  It will be interesting to see if the official investigation supports your analysis. 

 

Thanks again!

Edited March 25, 2019 by Clay Clayton

[puppycanducruise]

Thanks Chief.

I always learn so much from you (and a few others like Capt_BJ and Heidi13)

[chengkp75]

31 minutes ago, Clay Clayton said:

 

Chengkp75

Thanks for your educated speculation!  It’s the first that has made any sense to this poor dumb architect.  It will be interesting to see if the official investigation supports your analysis. 

 

Thanks again!

The situation is similar to what happens in a power outage on land.  One power plant trips off line, overloading other plants on the grid, and they go off line like dominoes.  It could also have been that one diesel generator went off line due to a problem, and overloaded the others, and load shedding was not quick enough in this instance, and everything just tripped off.  If it is confirmed that after the power outage, that there were only 3 engines running (and again this may be due to the slow speed necessitated by the weather), then this scenario of one engine failing and causing the rest to trip is also likely.

[buchhalm]

5 hours ago, VK3DQ said:

And this 

 

 

Surely THIS is not part of any regular drill. Imagine the cost...

[cruisenfreak]

30 minutes ago, puppycanducruise said:

Thanks Chief.

I always learn so much from you (and a few others like Capt_BJ and Heidi13)

Ditto.  Imparting your knowledge is very much appreciated.  I have eagerly read these posts.

[ditmar2007]

@chengkp75, you must be one of the most patient men I've encountered.

Thank you for spending so much time answering all the questions.

[chengkp75]

2 minutes ago, buchhalm said:

Surely THIS is not part of any regular drill. Imagine the cost...

Actually, it is.  The crew are required to exercise with these rafts at least once a year.  All the rafts are required to be taken off the ship annually, and inflated at the service provider to ensure the fabric is in good shape, that all required equipment inside is in good order and rations and water are still in date, and then repacked.  The ship typically gets "loaner" rafts from the service provider until the ship's own rafts are returned as serviced.  For regular life rafts, the ship will typically have a "training" raft that is not for emergency use, that is repacked onboard and is used for drill purposes.  An MES drill for a system like you show is co-ordinated with the service provider so that a replacement is ready to install in place of the inflated system.

[Aussie Cruise Nuts]

14 minutes ago, chengkp75 said:

The situation is similar to what happens in a power outage on land.  One power plant trips off line, overloading other plants on the grid, and they go off line like dominoes.  It could also have been that one diesel generator went off line due to a problem, and overloaded the others, and load shedding was not quick enough in this instance, and everything just tripped off.  If it is confirmed that after the power outage, that there were only 3 engines running (and again this may be due to the slow speed necessitated by the weather), then this scenario of one engine failing and causing the rest to trip is also likely.

 

Finally, some well reasoned, experienced, balanced commentary enters this long thread on page 37, nothwithstanding the fine efforts of Heidi13, Seadog and a few other posters.    Thanks Chengkp37, Heidi13 and Seadog et al for your valuable contributions.   So nice to have your thoughts gained over many long years in the industry, unlike the many keyboard warriors who sit on their PC, laptop, iPad etc espousing their theories, conspiracies and occasional vitriol gained from their “experience” of their many (or few) cruises as passengers.  

 

Thanks guys,    Much appreciated and keep up the good work.   I know the majority of CC readers appreciate your input. 

 

 

Edited March 25, 2019 by Aussie Cruise Nuts
Spelling

[chengkp75]

Sorry it took so long to join the party, but you could imagine these old fingers trying to type out long responses from a phone!

[gatour]

11 hours ago, jagsfan said:

I don’t have an issue. I was explaining that I thought I read 1300 passengers way back in the beginning. I have read every post, and obviously misread one (or more). 2am is not my brightest hour. 

I am not arguing. I do believe that my 1300 count was wrong. 

I also am not saying Sky is too small or not suited for ocean or storm. 

I’m saying in today’s world of 3000 pax and up ships, Sky is relatively small. 

I do kind of have an issue with your rather unkind comment, though. 

 

jagsfan in your defense in the early reports it was unclear if there were 1300 passengers onboard or 1300 souls on-board.  Many times when incidents happen they report the number of passengers, in this case it was 1300 souls.

 

I was also initially confused.

