Via Trains Magazine News Wire:

https://www.trains.com/trn/news-reviews ... 0v9_s_hzak


ALTOONA, Pa. — The first new Belpaire steam-locomotive firebox built in Altoona in 76 years is taking shape at the Railroaders Memorial Museum.

Over the last week, employees of consultant FMW Solutions LLC and volunteers have fabricated a new firebox for former Pennsylvania Railroad Class K4s 4-6-2 steam passenger engine No. 1361 (PRR Juniata Shops, 1918). The last such work was completed in 1946, when the PRR built 25 T1-class streamlined 4-4-4-4 passenger engines in its shops here. Those locomotives, along with 27 T1s built by Baldwin Locomotive Works, were supposed to replace the road’s 425-member K4s fleet, but instead were themselves quickly replaced by diesels, starting in 1947.

Interior of boiler and firebox of steam locomotive
View through the firedoor in the boiler backhead of No. 1361 shows the custom-fabricated side wrapper sheets, left and right, the Belpaire plates, upper left and upper right, and the roof sheet, top. The four horizontal stays are temporary to stabilize the components for fitting and welding. Dan Cupper
No. 1361 is undergoing a $2.6 million restoration to return it to running condition [see “PRR K4s engine No. 1361 to be restored …,” Trains News Wire, June 25, 2021]. One of the obstacles is that the original mechanical specifications — drawn up by PRR in 1914 — do not meet present-day federal pressure-vessel safety standards. The museum has hired FMW to engineer and build a new firebox that’s visually identical, but with thicker steel and other modifications that simplify and strengthen the component.

Shane Meador, FMW vice president-mechanical, and Zach Hall, an FMW foreman, oversaw the work of cutting out 7/16th-inch steel plates for the side and roof sheets, then assembling and welding them together to form a new firebox. PRR used 3/8th-inch steel, which doesn’t meet the Federal Railroad Administration’s “factor of 4” safety standard, meaning that a boiler must withstand a force of four times its normal operating pressure — for a K4s, 205 pounds per square inch.

The unusual squared-off Belpaire top results from a standard PRR adopted in the 19th century, differing from the radial, smoothly rounded shape of most North American locomotive boilers. Many British and European steam engines employed the Belpaire design, as did many Great Northern Railway engines.

Used on thousands of PRR locomotives of many classes, the odd shape added to the cost and complexity of No. 1361’s restoration, including press-brake work to gently bend the side plates to meet the dimensions of the squared top.

Computer program helps engineer boiler changes
Meador said FMW used a computer program named Solidworks to precisely engineer the wrapper side sheets to conform to the round third boiler course and the squared top. Earlier this week, the components — right wrapper side sheet, right Belpaire plate, roof sheet, left Belpaire plate, and left wrapper side sheet — were being welded to prepare them to make “one continuous structure,” Meador said. He added that some original PRR methods, including a riveted seam, were being replaced with an improved design that eliminates potential weak points and future maintenance headaches.

Side view of boiler and firebox
A left-side view shows the left wrapper sheet and left Belpaire plate positioned against the round boiler courses of Pennsylvania Railroad K4s-class 4-6-2 steam locomotive No. 1361 in the Railroaders Memorial Museum roundhouse at Altoona, Pa. Dan Cupper
Another modification is the use of a Flannery staybolt pattern instead of the original PRR design. “It’ll improve maintenance, improve longevity, and hopefully we won’t have as many broken staybolts,” Meador said. Pittsburgh-based Flannery Bolt Co. was a major supplier of staybolts, which create the space in a boiler for water to be heated into steam.

“When we get the fit done, [the outer shell] will be disassembled and heat-treated here in Pennsylvania, then it will be reassembled with rivets in the throat [where it meets the round third boiler course],” he said. That will involve some 250 to 300 rivets.

Once the outer structure is complete, the dimensions of the inner firebox, including the crown sheet, will be created in computer-aided design, Meador said.

Working with Meador and Hall are museum volunteers Andy Charlesworth, Tom McKelvey, Mike Reindl, and Brandon Sliko, as well as Dick Charlesworth and Bill Harella of the Horseshoe Curve Chapter of the National Railway Historical Society,

The outer wrapper work is expected to cost $150,000 of the total firebox work amount of $400,000, according to museum Executive Director Joe DeFrancesco. Of that, he said, the Pennsylvania Railroad Technical & Historical Society contributed more than $100,000 in June, which was matched by an anonymous donor. Another donation of $200,000 brought the total to $400,000.

“That will close out our current phase of the overall [$2.6 million] campaign,” he said. “Next year we’ll launch the next phase of fundraising.” That will address boiler and running-gear work.

“We’re very humbled and very pleased with the results,” DeFrancesco said, “I appreciate the team [effort by] donors big and small, members, volunteers, and staff. It’s momentum — it shows that it’s shared enthusiasm. All things, considering [the] post-pandemic [situation], we’re very happy and very grateful.”

No. 1361 was one of 425 K4s-class engines built by Juniata (350) and Baldwin Locomotive Works (75). The type dominated the carrier’s passenger-locomotive fleet for nearly 40 years, until the last were retired in 1957. The only other survivor is No. 3750 (Juniata, 1920), located at the state-owned Railroad Museum of Pennsylvania in Strasburg.

PRR retired No. 1361 in 1956 and the next year placed it on display at Horseshoe Curve. In 1985, the museum removed it from display and restored it to operation, briefly, in 1987-88.

