I have often read it was necessary to run steam pipes through oil bunkers to keep the oil in a state where it would flow freely enough to be able to burn freely in the atomizer.
How was oil stored for locomotive use kept in a sufficiently fluid state it could easily be transferred to the locomotive tender for use? Most of the oiling facilities I have seen on narrow gauges used gravity as the means of transfer. During winter weather, I would imagine the oil would thicken considerably.
Anyone know how this issue was dealt with?