Here's another useful platform for arranging Gravitrax tiles.  This one is five hexes long and can be used in a variety of different ways.  In my Gravitrax I've used them as:

• a bridge between two columns and placed tiles suspended above other track routes below,
• a platform for arranging transfers in a line, and
• as a cantilever for holding tiles in mid-air to enable routes that would otherwise high columns. 

I've provided photos for these examples with this design. There's short Youtube below demonstrating the bridge in action. 

Note: The five-tile bridge can only be printed on an A1 or bigger (ie 256mm by 256mm).  It is rotated 45 degrees to fit.  The bridge uses 50 grams of filament and takes about y minutes to print.  I've used tree supports to ensure that the tile holder sections are well formed.