Earl:
You make an interesting point about the Gramps tanks being placed next to the engine. If I remember from my rules examinations, (I'm too lazy to try to wade through the dust in the attic to hunt for the books) it stated that there were to be at least three cars between the engine and a car carrying hazardous materials. But then it want on to say words to the effect that if train length tonnage or other factors prevented this, it was okay to place them next to the engine. Obviously, a cab hop local with one tank to pick up would be an exemption. I have a hunch that the train crews were able to come up with many more. Aw for the creativeness of railroaders!
Les Clark