Here we explain step by step how to build a tunnel entrance and also explain general things about tunnel construction.
1 Initial situation
We have here the end of an incision section at the (absolute) height of -6m, which is realized with path elements and polygons at subground level 0. Particular attention should be paid to the transparent polygon, which roughly defines the tunnel mouth. Later, after completion of the tunnel, the shape can be changed at any time to obtain the exact transition. The tunnel mouth can then of course be shaped and decorated with the usual elements
It should be noted, however, that the tracks previously laid (on sub-surface level 0) are not built up to the tunnel mouth, but first end at a certain distance beforehand!
The length of this route is half the length of the longest continuous vehicle! If you want to be completely safe and plan your route for all compatible vehicles, you should use (if possible without problems) half the length of the longest train.
The distance between the track centres is 4m (Berlin post-war large profile).
3 Subground level -1
3. 1 Path elements
The first step is the construction of the underground routing elements. The first path element is placed on subground level -1. If the train is on it, then natural light can continue to fall into the tunnel and the aboveground landscape is still visible. To do this, we use the “subground layer” control at the bottom left to switch to the subground layer -1. It takes a while for the subground layer change to be completely completed.
Only the grid is displayed and darkened accordingly:
2 Conventions
Please pay attention to the building conventions regarding dimensions at the bottom of this article!
In contrast to the simulator, the MapEditor also hides the subground level (0) located directly above the selected subground level (-1). This allows you to work in peace on subground level -1 without disturbing subground level 0.
But we want to create the transition to the subground level 0, which is why we want to make it visible. This is done by placing the checkbox “Show next higher subground level” at the bottom left. Here, too, it takes a moment for the subfloor change to be completed:
On the one hand we see the terrain with the polygons of the subground plane 0 (light millimeter paper). In addition, we see the terrain of the underground level -1 (dark millimeter paper covering the tracks, etc.). For this purpose it is important to know that the terrains of the lower subsurface level are not visible in the simulator! Only the polygons and terrainsplines are visible, i.e. the tracks will be visible normally. As soon as you switch back to ground level 0 or remove the said hook, the tracks are visible again.
The dark terrain (underground level -1) is by the way 5m deeper than the light terrain (underground level 0), that of -2 another 5m, etc. These are arbitrary values, so that the respective terrain is not at the same height. The height is irrelevant anyway, because route elements are always used in tunnels anyway.
The first section of the tunnel is the one from which you can still/already see the outside world and fall into the sunlight.
Next, we place a polygon directly on the path element. The polygon does not have to exactly match the path element. The only important thing is to always see the correct number at the bottom left when constructing.
Next we place the tracks for the subfloor level -1. ATTENTION: The subfloor level 1 also includes those tracks that are located in front of the tunnel mouth on the last meters!
Before placing the tracks again at the bottom left, check whether the subsurface level is correct!
By the way, the parallel function can also be used if the reference line used as a base is on a different subground level.
If subground level 0 is set, the whole thing looks like this:
It is very easy to see which polygons and tracks are located on which sub-surface level: Light = sub-surface level 0, Dark = sub-surface level -1. If we then go “deeper” to the other tunnel lives, it will no longer be so easy to see. But then, in contrast to the tunnel mouth, the transition is also completely uncritical.
Before building, do not forget to set the subground level -1!
3.2 Building tunnels
So, now we build walls and ceiling on subground level -1, now with the checkmark “Show next higher level” off. The supplied objects refer to the tunnel floor, i.e. the routing element, which is 0.25m below the top of the rail when using the standard tracks. Accordingly, we work with relative height (
turned on) and Z = 0.
By the way, it should be noted that the enclosed walls for the Berlin large section are 1.65m away from the center of the track.
The elements “Tunnel_Wall_Podest”, “Tunnel_Ceiling_70_40” (ceiling with 7m width and 4m height above the path element) and “Tunnel_Columns_High” were used here.