[Jersey42]

1 hour ago, chengkp75 said:

When a ship is in heavy weather, the best thing is to head into the seas.  This reduces rolling, but increases pitching.  When a ship pitches, the stern rises and falls, with the propellers coming near the surface when the stern rises and going deeper in the water when the stern falls.  Anyone who has been on a small boat in seas will know this phenomenon, where the propeller speeds up when it gets closer to the surface (less water resistance) and slows down when it "digs in" again when the propeller is deeper in the water.  Further, the wind and seas being on the bow, causes a larger force that the ship needs to overcome to move forward, so once the ship reaches her maximum power on the propulsion motors, or the capacity of the generators to provide power, the ship starts to slow down.  Now, the ship is operating at full power, and the propellers dig in deeper, calling for more power, and you get into an overload situation, so in heavy pitching you will normally slow the propellers down to reduce the power, so that you don't run the risk of overloading the motors or generators and shutting them down.  In the extreme, this is the classic "hove to", where the ship is slowed down to where it is just holding a steady position while heading into the seas.

 

Another problem the ship and Captain face is the wave period and ship speed.  If you try to drive the ship "too hard" (too fast), then the ship will not be rising and falling at the same speed as the seas, and you will start to "catch" waves on the bow, where the bow of the ship is dropping when a new sea comes along, and the bow digs deep into the wave, causing a slamming against the hull, and problems all along the length of the ship.  Slowing the ship further will put the ship's motion back in synch with the seas, and reduce this slamming.

 

So, what does this have to do with the Sky?  I believe that something in the weather, either the known and familiar 10th or 100th wave phenomenon (the waves are known to be greater or faster than the ones preceding or following), or a confused sea state due to wave echoes from the near shore, caused the ship to slam into a wave, dig deep, and cause the propellers to rise very near the surface, losing resistance, speeding up and the safety system tripping the propulsion motors to prevent damage due to overspeeding.  This sudden loss of the majority of the electrical load caused the generators on line (and as I've said, there is no documentation that there were not all 4 on line at the time), to overspeed for the same reason (loss of resistance as the load on the generator dropped), shutting all the generators down.  This, coupled with the restoration of power within a couple of hours is how you can have a multiple engine, multiple propeller failure.

I do appreciate the time you are taking to provide us neophytes with lots of insights based on all of your real world experience. Am I reading your post correctly that the weather (rough seas) could have been the cause of the propulsion system shutdown?

 

There have been a lot other posts that indicate these ships are built to withstand a lot worse weather than what the Viking Sky ran into. Others have added that it was the propulsion system shutdown that caused the incident, not the weather.  But with no power, the weather made the ship very vulnerable.   You seem to indicate the weather could have been the cause, as opposed to some random mechanical or electrical breakdown. Am I misunderstanding?

 

I realize this is all speculation, but I tend to have more trust in speculation from informed people.

Edited March 25, 2019 by Jersey42

[gatour]

Thanks chengkp75.

 

I had forgotten that you are a proud grandpa.  Spending time with you family is definitely more important than correcting all of us armchair ship engineers.  I definitely appreciate someone taking time when they have no direct or even indirect connection with an incident in question. 

[geocruiser]

8 hours ago, just_dont said:

 

 

 

 

 

(sorry for not excerpting, but most seemed relevant)

 

This is actually a very interesting hypothesis. I suppose it's as valid a guess as any other for explaining the power failure.

I know ships' electric systems are different than those found on land because they lack a connection to "earth ground". Space-borne electronics (also lacking earth ground) have to be "radiation hardened" to protect them from all of the same sort of radiation that causes auroras. We don't worry about it much at all on the ground, because most radiation is blocked by Earth's atmosphere. But a ship's floating-ground electric system...? I'm a computer engineer. I don't have an answer. Maybe Chengkp75?

 

The freighter that lost power at the same time...? Would it also have a diesel-electric power system? If so, the causes could have been related.

 

Sent from my SM-G955U using Tapatalk

 

 

 

Thank you for your answer.  You gave me some interesting info about the freighter and electronics.

I too would love to see Chengkp75 answer,  I will be looking for it.

Edited March 25, 2019 by geocruiser

[chengkp75]

2 minutes ago, Jersey42 said:

I do appreciate the time you are taking to provide us neophytes with lots of insights based on all of your real world experience. Am I reading your post correctly that the weather (rough seas) could have been the cause of the propulsion system shutdown?

 

There have been a lot other posts that indicate these ships are built to withstand a lot worse weather than what the Viking Sky ran into. Others have added that it was the propulsion system shutdown that caused the incident, not the weather.  But with no power, the weather made the ship very vulnerable.   You seem to indicate the weather could have been the cause, as opposed to some random mechanical or electrical breakdown. Am I misunderstanding?

