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

[Pratique]

Is there a downside to carrying more oil in the tank? Why run near the lower limits?

[OnTheJourney]

6 minutes ago, chengkp75 said:

 

Okay, this puts a different spin on things, and is an interesting finding.  Interesting in that each engine has a separate oil supply, so all four engines must have had about the same level of oil in their sump tanks.  As I stated before, these engines don't have oil in their crankcase like a car or truck engine, the oil flows down to a separate tank that contains the oil below the engine.  These tanks are equipped with level sensors, both high and low, and the low sensor is required to be at a point where if the ship is listing 25* the pump suction will not be uncovered (lose suction of oil, causing low oil pressure).  If the tanks were above this level, then there might be a problem with the original design calculations, or the ship was rolling more than 25*.  There will be no change to limits on oil pressure, as low oil pressure is destructive to the engine, and the low oil pressure alarms are set at a point where the engine will stop before it gets damaged.  There will likely be a change either in Viking's policy of how low to maintain oil level in the sump tanks, and/or a change in the low level alarm setting.

 

So, what I believe the findings will be is that while the Captain was not aware of what level the engineers were maintaining (or what level they were currently at, and were soon to be replenished), knowing that the engines can operate in 25* rolling, he did not see any reason to not sail, if the predicted weather conditions were within the company's ISM policies, and no fault is found with the Captain.  All equipment operated as designed, with the possible exception of the original setting of the oil level sensor, and unless the actual oil level was below what the class society (doubtful, as they are the ones to approve the original heeling calculations), the manufacturer, or the company's ISM required, then there is no fault found with the engineers or the equipment.  The take away will be that Viking, and all ships of similar design review their policies on oil level in diesel engine sump tanks, and determine a more conservative level to operate at, and include this in the ISM policies.  Even at this, the chances of this happening to all four engines is pretty small, but as with all things, that small chance can and does happen once in a while.

 

Is there a way to translate that page?  Never had much luck with trying to do that.....

 

 

[chengkp75]

13 minutes ago, Hanoj said:

Which, if true, demonstrates the dangers of relying solely on such systems and alarms. Is it possible to manually check various levels and systems? 

Yes, there are manual ways to check the oil level in the tank, and this is done regularly, but again, if the level as checked was  above the known low level, there would be no idea there would be a problem.  And the engine did not shut down on low oil level, that is merely an "information" alarm, what happened is that the suction for the oil pump was exposed to air instead of oil, so it was no longer pumping oil, even if for only a couple of seconds, but when that pocket of air the pump pumped reached the engine oil pressure sensor, that sensor shut the engine down.  Engine oil pressure has two settings, a "low pressure" as an "information/warning" alarm, and a "low/low pressure" that will automatically shut the engine down in a second.  So, even if the oil pump (which is driven by a separate electric motor, not the engine itself) picked up pumping oil a couple of seconds after it took a suck of air, the engine would have shut down due to the initial pocket of air, without any recourse to try to stop the shutdown.

[Hanoj]

1 minute ago, gretschwhtfalcon said:

 

Is there a way to translate that page?  Never had much luck with trying to do that.....

 

 

In google chrome, right click anywhere on the page and you should see option to translate into English.

[chengkp75]

4 minutes ago, Pratique said:

Is there a downside to carrying more oil in the tank? Why run near the lower limits?

The engine burns oil all the time it is running.  Your car engine does too, which is why you have to add oil every so often, but these engines burn more.  So, this is just like you relying on your car's oil pressure light to warn you that the oil pressure is low (most commonly from low oil level), and only checking the dipstick every week or so, and not adding oil until you are a quart down.  The engineers will develop routines, and will fill the engine sumps on a routine, provided the level is not near the limit.  As for running near the full mark of the tank, yes, this can cause oil to splash back into the crankcase, creating some vapors in the crankcase, and the engines are equipped with "oil mist detectors" which are designed to sense oil mists caused by overheating bearings (near failure causing catastrophic failure of the engine), and these detectors are designed to shut the engine down as well.  So, too low an oil level can cause problems, and too high an oil level can cause problems as well.

