KevinM Wrote:
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> Interesting, thanks! I'm wondering how many
> tubes typically get replaced during the course of
> the 1,472 operating days or 15 years. I've heard
> reports from several museums and tourist railroads
> that indicated they were retubing as well, and
> none of the locomotives involved were even close
> to being due for the 1,472 SDI. The folks I
> spoke with just indicated that the quality of the
> steel in the tubes they were using just isn't what
> it used to be.
>
> /Kevin Madore
During a 1,472 SDI, all of the small tubes are required to be replaced. Replacing the superheater tubes is optional based on their condition, and accessibility to the bottom of the boiler around them.
It's true, it's often the luck of the draw when it comes to the life span of modern tubes. We have had to replace them after just 300 service days due to areas being corroded to 1/2 their original thickness while the rest of the tube looked brand new.
There was a lengthy thread about this subject on
Rypn several years ago.