If necessary, it is possible to work well lit underground. To do this just remove the checkmark “Ambiente shadow visible” ’at the bottom left:
3. 3 Precise positioning of scenery objects
Of course, we can install a few luminaires (type “Tunnel_Lgt_1”); if they are installed between the supplied columns of type “Tunnel_Columns_High”, they must be installed with a relative height of 3,844m. For precise mounting, the pillars have auxiliary polygons on the top, so that they can also be seen in the 2D view:
The procedure is now as follows:
Select 2D view
Enter height of Z = 3. 844 turn on,
turn off
in Scenery Object mode select the lamp
“New object”
Place the lamp as desired, if possible. . .
. . . show with [Ctrl] pressed on reference lines, tracks or path elements
If it turns out afterwards that lights are at the wrong height, mark all affected lights together ([Shift]+key), enter Z=3,844 again and press [Enter].
4 Deeper subsurface levels
The construction of deeper subfloor levels is done just as with subfloor level -1:
Visibility to -2 and enable the checkmark for visibility of the next higher subground level
Create path element
Place tracks and tunnelplines/objects
But the important thing is:
In tunnels at underground level -1 can – as I said – still shine sunlight, which is why shadows are still calculated there.
At subsurface level -2 the aboveground landscape is still loaded, but no longer visible in the simulator. Since reloading takes a long time, trains leaving the tunnel should also be “lifted” to the underground level -2 in good time beforehand. From this subsurface level no more (sun) shadows are calculated and the number of light sources is increased to the night value.
On the other hand, if the landscape can be completely unloaded, the train should run at sub-surface level -3 or lower.
5 Sunshine/natural light in the tunnel
As on all deeper subground levels, darkness prevails on subground level -1 as a rule. Subground level 0 is – like all higher subground levels – basically “bright” (daylight).
However, on the subground levels 0 and -1 the brightness of daylight can be influenced by the ambient segments (Tab “Terrain”). These are constructed in the same way as terrain segments, with the difference that they do not influence the height, but the brightness on the subground levels 0 and -1. It is important, however, that the construction of all ambient segments takes place in subground level 0!
So far, the tunnel mouth looks like this:
Now we create two ambient segments (terrain tab) – but they don’t have to be laid precisely, on the contrary, it’s even advantageous if they’re a little off, so you don’t always click on them automatically. Please note that the left segment is the full length of the longest vehicle (or the length of the longest platform):
The effect is immediately visible – let’s take a look at the whole thing again in 3D (I switched off the help lines):
You can see that there is a soft shadow formation, but there are still three errors that need to be corrected:
The front part should not be dark at all; it is only on subground level -1 for the transition from “top” to “bottom. ”
The rear part “shines” upwards through the ceiling
The shadow is too narrow.
All three things can be solved in the properties:
At the bottom are the specific properties: For the front segment, start brightness and end brightness must be set to 1. 0.
For the rear segment, the hook at “Surface level” must be removed
The width can be defined either in the properties or by mouse in the same way as for the path elements.
6 Ready!
This is the end of the cookbook – we have constructed a standard tunnel mouth, as it probably fits in most cases. Experimentation is welcome, we are looking forward to the screenshots! 
7 Bridges
Stop! There was something else. . .
Purely by chance we found the function, which can now also be used to form a shadow under bridges! Here you are welcome to try it out! So much only here: As soon as you reach level 1 or higher, then the shadow becomes ineffective.
8 Tunnelling Conventions and Dimensions
Please follow the following convention to avoid chaos with future tunnel components!
8. 1 Vertical reference
The reference height in tunnels is always the rail top!
Above ground there are usually two variants: grooved rails are built at the level of the road surface, which runs either at the level of the route elements or lowered around the height of the curb (in the base content -0,15). Or if it is a gravel track, then it is not laid at the level of the ground (the route elements), but raised according to its height, in the case of the base content it is usually +0. 25m.
In underground structures, however, the track elements are laid at the height of the rail’s top and the tracks are not at +0. 25, but always at ±0m. Any soils/gravel surfaces have to be lowered accordingly, in the base content usually to -0. 25m. Care must be taken that when selecting the track type at the top of the MapEditor the selected height Z= is not kept, but reset to 0!
8. 2 Dimensions of the Berlin Tunnels
If you want to use the supplied Berlin tunnel components and/or want to construct tunnels compatible with Berlin vehicles or your own vehicles, please note the following dimensions:
