Railway Tunnels in the United Kingdom — Complete List by Length

• 25entries listed
• 50.45 kmlongest bore
• 1803–2007openings span
• 147.5 kmtotal length

The record table

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

How this table is compiled

The three longest entries alone account for 68.11 km of the 147.5 km on this page, which is 46 per cent of the total from 3 of 25 rows. The shorter half of the table totals 32.55 km against 114.95 km for the longer half, from the same number of rows.

Where one of these 25 lengths disagrees with an operator's own figure for the United Kingdom, the table keeps the published value and notes the difference instead of averaging the two. After the 1840s the next busiest decade here is the 2000s with 3 openings, so the building effort came in more than one wave.

A new scheme in the United Kingdom would have to beat 50.45 km to change the head of this table, and that is the figure worth rechecking when one opens. Only Channel tunnel sits within ten per cent of the longest figure, so one structure stands 40.35 km clear of the field here.

Second and third place go to Stratford west at 10.11 km and Stratford east at 7.56 km. The table on this page runs to 26 rows and records Tunnel, Length, Date of opening and Line, section for each of them, which is the shape the original compiler chose rather than one imposed here.

5 of the 25 measured entries exceed five kilometres, and those are the ones that carry a full ventilation and escape regime. Laid end to end the entries on this page would run 147.5 km, which is a number with no engineering meaning but a useful sense of the scale of what is catalogued.

Reading the figures

Between the longest and the tenth-longest the drop is 46.39 km, which is the part of the table that changes when a single scheme opens. The tunnel column names 26 distinct entries on this page, Channel tunnel and Stratford west among them, each traceable to the operator or administration record it was taken from.

Further down the table, Totley is recorded at 5.7 km and Woodhead new at 4.89 km. Read down the length column, the 25 values run from 2 000 m to 50 450 m with a midpoint at 3 523 m; the spread rather than the maximum is what says how uneven this set is.

The longest entry is Channel tunnel, at 50.45 km, opened in 1994. A tunnel list for the United Kingdom reads differently from a neighbouring country's: 17 of these 25 structures pass three kilometres, and the same journey time is bought with one long bore in one country and a dozen short ones in another.

The 25 rows for the United Kingdom are ordered by length, not by date, so the 2007 opening sits well down the table without being any less current. The longest entry is 25.2 times the shortest and 14.3 times the median, which is the quickest measure of how uneven the table is.

Eighth on the list is Woodhead old I at 4.85 km, which is where the table stops being about record holders and starts being about ordinary infrastructure. The dated entries fall across 13 different years, which is a rough measure of whether this was a sustained programme or a handful of separate schemes.