It's not that "obvious" and is not always used. For a start, the power is often off at night so you need one of the few battery locos. You also need a clear rou

It's not that "obvious" and is not always used. For a start, the power is often off at night so you need one of the few battery locos. You also need a clear route from the station to the nearest loading/offloading point, which might be several mile away from the station. A lot of time, materials and tools are simply loaded through the station manually and since you are not allowed to store anything flammable below ground, some of it needs to be taken back out at the end of the shift. They are not keen to lose station time but sometimes I think they could afford to lose an hour either end when they are doing engineering work in a station. At least in this instance, they needed to close the station which saves so much time.