New Guanjiao vs Guadarrama: length, opening date and class compared

• 5entries listed

Side by side

New Guanjiao is recorded on data/rail.html and Guadarrama 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

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 New Guanjiao or Guadarrama has had. An immersed tube is built on land and sunk into a dredged trench, so its length is fixed before it reaches the water.

That gap is about 13 per cent of the longer bore, which is the figure worth holding on to rather than the raw metres. This archive separates 4 classes of structure and both entries here are indexed under railway tunnel, which decides the table each is ranked in and the convention its length was measured by.

At over twenty kilometres New Guanjiao sits in the small group of bores long enough to need intermediate ventilation and a full escape regime. Driven end to end the two would run 61.06 km, which is the figure to hold against the 57.1 km of the longest single railway tunnel in the record.

New Guanjiao and Guadarrama are compared here on the figures this archive records for each, taken from the same sources and the same measurement convention. 48 other structures in this record opened within two years of New Guanjiao, which is the cohort it was designed alongside and the fairer comparison for how it was built.

Across every class this archive records, New Guanjiao stands 10th by length and Guadarrama 11th, so the pair sits inside the top 11 of 244 structures. The 2000s account for 53 entries in this archive, and Guadarrama is one of them, which is the context a single opening date does not carry on its own.

Reading the figures

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. 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.

New Guanjiao is the longer of the two at 32.65 km, ahead of Guadarrama at 28.42 km, a difference of 4.23 km. Neither holds the record: Gotthard Base at 57.1 km is the longest railway tunnel recorded here, 24.46 km ahead of New Guanjiao. Two independent sources back every value.

Both are recorded in this archive as railway tunnels, so the measurement convention is identical and the comparison is direct. Among the railway tunnels this archive records, New Guanjiao stands 10th by length and Guadarrama 11th, adjacent in the ranking. Motorway crossings are usually twinned, and the second bore is often driven decades after the first.

9 recorded structures are longer than New Guanjiao, the nearest of them Koralm at 32.9 km. A tunnel outlives the traffic forecast that paid for it, and most of its lifetime cost is ventilation and lighting. Two-way traffic in one bore is what modern regulation avoids and what most older road crossings were built with.

New Guanjiao was designed under the modern regime, with cross-passage spacing and emergency ventilation specified from the outset. A comparison of two crossings is a comparison of two ground conditions, and the length column records neither. Catenary needs headroom a road tunnel does not, so an electrified bore is taller for the same traffic.