Eighteen months ago, RMM Board Chairman Wick Moorman and DeFrancesco announced the plan to reactivate the engine. Moorman and longtime PRR historian and benefactor Bennett Levin are leading the project to not only restore the locomotive, but also to assemble a train of coaches and display cars to travel the state in an educational mission to tell the story of railroading in Pennsylvania. Already the museum has two PRR B60B baggage cars that can be used to hold exhibits.

I'm so happy to hear this. Sounds like the best news this locomotive has had in a very long time. I was a teenager the last time this engine ran and the for the longest time I've said that it would have been best if 1361 never left her display spot on Horseshoe Curve. Maybe soon I'll be proven wrong (which I'll be happy to admit once I can).

I am not an expert but I'm surprised they went from 3/8" to 7/16". It just seems like a lot of work for a small change. Depending on the material cost difference I would have overbuilt a little and just went straight to 1/2".

Sounds like good progress! I look forward to seeing her under steam.

I thoroughly approve of the decision to use heavier outer-wrapper plate IF the design has carefully calculated the effect on bending where it joins with other plate structures such as the convection-section shell. Welded construction, as the A1 Trust discovered to their sorrow, can be different from simply welding up construction designed for riveting.

This is a restoration to operation, not a re-creation of built-to-a-price steam generation with a calculated 2 to 3-year maximum life. Accordingly it would pay to make the boiler like jewelry, and take care of it for many years of essentially trouble-free running.

They need to get better writers for their press releases.

Gents, We can pick all the nits you want but the bottom line here is that finally this poor creature is in competent hands both financially and in engineering terms after years of going from one well meaning but incompetent team to another.

I am 110% sure that in a reasonable amount of time she'll be back boiling water and bringing the magic of steam to the multitudes.

Merry Christmas, Ross Rowland

Considering what has happened to 1361 from being yanked off Horseshow Curve until recently and in whose hands she appears to be now, I can't help but agree with Ross again.

This project has been around almost as long as I've been in the business and a source of multiple painful lessons for all of us.

I remember it being pulled from the curve, and how it's ended the careers of several directors, and the enthusiasm of a lot of volunteers.

But from what I know, this plan addresses the root of the problem; PRR didn't design with a factor of 4 on these boilers, and when the new steam regs went in, it essentially blew out almost every Belpaire boiler design out there. The fact that restoration was started before the regs changed set it back for years and years.

But thicker is not necessarily better, you don't want it any thicker than it has to be, as the thicker the material for firebox, the more likely that you get stress between two sheets of different thicknesses under repeated heating that can do nasty things to staybolts. One such attempt led to chronic stay head erosion after only 300 days in service and ultimately a condemned boiler.

I really don't think there's much to worry about with the current 1361 project, based on who's involved. Something tells me it'll turn out just fine. Just cross your fingers NS has a another steam friendly CEO in 5-6 years time...

Do you really think FMW, who's doing all sorts of stress testing in solidworks, as well as having a pretty knowledgeable team is going to read a rypn post and be like " oh crap.. ya we should switch the sheets to 1/2" I don't think so... It seems very evident their new firebox design is very well thought-out and engineered.

Well then give Wolf a call at FMW. I'm sure he'd love to hear more about your ideas.

I've known Mr. Fengler for over two decades; we were on John's "S-Team" together on steam_tech. The only real technical disagreement I've ever really had with him was in a non-steam context: I did not, and still don't, think CNG is a superior locomotive fuel to LNG. But that is far from a criticism of his skill or experience; as Riddles so well put it when discussing the matter of Leader class, "if doctors may differ why then so may engineers" (not that I put myself fully in that category as I don't have a PE). Since you are on a first-name basis with him, please feel free to have him call me if his schedule permits if you feel the need to share your concern with him.

Much of the long, whining disaster that was restoration of 1361's 'historic fabric' boiler hinged not just on not having better than a 400% factor of safety, but in expedient design taken by PRR that might charitably be described as misguided (I personally think in order to save both material cost and weight). They intentionally used thin sections in the firebox that required double nutting, and the options wavered between derating the engine so that pressure would suit the as-produced fabric or rebuilding the firebox in some way. The "correct" answer as far back as I remember reading anything about it was an all-new welded boiler, but for various reasons best left undiscussed that was not a practical possibility -- until Moorman, Levin & Co. stepped in and made the thing possible.

I only mention the design-for-welded-fabrication hypothetically... but very good engineers were involved with Tornado's mud ring, too, and there was more than a little unpleasantness about what Meiningen delivered to the Australians. My opinion is that it's better to mention it, and find the professionals have it in hand as expected, than find out something was overlooked...

Yeah, on review, the press release is fine.

If you’re looking at readability issues, the press release is fine if you look at the original at the link. The post above is a copy/paste from the article that also picked up the image captions and ignored the original formatting making for wonky continuity. That happens when you copy from the internet.

I have been waiting to see this locomotive restored and operated since I was middle-aged. I feel certain I'll see her run before I am composted.

I'm convinced that it will be very quick, and very positively executed. And very probably easy to maintain in running condition at least as far as the next prospective major.

I suspect that much of the mechanical work that has been slowly done on the running gear may be torn down and redone just to provide a full audit trail, but that shouldn't be hard even if it turns out 'costly' within the allotted budget.

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Well, actually, that 1/16 inch difference is significant. It is a 16.6% increase in thickness. I pulled out my old machinery's handbook, and found the section plate loads. The deflection of the plate is a function of the inverse of the cube of the thickness.

The 1/16 extra thickness, with everything else being equal, means 64% of the deflection, where the original thickness is 100% deflection. That is a significant strength and safety increase.