Now, These Are Heavy Icebreakers

The Iceberg Design Bureau is going to deliver three Project 22220 nuclear-powered icebreakers before 2020. It also is designing other advanced nuclear-powered icebreakers, Iceberg Director General/Chief Designer Alexander Ryzhkov told TASS on Thursday.

Artist impression of nuclear powered dual displacement icebreaker “Arktika” (project 22220)
Image: Atomflot

NavyRecognition reports that Russia claims they will have three more nuclear powered icebreakers by 2020 (when the US plans to start building it first new heavy icebreaker since 1977). They also announced plans for two more classes of nuclear icebreakers and a floating nuclear power plant.

The new icebreakers are expected to have a power of 120 MW or more than twice the power of the Polar Star.

10 thoughts on “Now, These Are Heavy Icebreakers

  1. While I am by no means playing a Hitler card, the construction of a “super icebreaker” reminds me of said dictator’s obsession with super-sized versions of conventional weapons, all of which turned out to be complete waste of money and resources. I wonder if building the “Leader-class icebreaker” would ever be economically feasible, especially now that Russia’s economy is stalling due to low oil prices and more money is poured into weapons than ever before? Would there be enough cargo ships to follow the icebreaker on the high-latitude routes, where the proposed convoy speed would probably require icebreaker-level structural strengthening also from the ships following in the icebreaker’s wake.

    The same applies to the smaller nuclear-powered “offshore icebreakers”, vessels which waste their key feature (unlimited endurance and operating range) by circling around a stationary installation what is essentially a large gas station. Perhaps a conventional solution, which could be built at a fraction of the cost, would be better particularly now that it’s probably impossible to make money out of Arctic oil.

    Anyway, Project 22220 icebreakers are currently under construction with the lead vessel having a readiness of about 25%, so new nuclear-powered icebreakers are definitely entering service in the near future. They are probably solid performers along the Northern Sea Route, but having seen the ice conditions e.g. in the Kara Sea and the Gulf of Ob where there is going to be a lot of shipping activity in the future, I wonder if a different type of icebreaker would be better. It takes a long time for a “conventional” triple-shaft/single-rudder icebreaker to turn around when the escorted ships get stuck, and the combination of shallow water and thick broken ice rubble pose a challenge to a vessel which is essentially designed to break a straight path through thick unbroken ice. Let’s say there’s a difference between hammering in a nail and driving in a screw…

  2. @Tups, I am curious about your opinion of the relative effectiveness of one large icebreaker vs a pair of smaller icebreakers, say one 12,000 ton icebreaker with 80,000 HP vs two 6,000 ton icebreakers with 40,000 HP each. How would they compare in performance?

    • That’s a very interesting but also difficult question. I’ll do my best to answer it, but I’m afraid it won’t be a short and simple answer…

      I think in the end it depends on the mission: what do you want to do with the icebreaker and where you intend to do it? When a vessel concept is developed, the operational scenarios and other requirements of the client will define the general design. Usually, the aim is to come up with the most efficient and economical design, which basically means going for the smallest, least powerful and therefore the cheapest vessel that can fulfill the requirements. In case of icebreakers, one of the key factors is to design a hull form that has a low ice resistance. Model tests in an ice tank play an important role there.

      Generally, I would say that generally size is not an advantage to an icebreaker – it should not be larger than what is required to complete the mission. In case of the Finnish icebreaker, one of the requirements was related to the minimum width of the channel, which in turn was based on statistics about ships that require icebreaker assistance. There was no need for the hull to be wider and the vessel was then designed around this and other requirements. In case of the proposed USCG heavy icebreaker, there would be no need for the vessel to have longer endurance (i.e. bigger fuel tanks) than what is required for the most demanding mission, which is probably the annual McMurdo break-in. As ice resistance increases as a function of vessel size, keeping the performance at the same level would require increasing the propulsion power, which in turn would increase the required fuel capacity. Of course, the design would eventually converge to a solution instead of spiraling out of control, but the result would inevitably be a more expensive vessel.

