On the morning of August 17, the fire on the aircraft carrier "Minsk", which had been burning for an afternoon and a whole night, was finally extinguished!
Judging from the surveillance video of the Sutong Bridge and the photos taken by the onlookers at the scene, we can finally get a glimpse of the "Minsk" aircraft carrier after the fire. Judging by the situation after the fire, the aircraft carrier "Minsk" can be described as a mixed blessing:
The "good news" is that its overfire area does not seem to be as large as imagined, but it is concentrated in the amidships and the front part of the ship, and above its number "015" can faintly see smoke traces coming out of the portholes, while the most serious part of the fire is concentrated in the compartment under the bridge, and at the rear of the bridge there is basically no effect, and there is no trace of overfire;
On the night of the 16th, we saw that the flames that came out of the bridge were more than 10 meters high...... After the flames were finally extinguished on the morning of the 17th, everyone's hearts were half cold, and the front bridge of the "Minsk", including the navigation bridge, the aviation command bridge and the main mast in front of the chimney, was completely burned out, and it could be called a mess.
The reason why the bridge of the "Minsk" burned so badly was that someone soon came up with information that when the "Minsk" was built, the superstructure was not built with steel, but with an aluminum-magnesium alloy body.
Compared with traditional steel, the weight of the superstructure built by using aluminum-magnesium alloy can be reduced by about 1/10, the stiffness is higher, and the corrosion resistance is better, but the disadvantage is that it is not resistant to high temperatures, and it will quickly soften and deform in the case of fire, and there will be a combustion effect similar to that of thermite, which burns extremely violently and emits a dazzling strong light, just like what we saw on the night of the 16th.
The unusually fierce burning "Minsk".
Around the 70s of the last century, surface ships were built using aluminum-magnesium alloy, which is also a trend in the international shipbuilding community, such as the "Perry" class frigate of the United States Navy and the Type 42 destroyer of the Royal Navy of United Kingdom, and the "Minsk" aircraft carrier is naturally no exception.
However, after the Falklands War, the aluminum-magnesium alloy superstructure was not fire-resistant, not resistant to high temperatures, and was easy to collapse after combustion, so the international shipbuilding community gave up the aluminum-magnesium alloy superstructure and used the traditional steel structure instead, such as the frigate superstructure of the Chinese Navy in service is generally made of ship steel with the grade L907A and a yield strength of 390Mpa.
As a ship that appeared in the 70s of the last century, the "Minsk" naturally did not anticipate the subsequent trend of international shipbuilding, and did not expect that it was finally planted in the hands of this aluminum-magnesium alloy superstructure.
Follow-up treatment of fire accidents
Well, now that the aircraft carrier "Minsk" has burned like this, what to do with it in the future? Looking at international military and civilian ships, there are about the following ways to deal with the ship's fire:
Fire accident "Kuznetsov" in 2019
The first is to repair intact, the most typical such as the Russia Navy's "Kuznetsov" aircraft carrier, in the process of upgrading and improving, has suffered a floating dock power failure sinking accident and a fire accident at the front of the hull.
Afterwards, the Russia Navy eliminated all difficulties, the floating dock sank, the flight deck was smashed by the crane's beak, and a new large pool was dug in Murmansk to move the "library" ship into it for repair; The front of the hull caught fire, and after re-surveying, the burned area was cleared, and it was okay to make do with it.
The restoration of some civilian ships also follows this principle, and after cleaning up the burned area, it is re-renovated and painted, and it can barely continue to be used.
However, for this restoration to take place, several conditions must be met:
First, the ship repairer must get the technical information of the design and construction of the whole ship, otherwise you can't even figure out which cabin is which cabin, and even the strength data of the whole ship is not complete, how can you repair the ship?
Second, there is a special team to survey the ship according to the technical data, especially to find out whether the strength of the cabin and the whole ship can meet the repair requirements after the fire, and whether there is any repair value;
Third, to carry out the corresponding cost calculation, how much is the residual value of the ship after the fire, how much does it cost you to repair, and how much benefit can be created for you after repairing, otherwise, I spend hundreds of millions of dollars to repair the ship, and the result can only create tens of millions of value for me, why should I repair this ship?
Burning mess of Russia Project 20385 frigates
In addition to the original restoration, there are also repairs such as demolishing the east wall to replace the west wall and replacing the head, which generally occurs when one part of the ship is seriously damaged, but the other parts are relatively intact:
For example, the second frigate of the Project 20385 "Agile", which has just been launched by the Russia Navy, in the final stage before its launch on December 17, 2021, its superstructure suffered a serious fire, and due to the use of composite materials, almost all of them burned out, leaving a bare hull of the whole ship. Later, the shipyard "North", which was responsible for the construction, had to rebuild a composite material to replace the burned part, and in this way, the "Agile" was also repaired.
