MSTS Route - MegaCoaster

A route modeling 6 purely fictional roller coasters

Freeware for Microsoft Train Simulator (MSTS) by Michael Vone


INSTALLATION

See the file install-MC.txt.


OVERVIEW

This undecorated route includes 6 roller coasters (one being my older Arollercoaster, renamed MiniCoaster).  

The maximum height variation is about 6600 ft / 2000 m, giving speeds in excess of 400 mph / 600 kph.  

MegaCoaster uses default MSTS tracks.  It can be used with default or add-on rolling stock.

An annotated track plan is given as file MegaCoaster-map.gif.


USING MegaCoaster

Start the route in Explore mode with your choice of consist.  The GP-38 and Dash 9 locomotives work well.  Best are short consists with short wagons, but try out different types of consists.

Select the Mega starting locations to run on any of the 5 new large MegaCoasters.

Select the Mini starting locations to run on the older smaller MiniCoaster.

Select the "near" starting location for short trains.  Choose the "far" starting location for longer slower trains.  Select the "accelerated" starting location to boost the starting speed by starting on an acceleration ramp.

To choose one among the 5 new large MegaCoasters, throw the switches near the start zone:  from left to right you select track 1, 2, 3, 4 or 5, as labeled on the map MegaCoaster-map.gif.

You may use the yard view (press 7 when near the start zone).

Note:  Often, some terrain and/or track will be invisible.

For a change in terrain textures, try the Winter season.

(You may try out different levels of gravity, although this has not given different effects on my system - this is probably an unfinished MSTS option.  I would expect less acceleration and lower speeds in low gravity, as on the Moon, and more acceleration and higher speeds with stronger gravity, as on Jupiter.  You can change the gravity in the MegaCoaster.trk file.  Near its end is the statement GravityScale ( 1.0 ), which corresponds to Earth's gravity (1G).  Change the value 1.0 to 0.1653 for the Moon or 2.643 for Jupiter, the planet with the strongest surface gravity.)

CAUTION:  The Activity Editor may freeze when you try to zoom its map in, for reasons unknown.


TECHNICAL

To achieve steep slopes and sweeping curves, MegaCoaster uses dynamic track sections, suitably twisted by "banking" (sideways tilting).  Most dynamic track sections include two 90 turns, with start and end usually horizontal.

To twist a dynamic track this way, you need the Object Rotator (part of my Route Building Guide, see http://avsim.com/hangar/utils/mvchallenges/mstsguide/ORguideViews.html).  It gives dynamic track the needed "bank" by changing its QDirection values in the World files.

The effect of "bank" in a curved dynamic track is to make it tilt sideways as it turns.  Most surprising is that the crossties (sleepers) stay horizontal everywhere, and that the two rails match those horizontal crossties everywhere.  In other words, the visible track is not banked anywhere;  it is only sloped.  And a train riding on this track will always stay upright (not banked sideways), matching those rails.  So there is no superelevation.  

A train will in fact never run upside down on MSTS tracks, which is why there are no upside-down loops in MegaCoaster.

An oddity is that the steeper the track is, the narrower the gauge becomes.  Indeed, MSTS draws the rails closer together, and the crossties and track bed are also drawn narrower!  For dynamic track twisted nearly vertically, the gauge becomes tiny!

To understand how this banking works, imagine the centerline of the dynamic track section (the line running midway between the two rails):  by default, it lies in the surface plane, non-sloped, non-banked.  The effect of adding a bank is only to tilt that plane left or right around the initial direction of that track:  the track centerline remains planar, in that tilted plane.  A similar thing happens if you apply a slope to such a dynamic track section:  then the plane of that track section slopes up or down (as for any sloping regular track), keeping the track centerline planar in that sloping plane.

Note:  this twisting does not work with regular track sections (if you try it, they become superelevated with a bank, even though trains still don't bank);  you need to use dynamic track.


HOW TO MAKE THIS KIND OF ROLLERCOASTER

Here are some guidelines if you want to create such twisted dynamic tracks yourself.  The simplest case is a 180 left turn starting horizontally and ending horizontally (zero slopes at start and end).  Do the following:

- attach a dynamic track section to the horizontal (non-sloping) end of existing track;

- set its two curves to a maximum angle (-1.57 radians), with suitable radii (50m or more;  the two curves may have different radii), and include a straight mid-section of at least 2m length (otherwise you can't create the second turn);  you may include start and end sections of any length (these will remain non-sloped);

- do NOT give this dynamic track section a slope:  leave it horizontal;

- save the route;

- find the tile numbers for the tile containing the beginning of this dynamic track section and open the corresponding World file (see Object Rotator for more instructions);

- find the object coordinates of this dynamic track section and use them to find this track's entry in the World file;

- copy the QDirection data from the World file to the sheet "Turn about OBJECT axes" of Object Rotator;

- under step 3) of that Object Rotator sheet, enter a value for the "bank", setting the two other angles to zero;  you can choose any bank angle from -180 to +180:  0 leaves the track unchanged (horizontal left turn);  positive bank angles make it tilt up to the left (90 makes its middle portion go up vertically);  negative bank angles make it tilt down to the left (-90 makes its middle portion go down vertically);  going beyond +90 or -90 makes the left turn become a right turn (+180 = -180 gives a horizontal right turn, mirror of the initial left turn);

- copy the resulting QDirection data from Object Rotator into the World file, which you must then save;

- reload the route, using the Advanced option to Rebuild Track Database;

- check the resulting track shape;  if not satisfied, choose a different "bank" value in Object Rotator, update the track's QDirection in the World file, and reload the route as before;

- if you need to change the details of this dynamic track section (such as radii and lengths), close the old copy of the World file, select the dynamic track section in the RE, change these details (which will flip it horizontal again), save the route, re-open the World file, etc. (don't try to change these details in the World file).

Note:  the maximum turn angle of -1.57 radians is not quite equal to -90, but is about -89.95.  So the most you can turn with two "90" curves is about -179.9.

The relatively simple second case is a 90 turn.  Use the same procedure as given above for the 180 turn, but include only one 90 curve (or two curves that add up to 90) in one dynamic track section.  The result will be a 90 turn that ends up sloping up or down by the same angle as the "bank" angle used in Object Rotator.  For example, if you gave this 90 turn a 45 bank in Object Rotator, its end will slope up to the left by 45;  a -45 bank will make its end slope down to the left by 45;  a 135 bank will make its end slope up to the right by 45;  and a bank of -135 makes its end slope down to the right by 45.

The next case is a turn that is neither 180 nor 90, which is much more complicated:  the difficulty is to calculate or measure the slope of the end of the dynamic track section, since you will need to attach a sloping track section there.  I don't have a correct general formula for this, so I avoid this case as much as possible.

Here are some general guidelines in designing a successful rollercoaster in MSTS:

- arrange for the altitude of successive peaks to generally decrease:  if your train used no power, that would be essential, but even when using power, you must allow for friction and resistance in tight turns;  so the optimum result will depend on which train is used, and the distance between peaks!

- avoid too sharp curve radii (stay above about 50 m), especially with strong bank angles:  they produce large twists between cars and can easily cause couplers to break;

- test the route at each construction stage in MSTS with trains, especially after reaching the next peak, to make sure your trains survive your route;

- if you set a high speed limit for the route (such as 500 km/h, or anything else well above the maximum speed that a train will reach), the route can be run equally with the MSTS derail option switched on or off.


DISTRIBUTION

This route may be freely distributed and modified.

________________________________________________________________________
Michael Vone - mivone@pacbell.net
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