This forum section might become my new place to ask steam locomotive questions for my planned build, so I might ask a few more around here. The locomotive I am building has a 70” boiler diameter. Does that dimension include the lagging? If not, how much more diameter would the lagging and jacket add?
As far as I am aware, that does not, would not include lagging. Lagging I have seen and handled, (including old asbestos), was about two inches thick. Such thickness likely varied. Knowing if there was any engineering/design standard for computing lagging thickness could be an interesting learning point.
Another vote for dimensions excluding lagging! Again 2" was the norm at the time, some railroads experimented with thicker lagging but that would be documented.
