Como Wrote:
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> I seriously doubt the Boilers were replaced, they
> were still using Boilers from this period 40 years
> later. When they were looking at replacing
> Boilers/Frame and Cylinders this seemed a very
> high percentage of the value of the locomotive,
> not something they built in Denver, this was all
> coming from Pennsylvania,
If you were responding to me (could've been responding to other posters, not sure) I was admittedly a bit unclear, but I wasn't asking if a boiler was replaced but rather if the 24 was perhaps built with a steel boiler rather than the wrought iron that was more typical for circa 1880. I ask because it was stated earlier that 24 had a higher boiler pressure which would've been unusual (not impossible--but unusual) if it retained the same basic boiler shell as the others. My understanding is that some of the 14x16 engines used a 42 inch diameter boiler with 113 tubes while the last couple used a 44 inch boiler (tube count unknown to me), although perhaps the larger boiler was only fit to the 24?
Iron boilers from that period usually made it until about the WW1 period when changing regulations required their replacement for the most part. Iron boilers sometimes remained in use longer in specific cases but it was not particularly common.