2 ms·
It's combination of tunnel ceiling height, weight limit, and chassis mounting compatibility. I'm not completely sure there were protectionism of either directio
by numpad0 2y ago
It's combination of tunnel ceiling height, weight limit, and chassis mounting compatibility. I'm not completely sure there were protectionism of either directions are involved with JNR/JR 12/20/31ft system and ISO 20/40ft, both seem to have been conceived around the same time in mid 60s.