Friday, 9 August 2019

An itch that might need scratching (2)

Due to the reduced size of the "Man Cave" my intention for the rest of 2019 is to continue to sell off "stuff" that I've accumulated over the years. This is a double edged sword in that it will make space for the next project and will also help to raise some cash for future expenditure.

Since my decision to bin Grogley Junction I've been thinking about what's next. During 2017 I found the Ratio building kits along with rolling stock that I've collected over the years for a possible GWR Branch Line Terminus. All I need is a suitable location.

Two articles mentioned in a previous post "an itch that might need scratching", have been at the back of my mind for several years. If I used the research from one and the trackplan from the other they would make a very good starting point for a fictitious BLT. At the end of this post I've quoted in full, from the January 1975 Railway Modeller to show the diligence that Mr Pocock went to with his research and ideas. The depth of the article captured my imagination but with no offence meant to Mr Pocock, his track plan did not. For illustration I've placed a scan below of his track plan to show his thoughts on how it would fit into a garage setting.


When the April 1979 Railway Modeller landed on the door mat, the Plan of the Month article struck a chord. This plan is based loosely on Swanage so has some prototypical resemblance. Back in 1979 I was not in a position to create a layout of this size, but I always thought it would be a good starting point as a track plan for a BLT.



I'll offer no excuse in admitting that the 3D illustration of the track plan is probably why it has had such a lasting impression on me.  It also ticks all the boxes for including all features for a West Country Rural Branch Line Terminus. As for Bigbury Bay, the road over the bridge could be the B3392 from Bigbury-on-Sea to the A379. Then with a few minor amendments to Great Westernise the plan I think it would suit the location well. Whether these minor amendments could include features from Iain Rice's "Witheridge" track plan (from his "An approach to Model Railway Layout Design") we'll have to wait and see.

Well that's it really, the track plan will have to be finalised before this project progresses any further. So, for now, the Ratio kits along with all the rolling stock will be kept. Don't think there is any harm in dreaming of future projects, just wish I had more time available... don't hold your breath, this project has a very good chance of not getting beyond the dreaming stage, especially as I would also like to build a GWR Engine Shed layout.

Anyway, less of this frivolity, nearly a year has past since Scaleforum with little progress on Tredethy Wharf and I really need to focus on getting the layout ready for the Caistor show in October

"Plan of the month
Bigbury Bay 
A beginner's line by N. J. Pocock

A BRANCH IS BUILT: The GWR built the Kingsbridge branch late in the 19th century. It is assumed that the GWR also decided to construct a line from a junction just to the east of Ivybridge viaduct to run south over the undulating terrain to terminate on the coast, passing by the villages of Modbury and Aveton Gifford, and thence via the Avon estuary to Bigbury Bay. Fig. 1 gives the route chosen for the branch line. Originally, the route was drawn out on a 1 inch Ordnance Survey map but this was found to give insufficient contour detail so a 2 1/2 inch map was used in the end.

Despite the difficult contours of the terrain, only four major engineering works are necessary, viz. Sheepham Viaduct (300 yards long by 120 feet high), Modbury Summit Tunnel (500 yards long), Aunemouth Bridge (350 yards long by 25 feet above mean sea level), and Aunemouth Tunnel (1,000 yards long). The last two items, strictly speaking, are only there to provide. a natural scenic break for the model of the terminus since it is quite feasible for the tracks to continue around the estuary, dispensing with the tunnel and crossing the estuary at its mouth in the bay. It is assumed that the GWR built the line economically (to the “yellow” colour axle-load restriction) and hence only the lighter tank engines would be allowed over the metals- effectively, the ubiquitous 45xx and 55xx 2-6-2T’s. The line is situated in the heart of the Devon farmland so there would be no heavy freight trains; but a modest freight service would entail general goods transported into the area and milk and farm produce transported out of the area. By the 1930s, when West Country holiday traffic was at its peak, facilities would exist (like the Kingsbridge branch), not only for a local passenger service, but also a daily through-coaches service to and from Paddington. These would be supplemented with extra coaches and workings on summer Saturdays. Ivybridge Station was rebuilt to function as a junction station for the branch.



