Important:
Due to a bug in the editor, it is essential that you do not initially place any tunnels (this includes bridges over the railway) if you intend to construct the route in both directions using the route-reversing feature in the editor.

Once a tunnel or overbridge is placed, it is usually too late to remove the problem to do a reversal.

This bug manifests itself in two ways...

• Either the route will truncate, or you won't be able to finish your journey (or you won't see part of it) - or both.

Outward route construction:
I previously suggested you placed level crossings (grade crossings) where you intend to have your over-bridges, and where both tunnel portals will go.

Construct the route fully and drive along it to your satisfaction, then save the file(s) to a backup set of directories which are all "no tunnels backups".

My personal preference is to create a number of "work in progress" directories on a route, because when the line is absolutely finished, you can safely delete them; until then it is too easy to muck up the design, and building on from a recent backup is a great time saver.

Now if the route is otherwise finished, you are ready to do your route reversal.

Reversing the Route - what is involved:
You should understand that there will be several things which will need to be reworked.

• All automatic signals will be lost. These are the signals in between points (switches), generally single aspect ones, but also the two-aspect permissive signals placed next before a "home" signal. The Absolute signals associated with switches will remain.

• Some trackwork at the new start and finish stations will be incorrect. This is easily seen if you look.

• If you have named sections, they may not be properly associated with the correct feature... in many cases these will need to be reworked by hand.

• However, it is still far quicker and much more accurate to reverse the route, rather than re-constructing the whole line from B to A.

How to Reverse
Very Simple. Just press the Backspace key !

Using Reverse for creating intermediate starting points
Remember the following strategy on multiple intermediate journeys over the same route...

Assume we have a route like this...
starting at A, it goes through B to C and D. First construct A to D.

A - B - C - D

Reverse it, so you have D to A

D - C - B - A

Copy D to A as a new route; then you can remove A as the "end station" making it B instead.

D - C - B

Then reverse it, and you have B to D - which cannot be created any other way.

B - C - D

THis scheme can also be used to create a diverging route, for example B to C and taking a side track to another locality, perhaps X. You would remove end station D and rework the line to suit the road to X, inserting X as an end station...

B - C -X

The various combinations are without limit...but only if you have not yet placed any tunnels or overbridges.

By way of explanation, this is how all 26 of the South Australian current variations of the "Main South Line" were constructed, plus the as yet unfinished Victor Harbour and Mount Pleasant branches. The first track was from Tailem Bend to Adelaide, copied to new files with new end stations at Dry Creek, Keswick, Mile End. These were each reversed, and the routes shortened to Adelaide - Belair, Adelaide - Bridgwater, Adelaide - Murray Bridge. In turn, they were reversed to give the return journeys. Each time, signals and other features had to be added back. This is where a set of hand-written notes becomes invaluable.

Tunnels (and Bridges over the railway):
Now we can talk about these! Your patience has been rewarded!!
Having taken a backup copy of the route with tunnels, and made a route reversal copy as well, feel free to remove whatever you have used to pinpoint the places where tunnel portals are needed, and add portals in their place.

One portal only is used for an over-bridge. Even if it is a very wide road, like a six-lane highway on two seperate carriageways, use only one tunnel section - don't be tempted to add a second.

The reason for this is because two or more tunnel lengths will force a height of much more than the default 4 units - which will look ridiculous on a road over-bridge.

Actually, very few highways would ever be wider than one increment of editor position (165 feet)... here is the arithmetic...

At a nominal 15 feet per lane width, 165 feet works out at 4 lanes plus a breakdown lane in each direction, plus a 20 ft grassed shoulder on each outside edge, and a central "median strip" reservation between the carriageways 35 feet across!

So, we keep more than one tunnel segment for real tunnels.

As mentioned before, an automatic signal would normally be placed outside a tunnel mouth on the approach side.

There is a good reason for this. If the signal is not cleared, the train does not have to remain inside the tunnel waiting.

Not only can it be claustrophobic for passengers, but exhaust gases will build up - in the case of steam locomotives open to the weather this could cause crew asphixiation quite quickly. In the case of diesel powered trains, carbon monoxide poisoning could seep into crew compartments and through the air conditioning systems in cab and passenger accomodation.

It can also cause overheating problems and oxygen starvation in the locomotive(s)

Actually General Motors were forced into designing a tunnel variation of the SD40 locomotive with its cooling radiators moved from the roof and re-located down the sides of the carbody similar to their export model GT26C to overcome cooling system overheating from long hauls through the Rocky Mountains.

So, now you know...

Remember also that signals placed inside tunnels are all of the dwarf variety, and the one on the left-hand track will be at ground level. However, depending on the length of the tunnel and the block lengths being used on the railway, a tunnel even a mile long will probably not need a signal placed inside it.

Congratulations!
You have finished your route. Drive along it in both directions with several types of train to check out signal placements and other potential problems. When you have fine-turned this first route of yours and are satisfied with it, you will have acchieved a great deal.

Now is the time to consider your next one...

geography - gradients - curves - features - speeds - reversing the route