      The same applies to propulsion power. While the Russian Maritime Register of Shipping (classification society) has minimum power requirements for the highest ice classes, they do allow deviations as long as the required level of performance is demonstrated in an ice tank. If I had to rank icebreakers, I would do it based on their true operational performance, not power or displacement. I have seen the largest and most powerful nuclear-powered icebreakers up close, but while they were definitely impressive machines, they didn’t tickle my engineering nerve. Even the upcoming Project 22220 icebreakers have a rather conventional Russian icebreaker hull form which, in my eyes, wastes part of the immense propulsion power to added ice resistance. It could be made a lot better without going to the so-called “extreme ice bows”. The new Canadian polar icebreaker, CCGS John G. Diefenbaker, can provide nearly the same level of performance with a bit over half of the power at the shafts simply because it’s more advanced. I will expect the same from the new USCG icebreaker. Along the same lines, there is no need for the icebreaker to be more powerful than what is needed to achieve the required performance. Of course, it’s always better to have some “safety factor” and then be positively surprised about the “significantly overperforming vessel” (*cough* Healy *cough*) than the alternative, but it all costs extra in the end.

      There are many other factors related to whether one large icebreaker would be better than two smaller ones or not, and I’m not that familiar with some of them. “Economy of scale” may play a role in the cost of construction and operation – a ship twice as big would not necessarily be twice as expensive – but it also would cost extra to use a large vessel for a mission that could be completed by a smaller one. For example, if a medium icebreaker could complete all the tasks required from an USCG icebreaker, in my opinion there would be no need to build a more expensive heavy icebreaker. If some missions could not be completed by a single medium icebreaker but two would be sufficient, perhaps even the higher initial cost of a greater number of smaller vessels could be justified.

      I hope my answer above provides some insight to the vessel size/power issue. Of course, keep in mind that as a naval architect my task is to design a ship based on the owner’s requirements. While I can propose solutions, I can’t really question the “wish list” unless it is obvious that some requirements cannot be fulfilled simultaneously.

      Anyway, I’ll look into the issue later as well. By making some assumptions, I can probably even give some kind of answer to the original question (one 12,000-ton vessel vs. two 6,000 ton vessels).

      • I don’t recall ever seeing that kind of operation before. I was thinking about an escort operation where one icebreaker breaks the initial channel and the second one widens it.

      • I tried to make a quick and dirty study in Excel to see how the size of the icebreaker affects its performance by using the 34,000 kW CCGS John G. Diefenbaker as a starting point. I made some assumptions for hull angles and tweaked the numbers until I got roughly the known performance figures (3 knots in 2.6 m ice). Then, I generated a number of derivative icebreakers by scaling the displacement and back-calculating the main dimensions by assuming the same hull form and ratios. I also made assumptions regarding the number of propellers or propulsion units (two or three, based on beam) and the propeller diameter (assumed to be 60% of draft). It should also be noted that I’m using standard bending strength for ice (500 kPa) which is lower than the bending strength used by the USCG (100 psi/690 kPa).

        It all went well until I started thinking about the relation between vessel size and propulsion power, for which I attempted a statistical approach. If you disregard the fact that icebreakers are tailored for their specific missions and feature pretty unique propulsion arrangements, and perhaps also squeezed your eyes a bit, it almost looks like you can calculate the propulsion power from the difference in displacement to the power of three quarters. Basically it would mean the following:
        – 23,500 ton Diefenbreaker has a propulsion power of 34,000 kW
        – 11,800 ton icebreaker has a propulsion power of 20,000 kW (similar to Polaris)
        – 5,900 ton icebreaker has a propulsion power of 12,000 kW (similar to the port icebreaker featured in another post)

