Laerdal vs Ryfylke: length, opening date and class compared

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Side by side

Laerdal is recorded on data/tun10.html and Ryfylke on data/tun10.html, compiled to the same convention, which is what makes the two figures comparable at all.

How this archive measures: lengths, bores, dates and ordering

How this table is compiled

Laerdal and Ryfylke are compared here on the figures this archive records for each, taken from the same sources and the same measurement convention. Laerdal belongs to the 2000s and Ryfylke to the 2010s, two decades in which what a tunnel had to provide by way of escape and ventilation was not the same thing.

Laerdal is the longer of the two at 24.51 km, ahead of Ryfylke at 14.46 km, a difference of 10.05 km. Driven end to end the two would run 38.97 km, which is the figure to hold against the 24.51 km of the longest single road tunnel in the record.

That gap is about 41 per cent of the longer bore, which is the figure worth holding on to rather than the raw metres. Both rows are reachable from the road tunnel table they were taken from, where the note column carries the tube count, the gradient and any reconstruction Laerdal or Ryfylke has had.

14 other structures in this record opened within two years of Ryfylke, which is the cohort it was designed alongside and the fairer comparison for how it was built. Length is the dimension published most consistently across countries, which is why it governs an ordering, but it is a poor measure of the work involved.

Across every class this archive records, Laerdal stands 20th by length and Ryfylke 83rd, so the pair sits inside the top 83 of 244 structures. Counting every class, 62 recorded structures fall between these two by length; the comparison is a window on that part of the record rather than a gap in it.

Reading the figures

The 2000s account for 53 entries in this archive, and Laerdal is one of them, which is the context a single opening date does not carry on its own. Both pass ten kilometres, which 161 of the 244 structures recorded here manage, so this is a comparison inside a small group rather than across the field.

Both are recorded in this archive as road tunnels, so the measurement convention is identical and the comparison is direct. Laerdal is the longest road tunnel in this archive, which makes this comparison one against the record itself rather than two entries below it. A structure renamed after opening keeps both names in circulation for years afterwards.

Ryfylke was designed under the modern regime, with cross-passage spacing and emergency ventilation specified from the outset. A base tunnel trades much greater length for a far lower summit altitude, which changes what the number means. The rock between the portals decides the programme, and two bores of equal length through different geology are different projects.

Among the road tunnels this archive records, Laerdal stands 1st by length and Ryfylke 12th, 11 places apart. 10 recorded road tunnels fall between them by length, the nearest being Tianshan Shengli at 22.13 km. Compressed-air working made shafts through wet ground possible at a cost paid by the men who sank them.

19 recorded structures are longer than Laerdal, the nearest of them Pajares Base at 24.6 km. Nothing on this page requires scripting to read. Water management is the maintenance problem that never ends, and drainage design decides its cost. Pressure waves in a long rail tunnel are severe enough to require relief shafts or sealed carriages.