Investigation Into Change of Route
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Investigation into change of route Summary There were several reasons for promoting a railway between Monmouth and Chepstow. Prior to opening the railway, freight from the industrialised Wye Valley and passenger traffic had to make a journey of 43 miles instead of 15 miles by the new route shortening the journey time by two hours. Tourists would be expected to be attracted to the beauty of the Wye Valley. The 1866 Act of Parliament authorised a route along the west bank of the River Wye passing through Tintern. The 1874 route followed the east bank of the River Wye crossing the River north of Tintern then following the same route as authorised by the 1866 Act. The original plans held by the Gloucestershire Records Office have been consulted and analysed. The only WVR board account we have found of the reason for changing the alignment simply states that the new route ‘would probably be more economical’.1 We have made comparisons between both plans and have come up with no clear-cut financial benefits but from a risk point of view we have found supporting evidence for the decision. Investigations continue to locate contemporary evidence. 1865 route and 1874 route Two principal documents were reviewed at the Gloucester Records Office. 1 The 1865 plan Ref Q/RUm/355 which was incorporated in The Wye Valley Railway Act 19 August 1866. 2 The 1874 plan Ref: Q/RUm/402/2 which was incorporated in the Wye Valley Railway Amendment Act 14 June 1875. The Records Office have noted on their file that this plan was '[Carried out according to this plan except for branch line; 38-39 Vic., cap.51.] ' The route sketch to Llandogo that was included in the 1865 plans is shown in Fig.1. From Tintern to Monmouth both the 1865 plan and the 1874 plan follow the same route. Fig 1: 1865 sketched route to Llandogo following the west bank of the river Wye In Fig 2 the 1865 line is coloured red and the as-built 1874 line is in faint black and white. Two tunnels are marked on the 1865 line. Fig 2a shows the 1865 line in red and the 1874 line in black. Tunnel 2 entrance Fig 2: The 1865 route is in red. T 1 tunnel is 715 yds long. T2 tunnel is 249 yds long. The 1865 route follows Viaduct the Wye to join the 1874 route near Tintern Parva Tunnel 1 exit (maps.nls.uk/index.html CC-BY-NC-SA) More detail of the 1865 route to Tintern Parva is shown in Figs 3 and 4. Fig 3 also shows the location of Wye cottage that was lived in for many years by the Sydney Yockney the Resident Engineer and his descendants. Departure point from mainline close to the river Wye Fig 2a :1865 route in red. 1874 route in black Fig 3: 1865 plan showing the departure point from (maps.nls.uk/index.html CC-BY-NC- the South Wales Railway, the two tunnels and the SA) river Wye crossing. Fig 9 shows a photograph of the position of the tunnel exits and entrances and the viaduct. Fig 4: 1865 plan from the Liveoaks river crossing (top left) to Tintern Parva Reason for the change the railway alignment from the west to the east bank The only explanation we have found comes from a WVR special board meeting of 12 February 1875. This simply stated that the new route ‘would probably be more economical’ 1. Not exactly evidence of an in-depth analysis. For this reason, we have made comparisons between the two plans to find the missing evidence. Comparisons between the 1865 plan and the 1874 plan Approximate Length comparisons 1865 plans Length: 14 miles 4 furlongs 1 chain equivalent 14 miles 902 yards. 1874 plans Length: 13 miles 3 furlongs equivalent to 13 miles 660 yards. Plus 4 furlongs 2 chains equivalent to 924 yards for the Wireworks branch. Total 13 miles 1584 yards. The 1874 route is approximately 1078 yards shorter than the 1866 route. This difference is approximately the same as the extra length of the 1865 line as a result of the WVR leaving the South Wales Railway just after the Chepstow bridge instead of further to the east in the 1875 plan. This adjustment has nothing to do with the change of route to the west bank of the river up to Tintern. If an adjustment is made for this then there is little difference in the length of both routes. Tunnel length comparisons 1866 Act - from sections: Two tunnels: 249 yds + 715 yds = 964 yds plus one viaduct between the tunnels of approximately 150 yards 1875 Act: Tidenham as built in 1876 approximately 1120 yards + Tintern 182 yds =1302 yards. Difference