The Problem With Precision Scheduled Railroading

With PSR, you need the shorter dwell times and rail yards. So this train is locked in such a way it can be assembled and disassembled as quickly as possible. And before precision scheduled railroading, you'd try and block this train for better train handling. You put the heavy cars in the front and they're light cars in the rear. Which is why you've got the derailment of the week thing.