At 1,180 feet long and 230 feet across the sub tanker Pilgrim would dwarf the Typhoon, shown above. Credit: Handout.

Russia’s mighty Typhoon Class ballistic missile submarine rules the waves as the largest of its kind — 574 feet long and 75 feet wide. But a bigger fish is coming, a much bigger fish, if Russian engineers get their way.

A massive undersea tanker called the Pilgrim has been proposed to transport liquid natural gas (LNG) in the Arctic — submarine tankers can literally slip under the ice, undetected, unopposed, no matter the weather above.

An idea nobody really considered practical until now, according to a report in Forbes magazine.

St. Petersburg-based Malachite Design Bureau has unveiled a design for a massive submarine capable of carrying 170,000 to 180,000 tons at a time, the Forbes report said.

That is far in excess of the volume of any previous submarine. At 1,180 feet long and 230 feet across the submarine tanker would dwarf the Typhoon. In terms of volume it would be more than six times the size of the Typhoon, the Forbes report said.

To shift this incredible bulk it would be powered by no less than three nuclear reactors, each producing 30 megawatts.

This could propel it at 17 knots, which is only a few knots slower than regular tankers. Because it’s not a combat vessel the crew would be small by submarine standards, just 25-28 people, the Forbes report said.

At 1,180 feet long and 230 feet across the Russian submarine tanker Pilgrim would dwarf the Typhoon. Credit: Handout.

Malachite have designed many of Russia’s most famous submarines.

These include the potent Severodvinsk Class cruise missile submarine. And the secretive Losharik spy sub which was involved in a tragic accident last year. They are also working on the Laika, which will probably be Russia’s next generation attack submarine, the Forbes report said.

But nothing they have built so far is anything like the Pilgrim proposal. If it’s built it’ll be the first submarine tanker in the world. But the idea of transporting hydrocarbons underwater is not new.

In the 1950s the US considered them as an alternative to undersea pipelines from oil fields in Alaska. And enterprising Dutch naval architects proposed designs based on their then-unique multi-hull submarine technology, the Forbes report said.

The idea has also come up in Japan. In 1995 there was a patent for a submarine tanker to carry carbon dioxide in liquid form under the ice cap, the Forbes report said.

It has yet to be seen how submarine tankers could disrupt the world of commodity trading and international trade. They would be immune from piracy for example, but they could also complicate sanctions enforcement.