Tunnel fires and accidents: the record and the major catastrophes

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The record table

The catastrophes that changed tunnel design. Tolls are the figures established by the official inquiries. The full incident tables, including the minor fires that never made the news, are linked from each row.

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

How this table is compiled

The tables behind this page also record the many fires that hurt nobody, which is the half of the record that gets forgotten. Opening year means the year traffic was admitted. Records in this field move whenever one large scheme opens, and a page that is not re-checked drifts out of date without announcing it.

Three road tunnel fires in thirty months, at Mont Blanc, in the Tauern and in the Gotthard, killed sixty-two people between them. The table is short because the sourcing bar is high. Ventilation type constrains how long a bore can be driven without intermediate shafts, and its absence is often what caps a tunnel's length.

What changed after these events was cross-passage spacing, fixed firefighting, emergency ventilation control and driver instruction, in roughly that order of effect. Where a figure could not be corroborated it was left out. Corrections have historically arrived by letter rather than by form, and that is still how most errors in it have been found.

Cost figures are excluded for a harder reason: currency, inflation and differing project scope make them close to meaningless in comparison. Comparing one country's practice against a neighbour's is more informative than reading either alone. Where a structure belongs to two classes it appears on both tables, which is not double counting but two different measurements.

A tunnel fire that was contained is more instructive than one that was not, because containment is the design goal. Cross-passage spacing, fixed firefighting and emergency ventilation control are what modern safety regulation actually governs. Twin-tube crossings frequently show two slightly different lengths, because the two carriageways rarely follow the same line through the rock.

Reading the figures

A base tunnel trades a much greater length for a far lower summit altitude and a gentler ruling gradient. This archive has recorded tunnel data since the late 1990s, compiled from operator publications, national administrations and the engineering press. Traffic figures are excluded throughout this archive, because they date far faster than the structures themselves.

Tunnel safety regulation in Europe was rewritten between 1999 and 2003, and the reason is on this page. Tunnel engineering is a field where the qualifications attached to a number matter more than the number itself. Subaqueous tunnels are governed by rock cover above the bore rather than by the depth of water above that.

Rows are ordered so that the head of the table answers the question most readers arrive with. Reading the qualification before the figure is usually the faster route to understanding what a claim actually says. Figures are checked against one another where sources disagree, and the disagreement is recorded rather than resolved silently.

A contained fire is more instructive than an uncontained one. Dates use the day, month and year the event occurred. The archive grew through correspondence with engineers and administrations in more than twenty countries, and still does. Gradient limits are the main reason railway tunnels run longer than road tunnels on the same crossing.

The date of verification is published with the table. Promoter figures are used where no independent one exists. Deaths are the figures established by official inquiry. Disputed values carry the dispute in the note column. Every figure here is traceable to a named source. The note column is worth reading before the number.