 

I realize this is all speculation, but I tend to have more trust in speculation from informed people.

There are really two possibilities in my opinion.  Either a random failure of a generator caused a "waterfall" shutdown of the entire system, or weather caused the waterfall shutdown.  Yes, the ships are designed to weather far worse than what the Sky encountered, but there is always the random element to weather, just like there is a random element in any situation in life.  As I've said, I've experienced a shutdown of propulsion due to weather.  We were on a twin screw RO/RO vessel in the North Atlantic, at night when there is no one on duty in the engineering spaces of cargo ships, when the bridge reported (later when we could talk about it) that two seas from two directions hit the ship at the same moment, and the force of those two seas essentially stopped forward motion of the ship, and the stern rose as the seas passed the ship, and one propeller came so close to the surface that the engine attached to it (this is the type where the diesel engine is directly connected to the propeller shaft) oversped due to loss of water resistance.  In this instance, we still had propulsion from the other diesel and propeller, and power due to separate auxiliary generators, but it still took about an hour to restart the second main engine.  Was the ship in danger of foundering?  No.  Was the ship designed for seas greater than what we encountered?  Yes.  The random nature of the two seas meeting at the exact point where the ship was, at that exact moment, coupled with the randomness of the ship's speed in relation to the wave frequency led to the shutdown of the engine.  Other times, I've been on single screw ships that encountered a "rogue" wave (probably not an actual rogue wave, but one of the 100th wave phenomenon type waves) that shut our propulsion down due to overspeed when no one onboard was even thinking that the weather was anything to consider as dangerous.

 

Until I get a confirmation that an engine failure started the whole situation, I will lean towards a random sea causing an overspeed of the propellers, leading to the total loss of power.  Could a sister ship, with the same propulsion and power generating plant, sailing a half mile away at the same time have sailed through this storm without incident?  You bet.  I am of the opinion that this was an act of the randomness of the universe.

[chengkp75]

8 hours ago, just_dont said:

 

 

 

 

 

(sorry for not excerpting, but most seemed relevant)

 

This is actually a very interesting hypothesis. I suppose it's as valid a guess as any other for explaining the power failure.

I know ships' electric systems are different than those found on land because they lack a connection to "earth ground". Space-borne electronics (also lacking earth ground) have to be "radiation hardened" to protect them from all of the same sort of radiation that causes auroras. We don't worry about it much at all on the ground, because most radiation is blocked by Earth's atmosphere. But a ship's floating-ground electric system...? I'm a computer engineer. I don't have an answer. Maybe Chengkp75?

 

The freighter that lost power at the same time...? Would it also have a diesel-electric power system? If so, the causes could have been related.

 

Sent from my SM-G955U using Tapatalk

 

 

 

 

7 minutes ago, geocruiser said:

Thank you for your answer.  You gave me some interesting info about the freighter and electronics.

Actually, the ships have an excellent connection to ground, via the steel hull and the electrolytes in sea water.  This is why ships have a "floating ground" (not meant as floating in water, but where the power conductors are "floating" at voltages above ground), because that excellent ground can cause electrolysis of the hull and fixtures, corroding the ship.  Ships are frequently struck by lightning, yet the massive amount of power that would fry your home electronics if your house was hit and you didn't have surge protectors, goes quietly through the hull to the sea.  No electronics or power applications are affected, because the power system (both wires) are not connected to ground.  However, there is always a ground connection on the outlets in your ship's cabin, in case your hair dryer's insulation fails, to provide a better path to ground than through your arm.

[kearney]

Been following this thread for quite a while... I had not made any comments... I have no knowledge to share... really happy that chengkg75 was able to contribute... thanks for the information. I will go back and read it slowly... and hopefully will fully grasp the information more completely. Always enjoy your contributions to the discussion when these mechanical problems arise... thanks to the others with experience as well. Just glad things worked out, well as good as can be expected under the conditions....and that the ship did not hit the rocks.  

[larryfry50]

We are set to sail on this ship in May.  By then., I hope they have all the necessary repairs completed.  I have just one technical question.  What is the cause of the engine failure?   Does anybody know?  There was a problem with Norwegian Star in 2017 in Australia.  It was dead in the water and had to be towed back to Melbourne. Fortunately,  we were able to cancel that cruise ahead of time.  

