The Stad Ship Tunnel in Norway: Route, Dimensions and Published Plans

The record table

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

How this table is compiled

They are not uniform: the fullest runs to 67 words and the briefest to 25, and on a page of this kind the long ones are where the explanation lives — the caption carries what the picture cannot. Tunnel building in Norway is shaped by geology and settlement pattern as much as by transport policy.

Spoil disposal is a civil work in its own right, and on the longest crossings it has reshaped the valley floor outside the portal. Geology decides cost and programme far more than distance does; a short bore through squeezing ground can take longer than a long one through sound rock.

This page records the structures catalogued for Norway in a tunnel almanac maintained at this address since the late 1990s. Tidal range decides how deep an estuary crossing must sit, and it varies more between estuaries than the crossings themselves do. County and region codes follow the classification in use when the entry was recorded.

De-icing is a portal problem rather than a tunnel one: the bore stays above freezing long after the approach road does not. Trade press reporting is faster than official publication and less reliable, which is why an opening date sometimes moves after the event. Names follow the operator's spelling, including local diacritics, not an anglicised form.

The most useful sources are the least accessible: annual reports, inspection records and commissioning documents rather than press releases. The Faroese crossings connect islands that had no fixed link at all within living memory. Longitudinal ventilation pushes air along the bore and works until the bore is long enough that the air arrives already foul.

Reading the figures

Cost figures are omitted throughout, since currency, inflation and scope make them close to meaningless in comparison. Japan's rail network drove long-bore practice decades before its roads did, and its list reflects that order. A tunnel boring machine produces a circular bore, which is why cross-section area and length do not scale together across entries.

Motorway tunnels are usually twinned, and the second bore is frequently built decades after the first. Austria's north-south routes cross the main alpine chain three times, and its tunnel list is essentially that geography written down. The deepest point of a subsea tunnel is a sump, and its pumps run for the life of the crossing.

Wartime damage closed several crossings for years, and a few were never reopened to their original use. Where a tunnel crosses an international border, it is listed under both countries. A national administration publishes what it maintains, so a crossing that changes owner can vanish from one list and appear in another.

A projected opening date is a forecast, and on large schemes forecasts have historically slipped by years. Glacial till is loose, wet and unpredictable, and the Scandinavian entries that took longest were rarely the ones through granite. A single-track bore costs less than half a double-track one and constrains the timetable for the next century.

Water ingress is pumped out continuously on a subaqueous crossing, and the pumps are the one system that can never be off. A figure quoted to the metre implies a survey that was actually done, and not every published length carries one. A tunnel's gradient is often the more interesting figure, particularly on subsea and base tunnels.