Route Building Tutorial 16: Platform Ramps

In this part, platform ramps for the second station will be built.

Time to get to work….

Until quite recently, platforms in the UK were required to have ramps at the ends of the platform leading to track level on safety grounds. However, given the potential for misuse of these (by trespassers), new-build platforms are not required to have ramped ends.

Platform ramps should have a slope of between 1:8 and 1:12 meaning a ramp length in the region of 10-13m is required. New build platforms are also required to be on substatinally straight and flat track.

The ramps to be constructed are to fall to -0.1m to ensure the lower end is below ground level. As they are normally out of bounds to passengers, the surface is likely to be quite different in nature to that of the main platform and occasionally being quite rough and weedy.

A prototypical platform ramp

A prototypical platform ramp

Before starting construction of the ramps, the ground between the two tracks needs changing. At the moment, the height of the rails is 1m and the height of the grass in the ground object (ground1.CSV) is -0.5m. The height of the ground between the two tracks therefore needs to be raised by about 1.4m – if this is not done, the end of the ramp we are about to construct will be floating above ground level.

One of the easiest (but not necessarily the best) ways to fill the gaps between two tracks is to use the .crack command:
.crack X;Y;Z
Where X and Y are the indices of rails between which the crack object is to be applied & Z is the index of the crack object.

A suitable object has been included in the objects download and needs to be indexed in the route file before use after the grounds section:

Notice the use of left and right handed objects (.crackL and .crackR) – crack objects must always be indexed in pairs.

To fill the gap between rail 0 and rail 1 with the crack object, the crack command must be applied every 25m along the length to be filled, eg;

Repeat this command back to 2450m.

The gaps between the tracks at the far end of the platform can also be filled in using this technique, applying the crack command every 25m between 2825 and 2950m.

Notice how the crack object is distorted as it fits to fill the varying width between the rail; ideally, different objects should be constructed to take this into account or possibly a different ground object used rather than applying a crack object. Nonetheless, use of crack objects to fill gaps between tracks has been demonstrated and is certainly useful for filling gaps between parallel tracks.

It is also worth considering breaking up the vast expanses of ballast we have just created – in real life, it would be littered with rubbish, weeds and railway items such as discarded track and rails.

Now for the ramps:
To construct the first (up) platform ramp, create a new file named platform ramp_up_right.CSV in the objects directory. Index this in the route file as free object 61 and position it at 2600m.

It is worth noting that on the ramp, there is no requirement for tactile surfaces at the platform edge and, given the gradient of the ramp, there is also no need for a drain in the centre.

The first face to build is the main vertical face on the left hand side:

Basing the height and width of the ramp on what was used for the main platform, note how the x offset at 25m is the same as was used for the main platform object. However, at the start of the ramp, the offset is increased so that a “tapered” ramp is formed. The texture itself remains 2m high along the entire length – if the height of vertex 2 alone was reduced in order to form the ramp, the texture would become distorted. Because of the shorter length of this object compared with the main platform, the number of times the texture has been applied (in the x direction) has also been reduced so that a consistent appearance is maintained along the entire length of the platform.

Similar considerations must be given to the coping support:

The coping on the ramp uses a different texture from the main platform although the height and x displacements are treated in the same way as the previous faces:

For the main ramp face, an alternative texture has been used compared with the main platform. The texture included here was previously used on the waterfront; notice how the texture coordinates have been set to trim off the edges:

Finally, the right hand coping needs to be added:

A further addition to the ramp which can be made, if desired, is a set of railings to discourage public access. These may be constructed from a series of coloured cylinders by adding:

And that’s the ramp constructed!

For the down ramp, a similar process needs to be followed – indexing the object as free object 62 and locating it in the route file at 2825m. The easiest way to construct this ramp is to alter the z offsets using ‘find and replace’ in the up ramp object and then to alter the order of the vertices in the ‘add face’ commands to 3,2,1,0, (to ensure correct side of the face is displayed). The only point to be aware of is because of the slope present on the main platform face, the gap between this and the ramp needs to be either hidden or removed.

To remove it, reduce the height of the ramp at 0m to from 1.1 to 1metre (as I have done in the example included in the objects download). Alternatively, instead of having railings at the end of the platform, hide the gap with a small wall.

As preparation for the next part of this tutorial, in which a curved platform is to be built, let’s see why this might be desirable by positioning our platform on a curve. We can use the third station as our example and to make the curve, the route file must be modified (adding the curves and changing the rail types):

Under modern regulations, a curve radius of 500m would not be permitted for a new build platform (because of the gap between the carriage and platform caused not only by the curve itself but also by the cant), however, there are plenty of examples of older stations built on quite tight curves.

We should then straighten out the curve after the station:

Next, add the platforms (freeobject 60) between 4800m and 4850m at 25m intervals on either the left or the right (Where the object will require rotating by 180 degrees) side:

It is immediately apparent that there is a problem if a straight object is used on tightly curved track. This will be corrected in the next part by building curved platform objects (to match the smoothly curving track!).

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