Photos of exploded locomotive boilers

https://www.vintag.es/2020/02/steam-locomotive-boiler-explosion.html

Looks like the Loco threw up

About half the pix appear to be European.

Given the time and the science it was no wonder the Hartford Steam Boiler Insurance Company chose the name "The Locomotive" for its house publication.



Joe in NH

THAT'S what I call a "bad day at work".

Those are probably going to take more than a little fixing.

I was expecting the failures to resemble a cartoon KABLOOIE! explosion; the "tubes extruded through the front boiler sheet" look surprised me.

Time to re-tube

During the heyday of the river steamboats boiler explosions were an all too common occurrence, often while racing another steamboat.

John Garner said:

Those are probably going to take more than a little fixing.

Click to expand...

That'll rub out.

Some of the photos are fairly modern heavy locomotives. In one photo, the "hairpin" superheater elements are laid out and warped like over-cooked spaghetti, while the first course of the boiler and the flues which encased the superheater elements is blown away.

A number of the photos show explosions due to failure of the barrel courses, rather than due to firebox/crownsheet failures. In one photo, the failure ripped the barrel open along a longitudinal seam. This would point to possible weak or inconsistent material (old as the boiler in that photo appears, could have been wrought iron, and maybe a lapped seam).

In another photo of an older locomotive, the barrel course is blown away, and it looks like the dry pipe is the only thing holding the remaining portions of the boiler together.

From my own work with locomotive boiler engineering, the more common failures were crown sheet failures due to low water. Bad water chemistry adds its own failure mechanisms such as grooving and oxygen pitting. Interestingly, when a locomotive boiler is first having steam raised from cold, a phenomenon occurs within it: steam bubbles forming in the water surrounding the firebox tend to circulate and when they contact the cooler "wrapper" (outer shell surrounding the firebox/waterspace), these bubbles condense. In condensing, carbonic acid is produced, and this attacks the sheets of the boiler wrapper (and sometimes the barrel sheets). The result is grooving due to acid attack. This type of attack increases in areas of higher stress, such as along seams. Riveted boilers had a "calking line" along the seams, where the seams were made steam-tight by running a calking chisel along the lapped edges of the sheets. This calking produces a shallow groove in one sheet and upsets the metal against the overlapping sheet's edge. Higher stress area, and a groove to start with, this is often a place where accelerated corrosion or acid attacks occur.

Another interesting phenomenon I've come across is referred to as "halo'ing" by the boilermakers. This happens on the crownsheets. A ring of heavy corrosion/lost of metal surrounds each staybolt on the water-side of many crownsheets. If the sheet is ultrasonically thickness gauged, the UT's will generally show sufficient metal to handle the maximum allowable working pressure. Get inside the boiler when the tubes are removed and take a look across the crown sheet, and there is often this "halo'ing" around each crown stay. To my thinking, crownsheets are the most critical sheet in a locomotive boiler. If a crownsheet fails, it usually collapses into the firebox (either the sheet got red hot from low water/no water covering it, or the halo'ing around the stays finally caused the sheet to "unzip" from the staybolts). When a crownsheet fails, it is usually death to the engine crew. On heavier locomotives, a low water/crownsheet failure would literally blow the boiler right off the engine's frame, tearing it free at the smokebox seam. Locomotive boilers were anchored to the locomotive frame by the "saddle" on the cylinder block. The smokebox course of the boiler was bolted to the saddle with reamed and fitted bolts. When a crownsheet failure occurred, the blast of steam acted downwards into the ashpan, with some blasting out the firehole into the cab. The boiler tended to rocket up off the frame, and tore free at the smokebox seam.

In the 1940's a mallet type locomotive on the Delaware & Hudson RR had a boiler explosion near Central Bridge, NY. Low water was the culprit and the boiler blew right off the frame of that locomotive. The engine crew was killed. I did the boiler calculations for the "Royal Canadian Hudson" a good 20 + years ago. A package of records and drawings for the boiler on that locomotive was sent to me. In the records was the fact that locomotive got a new firebox sometime in the 1930's. The note is somewhat laconic and read: "low water explosion, Caron, Saskatchewan... 5 men killed."

