I know pennsy and GN were great on the belpaire firebox. Can anyone tell me what was supposed to be the advantage of it. I do not recall any other locomotive companies using this.

Winky 2:

I found the following in Wikipedia

"The Belpaire firebox is a type of firebox used on steam locomotives. It was invented by Alfred Belpaire of Belgium. It has a greater surface area at the top of the firebox, improving heat transfer and steam production. Its rectangular shape makes attaching the firebox to the boiler more difficult, but this is offset by simpler interior bracing of the firebox.

The Pennsylvania Railroad used Belpaire fireboxes on nearly all of its steam locomotives. The distinctive square shape practically became a PRR trademark, as no other American railroad except the Great Northern used Belpaire fireboxes in significant numbers. In Britain, the Belpaire design was a standard feature on most Great Western Railway locomotives, and a significant number of the London, Midland and Scottish Railway's locomotives also employed the design. Some other British railway companies used the Belpaire firebox on a handful of locomotives, but not to any major extent."

The lore of J.J. Hill and the Great Northern is that he wanted to optimize productivity and efficiency in vast spaces of the North West.

Post Removed

This message has been edited. Last edited by: Tim Botti,

More surface area? How is that accomplished? The firebox hasn't changed shape--only the boiler shell.

And where did this notion of a "cylindrical" firebox come from? The crown sheet in both a Belpaire boiler and a standard boiler are both relatively flat.

I believe you'll find that the PRIMARY benefit of a Belpaire boiler is that the stay bolts attach fairly perpendicluar to both the boiler shell and the firebox sheets. With a rounded boiler shell, the staybolts at the crown sheet must attach in a stressful, non-perpendicluar manner, either to the crown sheet, or to the boiler shell.

Here's an image showing the stronger perpendicular placement of staybolts in a Belpaire boiler:

Belpaire boiler

Here's a cross-section drawing of a standard boiler. Note how the staybolts engter the boiler shell at the top in stressful non-perpendicular angles:

Standard boiler

Sorry, guys. I know it's shocking, but Wikipedia was wrong this time.

Well, I was wondering how long the above BS about Belpaire fireboxes would last!

Smd4 hit the nail on the head! The REAL advantage of a Belpaire design firebox is the reduced stresses on the staybolts, since the staybolts are all pretty much the same length in their respective areas of the firebox. The Radial Stayed firebox however, has all different length staybolts in the crown sheet area, since the crown sheet is flat but the wrapper sheet is of corse radial. Also a Belpair design is more expensive to construct and on the PRR was considered a "throw away" furnice system. Every 15 years or so, the PRR just made new ones! Fireboxes only last about 15 years on coal burning locomotives anyway (10 years on oil burners).

Apologies for the apparent "BS," that's how it was explained to me. Can't win em all, eh?

A square shape the same dimensions as a circle or any portion thereof has both more surface area and more volumn than a circle or semicirle shape. For example compare a circle diameter with a square with the same side dimentions as the circle. The staybolt of the same diameter and steel strength has the same strength no matter how long they are. Staybolts do not know how long they are.

brasman
I had the same thought on heating surface question, but have never seen any comparisons in the literature.
Also, Did you consider that the longer a bolt the more it grows with differential temperature, the more it grows with the ends fixed - the more stress?

Another consideration
The Belpaire boiler is stayed both verticslly and horizontally between the crown and wrapper sheets, and there magnitude of the stresses is easy to calculate.
On the other hand, the radial stayed type of firebox presents an indefinite stress problem calculation which is due to the stiffing effect of the back-tube and door-sheet construction. The weakest spot is longitudinally through the top center rows of staybolt holes in the thin crown sheet[or any other greater top opening in the crown sheet]

quote:

Originally posted by brasman:
A square shape the same dimensions as a circle or any portion thereof has both more surface area and more volumn than a circle or semicirle shape. For example compare a circle diameter with a square with the same side dimentions as the circle. The staybolt of the same diameter and steel strength has the same strength no matter how long they are. Staybolts do not know how long they are.

The firebox in a regular, round-shelled boiler isn't round, it's square--and the crown sheet is where the "surface area" is that we're referring to. The square boiler shell in a Belpaire boiler doesn't increase heating surface one iota.

This message has been edited. Last edited by: smd4,

The Pennsylvania and the Great Northern were not the only major US railroads to use the Belpaire firebox. The Baltimore & Ohio also did. It had a quite a fleet of Belpaire-fireboxed 2-8-0's. Some were later converted to 0-8-0's. There was also the A-2 class 4-4-2's. One member of that group was still running by the end of WW II.

The B&O ran itself bankrupt by the late 1880's in its head-long rush to get into the metropolitan New York market. It also left relatively new B&O lines to Chicago and St. Louis without regular maintenance. Derailments out that way were many due to poor track conditions. Trains were frequently delayed and B&O's business was looking to other railway lines. In response to all this, financier J. P. Morgan removed the B&O management in his bail-out plan, and put in people from the rival Pennsylvania Railroad.

From that time until 1905 the B&O was under PRR control with Lenior Loree as president. He later went on to be president of the Delaware & Husdon. Many substantial improvements were made on the B&O in his adminstration. Among them were purchases of new locomotives. Most were built to existing PRR plans and specifications. This is how the Belpaire firebox got onto the B&O. Many of these locomotives remained in service until the end of steam on the B&O.

Ed Bommer

If lima was the king of steam, why didn;t they use the belpaire firebox of did they?
If I am not mistaken wasn;t both GN and Penn using home built locomotives and built the firebox themselves. Did any of the big 3 locomtive builders build belpaite fireboxs?

