Complex sentence: The use of Indian gauge rails was one of many unconventional design elements included in its design which, in addition to its unusual gauge, also uses flat-edge rail, rather than typical rail that angles slightly inward.
Split into simpler sentences: The use of Indian gauge rails was one of many unconventional design elements included in its design. In addition to its unusual gauge, it also uses flat-edge rail, rather than typical rail that angles slightly inward.