PREPARATIONS FOR A TIMETABLE:


Fig. 5 gives the final compilation of a timetable for the branch, but there are a few preliminaries before arriving at the final product! First, there is the drawing out of a Gradient Profile (see Fig. 3) to get an idea of the gradients the trains have to negotiate over the branch. This was done by drawing the proposed route on a 2 1/2 inch Ordnance Survey map and calculating the rise (or fall) in feet of a stretch of line and dividing this into the length of the track, also in feet of course. The neighbouring Kingsbridge branch had the convenient use of the comparatively flat Avon valley for most of its route, but the Bigbury Bay branch has no such convenience until it reaches Aveton Gifford and the Avon estuary. Nevertheless, after several attempts at route planning, it was found best if the branch turned south after leaving the main line just east of Ivybridge Viaduct and descend steeply (1 :42) at the steepest part to Ludbrook Halt where after a short level stretch, the line rises again towards Modbury before entering a level section to reach the station. This was found to be the most difficult part of the line to route-plan because of the undulating nature of the terrain and deep valleys of the river Erme’s tributaries which the line has to cross, yet in the final route chosen only one large viaduct (at Sheepham) was found necessary. At Modbury station the line turns east up a valley of one of the river Erme’s tributaries and ascends to Modbury Summit Tunnel; and after the line has emerged out of the gloom it finds itself in another valley, this time of a stream that flows into the Avon estuary. The tracks descend down this and into Aveton Gifford station, thence to use the Avon estuary as far as Aunemouth Halt, and then cross the estuary and enter Bigbury Bay by use of a tunnel through the earth cliifs. This last section is level. From the Gradient Profile the running times “up” (towards London) and “down” (from London) can be calculated. The first two columns of Fig. 5 shows these; allowing for a maximum train speed of 35m.p.h. and stopping times of passenger trains at stations and halts en route. These are realistic running times for the average branch line speed for this kind of branch on the GWR was 21-22m.p.h. (as per the Kingsbridge branch among others) and the Bigbury Bay running times correspond to this very well.

Fig 4
Finally, Fig. 4 shows a table of all trains stopping at Ivybridge, Monday to Friday, 4th July to 25th September, 1938. This was compiled from the official GWR working timetable at the Transport Historical Records Office in London. The table is not entirely accurate for the simple reason the branch from Ivybridge to Bigbury Bay is fiction, not fact. Thus, one of the North West expresses (Manchester and Liverpool via Bristol, South Wales, Shrewsbury and Crewe) has had its‚ schedule altered to stop at Ivybridge in both ‚”up”  and ‚”down” directions; likewise, one of the Paddington- Penzance expresses to stop and attach the through coaches from Bigbury Bay on the ‚”up‚” working, and detach the through coaches on the ‚”down” train; the parcels train, Paddington to Penzance via Bristol, has also had a stop inserted into its timetable at Ivybridge since it stopped at Brent for the Kingsbridge branch; the ‚”up” Tavistock Jnc. - Ivybridge goods originally carried on to the sidings at Brent so that the loco could help out with workings on the Kingsbridge branch but this now terminates at Ivybridge, and the return evening trip starts from Ivybridge, so that the loco can serve the Bigbury Bay branch‚ - Kingsbridge being served by a goods trip to and from Newton Abbot instead! I will end this section with a brief comment on the GWR mainline workings in the West Country - there was nothing that was symmetrical about them in the “up” and ‚”down” directions, as Fig. 4 bears out, and the official working timetable shows.

 

THE WORKING TIMETABLE FOR THE BRANCH: 
Fig. 5 is a working timetable for the branch, Monday to Friday, compiled from the running times and Fig. 4, taking care of course not to put a branch train on a collision time with a mainline train over Ivybridge viaduct! The table is more or less self-explanatory, but a few words need to be said here. Two locos only are required to work the branch, two “B” sets and a three coach rake of corridors, a couple of milk tanks, either a syphon “J” or 40ft. Dean luggage Van for the parcels, and an assortment of 30 or so wagons. All these are available in kits. A spare all-3rd coach‚ - how about a 58ft. Clerestory made up from two Triang brake/3rd Clerestories ?‚- can be kept in the coach siding for Saturday local passenger trains, to supplement the “B” set. Any parcels from Bigbury Bay branch would be taken in the van as far as Ivybridge and then put on a local passenger to connect with the appropriate parcels train at either Plymouth or Newton Abbot. The perishable traffic from the branch for the Crewe and Paddington freight expresses is attached to the rear of a local passenger train to Totnes and Plympton (for Tavistock Inc. sidings) respectively. The milk tanks are taken on to a dairy between Ivybridge and Cornwood by the 45XX that worked them up from Bigbury Bay, and at the dairy sidings marshalled into the appropriate train-set for their destination. A Saturday timetable has not been worked out since this would mean more coaches for through services, a longer traverser in consequence, and into the bargain the afternoon goods would not run, thereby detracting from variety in operation."

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