I've seen at some stations on the Hayes line that by the platform cameras that there are panels denoting that it is where 2 car, 6 car and 12 car trains should stop. Despite this, I have never seen a train of this arrangement stop on the line at any point in my life. What would the 2 car trains serve on that line anyway? The closed branch to Addiscombe? 12 car trains also seem silly considering 10 car trains pretty much take up the whole platform of most stations on the line.