[AmazedByCruising]

Already answered, thanks Chenkp! 🙂

Edited March 27, 2019 by AmazedByCruising

[OnTheJourney]

thanks....should have read further since there are other posts that present the essential info in English.

 

How very interesting about the oil level! So then does it just require a certain amount of time prior to reset/restart the engines following the sensor pick-up of the air that was introduced into the system?

 

  I'd love to see a complete minute-by-minute chronology of all that transpired from Saturday morning through Sunday morning. 

[Haworth]

10 minutes ago, Hanoj said:

In google chrome, right click anywhere on the page and you should see option to translate into English.

https://www.sdir.no/en/news/news-from-the-nma/press-release-viking-sky/

 

This should be it

 

[Pratique]

High performance automobiles have baffles in the oil pan to help prevent starving the pump under high lateral force or steep grades. Any such design on a ship?

[C1nnabar]

13 minutes ago, Hanoj said:

In google chrome, right click anywhere on the page and you should see option to translate into English.

 

Or paste the text into google translate if you're reading on your phone. 

[Pratique]

Another dumb question is what are the chances that all four engines would have near low oil levels at the same time? The fact that this happened independently on all four seems so remote to me.

[chengkp75]

2 minutes ago, gretschwhtfalcon said:

thanks....should have read further since there are other posts that present the essential info in English.

 

How very interesting about the oil level! So then does it just require a certain amount of time prior to reset/restart the engines following the sensor pick-up of the air that was introduced into the system?

 

  I'd love to see a complete minute-by-minute chronology of all that transpired from Saturday morning through Sunday morning. 

After an automation shutdown of an engine, prudent engineering requires a manual inspection of the engine and all ancillary equipment prior to restart.  However, with a total blackout as apparently happened, as I've noted before, the system will spew out hundreds of "informational" alarms, that are great under normal circumstances, but that are kind of "duh" when you have a blackout, like alarms of "engine #1 standby oil pump fail to start", well, of course it failed to start, there was no electricity to run it.  So, the engineers will have someone literally just pushing a button to acknowledge the hundreds of alarms, while others are trying to figure out what the status was just before things went dark to try to determine the cause, and others are checking the machinery to see if if can be restarted.  So, you first start things necessary to get the engines back on line, like a lubricating oil pump and a fuel pump (typically one of each of these is powered by the emergency generator so you can pull the plant back up "by the bootstraps", and then you start the engine without cooling water, get it online, and start a cooling water pump.  Then the rest of the ancillary equipment that the engine relies on.  Once you've got enough stuff restarted to keep that one engine running, you start to restart the same for the other engines, so they can be started, and then look at ventilation in the engine room to supply air for combustion to the engines, and all the other systems, and finally you can look at starting hotel services back up.  Add to this that unexpected trips like this can cause damage to electrical controls for the various pumps and things, so these will need to be repaired as you go along.

[chengkp75]

11 minutes ago, Pratique said:

High performance automobiles have baffles in the oil pan to help prevent starving the pump under high lateral force or steep grades. Any such design on a ship?

Since the engine sump tanks are integral with the bottom of the ship, there is a large amount of structural steel (supporting the weight of the whole ship, and the engine, above it) in these tanks, about every meter or meter and a half apart (the tank is likely 5 meters wide, 12 meters long, and 1.5-2 meters high.  These internal structural members go from the top to the bottom of the tank, and will only have a few "limber holes" to allow access into the tank (the standard limber hole is about 18" high by 24" wide.  I hate crawling  through sump tanks these days, as my old joints don't flex through these the way they did 40 years ago.

[just_dont]

Okay, this puts a different spin on things, ....
  Even at this, the chances of this happening to all four engines is pretty small, but as with all things, that small chance can and does happen once in a while.

