Source: Global Times
Recently, the news that Brazil's retired aircraft carrier "Sao Paulo" is "homeless" and has been adrift at sea for several months has attracted a lot of attention. The domineering aircraft carrier during the service ended up like this after retirement, which inevitably aroused the curiosity of the outside world: Why has the handling of the aircraft carrier after retirement become a "old and difficult" problem?
Why decommissioned aircraft carriers are "hard to find"
According to the Spanish "Defense News" website on January 14, the aircraft carrier "São Paulo", which once served as the flagship of the Brazilian Navy, was sold to Turkish shipbuilder Sek Maritime Trading Company for $2 million in 2021 after being decommissioned. The company had planned to send the Brazilian aircraft carrier from Rio de Janeiro to Turkey for dismantling, but because it contained a large amount of asbestos and other environmentally damaging materials, it was banned from crossing the Strait of Gibraltar and entering Turkish territorial waters. Sek Maritime Trading was forced to return the ship to Brazil, but the Brazilian port also refused to accept it. For months, the decommissioned aircraft carrier has been wandering off the coast of the Brazilian state of Pernambuco, in danger of ending up in abandonment.
According to the US "Business Insider" website, the handling of aircraft carriers in various countries after decommissioning is indeed a "old and difficult" problem. Generally speaking, due to the high cost and time-consuming construction of aircraft carriers, including the United States, most countries' aircraft carriers first consider mothballing after retirement for emergencies. However, during the mothballing period, it is still necessary to spend a considerable amount of money to carry out the necessary maintenance of the aircraft carrier, and it will also occupy valuable terminal resources, so due to financial constraints, some countries' aircraft carriers will be sold as soon as possible after retirement. For example, the aircraft carrier São Paulo is actually the aircraft carrier Foch purchased by Brazil from France in 2000, and the first aircraft carrier "Vikrant" in the Indian Navy is also a second-hand old aircraft carrier purchased from the United Kingdom in 1957.
But whether mothballed or sold to other countries, over time, these carriers will eventually be completely decommissioned. Except for a few "lucky ones" who can remain as memorial ships, most of the rest will be sent to shipbreaking yards to await dismantling. According to reports, in terms of aircraft carrier composition alone, its value is quite high, the hull is composed of tens of thousands of tons of high-performance steel, and a large number of rare metals can be recovered from internal equipment. For example, the British light aircraft carrier "Excellence", which has a standard displacement of 16,000 tons, was sold for £2.1 million and sent to a shipbreaking yard in Turkey in 2017, from which 11,854 tonnes of ferrous metals, 611 tonnes of non-ferrous metals and 112 tonnes of cables were recovered, with a recovery rate of more than 94% and a benefit of more than £10 million for the shipbreaking yard.
Previously, the deep-pocketed U.S. Navy also used decommissioned aircraft carriers as target ships for various weapons tests, but with the increase of environmental awareness in the international community in recent years, such practices have almost disappeared - the key factor is that these maritime behemoths contain many environmentally harmful substances, which can cause serious environmental pollution if they sink into the sea without treatment. The USS Oriscani sank as an artificial reef in 2006, but before sinking it into the sea, the dismantling team worked nonstop for eight months to make it environmentally sound.
According to reports, in order to strengthen wartime survivability, early aircraft carriers used asbestos as flame retardant materials, but follow-up studies proved that asbestos will gradually decompose into very small particles, and if inhaled for a long time, it may cause malignant diseases such as asbestosis and cancer. After the French "Clemenceau" aircraft carrier was decommissioned in 1997, because the hull contained 500-1000 tons of asbestos materials harmful to the human body and carcinogenic, it was called "poison aircraft carrier" by public opinion, making a fuss in the world, and there was nowhere to receive it after several years of drifting at sea, and finally India undertook the shipbreaking business with low environmental protection requirements, but the Egyptian government still refused the aircraft carrier to go to India through the Suez Canal under the pressure of public opinion. The aircraft carrier "St. Paul", which was adrift and landed at sea this time, is actually a sister ship of the "Clemenceau", so it is not surprising that it ended up in the same way.
In addition to carcinogenic asbestos materials, there will be waste oil, lead, mercury, polychlorinated biphenyls and other toxic substances in the process of dismantling the aircraft carrier, which poses a considerable threat to the surrounding environment and operators, and it is necessary to pay a high cost to harmless treatment. This is also an important reason why the US Navy sold the decommissioned aircraft carriers Kitty Hawk and Kennedy to shipbreaking companies for a symbolic price of 1 cent.