I've been working on the engineering to design repairs to a boiler on a smaller Alco/Cooke works locomotive built in 1920. The boiler shop cut some portions of the inside corners on the firebox tubesheet away and we got a look at the insides of the water leg. More work required. The crownsheet has the classic haloing. The rest of the crownsheet has plenty of steel left. I recommended going to larger diameter crown stays and using full penetration welds from the firebox side to put them in. This will remove the halo'd areas. The inner door sheet had too many thin spots to be repairable, so a new inner door sheet has to be "flanged up". There are a number of other areas to be repaired, and it is nothing I have not seen before on other older boilers. Ultrasonic thickness gauging is a wonderful thing, but it can only do so much. Visual inspections and a knowledge of how locomotive boilers were built as well as various types of corrosive or erosive attack are all needed to properly evaluate a boiler's fitness for service. Having fiberoptic 'scopes to take a look inside mudlegs and other inaccessable areas is also a great advantage the older generations of boilermakers, boiler inspectors and engineers did not have.

Most of the bigger railroads recognized the importance of maintaining proper water chemistry in their locomotive boilers. Water chemistry varies widely with the sources and even with the seasons of the year. The bigger railroads had water chemistry labs, and took water samples for analysis, then formulated the chemical treatment. Some of the later heavy steam locomotives actually had instrumentation to detect foaming (due to water chemistry) and pans within the boiler to try to capture the foam for blow-down.

Two boiler explosions in more recent times in the USA come to mind with this thread. One was at Gettysburg, PA, and was a low-water explosion on a locomotive boiler. The root causes were a lack of consistent maintenance, lack of water treatment, and gauge cocks (supplying water to the level glass in the cab) were clogged shut with "mud" from the boiler. The gauge glass had a trapped volume of water in it, so gave the false reading that the boiler had a safe water level. Had anyone properly blown that glass down, they would have known immediately that the glass was not connected to the boiler due to the clogged gauge cocks. It cost two men their lives. One survived for some years but had many reconstructive surgeries, talked with an electronic voice box, and eventually died of the long term effects of his injuries. The other boiler explosion was a locomotive type boiler on a traction engine, at Medina, Ohio. It was a case of people having a false sense of security since the boiler had passed a hydrostatic pressure test. When the traction engine was started in motion to be moved on the fairgrounds, the boiler blew up. Low water on the crownsheet due to a slight gradient that the traction engine was travelling onto, and a number of other causes including inaccurate pressure gauge and (possibly) a faulty safety valve. That explosion killed a few people.

I enjoy doing the engineering on the steam locomotive boilers, and each time I get into another boiler job, I realize how little I know and how much more there is to learn. When I evaluate a locomotive boiler, I run a "full set of numbers" on it, calculating the minimum required thicknesses of the different parts for a given maximum allowable working pressure with a minimum factor of safety of 4 on the older boilers. On new work, such as firebox replacements, I use a minimum factor of safety of 5. A set of calculations on a basic locomotive boiler (no superheaters, no combustion chamber) will typically run about 120 pages of hand-written calculations. These accompany the "Form 4" (boiler registration document) and the "Form 19's" (boiler repair or alteration reports) and are sent to the US Federal RR Administration for review/approval. The calculations are based on a current set of ultrasonic thickness gauge readings as well as as-found measurements and inspections. Measuring brace rod diameters, getting inside the boiler with a slag pick and banging away at any suspect areas are all part of the process.

I often use a combination of riveting and flanging as well as welding to repair or alter the older boilers. It's a kind of engineering that I enjoy doing, and I do it in the old ways, no computer software, no CAD, just get the drawings and "as found measurements", get the ASME boiler codes and maybe a stress analysis textbook, and a pad of graph paper and a calculator and go to it. I mentally put myself into the boiler, starting with the front tubesheet and work my way back through the boiler, evaluating each sheet, brace, stays, seams, and all else. Detail sketches accompany my calculations, and I "show all units", whether pounds per square inch, inches, feet, types of stresses (tensile, shear, crushing), and all my figures are neat and legible. Each locomotive boiler I've done engineering on has its drawings and calculations on file in my house. Rolls of drawings and ring-binders of calculations and folded up drawings and submittals in file folders all have accumulated over the years. For variety, I've also run calculations on Scotch Marine Boilers, Horizontal Return Tube (HRT) boilers, and Vertical Firetube Boilers (VFT), along with a number of compressed air receiver tanks. I am an old-time engineer and working on boiler engineering suits me fine. Proper evaluation, proper engineering, and properly done work are part of the puzzle. Operators of boilers have to be on top of their game with water chemistry as well as operating and firing practices. As an engineer, I can only do so much, but once a boiler is in service, the rest depends on the people entrusted with its maintenance and operation.

