Severn Tunnel - Wikipedia
Originally, during much of the steam era, a large number of pilot and banking locomotives were required to assist heavy trains traverse the challenging gradients of the tunnel, which were deployed from nearby marshalling yards. The tunnel is 7,008 m (4.355 mi) long, although only 3,621 m (2.250 mi) of its length are under the river.
Gradient profile and mileages - SVR Wiki
Gradient Profile. The gradient profile of the SVR Severn Valley Railway between Kidderminster and Bridgnorth is shown below. The diagram, which is reproduced from the SVR Severn Valley Railway Visitor Guide Eighth Edition (2001), is based …
Gradient Signs
The Severn Tunnel is over four miles (6.5 km) in length, with long steep gradients. A short section of level trackbed near the middle of the tunnel is approached from the Welsh end on a 1 in 90 falling gradient and from the English end at 1 in 100 falling.
The Severn Tunnel - Railway Wonders
As will be seen from the longitudinal section, shown above, the line is level for some chains under the deepest part of the river, but rises at a gradient of 1 in 100 towards the Gloucestershire side, and at 1 in 90 towards the Monmouthshire side.
Conquest of the Severn - Wonders of World Engineering
The tunnel has a length of more than four miles, of which about two and a quarter are beneath the estuary of the River Severn. THE building of the Severn Tunnel is an epic, a record of hope and heartbreak, of fourteen years’ fighting against the forces of Nature deep down below the bed of Great Britain’s longest river.
Severn Tunnel - Wikishire
Due to the access gradients, in the steam era assistance was needed by all heavy trains through the Severn Tunnel, which entailed (eastwards, from Severn Tunnel Junction): 3½ miles of 1-in-90 down to the middle of the tunnel; a further 3½ miles at 1-in-100 up to Pilning; a short level then 3½ miles more at 1-in-100 to Patchway.
2.13 The SWML corridor between Severn Tunnel Junction and Cardiff Station has a number of existing Distribution Network Operators (DNO) intakes and other trackside services in the area which may be impacted by proposals to enhance capacity / line speed on the Relief Lines.
THE SEVERN RAILWAY TUNNEL - Severn Tales
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. Act obtained to build the tunnel
The Severn Railway Tunnel. - Great Western
In his design of the tunnel, Richardson included cuttings at a gradient of 1 in 100 of which the cutting on the English side would be 60 feet at its deepest and 6,000 feet long. One danger that these cuttings produced was the prospect of being flooded by a storm and a high spring tide.
The Severn Railway Tunnel
The water rapidly flooded the area at the base of the shaft, driving the men up the completed tunnel which rose at a gradient of 1 in 90. In the meantime, a workforce was rapidly gathered on the surface to build a make-shift wall around the top of the shaft in order to prevent additional water entering the works.