There is attention to dismantling aircraft carriers
According to reports, dismantling an aircraft carrier with a displacement of tens of thousands of tons is a rather huge project. First, the parts on the carrier that can still be used need to be removed. The US "Stars and Stripes" revealed in 2019 that after the first nuclear-powered aircraft carrier "Enterprise" in the United States was decommissioned, hundreds of parts such as steam ejection devices, electronic equipment, engine fans and other parts were removed for use in other ships, "Although the aircraft carrier was commissioned in 1961, it has undergone many modernizations, and many parts still have a long service life." For example, the ship's 32-ton starboard anchor has been refurbished and installed on the USS Washington.
Dismantle the old aircraft carrier with all the recyclable parts, and the next step will be "unloading eight pieces". Compared with conventional warships, the structure of the aircraft carrier is complex, the strength of the hull material is large, and the internal pipeline layout is complex, so it is more difficult to disassemble. At present, there are many dismantling methods used in various countries. Ideally, in dry docks, dismantling works are carried out in the reverse order in which they were built. The hull should be cut according to the standard size agreed in the contract, and auxiliary facilities should be used during the construction process to ensure the stability of the hull and prevent accidents such as falling components or structural collapse. During this period, a large number of toxic and harmful flammable materials, including asbestos, paints, solvents, oil and fuel residues, must be properly disposed of, and good ventilation measures are required.
However, the problem with this method is that dry docks are limited in number and expensive to rent, not to mention that shipyards also need dry docks to build and repair ships, so the second most retreat is the boat pool dismantling method. This refers to the digging of a long, shallow pond-like trench along the shore of the sheltered waterway, into which the tugboat tows the aircraft carrier to be dismantled. This method is cheaper than dry dock or dock dismantling, pollution is controlled, there is no risk of sinking, and construction can be carried out from three directions of the hull. However, the disassembly needs to be carried out according to the steps, taking into account the strength and balance of the hull structure, otherwise it is prone to accidents.
In contrast, India's shipbreaking industry has been criticized for using the lowest-cost beaching method, in which aircraft carriers run aground at high tide and cut large pieces from front to back at low tide. When the front of the hull is disassembled, push the tow until the stern comes ashore. In this way, a large amount of contaminants are generated during the operation, and all the liquid and debris on board goes directly into the ocean. Ironically, due to their low cost, many Western aircraft carriers are being dismantled in India.
Decommissioned nuclear carriers face special challenges
Compared with the conventional aircraft carriers of various countries that were previously decommissioned, the nuclear-powered aircraft carriers built by the United States during the Cold War have entered the stage of decommissioning, posing a severe challenge to the US Navy. Taking the USS Enterprise as an example, after the aircraft carrier was decommissioned in 2017, due to the undecided dismantling plan, it has been parked at the shipyard dock, which directly affects the maintenance of the active ships of the US Navy. According to the Stars and Stripes, the 428-page dismantling operation plan proposed by the US Navy first requires the removal and dismantling of the eight nuclear reactors of the aircraft carrier, of which the cooling water of the reactor can be removed for several months. The carrier's nuclear fuel rods have been removed and mothballed, but the reactor may contain low-level radiation and must be dismantled and packed in hundreds of small containers before being transported to three disposal sites permitted by U.S. law. It is expected that the entire dismantling process may take more than 10 years.
The U.S. Navy has also noted in related reports the difficulty of handling nuclear-powered aircraft carriers. Countries now use "lifetime costs" to assess the cost of a ship, including the total cost of planning, designing, manufacturing, installing, commissioning, using, maintaining and repairing, modernizing and finally disposing of the entire life process. In the "life cycle cost", the cost is only a small part of it, and the proportion of scrapping cost cannot be ignored. According to the U.S. Government Accountability Office, the dismantling of the USS Enterprise is time-consuming and laborious, costing as much as $1.5 billion, equivalent to the cost of building a medium-sized conventional aircraft carrier. To make matters worse, the dismantling process takes too long, which will affect the maintenance of active ships by U.S. Navy shipyards. If the U.S. Navy decides to let private companies dismantle the aircraft carrier, it is estimated that the cost will be slightly lower, but because the nuclear-powered aircraft carrier involves many military secrets, the US Navy is worried that the core technology may be leaked. To make matters worse, as Nimitz-class nuclear-powered carriers are also to be retired in the coming years, the handling of these carriers will become even more troublesome.
It is precisely because the dismantling of nuclear aircraft carriers is difficult and expensive that it has become one of the important reasons for opposition to the construction of nuclear aircraft carriers within the Pentagon.