Did they say that the oil level issue occurred on all 4 (or 3) engines?
Could it have been a situation where they may have been running 3 engines, and one of the engines experienced the low-oil shutdown, which then caused the electrical system overload/shutdown you'd theorized? Or if that had happened, would the preliminary statement have said that?

Sent from my SM-G955U using Tapatalk

[chengkp75]

6 minutes ago, Pratique said:

Another dumb question is what are the chances that all four engines would have near low oil levels at the same time? The fact that this happened independently on all four seems so remote to me.

I agree, as I pointed out in a previous post.  Because of the remote chance of this, there will be directives (I believe the Norwegian Maritime Authority has already said they've posted one) about oil level, but that will likely be that.

[LMaxwell]

21 minutes ago, Pratique said:

High performance automobiles have baffles in the oil pan to help prevent starving the pump under high lateral force or steep grades. Any such design on a ship?

 

Real high performance cars have dry sumps and won't rely on wet sump, even with baffles.  Too much G force away from the oil pickup could still starve the motor even with baffles in the pan.  

[LMaxwell]

3 minutes ago, chengkp75 said:

I agree, as I pointed out in a previous post.  Because of the remote chance of this, there will be directives (I believe the Norwegian Maritime Authority has already said they've posted one) about oil level, but that will likely be that.

 

When the sensors encounter that air pocket and automatically shut down, what is the process and timeline towards getting an engine running again?  Is there a way to vent/burp the oil supply or bypass the automatic shutdown system?  Once a shutdown event occurs I imagine there's a pretty lengthy checklist to ensure it is safe to restart the plant?  Is there any sort of system that could introduce oil supply from remote reservoirs, T'd into the main line, with their own pumps triggered by roll sensors as a means to maintain consistent feed?  

[OnTheJourney]

3 hours ago, Vineyard View said:

You must have missed my post where I sincerely apologized.

 I was wrong in this. 

It was sincere and I am sorry for it. 

 

Vineyard...absolutely no problem and I appreciate the apology. 🙂 This incident has generated strong emotions and feelings among those who were either on the Sky or not, and this certainly comes out in some posts. The fact that members here care so much about this incident, and cruising in general, is evident in the currently 1268 posts! I appreciate much of the background info that has been given here as to how both the organizational and mechanical aspects of these ships operate. Having been a passenger, I deeply appreciate the many kind words expressed by so many here. It will indeed be interesting to see what further info results from the investigations. 

Edited March 27, 2019 by gretschwhtfalcon

[Pratique]

13 minutes ago, just_dont said:

Could it have been a situation where they may have been running 3 engines, and one of the engines experienced the low-oil shutdown, which then caused the electrical system overload/shutdown you'd theorized?

 

Aye, what good is redundancy if a single point failure leads to a cascaded shutdown. I'd be interested to hear if this was the case but it sounds like each engine shut down due to low oil pressure.

[OnTheJourney]

6 minutes ago, LMaxwell said:

 

When the sensors encounter that air pocket and automatically shut down, what is the process and timeline towards getting an engine running again?  Is there a way to vent/burp the oil supply or bypass the automatic shutdown system?  Once a shutdown event occurs I imagine there's a pretty lengthy checklist to ensure it is safe to restart the plant?  Is there any sort of system that could introduce oil supply from remote reservoirs, T'd into the main line, with their own pumps triggered by roll sensors as a means to maintain consistent feed?  

 

I was wondering about this also...you expressed it much better than I did. 

