`  ==Vague and Unsourced==  This statement, near the end, is vague and unsourced: ``Three carriages, including the bar carriage in the centre, is the minimum possible configuration because of the way the sets are articulated.``  :1. Does this mean three carriages, exclusive of the power cars, or can the power cars be the other two carriages? :2. Why are three carriages, including the bar carriage, needed? ``The way the sets are articulated`` makes no sense.  Given these problems, the statement should be sourced and clarified—or else deleted (probably the better option).`