International Textbook Company, Volume 68, Locomotive Boilers, Valve Gears, Breakdowns (1905), has this to say: "A Belpaire boiler with exstension E is shown in Fig. 2. This construction was adopted to have the crown sheet and top of the shell parallel, and thus have the staybolts at right angles to the sheets. It also adds considerable steam space to the boiler."

Grimshaw, in his Locomotive Catechism (1908), has this exchange:

Q "What is the Belpaire Boiler?"

A "One having a fire-box with a flat crown sheet joining the side sheet by a short curve, and having outside crownsheet, and upper part of the outer side sheets flat and parallel to those of the inner fire-box, and stayed by straight direct vertical and tansverse horizontal stays, obviating the necessity of crown-bars to support and strengthen the crown sheet."

As for other railroads using the Belpaire boiler, the IC was a BIG proponent of the design early on. Rogers built most of those (soon to be merged in with Alco) Brooks built them as well.

As for the "Big Three" building them, I see that Baldwin built them for the GN, the South African Ry, the Pennsy, the Akron & Barberrton Railroad, teh Hannibal & St. Joseph, the B&O, and the Pittsburgh and West Virginia, to name a few.

This message has been edited. Last edited by: smd4,

pennsyk4, The increased extension of the longer bolt would not be a problem if it did not conflict with a portion of the sheet where the sheet was fixed by a corner for example which would retain the sheet expansion and possibly rupture the sheet. The designer would avoid such a situation.
The pressure exerted on the sheets are all equal and only when the bolts were not at right angles would there be a problem as stated above. The boiler designed would have to take these stresses in his design. Ed

brasman
thank you for the explaination. It has been an in teresting and informative thread.

[QUOTE]Originally posted by winky2:
If lima was the king of steam, why didn;t they use the belpaire firebox of did they?

Winky, it just didn't work that way in steam days. If you bought an Alco diesel, you got Alco's supplied engine, generator, and auxilliaries, and could have a choice of a limited amount of optional equipment from competing suppliers (examples: your choice of signal light, air horn, seating, mirrors, couplers etc.).

In steam days, you went to the builder with specifications and they designed a locomotive for you around your own specs; or you designed the locomotive and then you and the builder argued about what had to be changed, then a deal was made and they constructed the locomotives to your design. I am not sure whether Lima ever built a locomotive with a Belpaire firebox, but am sure they would have done it if a railroad had given them a design and money.

Lima did build locomotives with Belpaire fireboxes. Here is one for the GN, a P-1 mountain.

quote:

Originally posted by Number 90:
[QUOTE]Originally posted by winky2:
If lima was the king of steam, why didn;t they use the belpaire firebox of did they?

Winky, it just didn't work that way in steam days. If you bought an Alco diesel, you got Alco's supplied engine, generator, and auxilliaries, and could have a choice of a limited amount of optional equipment from competing suppliers (examples: your choice of signal light, air horn, seating, mirrors, couplers etc.).

In steam days, you went to the builder with specifications and they designed a locomotive for you around your own specs; or you designed the locomotive and then you and the builder argued about what had to be changed, then a deal was made and they constructed the locomotives to your design. I am not sure whether Lima ever built a locomotive with a Belpaire firebox, but am sure they would have done it if a railroad had given them a design and money.

Lima built a number of locomotives for PRR Lines West with the Belpaire designed firebox. The class N1 2-10-2 Santa Fe type is one example.

A Belpaire firebox gave about 25% more heating surface over a radial firebox of the same grate area because the vertical sides of the Belpaire firebox gave a wider crown sheet than a radial firebox could give.

Stuart

quote:

Originally posted by Stuart:
A Belpaire firebox gave about 25% more heating surface over a radial firebox of the same grate area because the vertical sides of the Belpaire firebox gave a wider crown sheet than a radial firebox could give.

Stuart

Where did you find that statistic--which I disagree with 100%, because the firebox shape in a Belpaire boiler vs. a standard boiler are the same. The vertical sides of a Belpaire boiler aren't any wider than the rest of the boiler (ergo the firebox crown sheet isn't any wider, either), so how did you reach this conclusion?

The professional treatises I've read say nothing of greater heating surfaces (besides, most of the heating surface is in the tubes).

BTW, I think there's a reason that you often see references to Belpaire boilers, but hardly ever do you see references to Belpaire fireboxes in the professional literature.

Its been published in many books on steam locomotives. Consider that the curved top of the radial firebox limits the width of the crown sheet compared to the Belpaire firebox.

Stuart

Stuart you are correct. That is what I have been saying. Ed

A radial firebox?

I see. While most modern fireboxes have a slight curve to them (to lessen the stresses on the staybolts that the curved boiler shell creates) the tops were relatively flat.

The fact remains--supported by the litterature of railroaders, not railfans--that the primary benefit of a Belpaire firebox was not steam capacity or more surface area--it was for less maintanence on the staybolts.

For the phonetically challenged , how does one pronounce "Belpaire"? For example, my Hooked on Phonics books would show Monon as "moan on".

Thanx,
Stack

quote:

Originally posted by Stuart:
Its been published in many books on steam locomotives. Consider that the curved top of the radial firebox limits the width of the crown sheet compared to the Belpaire firebox.

Stuart

Sruart, think about it: The width of the Belpaire boiler, where it meets the round first course, is no wider than the rest of the boiler! How can you possibly say the firebox is wider? The corners stick up (and still aren't wider than the rest of the boiler!), but the crown sheet isn't even that high!

So..if the firebox is the same width at the top in either a Belpaire or standard boiler...If the crown sheet were flat, then I think we can agree that sheet would represent the shortest distance between the two side sheets (it's straight, like a line in cross-section). So...A curved crown sheet (being longer between the two side sheets), actually presents us with MORE surface area!

Your conclusion isn't supported by anything written (unless you can cite a source--"many books" just doesn't cut it for me) or common sense!

This message has been edited. Last edited by: smd4,