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

[bbwex]

I cannot think of any modern cruise ship that has a backup engine for the two diesel electric propulsion engines that they have.  Each one generally has a high output and a lower output generator, and they now have isolated and redundant systems.  Since there were some engine casualties a few years ago, and they have to make the systems independent of each other, this sort of thing should not happen.  It would not have happened if they had maintained proper oil levels.  Once the low oil alarms started going off early in the morning, they had ample time to bring the oil levels up, but they did not.  They did after they lost all power, but that was way too late, and the ship was one ship-length from going aground. 

 

 

[chengkp75]

On 1/13/2020 at 12:20 AM, neutrino78x said:

They should have two more propulsion systems as backup. On submarines the nuclear reactor is the main propulsion system, and we have a diesel engine as backup which can also drive the boat at high speed (our max speed is classified) and then there's the outboard, a small electric propeller that can drive the boat off battery power, at a very low speed.

Sounds like they have backup power but not backup propulsion (or at least not sufficient backup propulsion). Oh well, Norway has a decent Navy (one reason why they are not a FoC), they'll get everybody to safety. 🙂

Just like your "outboard" propeller on a submarine, a cruise ship has two propellers and propulsion motors, each independent of the other, to act as "backup" to each other.  Further, they have 4-6 diesel generators powering the propulsion motors, providing further redundancy in that any of the diesel generators can power either of the propulsion motors.

 

Never heard of US nuclear subs having diesel engines, how do you provide oxygen to the engine while submerged?  I've heard of the AIP systems used by other countries to fuel heat engines with liquid oxygen, so could you explain?

[chengkp75]

13 hours ago, bbwex said:

I cannot think of any modern cruise ship that has a backup engine for the two diesel electric propulsion engines that they have.  Each one generally has a high output and a lower output generator, and they now have isolated and redundant systems.  Since there were some engine casualties a few years ago, and they have to make the systems independent of each other, this sort of thing should not happen.  It would not have happened if they had maintained proper oil levels.  Once the low oil alarms started going off early in the morning, they had ample time to bring the oil levels up, but they did not.  They did after they lost all power, but that was way too late, and the ship was one ship-length from going aground. 

 

 

Typically, all of the diesel generators are high voltage (10,000 volts), so that they can be used for whatever electrical service is required (hotel load, propulsion, AC, etc).  The propulsion motors are 10k volt, the thrusters are 10k volt, and the AC chillers are 10k volt.  Then the power is stepped down with transformers to 480 volt for things like engineering equipment, ventilation fans, and large galley and laundry equipment.  This 480 volt power is then stepped down again to 220v and 110v for use throughout the ship.

[neutrino78x]

15 hours ago, chengkp75 said:

Never heard of US nuclear subs having diesel engines, how do you provide oxygen to the engine while submerged?  I've heard of the AIP systems used by other countries to fuel heat engines with liquid oxygen, so could you explain?

We would come up to periscope depth and snorkel 🙂 (the diesel mast sticks up above the water and draws air into the diesel and the exhaust comes out through the same mast). Also we normally run the diesel when coming in and out of port, and fire up the nuclear reactor at sea.

Of course, in many situations, you would not want to snorkel, because that would reveal your position, so instead of going to the diesel, you would go straight to the ship's battery that drives the outboard. 🙂 (the battery system, of course, also provides general "hotel power".)

One way they like to trick you if you're an electronics guy like I was (sonar tech), when you're getting Qualified in Submarines and you are doing your Diesel Propulsion checkout, is ask you how many spark plugs the diesel has. Being a computer nerd, and not knowing much about cars, that had me pursuing the manuals! Finally it hit me when I read (for the fourth time) in the beginning of the manual that a diesel engine is an "external combustion machine". External combustion! Hence no spark plugs....a trick question! lmao. You have to learn all the major systems and how they work and how to deal with their failure modes...nuclear reactor, diesel, "trim and drain" (the system that moves water around to change depth, fight fires etc), potable water, high pressure air, torpedoes, hydraulics, etc. and of course you qualify as Advanced Firefighter and Advanced Damage Control (everybody does), and after you learn all this stuff you do a 2 hour board interview with a Line Officer (in my case The Ship Diving Officer, BS in physics...submarine officers have to have STEM degrees so they can learn advanced operation of the nuclear reactor), a senior enlisted person who is assigned to work with the reactor and a senior enlisted person not assigned to work with the reactor...and can they can ask you anything they want. Literally. The weight of the diesel. What kind of nuclear fuel we use. How to pressurize a compartment...you have to know this off the top of your head. It's hard  but everybody has to achieve it in less than 12 months or risk getting sent to the surface Navy. 🙂

