I want to add another set of tracks to my existing setup that would go between and above two existing sets of tracks.  Problem is there is very narrow space in between the 2 existing tracks for the bents to hold up the new track, which would have to be about 11-12" high.  The bents would have to be 1 1/2 to 2" wide.  I envision something like the steel girders that hold up the NYC elevated subway tracks, narrow at the bottom at street level and fluting up at the top to hold the train tracks.  Has anyone ever created such a trestle with bents of this size and shape?  Can it be done?