in length: the total length of the 1874 tunnels are 338 yards longer than the 1865 tunnels. If the 1866 viaduct was replaced by additional tunnelling then the difference would be approx 188 yards (approx 15%) The southern portal location on the 1874 plan is shown in fig 5. The northern portal was in the same location on the plan as it is today. Fig 5: 1874 route showing start of Tidenham tunnel before the Netherhope cutting was arched over. Netherhope bridge is shown a short distance to the left. The 1874 plan was altered slightly during construction at the southern end to include a short extra tunnel where the southern portal is now, followed by a cutting leading to the southern portal on the 1874 plan. The short extra tunnel can be seen on the 1880 25 inch to the mile map (Fig 6). Between 1900 and 1919 the cutting was arched over resulting in the continuous tunnel seen today 2. Fig 6: Short second tunnel shown on the 1880 25 inch to the mile Ordnance Survey map (maps.nls.uk/index.html CC-BY-NC-SA) Fig 7 shows a measured section3 of the tunnel marking the southern portal as located on the 1874 plan. Fig 7: Measured section from Greenways and Cycleroutes planning application on which a black dot marks the position of the south portal on the 1874 plan Bridges across the River Wye comparisons 1865 - 2 bridges: Redbrook and from Lancout to the Livox peninsula. The bridge/viaduct across to the Livox peninsula could have been up to 700m long but it is difficult to tell from the plans (Fig 3 and 4) and sections (Fig 8). There are three references to a bridge in this location on the plans/sections which don’t seem to be consistent with each other and are difficult to read. Resolution will need to wait until a further visit can be made to the Records Office. Scaling from the section indicates a length of viaduct and bridge of around 500 yards. 1874 - 3 bridges: Redbrook, Tintern, Wireworks. Fig 8 Section of 1865 route between Tunnel 1 and the Livox peninsula 1865 route between the two tunnels We have found no information about the WVR intentions of the route between the two tunnels. Jeremy Cowen, Greenways and Cycleroutes volunteer has come up with a tentative conclusion. He knows the area well as a climber. This is a summary of his findings so far: ‘Tunnel 1 (Fig 8) appears to exit from a vertical cliff face now known to climbers as 'North Wall'. The first attachment indicates this location and the direction of the line to the left. The line then re-enters the cliff face after approx. 150 yards at the point shown in Fig 9. The only practical option between exit and entry seems to be a viaduct which would not be out of the question for Victorian engineers. It would afford a magnificent view of the river Wye and could have enhanced the reputation of the engineers. It is assumed that a continuous tunnel was not chosen on grounds of cost.’ The northern portal of tunnel 2 is situated on the northern side of the Lancaut peninsula in the midst of another set of cliffs known Ban y Gor. Fig 9 Tunnel 1 exit on the right not far from Wintour’s Leap. Tunnel 2 entrance is on the left (Jeremy Cowen) Comparison of routes after the northern tunnel exits On the 1874 route there is a long shelf with embankments and a three-span viaduct leading to the Tidenham tunnel. There may have been a similar complexity on the 1865 route. Summary of Differences Length: Little difference resulting from routing the line to the east bank of the river Tunnels: The 1874 route has approximately 170 yards of tunnel (15% extra) assuming the 1865 route was modified to provide a tunnel between T1 and T2 This is approximately the length of the Tintern tunnel. Tunnels are by far the most expensive feature to build so this is a significant cost difference. Bridges: One additional bridge on the 1874 line but as the Lancaut bridge on the 1865 route could be 500 yards or more long the total bridge cost of the 1865 route could have been more than that on the 1874 plan. Wireworks branch line: This contributed to extra track length and bridge count for the 1874 plan Income: The Tintern station on the 1865 plan could have been positioned closer to the centre of population and so attract some additional traffic Complexity of construction: The access to the 1865 tunnels during construction in the two locations where they entered the cliff face would have been very limited. An extra deep shaft may have been needed for both tunnels to remove spoil and for access.