Atomic Systems

As the track is a loft (like roads, wall, etc) it is possible to adjust the height at the end of sections, or even mid section, using the gradient tool (there are video tutorials showing this being done). However, I would seriously advise AGAINST DOING THIS. The track sections are interlinked through the tracks bin file, and amending one section of track like this can affect another section further down the line (even several miles away). I know this from bitter experience (fortunately I backup the track files at least once per day when working on a route).
The Ian Allen gradient book is excellent, but only shows RULING GRADIENTS in sections. Also, the DEM data do give good information, but only show an average height over a given area (depending on the detail of the data). The track itself may be passing through a cutting or sitting on an embankment in the section you are looking at. I use several approaches, but find that marking the track line, then seeking a suitable point several hundred metres in advance of your current position, and determining the height (elevation) of that point in relation to the current end of track, enables me to determine the ruling gradient for that section. Once the line is laid, go back to the join, and "ease the gradient change". This is done by using the loft selection tool (first item on the loft menu) to select a good length of track either side of the join, and then using the gradient ease tool (last item on the loft tool).

Nick

I find it best to have the DEM data loaded (my advice is load this for the whole of your route before doing anything else and check you are happy with it) and have Google maps overlay active when track laying. You can set the gradient in the bottom left flyout (see image) but remember to to set it to minus when going downhill. If you have real gradients you can use them, if not make best guesses based upon the topography and nearby assets. Changing track levels later on can have unexpected consequences so avoid that if possible. It is nice to have gradients realistic, but as long as they are about right it doesn't change the driving experience.

I always back up my route before every editing session as disasters can happen, particularly when laying track. I also use a blank terrain to practice making complex track work as sometimes the sequence of laying is critical.

Thanks everyone, all your help and advice is very welcome.

John.

It can also be helpful to look at an Ordnance Survey map of the track, major cuttings and embankments are clearly shown.