The Longest Canal Tunnels: Historic Navigation Routes by Length

• 33entries listed
• 7.12 kmlongest bore
• 1802–1911openings span
• 87.11 kmtotal length

The longest canal tunnels, ranked by length

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

Navigation dimensions rather than length

A list of longest canal tunnels is only as good as its sourcing, and each figure here comes from an operator or an administration. The median entry measures 2.56 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 table below lists 33 entries with a recorded length, each giving a name, a length in metres and, where documented, the year of opening. The middle half of the table runs from 1.35 km to 3.55 km, and that band is where most of the engineering on this page actually sits.

The entries sum to roughly 87.11 km of bore, an average of about 2.72 km each, though that average describes no actual row. The three longest entries alone account for 18.01 km of the 87.11 km on this page, which is 21 per cent of the total from 3 of 32 rows.

16 entries sit above the median and 16 at or below it, so the table is evenly weighted and not clustered at one end. Between the longest and the tenth-longest the drop is 3.79 km, which is the part of the table that changes when a single scheme opens.

Roughly 0 of the dated entries opened in this century, which is a rough measure of how much of the network is recent. Lengths for the world are recorded in metres which is how the operators publish them and why the shortest entry here reads as 1 000 m and not a rounded figure.

Historic bores, abandonment and reopening

The shortest recorded entry is 1 km against 7.12 km at the top, a spread of 7.12x across the same table. Where one of these 32 lengths disagrees with an operator's own figure for the world, the table keeps the published value and notes the difference instead of averaging the two.

A new scheme in the world would have to beat 7.12 km to change the head of this table, and that is the figure worth rechecking when one opens. 10 of the 32 entries fall within a quarter of the median length, which is how tightly this particular list clusters around its typical structure.

The 32 rows for the world are ordered by length, not by date, so the 1911 opening sits well down the table without being any less current. The longest entry is 7.1 times the shortest and 2.8 times the median, which is the quickest measure of how uneven the table is.

The shorter half of the table totals 24.59 km against 62.52 km for the longer half, from the same number of rows. Eighth on the list is Lapal at 3.57 km, which is where the table stops being about record holders and starts being about ordinary infrastructure.

Measuring length, and why sources disagree

After the 1800s the next busiest decade here is the 1810s with 3 openings, so the building effort came in more than one wave. The dated entries fall across 12 different years, which is a rough measure of whether this was a sustained programme or a handful of separate schemes.

The ten longest average 4.61 km against 1.86 km for everything below them, and that ratio is the clearest thing this table says about the distribution. Only Le Rove sits within ten per cent of the longest figure, so one structure stands 1.44 km clear of the field here.

Reading a list of longest canal tunnels

Where a figure could not be sourced the cell is left blank, so what is shown is measured and nothing is inferred. Laid end to end the entries on this page would run 87.11 km, which is a number with no engineering meaning but a useful sense of the scale of what is catalogued.

Second and third place go to "Le Grand Souterrain" at 5.68 km and Standedge at 5.21 km. The table on this page runs to 34 rows and records Country, Tunnel, Length, Canal and Year of construction for each of them, which is the shape the original compiler chose rather than one imposed here.

Treat the table as the argument and the prose as the footnote: the numbers carry the case. Read down the length column, the 33 values run from 1 000 m to 7 120 m with a midpoint at 2 492 m; the spread rather than the maximum is what says how uneven this set is.

Navigation dimensions matter more than length here, since beam and headroom decide what can pass. 24 of the 34 rows carry an entry in the comment column — 71 per cent of the table — and that column is where the qualifications live: tube counts, closures, boundaries and the reason a figure reads the way it does.

Dated entries run from 1802 to 1911, and the busiest decade is the 1800s with 3 recorded openings. The material on this page is held in 13 captions rather than in running text, 116 words of it, each written against the image or row it belongs to by the compiler who put the page together.

The longest stands 1.44 km clear of the next longest, which is the margin to watch when a new scheme is announced. The captions name 16 distinct places and structures — Marne, Dijon and Navigation among them — and those names are the index into the length tables where each is recorded with its own figure.

The dated entries carry 12 distinct opening years across 109 years, and the median opening year is 1824. They are not uniform: the fullest runs to 26 words and the briefest to 6, and on a page of this kind the long ones are where the explanation lives — the caption carries what the picture cannot.

The country column sorts these 34 rows into 4 groups, the largest being England with 19, then France with 13 and Norway with 1. The tunnel column names 31 distinct entries on this page, Le Rove and "Le Grand Souterrain" among them, each traceable to the operator or administration record it was taken from.

Sorting on that one dimension is imperfect, since geology decides difficulty, but it is the measure published consistently enough to rank on. What follows is a list of longest canal tunnels and not a selection, with every row traceable to a published source. Most were driven between the 1770s and the 1840s for canal freight.

Most entries are historic, driven between the 1770s and the 1840s for canal freight. Historic bores are retained in the record even where they have since been abandoned. Dates for the world refer to opening to traffic, not breakthrough, so the 1802 entry was under construction for some years before that.

Length is recorded in metres for every entry, and length alone decides the sort order. Where two sources disagree on a length, the operator's own published length is preferred. The 1800s account for 3 openings here and the 1810s for 3, so the building effort was not spread evenly across the period.

Nothing in this table is estimated: where a value could not be sourced it is left blank. Anyone comparing these figures across borders should read the note column too, since national practice varies. This page records the canal tunnels catalogued for the world in a tunnel almanac maintained at this address since the late 1990s.

The longest entry is Le Rove, at 7.12 km, opened in 1911. Further down the table, Balesmes is recorded at 4.8 km and Ruyalcourt at 4.35 km. Lighting at a portal is brightest in daylight, because the eye adapting from sun to bore is the hazard, not the darkness inside.

3 of the 32 measured entries exceed five kilometres, and those are the ones that carry a full ventilation and escape regime. Openings average one every 9.1 years across the dated entries here, though they arrive in clusters, not at that rate. Few new ones have been built since railways displaced canal haulage.