All too often, on the railroads, low water explosions resulted from either injectors failing to "pick up", or a fireman not realizing that an injector, instead of "picking up" was putting the water on the ground via the injector overflow. Sometimes, a crew would be low on water and would gamble on making it to the next location where there was a water tower or other means of getting water in the tender. Towermen or men working along the line would hear the low water whistle (an alarm in the later/heavier engine cabs) shrieking as the engine and train went past. Sometimes the crew made it and took on water, and many times they didn't and there was a classic low water explosion. Being out on the mainline with a locomotive and train and realizing there was insufficient water in the tender tank to keep the boiler water at a safe level if the locomotive was working had to have been the worst imaginable feeling. The alternative was to foul the mainline with the train (setting out fusees and torpedoes) and cut off the engine and run it light for water was something no crew wanted to do. No radio communication in those days, so a crew was on their own once out on the road. If a tender had next to no water in its tank and there was a heavy train behind the engine, the only safe alternative would have been to stop right there, cut off the engine and move it light (assuming a water source was in reasonably close distance), take on water and get back to move the train. This meant placing fusees (flares) and torpedoes (explosive warning devices fastened to the rails) and having brakemen or flagmen sent out to flag trains coming along that same track. Most crews took the gamble and made a run with the train for the next place to take on water. Most made it and survived, but plenty didn't, hence some of the photos posted here.

Another nice chapter for Joe's book, thanks again for taking the time to type all that.

Could you please indicate what kinds of pressures and temps these ran at ?

Doug:

Thanks for the compliment. As for temperatures and pressures:

The older locomotives built in the 1850's-1900 used saturated steam. By the later 1800's, 100 psi was a common working steam pressure, and by the 1890's, 150 psi was fairly common. By 1900, 200 psi was the common boiler pressure in many locomotives, still saturated steam. Sometime in the 'teens into the 1920's, superheating was introduced on US Steam locomotives. This raised steam temperatures to around 600 degrees F, but pressures remained around 200 psi.

By the later 1920's heavier locomotives were carrying a bit more than 200 psi steam pressure, superheated. By the late 1920's when the "superpower" era really got going, pressures climbed to as high as 275 psig.

I read the investigation report of a boiler explosion on the C & O in 1953. Interesting reading. The locomotive was a heavy engine, carrying something like 275 psi and superheated. it had a boiler explosion that killed the crew and blasted the boiler right off the frame (tearing away at the smokebox seam). Bits an pieces of the locomotive were all over the countryside. The federal inspectors gathered all the pieces they could find, particularly the level glasses, try cocks, injectors, and feed pumps (the locomotive had a hot water feed pump driven by a steam turbine, and a cold water feed pump which was a reciprocating pump). They could not find the pressure gauge, but did find the safety valves and what was left of the firebox, particularly the crownsheet.

The inspectors got a sister engine to the one which blew up, and mounted the safety valves from the engine which had exploded on the un-damaged sister's boiler. Safeties opened as they should have, so over pressurization of the boiler was ruled out. The injectors were damaged by the explosion, but enough remained to put back together with undamaged parts and also try on the sister locomotive's boiler. The injectors were found to put water into the boiler at an acceptable delivery rate.

The feed pumps were too badly damaged to reassemble and try, but enough parts remained to establish that they were in working order at the time of the explosion.
There had been reports by locomotive engineers that the turbo feed pump had been giving trouble, and machinist's repair orders and repair reports were all on record.

The crownsheet had been made integral with the partial side sheets of the firebox, and had pulled off of something like 1600 staybolts, and the steel was "burned blue". Clearly this was a low water explosion. The level glass was too damaged to connect to the sister boiler, but inspection of what was left of it as well as the gauge cocks showed it was not clogged and should have been reading correctly.

The steam pressure gauge, noted as a "6 inch Ashcroft double face gauge" was missing, never recovered, so no way of knowing if it were reading correctly. The inspectors listed every piece of equipment on that engine, including the "Franklin Railway Supply air operated 'Butterfly' firedoors", size/type/model of the injectors, and on it went. They did recover the feedwater check valves and feed water diffuser pipes from within the boiler- also found to be in sound operating condition.