        Now, the above figures may not sound very dramatic if you think about past icebreakers, but while the USCG Polar-class utilized a pretty unique (and in many ways problematic) propulsion arrangement with gas turbines and controllable pitch propellers, today the only feasible alternative for a polar icebreaker is diesel-electric propulsion with medium-speed diesel engines driving frequency-controlled AC electric motors. In addition, today you simply can’t build icebreaker like you could in the past (think about the location of fuel tanks in the hull, for example). Of course, the power-to-weight ratio of modern engines is far better than in the past, advances in structural design mean the steel hull can be made lighter, and we know how to make more efficient hulls than in the 1970s…

        Curiously, when I scaled the vessel up to the size of Project 22220 (about 33,000 tons), I got the same performance (2 knots in 2.8 m ice) with about 44 MW. However, I know that the actual hull form is not as good as that of the Canadian icebreaker. In the good old days, Russian icebreaking vessels tended to follow “30/30” approach (stem angle 30 degrees, waterline angle 30 degrees). The required propulsion power with these angles is almost exactly 60,000 kW…

        Now, let’s look at the performance of my icebreaker family:
        – 23,500 ton/34 MW/triple-shaft heavy icebreaker: 2.6 m @ 3 knots
        – 17,600 ton/27 MW/triple-shaft medium-heavy icebreaker: 2.4 @ 3 knots
        – 11,800 ton/20 MW/twin-shaft medium icebreaker: 1.95 m @ 3 knots (this is quite close to Polaris’s 1.8 m/4 knots)
        – 5,900 ton/12 MW/twin-shaft light icebreaker: 1.6 m @ 3 knots (the port icebreaker can break 1.5 m ice at 2 knots, but it has considerably smaller bollard pull and pretty extreme hull form)

        By putting the above figures to Excel and drawing a scatter plot, it looks like you can get pretty big gains in performance when you move from relatively small icebreakers to medium-sized icebreakers (say, move from Great Lakes icebreaker to a medium arctic icebreaker), but as you increase the size of the icebreaker, it gets more and more difficult to get significant performance gains. It almost looks like at some point nuclear power becomes feasible because you can leave thousands of tons of fuel oil ashore and replace it with bigger propulsion motors.

        There’s one more trick that you can do to increase the icebreaking performance: sacrifice the seakeeping characteristics. When Kapitan Nikolaev was fitted with an extreme ice bow developed by Wärtsilä, the theoretical continuous icebreaking capability of the 15,000 ton, 16,200 kW triple-shaft icebreaker increased to about 2.5 m of level ice. However, the drawback is that this kind of hull form suffers from pretty bad slamming even in moderate seas…

        Anyway, the above is a simple Excel study done without any thought about the actual vessel design and mission requirements, so I would take the results with a big grain of salt.

      • Tups, thanks for a very interesting mini-study. Sounds like a productive evaluation.

        From what you have said, sounds like, if the mission is escorting non-icebreaking vessels, we might be better off with two medium sized vessels, while if it is to operate independently then perhaps the single heavy icebreaker is the way to go.

        Still I see the potential benefits of having two mediums cooperating in terms of providing an assistance capability if one icebreaker has a failure.

  3. Rosmorport, Russia’s top icebreaker operator, is working on proposals to expand the fleet with new shallow draft and line icebreakers in 2025-2030:

    http://en.portnews.ru/news/219469/

    The Russian state-owned icebreaker fleet was largely built in the 1970s and 1980s, and most vessels are due to be decommissioned within the next decade. However, since the nuclear-powered icebreaker business is Atomflot’s territory, I would expect the largest new line icebreakers to be about the size of USCGC Healy. If the 25-megawatt LK-25 is ever finished (Rosmorport’s latest estimate is delivery in 2018), there could be a repeat order for “LK-25M”, a further development that corrects the issues faced with the lead vessel. I wouldn’t be surprised if the Russians continued the LK-16M/21900M series as two vessels are already in operation and the third one is due to be delivered later this year.

    Of course, if Russia goes bankrupt due to low oil prices, none of that will happen…

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