The barrel shape in all its variations of height, diameter, taper, roof, and support stand has been the basis of countless railroad tanks. But the so-called square tank falls into two distinct categories: One is a rectangular box that is the water vessel itself. The other is a secondary enclosure for the water vessel for the purpose of enclosing the vessel in a heated space in order to prevent freezing. In the case of the latter, that water vessel may be a steel tank of some cylindrical variety.
In Hancock, Michigan, there is a tank miraculously surviving from the Quincy & Torch Lake Railroad. It is like a miniature barn with a double pitch roof, containing a horizontal steel cylindrical tank. In the barn, below the tank, is a serious coal stove. A smokestack goes out the roof. From the outside, it looks like a small barn on timber legs with a spout on one end. This is a variation of the enclosed, heated tank. As has been mentioned, tanks were commonly prevented from freezing just because of their frequent replenishment with well water that was relatively warm. But this depended on cycling the water at a rate that kept ahead of the ambient heat loss. If this rate of use could not keep up, a heated tank was necessary. What showed with these heated tanks was the structure of the tank enclosure, not the tank itself. Since the enclosure was simply a building, there was a wide latitude for its design and appearance. I believe EBT, as well as one or more of the Maine two-footers had one or more of these enclosed, heated tanks. I also wonder if some tanks were not insulated whether heated or not.
The other category of the square tank is where the vessel itself is built as a rectangular box. This is most curious. There must be some reasoning that favors a box construction even though the pickle barrel shape is the most structurally logical. I would love to hear the case for the box vessel railroad tank (for lineside, not for tenders, that is).
RK
