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COVID Pause = Extended Life?


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A question I have been pondering, and wondering what you all may think. When she does get back up and running, QM2 will essentially have been in "hibernation" mode for more or less 2 years. While she hasn't been completely shut down, she also hasn't undergone the rigorous pressures of her cruising/crossing schedule. Do you feel this will ultimately result in her being in service for a few more years than initially planned? QM2 was built with a service life of 40 years. Obviously, economic factors could make or break that lifespan, but strictly speaking on hull stressors alone, I'm curious if being fairly idle for the past 2 years will extend her lifespan. Thoughts?

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That's an interesting question. I don't know if he monitors this particular board, but chengkp75 is a ship's engineer and would probably be most qualified to provide the definitive answer.

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It's not a perfect analogy, but think of a car that hasn't been driven in a year or more. All kinds of problems can develop if the fluids aren't circulating the way they're meant to and lubricating the parts that require regular lubrication. The fluids themselves can degrade, and belts and hoses can crack. Most of those issues can be minimized if the car is started up and driven a few miles once or twice a month. My guess is these same principles apply to a ship's engine, but on a much larger scale. Instead of being driven occasional short distances to ward off "hibernation" damage, a ship's engines would have to run more often and/or for a longer time to keep them running right, which I'm sure has been what the QM2's engineers and maintenance crew have been doing. It's undoubtedly less stressful on the engines than weekly transatlantic crossings would be, but those engines are still getting a (necessary) workout. I doubt that longevity is going to be significantly affected, one way or the other.

 

I'm not, however, in any way an engineer, nautical or otherwise, so if I'm wrong I hope chengkp75 or some other qualified person will correct me.

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QM2's engines are being run since it's essentially at sea full time (unless I'm mistaken). I imagine that each of the engines - both diesel and turbine - are run at least the minimum hours necessary to remain in operations condition.

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I totally agree with all as a Cunarder with the state of health of the Queen Mary 2.

 

As a subscriptor of Marine Traffic I have been watching the QM2 and others wandering around and then laying up for awhile. They are keeping her moving and active though there are no passengers on.

 

I agree about when vehicles are laid up for a long time having been around a crowd of auto mechanics in the past.

 

I believe there has been many discussions even btw the engineers of the different line on maintaining the vessels.

 

We too (My DW & Myself) want to see the Grand Lady return to her former self and sparkle across the seas..

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I can’t imagine how this would make any difference. The interior finishes will go longer between refurbishment no doubt from lack of wear and tear. But the ship has been sailing and is in salt water surrounded by salt air. Granted, she has put less miles on but it is hard to see where that will make an appreciable difference  the course of four decades or so.

 

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Interesting question, and I will likely wax fairly technical, and possibly at length, so if you are really interested, get a coffee and buckle up, otherwise this will be like Charlie Brown's "wah, wah, wah".

 

First off, vessel "service life" is a fairly indeterminate and vague concept.  It is not some definitive age, when the ship must be scrapped.  If you look at a graph of time (horizontal) v maintenance cost (vertical), it will be a parabolic curve.  In the first few years of a ship's life, the maintenance cost is fairly low and constant (a near horizontal line), but at some point, the cost will start to rise, and then rise dramatically, becoming a nearly vertical line.  "Service life" is that point where the cost/year for the vessel makes that "corner" on the graph and starts to rise dramatically.  When does the ship reach that "corner"?  That depends on many factors.

 

Service life can be affected by fiscal determinations regarding the vessel's service.  If corporate feels that the revenue generated by the ship still outweighs the maintenance cost, they move that "service life" to the right (older), but if the revenue isn't there (for whatever economic reasons), the "service life" can be shortened.  Service life can be affected by maintenance practices, some practices if started early enough in a ship's life, and continued throughout the life, can extend the service life by lowering maintenance costs over the life of the vessel.

 

Service life can be affected by construction.  Things as esoteric as the health of the metallurgist overseeing the formulation of the steel on a particular day, or the machine operator who rolls out the plate from that steel, as both of these factors can affect how steel reacts to repetitive load and corrosion.  Service life can be affected by the weather on the day the ship is assembled, or more accurately the weather over the span of time the ship is assembled, as this can affect the quality of welds.  Shipbuilding is far more art than science, still, and I've seen ships in a 12 ship class that have very different vibration characteristics, just because they are not identical.

 

Ships that are 15 years old are subject to more rigorous inspections every dry docking (and those dockings are more frequent), and result in more cost due to steel replacement in the hull and structure as found in those inspections.  So, unlike a car or airplane, ship's hulls are being constantly renewed as necessary, due to corrosion (mainly) or cracking due to stress.  Will 2 years of light/no operation change the life cycle of the hull steel?  Not to any appreciable extent, certainly only 2 years at most.

 

As far as engines go.  The gas turbines have a limited life span and are then typically disposed of rather than repaired, but they are run only very infrequently when in service, and I would suspect not at all during this cruise halt.  They will have mechanisms to rotate the turbines, without actually running them, just to keep oil film in the bearings, and they will have covers to keep salt air out of the turbines, so the 2 year hiatus will have no effect on them.  Marine medium speed diesel engines like the QM2 has, are overhauled every 12,000 hours (about 2.5-3 years in service).  Unlike taking your car in for a tune up, these overhauls tear the engine down completely, inspect every part, renew those that are not felt able to last until the next overhaul, and then assembled.  You basically have a new engine every 3 years, so whether the ship is operating or idle, engines will have little effect on service life.  And, diesel engines will suffer more wear and tear when operating at low loads (slow steaming, light hotel load) than when at rated load (about 80%).

 

Unless the ship is put into "lay-up" condition (and I won't get into the hot, warm, or cold terms) with the class society and flag state (meaning that the ship is docked or anchored in a secure port, and the crew reduced to watchmen alone and the power shut off), in order to keep the vessel's certification active, the planned, preventative maintenance program must be maintained at all times, so routine inspection, testing, and overhaul of all systems will continue.  Since the vast majority of systems on a cruise ship are not to propel the ship, but to provide living conditions onboard, most all systems are in operation, albeit on a perhaps reduced capacity.  This is why the engineering departments on these idle cruise ships are the one area where crew has not been reduced by much over normal operations.

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Interesting feedback, thank you for the technical description, chengkp75I love hearing from people who know the information behind the curtain. 

 

I had a feeling at the end of the day, the last year or so wouldn't have an overall effect on her lifespan. If anything, I'm sure we all agree as long as this doesn't *shorten* it, that is all that matters. It is a bit of a disappointment that this has delayed her interior refit (by how long is anyone's guess) since she could use a touch up in some areas, but if that's what Cunard has to do for now to get the lady back on track, so be it!

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There was a discussion someplace somehow about unexpected extra vibration /stress related to azipods  that would potentially shorten an otherwise long QM2 service life.  I can't find a reference to it in the Payne book, but this may have prompted the question.  

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