Tuesday, 13 May 2014

Stainmore: Lines and Triangles

Lines and Triangles by Ben Yates

  When I first started building routes (and as per my last blog, I see simulation as a means of recreating what isn't there any more) , I had no contemplation that route building involves most of the time not building routes at all. Stainmore is no different.
Credit: NER Society
  To build something modern has the huge advantage of it being there. There's likely a cab ride video, you can ride the thing first person, if you've got a friendly contact in the industry it's not too hard to get the engineers profile of the route with every conceivable detail of crossovers, signals and gradient changes to the metre.
  Stainmore is well documented thanks to Peter Walton's superb 1992 book, but so much is unphotographed, the gradient profile is a good effort but won't win any awards for accuracy, so a great source of information is my battered pair of walking boots!  
  Phil made a wonderful discovery whist visiting the good folks at Kirkby Stephen East that the North Eastern Railway Society publish the engineer's line drawings for the route.
Credit: NER Society
  These show the track layout, and every bridge, gradient sign, field crossing, platform, PWay hut and platform measured to the chain and yard. Gold dust to route builders, and a great reminder that the "fer" in "chemain de fer" is such a fundamental part of railways we readily forget - its not far back that a team of men "walked the line" on first name terms with each fishplate and piece of ballast. The drawings here were a working document, with crossings out as sidings, junctions and stations were taken out of use. This makes them and extraordinary historical reference, and I doff my hat to the NERS for their preservation.

  It also means we have no excuse for getting the details wrong!

  I mentioned gradient diagrams - a source of fascination usually reserved for locomotive performance aficionados, but a fundamental tool to the route builder. The RailSimulator/Railworks/TS franchise uses NASA DEM data to create the terrain, which can be quite stunning, but is not without error, particularly satellites assuming the treetops are the ground! There is something magical about running a length of track through DEM terrain to find the cuttings and embankments form just as per the map. Equally, measuring gradient, distance and checking reference heights to an OS map and GPS altitude data, and measuring to within inches doesn't guarantee it looking right - I always start with science, but route building is definitely more of an art.

  I reckon we've got this one pretty close - the descent from the Summit to Barnard Castle was within inches.

  If you've done any route building, the inadequacies of the 8m triangular terrain mesh will be readily apparent. I  suspect that a smaller mesh and some more tools could easily halve the time taken to build a route. Even with a mastery of tools, it is incredibly time consuming to get a decent look on any route with cuttings, turns and embankments, and there we picked the absolute worst prototype! I can think of many routes where you can get away with what's there, but I realised early on this wouldn't cut the mustard. (curiously, this is why there is almost no narrow gauge in this sim, which is a crying shame. Scaling up to full size was a clever trick of the MSTS era, maybe the pics RS posted of the WHR may come to something? Holding breath may result in asphyxiation.)

  Phil, as so often the case, tied his white horse up outside, hung up his armour and delivered a set of embankment and cutting lofts that make the route feel like it is to walk the line.

Here's some progress pics:

Next time: track laying, Smardale and the Lune Valley to Tebay.

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