Plarail Height Clearances, Limitations, and other helpful bits.

Some actual measurements:

Plarail J-14 Block Pier / Tomica World 7489 Rail Girder
Stacking height 66mm, clearance from rail running surface 54mm.

Plarail J-15 Mini Pier / Tomica World 7500 Rail Bridge Support
Stacking height 16.5mm (i.e one quarter of Block Pier height)

Tomy Train 1305 Girder, red
Stacking height 110mm, clearance from rail running surface 95mm.

Stacking height of J-14 + (2x J-15) = 99mm
Stacking height of 1305 = 110mm
Stacking height of J-14 + (3x J-15) = 115.5mm