Absolutely. I once read a reprint of a book written by Oliver Evans in about 1820 or thereabouts, in which he describes the need to allow the boiler to "breathe" as it expands and contracts in service.

dave

It's unfortunate that so many have turned out bad and so much difficult-to-raise money was wasted. One would think that that would be a freakishly rare thing. Is it really that difficult to copy what was done before and even if making changes to conform to newer safety codes or going from riveted to all-welded, conforming to the dimensions of the old boiler would seem like a "duh" item.

When you think about it a little, there are problems with dimensions. A cylindrical riveted boiler has a diameter change at each course so that one course will fit INSIDE the last, and the courses are typically cylindrical. A welded boiler has no laps at the courses. So a 3 course welded boiler using 3/4 inch plate needs to compensate for a difference in diameter of each course of 1-1/2 inches, or 5-1/2 inches from first course to last. To compensate for the diameter changes at the course seams, the welded courses must have a slight conical section. Now try to fit that onto the frame that was designed for the riveted boiler. Not so easy. It requires lots of fudging, and that changes the design and all of the stress calculations. Back in the steam era, the RRs had no trouble with this because they had engineers that did this kind of thing every day. Just another skill that, while not exactly lost, is pretty scarce today.

Is it possible to lap the telescoping courses of a cylindrical welded boiler so that it has the same dimensions as a boiler that is riveted and lapped at the courses? Or, does this introduce other safety problems? (I don't mean a boiler that is riveted and lapped at its seams.)

Surprised that the riveted boiler must get progressively larger when they could just do the courses as bigger / smaller / bigger/ smaller. Is that simply a custom or is there a specific reason?

There are stationary boilers with alternating course diameters.

In a locomotive boiler, a larger size at the firebox end is a good thing, so why not lap the courses in increasing diameter?

http://upload.wikimedia.org/wikipedia/commons/6/6d/Dampfkessel_f%C3%BCr_eine_Station%C3%A4rdampfmaschine_im_Textilmuseum_Bocholt.jpg

J. David, and contributors, thanks for this thread, and the very interesting one on 1385. One recent boiler which may not be well known in the US is that on Prairie Dog Central #3 in Winnipeg, Canada. This is an 1882 Dubs (Glasgow) built 4-4-0, Ex CPR, Ex City of Winnipeg Hydro Rwy. I include a link to an article in Canadian Rail magazine describing the re boilering of the engine between 2002 and 2009, to replace it's 1910 CPR built boiler. The article does not get very technical but it was built by Saskatoon Boiler works to the ASME code, as such the stays have full penetration welds and from the photo's appear to have a greater than 4" pitch. The run is about 15 miles each way on level terrain at about 25mph pulling 5-6 wood coaches, as far as I am aware the boiler steams and has been performing well. A friend was involved in the design of this boiler so I will ask him for more information when I get the chance.

http://www.exporail.org/can_rail/Canadian%20Rail_no531_2009.pdf

Out of curiosity, what changes were required to the 1980's Chinese SY boilers to make them ASME compliant, apologies if this has been discussed before.
P. Hosford

Dear P.Hosford:
At the time Valley Railroad SY1647M was purchased, we were under the jurisdiction of the State of Connecticut. With the assistance of Hartford Steam Boiler and various State officials, we got an act of the legislature passed allowing for the boiler to be operated in the state if it were to be EQUIVALENT to an ASME boiler. We retained the services of Joe Micheal, M.E. (Catskill Mountain Railroad) to do an engineering analysis (reverse engineer) the standard SY boiler verses ASME Section 1 and 49CFR Part 230 and identify items which were at variance.
The major areas were: the use of fillet welds rather than full penetration welds on staybolts and such and that the entire boiler wasn't stress relieved. Also the stress on the crownstays was slightly over the FRA maximum.
After over a year of negotiations and planning, Valley and Tangshan agreed on modifications to the standard SY boiler including full penetration welds and larger diameter crownstays. Tangshan insisted on a thicker firebox (1/2") as their welding engineers were concerned about controlling warping with thinner sheets (3/8") with full penetration. They imported the steel for the firebox from France. Joe wrote a paper which argued for the non-necessity of stress relieving the boiler (made of 5/8" material).
We hired Hartford Steam Boiler to provide an AI (Authorized Inspector), (Larry Loke, a Mandarin speaker from their Singapore office) who made on site inspections prior to construction to check Tangshan's material tracking and certification, welding procedures and welder qualification as well as quality control and inspection; during fabrication and fit up and again for the hydro test when the boiler was finished.
SY1658M (now VRR 3025) was constructed a couple of months later using our modifications. A third modified SY, 1698M, was constructed the following year, but it was lost when the ship carrying it ("Braut Team") sank in the Indian Ocean.
J.David
PS: The "M" stands for "Meiguo", (Beautiful Land); America in Chinese. JDC

Thanks again J. David, a fascinating story! Also relevant to this discussion is an interesting little paperback book I recently picked up on holiday in the UK, called "Locomotive Boilers for the twenty first century" by Alan J. High (C. Eng, M.I. Mech. E). While the book is entirely from a UK perspective, its probably a worthwhile read for anyone contemplating going the new boiler route. With the caveat that some of his ideas may not meet every jurisdictions codes. It contains a lot of interesting and useful information, including a description of the some of welded joints used in the all welded boiler for Bullieds Leader in 1948. The author breaks down new boilers into four options ranging from traditional techniques to a radical redesign including the use of water wall construction for fireboxes. He maintains that while water wall fireboxes were not successful in the past that was only because of the construction techniques available at the time. It would certainly be sticking your neck way out to try it though! Whether you agree with him or not its and interesting little read.
Pat Hosford

On the topic of firebox steel, below is a 1920 photo and caption of the largest plate of firebox steel made to that date.

Image source: Hagley Digital Archives: "Largest Fire Box Plate Ever Made"

How about the new boiler made for Heisler #6 at Cass. I think it was done in the late 90's? If I recall correctly, Sisterville Tank in West Virginia made it.

The boiler from Cass Heisler #6 seems to be doing well. There were some initial issues (like the domes being mounted crooked), but other than that, it seems to have few issues.

Biggest gripe I have seen is the corner washout plugs were put on the throat and backhead sheets, not in the corners, (even though to was built with flanged corners) making it tougher to get the corners clean on boiler washes.

#6's boiler runs out of flue time (on the 15 year clock) this month. It will be interesting to see how she fares on the new Form 4. She has little actual service days on her, only because the crews at Cass hate the engine and don't like to run it. It only sees service when something else is down for service.

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