[OnTheJourney]

24 minutes ago, chengkp75 said:

After an automation shutdown of an engine, prudent engineering requires a manual inspection of the engine and all ancillary equipment prior to restart.  However, with a total blackout as apparently happened, as I've noted before, the system will spew out hundreds of "informational" alarms, that are great under normal circumstances, but that are kind of "duh" when you have a blackout, like alarms of "engine #1 standby oil pump fail to start", well, of course it failed to start, there was no electricity to run it.  So, the engineers will have someone literally just pushing a button to acknowledge the hundreds of alarms, while others are trying to figure out what the status was just before things went dark to try to determine the cause, and others are checking the machinery to see if if can be restarted.  So, you first start things necessary to get the engines back on line, like a lubricating oil pump and a fuel pump (typically one of each of these is powered by the emergency generator so you can pull the plant back up "by the bootstraps", and then you start the engine without cooling water, get it online, and start a cooling water pump.  Then the rest of the ancillary equipment that the engine relies on.  Once you've got enough stuff restarted to keep that one engine running, you start to restart the same for the other engines, so they can be started, and then look at ventilation in the engine room to supply air for combustion to the engines, and all the other systems, and finally you can look at starting hotel services back up.  Add to this that unexpected trips like this can cause damage to electrical controls for the various pumps and things, so these will need to be repaired as you go along.

 

great info....thanks! Suffice it to say that the engineers were sufficiently occupied during all of this. 

[Hanoj]

So I can imagine the class society Lloyd's Register can be none too pleased by this. Are they on the hook for the costs of repairs and other claims?

Edited March 27, 2019 by Hanoj
typo

[AmazedByCruising]

30 minutes ago, chengkp75 said:

Because of the remote chance of this, there will be directives (I believe the Norwegian Maritime Authority has already said they've posted one) about oil level, but that will likely be that.

 

To get an idea of this "Swiss Cheese", how often does it happen that just one engine decides to stop because of oil levels & inclement weather? 

Edited March 27, 2019 by AmazedByCruising
spelling

[Pratique]

1 minute ago, AmazedByCruising said:

 

The get an idea of this "Swiss Cheese", how often does it happen that just one engine decides to stop because of oil levels & inclement weather? 

I bet that the ship builders have statistically modeled this. Hate to say it but good info for the lawyers to obtain.

[chengkp75]

11 minutes ago, LMaxwell said:

 

When the sensors encounter that air pocket and automatically shut down, what is the process and timeline towards getting an engine running again?  Is there a way to vent/burp the oil supply or bypass the automatic shutdown system?  Once a shutdown event occurs I imagine there's a pretty lengthy checklist to ensure it is safe to restart the plant?  Is there any sort of system that could introduce oil supply from remote reservoirs, T'd into the main line, with their own pumps triggered by roll sensors as a means to maintain consistent feed?  

Believe I answered your question about restarting in a post about a half hour ago.  Timeline?  Depends on whether you're dealing with just one engine shutdown or a blackout, and what happened to cause the shutdown.  Bypassing an automatic safety shutdown kind of defeats the purpose of a safety shutdown, don't you think?  The whole idea is that loss of oil pressure can destroy an engine in less than a minute, and even a momentary loss of flow can result in permanently damaged bearings or pistons and rings, so there are certain shutdown alarms that cannot be bypassed or overridden, by law.  Typically, the engine has two motor driven lube oil pumps allocated to it, and the "standby" pump will start on receiving a low pressure alarm, but these "standby start" signals always have a time delay built in to prevent nuisance starts to the pump, and a slug of air in the engine will shut it down before the standby can start, and then if you've gone black, the standby cannot start anyway.  Some systems, like turbochargers, that continue to spin even after the engine stops, will have small reservoirs that feed the oil to the bearings at all times, and that it refilled by the engine oil pumps, and if the oil pump stops and the engine stops, this reservoir will supply oil until the turbo stops spinning (in theory).  Having pumps start based on ship roll would be a little overkill, as there is no guarantee that a standby oil supply would be needed in all rolling conditions.  Also complicating the scenario is the fact that the ship was pitching as well, and there is no requirement for operation at a certain amount of pitch (mainly because it is far more transitory than listing can be), so if the ship rolled to port and pitched bow up at the same time, and the pump suction was on the starboard side and forward, the oil level could possibly go very low (don't know the actual design or shape of the Sky's sump tanks).