Yulhyeon vs Shanghai Airport Link: length, opening date and class

• 5entries listed

Side by side

Yulhyeon is recorded on data/rail.html and Shanghai Airport Link 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

Yulhyeon opened in 2016 and Shanghai Airport Link 8 years later in 2024, and that gap usually matters more than the length difference. 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 Yulhyeon or Shanghai Airport Link has had.

A 8-year gap spans real changes in ventilation, escape provision and excavation method, so the two were not built to the same standard. 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.

That gap is about 20 per cent of the longer bore, which is the figure worth holding on to rather than the raw metres. Driven end to end the two would run 90.49 km, which is the figure to hold against the 57.1 km of the longest single railway tunnel in the record.

At over twenty kilometres Yulhyeon sits in the small group of bores long enough to need intermediate ventilation and a full escape regime. 19 other structures in this record opened within two years of Shanghai Airport Link, which is the cohort it was designed alongside and the fairer comparison for how it was built.

Yulhyeon and Shanghai Airport Link are compared here on the figures this archive records for each, taken from the same sources and the same measurement convention. The 2010s account for 69 entries in this archive, and Yulhyeon is one of them, which is the context a single opening date does not carry on its own.

Reading the figures

Across every class this archive records, Yulhyeon stands 4th by length and Shanghai Airport Link 5th, so the pair sits inside the top 5 of 244 structures. 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.

Yulhyeon is the longer of the two at 50.3 km, ahead of Shanghai Airport Link at 40.19 km, a difference of 10.11 km. 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.

Shanghai Airport Link was designed under the modern regime, with cross-passage spacing and emergency ventilation specified from the outset. Neither holds the record: Gotthard Base at 57.1 km is the longest railway tunnel recorded here, 6.8 km ahead of Yulhyeon. Round figures in an old record are usually estimates that hardened into fact.

A national administration publishes what it maintains, so a crossing that changes owner can move between lists. A pilot bore driven ahead of the main tunnel is usually kept afterwards as the escape route. Lighting is brightest at a portal in daylight, because the adapting eye is the hazard rather than the dark.

3 recorded structures are longer than Yulhyeon, the nearest of them Chunnel at 50.45 km. The first long bores were driven by hand and gunpowder, and their alignments still show it. Motorway crossings are usually twinned, and the second bore is often driven decades after the first. Only structures open to traffic are compared.