If replacing a riveted boiler with a welded boiler can create problems concerning the overall dimensions of the welded boiler (for example the problem created by replacing a 3-course, telescopic riveted shell, with a cylindrical or conical shaped shell), and weight issues, among others, how come replacing a riveted boiler with a riveted boiler is off the table?

Few code boiler shops rivet any longer.

dave

The "conflict" between FRA rules, ASME code, and individual railroad practices is a long one, and goes back to well before there was an FRA. Back when it was the ICC.

ASME is working on a fully revised and updated code of original construction for new locomotive boilers. Maybe it will be issued soon. ('Soon' meaning in a couple of years). Someone please correct me, but I think the last time this code was issued or revised was in the late 1940s or early 1950s.


Hopefully, that will make ASME shops aware of the differences required for locomotive boilers, such as the closer staybolt spacing. It will definitely make them accountable to adhere to the code.

It will still require customers to stay on top of what they are buying to insure the shop is using the correct code sections in the design and construction of a new boiler so that tehy don't end up with a large, expensive, conversation piece sitting in their parking lot.

Caveat emptor.

Does anyone have photos, drawings or other information detailing the location of the arch tubes in 1385's boiler?

I'm curious as to why you couldn't relocate them to come into contact at the throat sheet, or lower in the throat sheet, in order to change the ach of the firebrick and keep the "blanked" area open for tubes, but above the arch brick?

Also, has anyone looked at the boiler on the other two R1s still around? Do they have the same arrangement?

Also, what solution did Mr. Austin propose back in 2001 that has apparently been forgotten?

Dave:

From experience, thermic syphons do NOT reduce headaches. They increase them.

Chattahoochee Valley 21 - installed home made thermic syphons, and the firemen couldn't keep her from [popping off, while the boilermakers couldn't keep her from leaking. I was simply floating an idea that wasn't arch tubes in an intrusive location. Circulators may have been a better choice.......

What's your syphon story, Linc? I never had any hands-on with one.

dave

They are 2" diameter X 196" long sheet to sheet. Very close to your stated optimal ratio.

mld

Probably a combination of design of the firebox hardware and front end appliances together would solve the problem of clogging tubes. The Master Mechanic's front end supposedly could be adjusted for shifting the draft across the tube bundle, but perhaps it lost some ability to be adjusted when it had to share the front end with the superheater hardware.

dave

If the arch came down to the base of the arch tubes, then the addition of some heel bricks could solve the tube plugging issues.

I think we all prefer low tech solutions.

A somewhat better picture shows all 3 rows. The arch tube holes also show well in the throat sheet. Conjecture on my part: If you drop them much more then the bottom of the brick may be getting close enough to the grates to make it difficult to fire without bouncing coal off the brick. mld

Thanks to Brian Allen for sharing the photograph.

This is a really typical early application of superheat to a saturated loco. At the Minnesota Transportation Museum we have a pair of NP Class Q3 Pacifics that were built as saturated and later had superheaters installed. They also have only three rows of superheaters.

Kelly mentioned the K-28 and bottom flues in relation to the arch brick. I looked around and couldn't find a good one of the 28's, but you can see them on a K-36 which are pretty similar. When the K-28's are working hard, you have to fire them with a massive heel to force the area under the brick to draft continuously, otherwise the front foot or so "goes out" or takes an incredibly long time to clean itself of ash. Frustrating when you're training new fireman and the engine has to be fired right on the edge or you'll have to stop.

Well, both. Keeping the engine hot and failures to do so can go both ways on blame.