Kerch Strait - A bridge too far?

It was on 8 October 2022 at 6:07am local time that an explosion occurred on the Kerch-bound lanes of the road section of the Crimean Bridge. Two entire road spans collapsed into Crimean territorial waters in the strategically important Kerch Strait that separates Russia from the annexed territory of Crimea. Seven fuel tankers of a 59-wagon train caught fire on the parallel rail section, which also incurred structural damage. Both road and rail traffic has been significantly disrupted. At the time of going to press, no organisation has formally taken responsibility for the explosion and there is no definitive explanation for what happened.

The heavily defended infrastructure is a crucial military resupply route for Russian troops and is regarded by the Ukrainian government as a legitimate military target. But it is also a potent symbol of Russia’s annexation of the peninsula from Ukraine in 2014. Following the break-up of the Soviet Union in 1991, there had been protracted discussions between Russia and Ukraine aimed at reaching an agreement for the joint construction of an international road and rail link across the Kerch Strait. Talks eventually broke down, and after the annexation of Crimea the construction of the bridge went ahead without Ukraine’s consent. According to a report from the BBC, the bridge, which is frequently described by Russian officials as “the construction of the century”, is ‘hated’ by the Ukrainian public. Reacting to the explosion, an adviser to President Volodymyr Zelensky, Mykhailo Podolyak, while not claiming Ukrainian responsibility for the destruction, wrote: “Crimea, the bridge, the beginning. Everything illegal must be destroyed.” Another official tweeted: ‘sick burn.’

Looking beyond its strategic and symbolic significance, from a technical standpoint the Crimean Bridge is without doubt a major feat of engineering. Apart from being the longest bridge in Europe – the road component is 18.1km (11.25 miles) long, with the rail part only slightly shorter – the double parallel railroad-road truss arch bridge also represents the massive financial investment of $3.7bn. Apart from the sheer scale of the project, there was also the tricky geology of the region as well as severe climate factors (such as pack ice) to consider. Not only is the strait on a tectonic fault, but there were also the multiple challenges of the strait’s bedrock being covered by a 60m layer of silt, and the presence of as many as 70 mud volcanoes in the area. These conditions meant that the bridge required 7,000 piles to support it, driven up to 90m beneath the water surface. Some of the piles are at an angle to make the structure more stable during earthquakes.

When it comes to knowing who or what was responsible for the events on the Crimean Bridge in October 2022, it is too soon to tell with any degree of confidence. With the Ukraine government not admitting responsibility for the explosion, and Russia claiming that the damage was an “act of terrorism”, the truth is unlikely to be known soon. In the court of public opinion, there are plenty of theories circulating on social media, most of which lack credibility. British explosives experts dismiss the widely circulated idea of the damage being caused by a truck bomb as “improbable”.

Perhaps the only known fact in the aftermath is that Russia has ordered contractors Nizhneangarsktransstroy to finish repairs to the bridge linking annexed Crimea to Russia by July 2023.