Knowlesands Tunnel

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The south portal of Knowlesands Tunnel, looking towards Bridgnorth

Knowlesands Tunnel (Bridge 32) is the shorter of the two tunnels on the present day SVRSevern Valley Railway, being only 40 yards 2 feet in length.[1] It is located on the 1 in 100 climb from Bridgnorth towards Hampton Loade, just north of milepost 149, between Bridgnorth Down Distant and Down Outer Home signals. The main B4555 Bridgnorth to Highley road passes over the railway at this location, although the railway is not visible from it.

To the south of the tunnel, the railway continues uphill through a cutting towards the summit of Eardington Bank. To the north of the tunnel, the cutting continues for a short distance before reaching the site of the former Knowlesands Sidings.

Construction

Although the foundation and bridges of the original Severn Valley Line were laid out to accommodate a double track at a later date, Mount Pleasant Tunnel and Bridgnorth Tunnel were both built to single track width as an economy measure, while Bewdley Tunnel on the later Kidderminster Loop Line was also built to single width. However Knowlesands Tunnel was classed as an overbridge and therefore has much more clearance than other tunnels, having a segmental arch roof of 25ft span.[1] Insufficient traffic ever materialised to justify widening the Severn Valley Branch to a double track.

The width of Knowlesands Tunnel has occasionally led to suggestions that it was built to double track width to accommodate a future railway between Bridgnorth and Wolverhampton. However the timeline of its construction does not provide any evidence to support this:

  • After the final plans for the Severn Valley Railway were drawn up and approved, construction was authorised by Royal Assent in July 1858 and began later that year. Nothing has been published to suggest that the original Severn Valley Railway Company had any plans for an extension to Wolverhampton at that time, or that it had been in discussions with other railway companies about such an extension.
  • The first proposal for a railway between the two towns, the "Wolverhampton & Bridgenorth Railway" (sic), was not advertised until 1860. This would have joined the Severn Valley Railway around 2 miles north of Bridgnorth rather than approaching from the south via Knowlesands Tunnel.
  • Most of the other later unsuccessful plans involved joining the Branch south of Bridgnorth and making use of Knowlesands Tunnel, however these were drawn up after the tunnel was completed.

Many of the bridges and tunnels on the Severn Valley Branch and the Loop Line underwent subsequent significant repairs or upgrades, including Bewdley Tunnel which was relined. However none of the histories of the Railway refer to subsequent work on the Knowlesands Tunnel by either the GWRGreat Western Railway or BRBritish Rail or British Railways, suggesting that its brick construction and short length meant it required only routine maintenance.

Preservation

The tunnel was part of the first section of the SVRSevern Valley Railway to be preserved. At the time of the Severn Valley Railway Society's first visit on 11 July 1965, BRBritish Rail or British Railways had taken up the track working southwards through Bridgnorth Tunnel as far as the north end of the station. The society returned on 25 July to find that BRBritish Rail or British Railways had resumed taking up the track towards Knowlesands Tunnel; after a telegram was sent to BRBritish Rail or British Railways work was suspended on 28 July.[2]

During February 1966, BRBritish Rail or British Railways ran an inspection train from Bewdley to Bridgnorth via the tunnel, hauled by BRBritish Rail or British Railways Standard Class 4 76039. In March 1967 3205 was the SVRSevern Valley Railway's first locomotive to arrive at Bridgnorth via the tunnel. The first passenger rides through the tunnel to Hampton Loade took place during first full 'Steam Weekend' on 14-15 October 1967.

When the Society took possession of the line between Bridgnorth and Alveley, weeds and saplings were sprouting everywhere, with Knowlesands Tunnel and Sterns being "particularly bad spots".[3] Work to tidy and improve the track between the station and the tunnel was completed by February 1969,[4] at the same time work on improving the track south of the tunnel was also under way. The SVRSevern Valley Railway officially opened as a preserved railway in May 1970.

On 28 November 1971, an earth slip was discovered in the embankment immediately south of the tunnel. A temporary repair was carried out to allow works trains to carry out relaying work further south, with more permanent work following at a later date.[5]

In spring 1978 the company involved in filming Hanover Street funded the purchase of 300 tons of ballast which were spread in the track at Knowlesands and Foley Park tunnels.[6]. Later that year the SVRSevern Valley Railway acquired some brand new flat bottom rail at scrap prices,[note 1] together with a supply concrete sleepers. The section from the tunnel towards Crossing Cottage was first to be re-laid using CWRContinuous Welded Rail, where joints between lengths of rail are welded rather than connected by fishplates., resulting in "a very smooth passage from Oldbury Viaduct to the summit beyond Knowlesands Tunnel".[7]

During autumn 1981 a water main was installed from the tunnel to the station, as the deteriorating quality of the local Bridgnorth water supply was affecting the SVRSevern Valley Railway's water softening plant.[8][note 2]

In 1987 the fishplate bolts were replaced on the flat bottom section through Knowlesands Tunnel, to eliminate some non-standard hexagonal nuts.[9] The following year a fall of sand in the cutting led to a temporary speed restriction until it was cleared.[10]

In March 1999 contractors carried out an inspection and repointing work on the tunnel itself.[11] The following year, torrential rain on 5 November 2000 caused the stream that runs on the top of Eardington Bank to burst through, depositing around 100 tons of sand onto the track. The water then flowed down through the tunnel, and disappeared through a hole at the side of the track. The entire railway formation alongside the lorry park (at the site of the former Knowlesands Sidings), around 300 yards north of the tunnel, eventually gave way, washing away the bank on the river side. Three lengths of track were left hanging in space and the embankment spread across the field below. Contractors completed the reinstatement allowing the railway to re-open later that month, with Shropshire Council providing significant assistance in rectifying the damage outside the SVRSevern Valley Railway's land.[12]. The flood left the ballast inundated with sand which resulted in further problems of 'wet beds' and 'pumping sleepers', with the affected section being re-laid in winter 2002-03.[13]

The tunnel itself was unaffected by the freak storms in 2007, although three sections of the embankment between the tunnel and Oldbury Viaduct were washed out[14].

See also

Towards Kidderminster
List of infrastructure
Towards Bridgnorth

Notes

  1. The rail was manufactured for BRBritish Rail or British Railways but had a slight imperfection on the top, rendering it unsuitable for 100 mph running but suitable for heritage line speeds.
  2. Following the 1980 boiler crisis, a reverse osmosis plant replaced the simple water softening plant.

References

  1. 1.0 1.1 Marshall (1989) pp. 40, 104.
  2. Magner (1997) p. 100.
  3. SVRSevern Valley Railway News 16
  4. SVRSevern Valley Railway News 12
  5. SVRSevern Valley Railway News 22
  6. SVRSevern Valley Railway News 47
  7. SVRSevern Valley Railway News 49/56
  8. SVRSevern Valley Railway News 60-61
  9. SVRSevern Valley Railway News 85
  10. SVRSevern Valley Railway News 88
  11. SVRSevern Valley Railway News 130
  12. SVRSevern Valley Railway News 134, 135
  13. SVRSevern Valley Railway News 143
  14. Sowden (2012) pp. 8-10.