Victorian brick tunnel joints provide clues to their construction that can help improve maintenance and reduce costs. Jack Knight and Scott Wilson report. This paper was first published in GE’s August 2006 issue.
Most rail passengers travel through tunnels every day and think nothing about them. Travelling from south Wales to London, for instance, trains pass through the longest tunnel in Britain: 7km of Victorian brickwork that is mainly unseen today, but is the result of the truest engineering skills beneath the River Severn.
Mainly built between 1830 and 1900, there are 628 operational tunnels in Britain covering 335km. There are also, it is thought, more than 200 disused railway tunnels.
The engineering of these Victorian tunnels remains much of mystery even to the railway companies that own them. With no plans or paperwork, those responsible for safety and maintenance of the tunnels are, like their passengers, in the dark.