[Jersey42]

15 minutes ago, chengkp75 said:

. . .

 

Until I get a confirmation that an engine failure started the whole situation, I will lean towards a random sea causing an overspeed of the propellers, leading to the total loss of power.  Could a sister ship, with the same propulsion and power generating plant, sailing a half mile away at the same time have sailed through this storm without incident?  You bet.  I am of the opinion that this was an act of the randomness of the universe.

Thanks for your quick response and thorough explanations (as always).  We are heading out on a 28 day cruise later this week (not Viking).  I am sure this will become a big topic of conversation.  

[sasmmb]

2 hours ago, chengkp75 said:

 

 

Okay, here's my take on this incident.  I am a person with knowledge of ship's power generation and propulsion equipment, and who has personally experienced both total loss of propulsion and partial loss of propulsion due to heavy weather.  Let me start out with what I consider to be the scenario given what I've read.  The ship experienced either a total blackout or a major reduction in power capacity (haven't noticed confirmation that there was even a short total blackout) in heavy weather, and drifted towards shore.  Ship managed to anchor and power was started to be restored within 2-3 hours.  If I'm off on this scenario, could someone who was onboard correct me?

 

Okay, lets deal with a couple of ideas that have been floated.  I seriously doubt the aurora could have caused this problem, while I do know that it can affect electronics, I've never heard of it affecting ships.  Could be, just doubt it.

 

Water in fuel.  This I discount as well, knowing the fuel pre-treatment a ship uses.  While there is always some water in the fuel as it comes from the refinery, the fuel is transferred before use to a "settling" tank, where it can "rest" for a day and let the water separate from the fuel and settle to the bottom of the tank, and then be manually drained off daily.  From the settling tank, the fuel goes through a centrifuge that is designed to separate fuel from water based on their difference in density, and these remove 99.9% of water from the fuel.  Then, the fuel is heated and pressurized to 280*F and 100psi before being pumped to the diesel engine, and water would flash to steam in these conditions and not cause significant problems for a large diesel engine.

 

There is also a lot of talk of "repeated" "mechanical issues" and "engine failures" and "propulsion problems".  From what I've read, the previous problems with Viking ships' propulsion has been in the electrical control systems for the electrical propulsion motors, though many sources call these "engine problems" and the like.  In this instance, a near or total power failure, with a relatively quick restoration of power does not lend itself to a "failure" at all, or a serious systemic failure.

 

The relatively quick restoration of power also leads me away from a failure of the electrical distribution system, as this would take longer to repair, if not be impossible at the moment, requiring materials not available onboard.

 

When a ship is in heavy weather, the best thing is to head into the seas.  This reduces rolling, but increases pitching.  When a ship pitches, the stern rises and falls, with the propellers coming near the surface when the stern rises and going deeper in the water when the stern falls.  Anyone who has been on a small boat in seas will know this phenomenon, where the propeller speeds up when it gets closer to the surface (less water resistance) and slows down when it "digs in" again when the propeller is deeper in the water.  Further, the wind and seas being on the bow, causes a larger force that the ship needs to overcome to move forward, so once the ship reaches her maximum power on the propulsion motors, or the capacity of the generators to provide power, the ship starts to slow down.  Now, the ship is operating at full power, and the propellers dig in deeper, calling for more power, and you get into an overload situation, so in heavy pitching you will normally slow the propellers down to reduce the power, so that you don't run the risk of overloading the motors or generators and shutting them down.  In the extreme, this is the classic "hove to", where the ship is slowed down to where it is just holding a steady position while heading into the seas.

 

Another problem the ship and Captain face is the wave period and ship speed.  If you try to drive the ship "too hard" (too fast), then the ship will not be rising and falling at the same speed as the seas, and you will start to "catch" waves on the bow, where the bow of the ship is dropping when a new sea comes along, and the bow digs deep into the wave, causing a slamming against the hull, and problems all along the length of the ship.  Slowing the ship further will put the ship's motion back in synch with the seas, and reduce this slamming.

 

So, what does this have to do with the Sky?  I believe that something in the weather, either the known and familiar 10th or 100th wave phenomenon (the waves are known to be greater or faster than the ones preceding or following), or a confused sea state due to wave echoes from the near shore, caused the ship to slam into a wave, dig deep, and cause the propellers to rise very near the surface, losing resistance, speeding up and the safety system tripping the propulsion motors to prevent damage due to overspeeding.  This sudden loss of the majority of the electrical load caused the generators on line (and as I've said, there is no documentation that there were not all 4 on line at the time), to overspeed for the same reason (loss of resistance as the load on the generator dropped), shutting all the generators down.  This, coupled with the restoration of power within a couple of hours is how you can have a multiple engine, multiple propeller failure.