chengkp75...I might join Military Sealift Command...something I look at a lot. My civilian life has been disappointing, need to make some changes. Read where the Captain of an MSC ship said if you liked going to sea but hated being in the Navy, MSC is for you. lol. Other submariners have said that the Puddle Pirates don't count time in Control (room where the officer of the deck drives the boat, where the periscopes are) as having stood navigational watches because we're underwater and therefore not subject to The Rules of the Road. Makes sense in a way but means I would basically start out as deck div, not sure if I want that...

[chengkp75]

7 hours ago, neutrino78x said:

chengkp75...I might join Military Sealift Command...something I look at a lot. My civilian life has been disappointing, need to make some changes. Read where the Captain of an MSC ship said if you liked going to sea but hated being in the Navy, MSC is for you. lol. Other submariners have said that the Puddle Pirates don't count time in Control (room where the officer of the deck drives the boat, where the periscopes are) as having stood navigational watches because we're underwater and therefore not subject to The Rules of the Road. Makes sense in a way but means I would basically start out as deck div, not sure if I want that...

Okay, understand about the diesel and snorkeling, thought that went out with the old diesel boats.  So, basically an emergency propulsion, since it makes you mission inoperable.

 

As for MSC, there are far more positions at sea out there than MSC, that provide a better experience (more time off, better pay), but whether you go with a civilian maritime union or with MSC, the requirements are the same.  You would be best to navigate around this site, which lists the requirements needed to get USCG documentation:

 

https://www.dco.uscg.mil/nmc/merchant_mariner_credential/

 

There will be sea service requirements (not all Navy time is counted), some training courses (or documentation of completion of equivalent course in Navy), and some examinations.  On a merchant ship, there are only two departments, deck and engine.  Depending on your training and sea service, you may only be entitled to be credentialed as an "unlicensed" deck crew (Able Seaman), or you may have the required things to be able to sit the exam for Third Mate (the junior deck officer rating).

 

If you have other questions about a merchant mariner career, I would talk to the USCG about requirements, google some searches about "jobs at sea", and they may allow a limited thread on the general "ask a cruise question" forum to discuss this, but let's take this away from this thread.

[chengkp75]

7 hours ago, neutrino78x said:

Finally it hit me when I read (for the fourth time) in the beginning of the manual that a diesel engine is an "external combustion machine". External combustion! Hence no spark plugs....a trick question! lmao.

Unfortunately, another example of the Navy getting it wrong in their technical manuals.  A diesel engine is not an "external" combustion engine, the steam turbine is.  External combustion means the fuel is burned outside the engine, which it most certainly is not in a diesel.  However, a diesel is a "compression ignition" engine, meaning that the heat of compression of the air in the engine provides the ignition source for the fuel.

[neutrino78x]

On 1/15/2020 at 2:44 AM, chengkp75 said:

 However, a diesel is a "compression ignition" engine, meaning that the heat of compression of the air in the engine provides the ignition source for the fuel.

You're right that compression ignition is correct...I also could be remembering the wondering incorrectly...it might well have said "compression ignition"....this was 17 years ago. What I was trying to say is that I eventually figured out, from reading the manual, that there is no spark plug in a diesel engine. Within my field of expertise, I can't think of the Navy getting things wrong in their technical manuals. Maybe not necessarily wording things the way I would have, but per se getting it wrong, I do not recall anything like that. I don't even remember anything being wrong in any of the submarine technical manuals. Might be a surface Navy thing.

The point of the story was that the a-gangers ("machinist mate, auxiliary" as opposed to nuclear machinist mate) are playing a joke on electronics guys, making us  hunt through manuals, when a car guy or mechanical type of guy would say, off the top of head, "there are no spark plugs on a diesel, shipmate"...but it's actually a good thing because submariners are expected to be able to solve problems outside of our field of expertise -- that's the whole point of getting Qualified in Submarines -- so I support the practice, and am amused by it. :) lol :)