Only the skeleton of the France "Pearl" was burned
Another example is the France Navy, the France Navy's "Pearl" attack nuclear submarine on June 12, 2020, a fire broke out during dock repairs in the port of Toulon, and the entire head non-pressure-resistant shell structure was burned, leaving only the frame. After judging by the France Navy, the bow of the "Pearl" lost its repair value, and in desperation, the French had to cut a bow from another decommissioned ship of the same class, the "Sapphire", to repair the "Pearl", which was considered to be completed.
For example, the "Seawolf" class attack nuclear submarine "Connecticut", which the United States Navy is currently under repair, is also expected to use the "head replacement technique" to rebuild a bow and replace the bow that had previously hit the seamount.
"Connecticut" missing a head sonar mask
However, if you want to carry out "head replacement" on the hull, the problems faced are similar to the repair of the whole ship:
First of all, you have to have the technical information of the design and construction of the whole ship, and if you don't have the data, you have to go up and survey it, otherwise, you can't even figure out the structure of the ship, how can you remanufacture the hull part of the damage pipe?
Secondly, you have to have the construction skills to be able to recreate the same structure as it is. For example, when France repaired the "Pearl", it encountered problems at the beginning, because the construction of the "Ruby" class had ended, all the tooling had been destroyed, and the workers had been dismissed, and it was impossible to make another bow, so it retreated to dismantling a second-hand bow from the "Sapphire" nuclear submarine.
Finally, the part you want to replace also needs to be relatively independent, and it does not have much impact on the structural strength of the whole ship, such as the bow, such as the superstructure, you can't cut out the amidships of the hull and replace it, what is the difference between this and rebuilding a ship?
So if it can't be repaired, this overburned ship can only be abandoned, in fact, over the years, there have been many overheated ships abandoned:
In 2020, the amphibious assault ship "Good Guy Richard" caught fire and was finally decommissioned ahead of schedule
For example, the amphibious assault ship "Good Man Richard" that caught fire at the San Diego Naval Base in July 2020, after the ship caught fire, the United States Navy evaluated it, and the assessment result was that if the ship was to be repaired, it would take too long and cost too much, and it would not serve for a few years after the repair and would be decommissioned, so it was considered to have no repair value and could only be directly abandoned.
"Miami" after the fire
Another example is the May 23, 2012 Portsmouth shipyard in Maine 688I attack nuclear submarine "Miami" was repaired sailors deliberately set fire, the boat caught fire after the United States Navy assessed it, believing that the repair cost would be $450 million or more, and the boat has been in service for 22 years, even if it is repaired, it will not serve for a few years, so it decided to retire the "Miami".
The fate of the Minsk after that
Therefore, after reading so many cases of ship repair or abandonment, let's roughly summarize some of the technical elements of ship repair or abandonment:
First, it depends on the damage to the ship, which can be repaired if the damage is not serious, and cannot be repaired if the damage is serious.
Second, it depends on whether there is technical information on the design and construction of the ship at hand, whether there is a special ship repair team involved, and only if there is technical data can it be repaired.
Third, it depends on whether there is a supporting production line, for example, if the superstructure is gone, you have to rebuild one, and if the bow is broken, you have to rebuild one.
Fourth, it is necessary to look at the cost performance of repair, and the benefits generated after repair can cover the cost of repair, so it can be repaired, and if it does not take a few years after repair, and the cost cannot cover the cost, there is no need for maintenance.
Looking back at the current "Minsk" from this point of view, we can only say that the situation is really not good, and it is even more difficult to restore the superstructure that has been burned down:
First of all, we do not have technical information on the design and construction of the "Minsk" aircraft carrier, and if we want to find it, we are afraid that we will have to go to the archives of the Nikolaev "Black Sea" shipyard to pick it up.
And the superstructure of the "Minsk" that has burned down, we can't even repair it, which shipyard is willing to undertake this kind of errand, just repairing it must be a large expense, and there is no way to repair it on site, and it has to be towed to the dock to dock for repair, and after tossing such a big circle, all it is to build an aircraft carrier theme park, and the benefits are not clear at all......
So what else is there to say about this? This is fundamentally because the ship is seriously damaged, and it faces a lot of technical problems when repairing, and the cost of repairing the ship and the benefits obtained are not equal, and all the mines are accounted for.
Therefore, in Ivan's opinion, the "Minsk" has completely lost its repair value, and perhaps it is a better choice to disassemble it and sell it for scrap, or simply leave it in place and leave it alone, or sell it to the Chinese Navy as a target ship to test the combat effectiveness of the anti-ship missiles in its hands.
"Minsk" is already in our eyes, fading away.