Good evening,
While rummaging through the interweb, I found this lovely little excerpt from the Journal of the Inst. of Loco Engineers, 'The Design and Construction of Steel Fireboxes'. It's a short read, 22 pages. Do check it out.

https://journals.sagepub.com/doi/pdf/10.1243/JILE_PROC_1953_043_048_02

Several comments about U.S. practices made me rather curious.

On page 8 is this interesting line, "the practice in the United States of using plain rod stays welded to the plate on the outside should ... be acceptable and preferable for several reasons."

It appears to me this is a reference to fillet welded staybolts? If so, I was unaware of their use in the U.S. during the steam era.

Also, on page 21, "automatic welding was done in the States when they were building steam locomotives".

According to preceding sentences it seems this is in reference to submerged arc welding (SAW). Does anyone have additional information on the application of automated welding process(es?) to steam locomotives, related to fireboxes or not?

Thanks,
John

Also interesting is the drawing showing a "vee" in 3/8" plate (side sheets?)-- with the weld prep bevel opposite of US practice: wider at the waterside root, and tapering toward the fireside. Indication of weld order is the put in the wide root first. Or am I looking at the drawing wrong?

Howard P.

Reading the text, it appears the method described is to fill and cap on the water side, then grind into the weld from the fireside and lay the root of the joint from that position. This joint design is for the construction of fireboxes, therefore it would be accessible from both sides.

A bit of explanation is offered in that "[t]he main run of weld is therefore on the outside or compression side of the box". It didn't make sense to me at first, but if you look at the moment (of rotation), the water side of the sheet is being compressed while under load.