The Norwegian Public Road Authority recently awarded two contracts, together worth $900 million, for the world's longest subsea road tunnel. The 16.5-mile long Rogfast tunnel, under Boknafjord north of Stavanger, would form the southern end of the planned 690-mile E39 coastal highway.

A joint venture led by Switzerland-based Implenia A.G. with Norway's Stangeland Maskin A.S. started the New Year announcing its $400-million contract for the fjord's southern 5.3 miles of twin rock tunnels, due for completion in 2030. Implenia’s global tunneling chief, Erwin Scherer, described the contract as "large and complex."

Implenia’s win followed last month's signing by Sweden-based Skanska A.B. of a $500-million contract covering roughly 5.5 miles at the north end of the crossing. Due for completion in 2029, the contract is Norway's largest ever highway contract, according to the NPRA.

The authority has yet to award the contract covering the tunnel's central section around Kvitsøy island. Though it was the first main contract to be launched in 2018, negotiations were halted when the price was found to be excessive. The crossing's total budget was then increased from $2.1 billion to $2.5 billion.

The 34-ft-dia twin Rogfast bores would descend to 1,286 ft below sea level, forming the first fixed ferry replacement of several fjord crossings on the E39 coastal highway between Kristiansand and Trondheim.

Ferry replacement plans include a roughly 3-mile-long floating suspension bridge crossing the 1,800-ft-deep Bjørna fjord south of Bergen. By eliminating seven ferry crossings, the current 20-hour drive between the cities will be cut by 8.5 hours, according to NPRA.