 

Someone mentioned an auxiliary generator.  Yes, there is an emergency generator, which will automatically come on line within 45 seconds of losing power, but it is designed by regulation to only provide power to the essential loads needed to abandon the ship (reduced lighting, communications, navigation equipment, steering, fire pumps, bilge pumps, lifeboat and life raft winches).  This will also provide power to just enough engine room auxiliary systems (fuel pumps, lubricating oil pumps, for one or two engines) to "bootstrap" restart the ship's power.

 

So, everything has tripped off line and the emergency generator comes on line.  The engineers will work to ensure that all necessary systems are available, and reset an engine, and restart that engine, then connect it to the power buss, and then start to reset all the power user circuit breakers that tripped in the blackout in priority, to get to restart another generator, so that with two online, you can likely start propulsion at slow speed, and then carry on until full power is restored.  The time window of 2-3 hours that I've read to get propulsion back is pretty standard for something like this, where you have to go around and check everything before putting power back to it, and then starting systems one at a time.

 

The fact that a cargo ship responding in the area also suffered a power failure puts some more strength to my argument.  That ship would have had a diesel engine connected to their propeller, and if it shut down due to overspeed, it would likely turn broadside to the seas, and start rolling sufficiently that their generators would shut down on loss of oil pressure due to the oil rolling in the engine.  The cruise ship's larger generator engines are different in that they use a separate oil tank and not the crankcase of the engine, like your car, for oil storage.

 

 

 

 

 

Thanks for the detail. If your theory is true, and it seems plausible enough to be so, what options would have prevented this apart from not sailing that day?

[chengkp75]

Just now, larryfry50 said:

We are set to sail on this ship in May.  By then., I hope they have all the necessary repairs completed.  I have just one technical question.  What is the cause of the engine failure?   Does anybody know?  There was a problem with Norwegian Star in 2017 in Australia.  It was dead in the water and had to be towed back to Melbourne. Fortunately,  we were able to cancel that cruise ahead of time.  

I have seen no confirmation that there was an "engine failure".  Given the time frame, I can't say there was any failure.  The Norwegian Star's problems were related to her azipods (electric motors) not her engines.

[chengkp75]

Just now, sasmmb said:

 

Thanks for the detail. If your theory is true, and it seems plausible enough to be so, what options would have prevented this apart from not sailing that day?

Sailing a mile further offshore, or a mile closer to shore, sailing at a slower speed so that the ship was not in the exact location it needed to be in order to experience what happened.  This, to me, is an example of the Swiss cheese theory of accidents.  The "cheese" is the safety system and procedures you utilize in ship operations, and the "holes" are things that can go wrong.  However, if one thing goes wrong (one hole), you can't get from one side of the "cheese" (the planned task) to the other side (the accident).  Only if all the holes line up will the accident become a result of the planned task.  Here you had the ship in the right location (and I mean exactly, not just in that area of the Norwegian Sea), the seas at exactly the right frequency, height and direction, the ship's heading exactly right, and her speed exactly right.  How do you prevent all of these things from happening at the exact same time?  You don't, but you try to do everything possible to prevent it (change heading, slow the ship, speed up the ship, etc).

[Pratique]

I am curious why the engine is not on a torque limiter that would delay or prevent the overspeed condition from occurring.

[Hanoj]

15 minutes ago, chengkp75 said:

  How do you prevent all of these things from happening at the exact same time?  You don't, but you try to do everything possible to prevent it (change heading, slow the ship, speed up the ship, etc).

Kind of like the opposite of winning a lottery jackpot.

 

Have you, or others, considered the ship's proximity to shore in this incident? Based upon these explanations, it seems the proximity to the rocky shore and underwater rocks is what necessitated the distress signal and evacuation. Had the the Sky been further out to sea it may not have been necessary to evacuate?

Edited March 25, 2019 by Hanoj
typon

[larryfry50]

chengkp75 Thank you for your analysis.  It gives me some relief as it sounds like the conditions at the time, could be the cause.  And, it sounds like, if you are correct, the protection systems for overspeed etc,  worked correctly because eventually, they were able to restore power.  

[drsue]

A crew drill on the sister ship Viking Sea in St. Lucia December 2018