Steam Locomotive Feed Water Heaters

[AltonFan]

I think a lot had to do with plumbing. The easiest place to put a feedwater tank so that it could use the heat passing through the boiler and coming from the exhaust was the smokebox. The heat and smoke from the firebox passed through the flues into the smokebox, where it was forced out by the hot exhaust from the cylinders. One type of feedwater heater hung on the side of the boiler, but this could interfere with other plumbing, runningboards, and other appliances. It also could be unsightly, and create clearance problems.

It seems one theme in the operation of steam locomotive appliances was an attempt to get more thermal efficiency. At first compounding was attempted with generally poor results. Superheating heating and feedwater heating were much more successful.

[Anonymous]

What were the reasons for the different locations of the various makes (Worthington, Elesco, Coffin, etc.) some on the side of the boiler, some on the front of the smokebox, some just ahead of the stack. Anybody on the forum old enough to have been with one of the companies or roads to pontificate on the subject?