Russian aircraft carrier Admiral Kuznetsov runs on dirty Mazut fuel

  • The Russian aircraft carrier Admiral Kuznetsov uses Mazut, an ultra-thick black tarry substance.
  • Mazut is known to be quite toxic, sticky and emit clouds of smoke.

The only Russian aircraft carrier has a problem: For most sailors who served on Admiral Kuznetzov, Mazut is a legend.

The ultra-thick, tarry black substance that powers the ship is known to be rather toxic, sticky, and difficult to remove from clothing. But why did the Soviet Navy continue to fuel its ships with Mazut? What are the pros and cons of fuel? Why exactly is the Kuznetsov so smoky?

Not all Russian ships operate on Mazut. Of all the large ships currently operated by the Russian Navy, only the Sovremenny-class destroyers and the aircraft carrier Admiral Kuznetsov sail Mazut. Given Admiral Kuznetsov’s high profile on the world stage – being Russia’s only aircraft carrier – naturally some curiosity arose as to what it operates on and why it produces so much smoke.

Mazut is a heavy petrochemical fuel. Although most sources say it comes from the bottom of a distillation pile, this is incorrect because “mazut” is a generic term for very heavy petroleum products, including those that can be formed by mixing heavier oils. heavy with slightly lighter oils. .

In the West, Mazut would fall into the Bunker B and Bunker C fuel oil classifications, although ISO 8217 replaced those categories. According to ISO 8217, Mazut can be classified as RMG or RMK fuel.

These thick, heavy fuel oils were, by and large, the standard for military and commercial vessels until the 1960s and 1970s. Their thick nature gives them a very high volume to energy ratio compared to lighter distillates. But to be burned, they often had to be preheated and pressurized in a complex series of boilers and pipes.

Russian aircraft carrier Admiral Kuznetsov

A Su-33, left, and a MiG 29K, right, over Admiral Kuznetsov off Syria, January 8, 2017.

Andrei LuzikTASS via Getty Images


Burning these fuels could also produce large amounts of sulphur, as these heavy minerals tended to settle to the bottom of a distillation stack.

As a result, these fuels can be expensive to source in countries with stricter environmental standards, as they must be distilled from low initial sulfur crude or removed by a chemical process.

For these reasons, Western navies began to switch to gas turbine propulsion in the 1960s and 1970s. Gas turbines use natural gas and distillate fuels, not heavy bunker fuels. Currently, all US Navy ships use gas turbines for propulsion except those powered by nuclear power or the Freedom class, which uses an electric drive system.

However, the Soviet Navy seemed hesitant to switch so completely to gas turbines.

While the Slava-class cruisers established in the 1970s used gas turbine engines, the Sovremenny-class destroyers established around the same time were still designed with a Mazut engine propulsion system, apparently due to the inability of the Soviet industry to produce enough turbines. at the time. The later Udaloy-class destroyers continued the trend of using gas turbines.

The big question is why Admiral Kuznetsov continued to use Mazut. Nuclear power was an option on the table, as Kirov-class battlecruisers designed around the same time used nuclear power plants – although Ulyanovsk’s later class of carriers planned to use nuclear power. nuclear.

One possible reason was that the class was partly based on the shape and hull layout of the older kyiv-class aircraft carriers, which operated on Mazut.

Opener of Typhoons Kuznetsov


Crown copyright


While Mazut was certainly not an optimal fuel choice for Admiral Kuznetsov, its long and difficult construction process only compounded the problems.

A Russian news article describes the Kuznetsov as having a “weak heart” due to poor shipbuilding standards when completed in the 1990s at the Nikolayev Black Sea shipyard in Mykolaiv.

Additionally, Admin. Valentin Selivanov said: “From the very beginning, poor quality pipes were installed in his boilers.”

The same admiral then described the sea trials of the Kuznetsov in the 1990s. Due to the problems with the pipes, not all the boilers could work at full capacity all the time, and they often failed. Sometimes the ship was reduced to running on a single boiler, which gave her a speed of around 4 knots.

These same reliability issues lead the Russian Navy to send tugboats to accompany the Kuznetsov on its 2016 voyage to the Syrian coast.

Admiral Kuznetsov

Admiral Kuznetsov in international waters off northern Norway, October 17, 2016.

Reuters


These engineering difficulties are also given as a potential reason for the Kuznetsov’s super-smoky nature. Vice Admiral Pyotr Svyatashov explained that due to incorrect calibration of the preheating or injection mechanisms, the Mazut injected into the combustion chamber might not have had time to burn completely – in d In other words, partially burned products cause black smoke.

This is supported by some other analysts, who say the color of exhaust gases can be broadly categorized into three colors – gray for oil, white for water and black for fuel.

Some blogs have gone deeper into the analysis of potential mechanical issues that could cause black smoke, albeit on Sovremenny-class ships, which suffered their own black smoke episodes.

However, some Russian military experts have tried to completely downplay the issue. Admiral Ivan Vasiliyev said in the program “Tsargrad” that the black smoke was a deliberate gesture to show the British that Admiral Kuznetsov was there, according to the “tradition of sailors”.

Russia, however, could work to solve the problem. While the ship is currently undergoing years of repair work with reports that the black smoke issue was being resolved, it has been some time since new information about the only Russian aircraft carrier became available. . It seems that only Russia knows for sure.

Charlie Gao studied political and computer science at Grinnell College and is a frequent commentator on defense and national security issues.

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