Structures on the Rhaetian Railway Bernina Line, St. Moritz to Tirano

• 33entries listed
• 0.84 kmlongest bore
• 4.73 kmtotal length

The record table

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

How this table is compiled

The next two longest are Charnadura II at 0.69 km and Lunga at 0.63 km. Read down the altitude (m) column, the 54 values run from 429 m to 2 253 m with a midpoint at 1 774 m; the spread rather than the maximum is what says how uneven this set is.

Also recorded here are Grum at 0.26 km and Val da Pila at 0.23 km. Read down the km column, the 54 values run from 61.6 km to 122.3 km with a midpoint at 90.8 km; the spread rather than the maximum is what says how uneven this set is.

The median entry measures 0.05 km, so half the table sits below that and half above, which is a better guide to the typical structure here than the headline figure. The shorter half of the table totals 0.39 km against 4.34 km for the longer half, from the same number of rows.

The shortest recorded entry is 0.01 km against 0.84 km at the top, a spread of 84x across the same table. Only 34 of the 58 rows carry anything in the tunnel / viaduct column, so that field describes a minority of this table and the rest of the rows are recorded without it.

The longest stands 0.15 km clear of the next longest, which is the margin to watch when a new scheme is announced. Only 34 of the 58 rows carry anything in the lenght (m) column, so that field describes a minority of this table and the rest of the rows are recorded without it.

Reading the figures

16 entries sit above the median and 17 at or below it, so the table is top-heavy and not clustered at one end. The captions name 8 distinct places and structures — Mason, Sassal and Palù among them — and those names are the index into the length tables where each is recorded with its own figure.

Between the longest and the tenth-longest the drop is 0.69 km, which is the part of the table that changes when a single scheme opens. Where one of these 33 lengths disagrees with an operator's own figure for Switzerland, the table keeps the published value and notes the difference instead of averaging the two.

Lengths for Switzerland are recorded in metres which is how the operators publish them and why the shortest entry here reads as 10 m and not a rounded figure. The longest entry is 84.0 times the shortest and 16.5 times the median, which is the quickest measure of how uneven the table is.

A new scheme in Switzerland would have to beat 0.84 km to change the head of this table, and that is the figure worth rechecking when one opens. The eighth longest is Arlas at 0.18 km, which is about where this record stops being about record holders and starts being about ordinary infrastructure.

The entries sum to roughly 4.73 km of bore, an average of about 0.14 km each, though that average describes no actual row. The three longest entries alone account for 2.16 km of the 4.73 km on this page, which is 46 per cent of the total from 3 of 33 rows.