The Finnish Stopped Soviet Mines from Exploding by playing a Single Polka Song on Repeat

Finnish military parade in Viborg on 31 August 1941, after its recapture from the Soviet Union (Photo Credit: Wikipedia / Public Domain)

During both the Winter War and the Continuation War the Finns utilized creative and often outright comical tactics against the more numerous Soviet forces. On one occasion, the Finns slowed down a Soviet advance with just the smell of warm sausage, something the hungry Soviet troops could only dream of receiving from their own side. But in 1941, in a similarly creative fashion, Finland played the same polka song over and over again to defend against Soviet explosives.

Explosives and polka music aren’t usually linked, but the Finns actually used it to save lives.

Vyborg mines

After the Finns wrestled the city of Vyborg back from the Soviets in the Continuation War (1941-1944), the Soviets, while retreating, scattered the area with mines and explosives. These mines claimed many Finnish lives, so many in fact that civilians weren’t allowed to return even after the Soviets had been pushed out.

With the Soviets gone, the mines continued detonating, causing great confusion among the Finns as to how they were being set off. One theory was they were set on a timer. However, on August 28 1941 the Finns discovered 600 kgs of explosives and its triggering device. It was quickly realized that the mines were being triggered by radio signals.

Russian Radio Signals
Photo Credit: National Archives / Public Domain

The devices were sent to the Finnish Communications Department and inspected by the Captain of Engineering Jouko Pohjanpalo. Pohjanpalo was the local expert on radios and learned that inside the trigger were three tuning forks that vibrated at specific frequencies. When needed, a specific three-note transmission vibrated all three forks and caused the mine to explode.

Shortly after learning this, the Finns discovered the entire city had been mined by radio-operated explosives.

Before they could be dealt with, they had to stop the Soviets from detonating them. To do this they needed a jamming signal that prevented the three-note sequence from triggering the mines, yet wouldn’t itself cause the mines to explode.

Operation Polka

An REO Speedwagon broadcast car was brought to the city and started playing the fast-paced Säkkijärven Polkka by Viljo Vesterinen. This song was a hit in Finland at the time and invoked a great sense of national pride even before it was used to defend its people.

Over and over, the song was played in a desperate bid to block Soviet signals. Over time the Soviets clocked on to what was happening so they started broadcasting a triggering transmission over different frequencies. To counter this, Säkkijärven Polkka was played on any frequency the Soviets could theoretically use.

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The plan worked too: the city contained around 1,000 mines, but only 12 were successfully detonated.

Of the event, Pohjanpalo later said “In the crowds and the homeland, the operation received a legendary reputation because of its mystery. Säkkijärvi’s polka went together about 1,500 times. All kinds of rumors circulated about somebody crazy enough to have emitted it on every radio station.”