I’ve been wondering about the design decision behind armored trains and what they are supposed to represent. In reading AAR’s people seem to overlook what a fantastic unit it is.
No not for offensive combat – they suck at that, for static defense I mean. I know it sounds counterintuitive but that is what I use them for with amazing success, garrisoning cities and any part of static front containing railways.
The reason is of course the extremely low maintenance cost. They only cost 1 to maintain and are extremely cheap in manpower to build as well. So, much cheaper to maintain then even a garrison and much better defense factors – it just seem such a no-brainer to build heaps of them for holding quiet sectors with.
I realize the drawback include an inability to counterattack (unless enemy happens to occupy a railroad) and eventual obsolesce as infantry benefits from technology advances (although armored trains are an excellent reason for every nation that can build them have one research lab to the tank branch.)
Even so I routinely saving 10+ build point pr turn in maintenance by using them as static garrisons and wonder why no one else are doing it. Am I missing something?

In this example I save 5 BP pr turn on the Western front if we assume the alternative is using garrisons and the line is actually stronger defensively. Am I a military genius or overlooking some obvious fatal drawback?