Lötschberg vs Koralm: length, opening date and class compared

• 5entries listed

Side by side

Lötschberg is recorded on data/rail.html and Koralm on data/rail.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

Lötschberg and Koralm are compared here on the figures this archive records for each, taken from the same sources and the same measurement convention. Lötschberg belongs to the 2000s and Koralm to the 2020s, two decades in which what a tunnel had to provide by way of escape and ventilation was not the same thing.

Lötschberg is the longer of the two at 34.58 km, ahead of Koralm at 32.9 km, a difference of 1.68 km. Driven end to end the two would run 67.48 km, which is the figure to hold against the 57.1 km of the longest single railway tunnel in the record.

That gap is about 5 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 railway tunnel table they were taken from, where the note column carries the tube count, the gradient and any reconstruction Lötschberg or Koralm has had.

Across every class this archive records, Lötschberg stands 8th by length and Koralm 9th, so the pair sits inside the top 9 of 244 structures. 16 other structures in this record opened within two years of Koralm, which is the cohort it was designed alongside and the fairer comparison for how it was built.

The 2000s account for 53 entries in this archive, and Lötschberg 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.

Reading the figures

Neither holds the record: Gotthard Base at 57.1 km is the longest railway tunnel recorded here, 22.53 km ahead of Lötschberg. Opening year means the year traffic was admitted. Where a structure has been lengthened by a later extension the current figure is the one recorded, with the original noted alongside it.

Both are recorded in this archive as railway tunnels, so the measurement convention is identical and the comparison is direct. Water management is the maintenance problem that never ends, and drainage design decides its cost. Cost figures are excluded throughout this archive, because currency, inflation and differing project scope make them close to meaningless in comparison.

7 recorded structures are longer than Lötschberg, the nearest of them Shenzhen at 35.66 km. A hard shoulder inside a tunnel is expensive width, which is why a breakdown there is treated as an emergency. Base tunnels replaced summit lines that climbed by spiral and switchback, and several of those older routes survive above them.

Koralm was designed under the modern regime, with cross-passage spacing and emergency ventilation specified from the outset. Among the railway tunnels this archive records, Lötschberg stands 8th by length and Koralm 9th, adjacent in the ranking. Catenary needs headroom a road tunnel does not, so an electrified bore is taller for the same traffic.

Widening an existing bore is rarely economic, so capacity is added by driving a second one alongside. Sequential excavation is slower per metre and far more tolerant of ground that changes without warning. Reconstruction after a fire is recorded because it usually changes both the profile and the ventilation arrangement.