Keep in mind that the ability of the sheet to deflect as the boiler heats up and cools down takes some of the stress of off the staybolts. Unnecessarily thick sheets can have unintended consequences.

Roger

I realize it's irrelevant since the new regs demand higher strength. I am curious though, did any of the many K4's that Pennsy built suffer failures due to the poor design?

Talk about flexing - the seminal work "Steamboats on the Western Rivers" of Louis C. Hunter talks about boilers "panting", the plates visibly moving with every power stroke of the engines.

So you can come very close to that safety margin without experiencing a "failure"!

.

My late father-in-law, while not a boilermaker, was a machinist and gang foreman at the Harrisburg enginehouse from 1939-1963. He once told me that in heavy wartime service, a K4s needed a new firebox after 15-18 months.

Mr. Laepple,
That is very interesting. Thank you.
Not to put you on the spot, but do you have other observations that your father made from back then? It would be interesting to get the feel for what the average backshop dealt with.
Having looked into a few locomotive fireboxes, it is interesting to see some of the repairs from the working days, including new pieces welded in.
I wonder what the usual turnaround was for engine fireboxes? Certainly, one can see in wartime, that the shop staff would have been pushed to the edge keeping those old hogs running. Even in more normal times though, there must have been a lot of heavy firebox work.
Also, would oil firing be harder on a firebox than coal firing? Just asking, because I don't know. Being around CNR No. 6060 many years ago, it was interesting to observe the interaction between the fireman and hogger. It seemed that the fireman had to be always on the ball with the fuel valves to match the hogger's actions with the throttle and quadrant so as not to over fire or underfire. It just seems to me that those fellows had to be in tune or there could have been problems, although I am likely off base.
Great discussions here on RyPn!
Oh, and best wishes to all of those working on 1361. It will be interesting to watch this project through to operation.

My impression is the K4 (~420) and L1 (~600) shared the same boiler, or they were very similar - meaning there were about a 1000 of these boilers in service, give or take. At least in my eyes, this aligns with the business concept the boilers were tweaked in the redesign Kelly mentions to have a limited lifetime and then be scrapped; it was cheaper to keep a production line making new boilers running than tie up large amounts of shop forces and space making one-off firebox repairs.

I think it was WWII US submarine commander ‎Eugene B. Fluckey (USS Barb) who commented in his book how it was amazing how much more resources were going to repair damaged warships, where every part had to be custom built and fitted, compared to new construction.

Bob

USS Barb (SS-220) was a USN Gato-Class Fleet Submarine. She was not steam-powered, but diesel-electric with four GM Cleveland 16-248 propulsion engines.

Barb is the only USN submarine credted with"sinking" a train.

RADM Fluckey (then a CDR) was in command of Barb. In late 1945 targets afloat were few and far between. Barb was cruising along the coast of Karafuto, then the Northernmost Japanese province, on the Southern half of Sakhalin Island. The Northern half was Russian and Russia took the Japanese half and still has it.

The crew noted Japanese train traffic along the coast and during the night of July 22-23, 1945, the boat's demolition squad set up an explosive device ashore. When a train came, the device detonated and derailed the train, disrupting Japanese logistics.

Thus the irony that RADM Fluckey should appear in this rail forum: the only sub Captain to have "sunk" a train.

Phil Mulligan

Great Western --

I'm sorry that I cannot answer your questions. My father-in-law was a machinist, not a boilermaker, and the Harrisburg enginehouse was not considered a backshop. It performed day-to-day and running repairs. Replacing a firebox would have been done at Altoona. I believe as well that only the actual firebox and not the wrapper sheet would be replaced.

Having worked on No. 1361 during its first reincarnation in 1986-87 and again when it was at Steamtown in the mid-90's, it was my observation that forces often cut out defective sections of the firebox and replaced only those portions. There were at least two such repairs on the engine, one of which had the date stamped in the metal. There was also evidence of pad welding, by which they built up the thickness of the sheets by laying down multiple passes of weld metal, grinding smooth and then adding additional passes.

For what it might be worth, both LIRR G5's have Juniata shop dates stamped in their fireboxes, indicating post service shopping in Altoona. Obviously, this would imply a regular "deep down" check and review by PRR.

If NS gets another steam friendly CEO in the future. That would give me some hope that 1218 might see steam again. But even that is a massive stretch

Yes, oil firing is harder on a firebox necessitating the lining of a portion of the firebox with refractory brick. If the flame were to play directly on the steel it would be eaten away in a relatively short time.

Yes, the engine crew very much has to work as a team and more-so with oil. Every notch on the throttle effects the amount of exhaust steam and hence the amount of draft placed on the firebox. A sudden reduction of throttle and draft means a lot less air for combustion possibly resulting in a smoky stack. The smoke is not only a waste of fuel but it contains a lot of soot that will coat the tubes and quickly build up very effective insulation. A sudden, large increase of throttle and draft can actually suck the fire out of the firebox and suddenly the burner/atomizer is spraying raw fuel into a firebox of red hot brick with no flame to consume it. It usually relights off the brick before the fireman can react much with a BOOM!! and flame issuing out the stack, firedoor and ashpan - depending on how much fuel was sprayed in before relight.

The fireman not only has the fuel valve but is controlling the steam pressure to the atomizer which has to vary with the fuel rate and also an air inlet damper that has to change with firing rate and draft.

Having fired both coal & oil I've found I'm just as exhausted at the end of the day with either one but there is one fundamental difference. Coal is physically tired. Oil is mentally tired..............mld

Apologies for thread drift and also best wishes to the 1361 crew!

Thank you to Mr. Laepple and to Mr. Deets for their responses to my questions. This is all so very, very interesting and educational.
My apologies again for causing any drift in this thread.

Some roads that ran oil burners, had lights on the stack to show the smoke color; too "rich (black smoke)" was undesirable for obvious reasons; too "Clear" of a stack indicated a reducing flame which damaged the fire-box plates; my oil firing experience was smaller engines; maybe someone can "Chirp" in.

The general rule I heard was that you fired to a 'light gray haze' which was the ideal "compromise" between black smoke and euphemistically-named 'furnace puffs'.

One important consideration in my opinion is flame impingement.