Norway drills world’s longest undersea road tunnel through risky rocks

While most coverage of Norway's Rogfast tunnel focuses on the record it will hold, the world's longest and deepest undersea road tunnel, the real story engineers are dealing with sits underground, in rock that has spent millions of years being crushed, fractured and folded into some of the most unpredictable terrain along the entire Norwegian coast. Stretching nearly 27 kilometres beneath the Boknafjord and reaching almost 400 metres below sea level, Rogfast is not just a длинный tunnel; it is a direct fight against unstable geology, constant saltwater pressure and a fjord shaped by forces engineers cannot always predict in advance.Why the Boknafjord posed such a difficult engineering problemBoknafjord is one of the largest fjords in Norway, stretching 45 kilometres inland and reaching depths of hundreds of metres, cutting straight through a region responsible for a large share of the country's fishing, oil and gas industries.