Shanghai Airport Link vs Songshan Lake: length and opening date

• 5entries listed

Side by side

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

The median railway tunnel in this archive measures 15.3 km, so both entries here are well clear of the ordinary case and the comparison is between two outliers rather than two typical crossings. Nothing in either row is estimated: a value that could not be corroborated is left blank rather than filled in.

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 3 per cent of the longer bore, which is the figure worth holding on to rather than the raw metres. 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.

At over twenty kilometres Shanghai Airport Link 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 79 km, which is the figure to hold against the 57.1 km of the longest single railway tunnel in the record.

Neither holds the record: Gotthard Base at 57.1 km is the longest railway tunnel recorded here, 16.92 km ahead of Shanghai Airport Link. The 2010s account for 69 entries in this archive, and Songshan Lake is one of them, which is the context a single opening date does not carry on its own.

Reading the figures

Shanghai Airport Link and Songshan Lake are compared here on the figures this archive records for each, taken from the same sources and the same measurement convention. Across every class this archive records, Shanghai Airport Link stands 5th by length and Songshan Lake 6th, so the pair sits inside the top 6 of 244 structures.

Shanghai Airport Link is the longer of the two at 40.19 km, ahead of Songshan Lake at 38.81 km, a difference of 1.38 km. 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.

Songshan Lake opened in 2016 and Shanghai Airport Link 8 years later in 2024, and that gap usually matters more than the length difference. Opening year means the year traffic was admitted. Emergency lay-bys are spaced by regulation rather than by geometry, and their interval dates a crossing as clearly as its opening year.

4 recorded structures are longer than Shanghai Airport Link, the nearest of them Yulhyeon at 50.3 km. Opening dates refer to the admission of traffic, not to breakthrough, which normally falls a year or two earlier. Compressed-air working made shafts through wet ground possible at a cost paid by the men who sank them.

Rock cover above the bore governs a subsea design, not the depth of water above that. Length is measured portal to portal. Comparing two national records says as much about how each country documents its infrastructure as about the infrastructure. Smoke moves uphill, so the two portals of a burning tunnel are not equally dangerous.