To the Victorians the London to South Wales was an important route, but one obstacle got in the way, the Severn estuary.

In the 1860s rail travellers on this route would have had to break their journey on reaching the Severn and take a ferry to rejoin a train on the other side.

Unfortunately the Severn Estuary is known for its treacherous tides and bad weather, making an unpleasant interlude on an otherwise pleasant journey.

The Victorians produced some great engineers and they were prepared to accept the technical challenge of tunnelling under the Severn. Unaware of one hidden danger, the Great Spring!

The project began in 1873 and six years later they hit the Great Spring. Only 152 metres separated each tunnel running from the English and the Welsh shore. Within 24 hours the tunnel was flooded to river level, thankfully without any loss of life.

Thomas A. Walker was engaged for seven years in the construction of the Severn Tunnel.

When he began work on the project he had already accumulated considerable experience in railroad survey and construction throughout Canada, Russia, Egypt and England. In writing his memoirs of his work on the Severn Tunnel he states: 'Sub-aqueous tunnels have recently become quite the fashion.

One such experience as the Severn Tunnel, with its ever-varying and strangely contorted strata, and the dangers from floods above and floods below, has been sufficient for me. One sub-aqueous tunnel is quite enough for a lifetime.'

This portrait of Thomas Walker (who died in 1889) is taken from his memoir of the project. Source: T. A. Walker, 'The Severn Tunnel: its construction and difficulties, 1872-1887' (London, Richard Bentley & Son, 1888).


Huge pumps were brought in to try to pump out the water, but the spring was so big that they couldn't cope.

A diver by the name of Lambert bravely entered the workings and managed, with considerable difficulty, to seal off the spring. But it wasn't until 1881 that the Great Spring was sealed off behind a giant headwall.

Since that day a massive pump has continued to pump out 50 million litres of water per day and is now sold to a local water company.



The large pumping station, required to pump water from the tunnel, including three large brick engine houses housing six steam engines, and ventilation towers.

The steam engines were replaced by electrical engines in 1962, and the chimney stacks taking smoke from the furnaces were demolished in 1968.

The Great Spring persisted throughout the remainder of the time spent in constructing the tunnel to give problems, As did the weather, even a large tidal wave gave rise to flooding.

But on the 1st December 1886 a regular passenger service was opened, cutting the journey from London to South Wales by one hour.



Most of Sudbrook was built as a new village for workers on the Severn Tunnel, on which construction began in 1873.

The first cottages were built by contractor T. A. Walker in 1877, and rapid development took place over the next decade, including a school, post office, mission hall and infirmary.

Some of the houses - originally known as Concrete Row - are believed to be the first concrete houses built in Britain.




Work had begun two years earlier in 1875 on the construction of the Severn Railway Bridge which crossed the river a little upstream of Lydney and Sharpness.

There was to be a lot of jealousy during the period of construction between both the tunnel and bridge companies until the bridge was finally opened in 1879.

On a foggy night on the 25th October 1960 two tanker barges owned by John Harker Ltd, the ARKENDALE H and WASTDALE H were swept by a large tide into the bridge.

Two spans of the bridge dropped onto the tanker barges, setting both craft and the river ablaze. Five men lost their lives that evening, and is now always referred to as "The Severn Bridge Disaster". The bridge was never repaired and was finally dismantled in 1967.

Today the tunnel has modern diesel express trains roaring through, but the maintenance of the workings is continuous. Every Sunday the tunnel is closed to allow teams of engineers in to carry out vital work to ensure the safety of the passengers that use it.


The Severn Tunnel -
Statistics Description:

A double track, brick lined tunnel with long approach cuttings and carrying the trains under the estuary of the River Severn between Pilning and the Severn Tunnel Junction.


4 miles 574 metres

1 in 100 descent from the Bristol side.
1 in 90 rise to the Welsh side.
Begun in 1873 and completed in 1886
27th June 1872
Act obtained to build the tunnel
18th March 1873
Construction work began
16th October 1879
Inundation by the Great Spring
18th December 1879
Work taken over by Thomas Walker
8th November 1880
Lambert, the diver, closed off the eastern heading
4th January 1881
Great Spring sealed off
18th January 1881
A great snowstorm
26th September 1881
Heading joined under the Severn
10th October 1883
The Great Spring broke in again
17th October 1883
Flooding by an abnormal tidal wave
17th October 1884
A through passageway completed from end to end
18th April 1885
The last brick was keyed in
5th September 1885
Sir Daniel Gooch travelled through the tunnel by train
1st September 1886
A regular goods service commenced
1st December 1886
Regular passenger train services commenced


History of the Severn Tunnel The Great Western Archive



Rare glimpse of Severn Tunnel pumping power


AROUND 500 people were treated to a rare glimpse of Sudbrook Pumping Station at a
celebration to mark the 125th anniversary of the Severn Tunnel.

Visitors joined members of Sudbrook Community Council, Caldicot and District Local History Society and Sudbrook Action Group to see John Harvey, great-grandson of engineer Thomas Walker, open Sudbrook History Centre at Sudbrook Non-political Club, and to visit the pumping station.

Mr Walker created homes for the workforce constructing the Severn Tunnel and built the village of Sudbrook, with a school, hospital, mission hall and coffee house.

The four-and-ahalf mile tunnel was completed in 1887. Mr Harvey’s talk about his great grandfather’s achievements was so popular he held a second sitting. Visitors also enjoyed a model railway display, an exhibition featuring artefacts and performances fromthe Severn Tunnel Band.

Pete Strong, of Caldicot and District Local History Society said: “For many, including myself it was the first time we had been inside the Pumping Station whichis still in use. Itwas impressive, cavernous and very noisy!”

The history centre is open Fridays, Saturdays and Sundays from 10am-3pm. To arrange a group visit contact Mr Strong on 01291 425638.

South Wales Argus: September 2011


*Please click here to access our webpage "Special Events" on the Severn Tunnel 125 Celebrations


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