The run the locomotive had been on and weight of the freight train it pulled was noted, as well as stops where water (and sometimes coal) were taken on. It sounded like the tender had sufficient water, injectors were working (2 injectors as well as 2 feed pumps), gauge glass working, safety valves correctly set and opening and maintaining correct pressure differential before closing... with a burned crown sheet that pulled free of the staybolts, it was clearly a low water explosion. The inspectors had done a thorough job of going over the wreckage, and from the sounds of it, human error was the most likely cause of the explosion.

Getting back to boiler pressure and steam temperatures: in the later years of steam locomotives, the railroads were trying to pull more tonnage with single locomotives that fit into a given envelope. The result was experiments with water tube fireboxes/firetube barrels (B & O RR) and with similar hybrid boiler designs were tried on various railroads. The Delaware and Hudson RR had a president named Lenor Loree. Loree was a mechanical engineer, and he was always trying to increase tonnage and speed of the D & H locomotives. He had some radical locomotive trial designs built, some of which carried 400 psi superheated steam in the boilers. These engines were failures. Another set of experiments was done to use nickel alloy steels for the boilers in order to increase working pressures without undue weight increases. This was another set of failures due to cracking of some of the sheets in service, no explosions though.

For the most part, 200 psi and 600 degree (approximate) superheated steam was used on US locomotives from the 'teens to the end of steam on the railroads. Heavier mainline engines or 'hogs' used as helper engines on heavy freight service ran higher boiler pressures. In Germany, a mechanical engineer named Schmidt is given credit for introducing superheaters, particularly on steam locomotives. Schmidt was known as "supeheat Schmidt", and supposedly, this appears on his gravestone.

The US lagged behind Europe as far as adopting superheating on the locomotives. We have an ex Lake Superior and Ishpeming RR 2-8-0 locomotive sitting in pieces (never entrust steam locomotives to some museum types, and then the NIMBY crowd who wanted their rail trail put the stop to a restoration shop for that locomotive).
The 2-8-0 is a "consolidation" type locomotive, built originally in 1910 at the Pittsburgh works of the American Locomotive Company. It was delivered to the LS & I as a saturated steam engine with slide valves. The saving grace was that it was ordered with "outside Walschaert's valve gear" rather than more usual Stephenson's Link Motion located inside the frames as was used on saturated/slide valve locos. In the 1920's, over a winter when the iron mines were shut down, the LS & I converted this locomotive to a superheated engine. Alco supplied a new cylinder block with piston valves, a new front flue sheet with openings for larger superheater flues, superheater (hairpin elements to go in those larger flues), new firebox with "Nicholson Thermic Syphons" to increase circulation and heating surface.

In 1976, on a powerplant construction project in Marquette, MI, I got to work on that locomotive and fire it when it was in steam on a tourist railroad. I also got to meet the boilermaker's son (who ran the L S & I airbrake shop) and he introduced me to his father, the master boilermaker who was on the job of converting that engine from saturated to superheated steam. The conversion, while not changing the overall dimensions of the locomotive, increased drawbar pull and resulting tonnage it could move by a wide margin. That engine carried 200 psi steam, and the estimated superheat temperature was 600 degrees F.

I was fortunate to come into my introduction to steam locomotives when men who had "come up in steam" were still active, some working on diesels, some working tourist trains in retirement. I fired for a locomotive engineer who started on the railroad in 1915, and I worked with a retired Chicago and Northwestern RR boilermaker foreman. These men had plenty to teach if they liked you, and if they didn't, they could make life miserable. I was fortunate in that I never had a problem with these men, and they were only too happy to teach me. I never "wore my degree on my sleeve", but they would figure out quickly enough that I knew a bit more than many people about boilers and machinery, and also was able to crawl into a firebox and work without having to be wet-nursed. That whole breed is long dead and gone now. I was fortunate to have a little time with them. There are some fine boilermakers who came up under these same men, and these boilermakers are sharp and know firetube boiler work and riveting and all else that goes with locomotive boiler work. I enjoy working with these boilermakers, and they know ASME code, US Federal RR Administration rules for locomotive boilers, and National Board codes and rules for boiler repairs. We never take the old view of "they don't build 'em like they used to" or "back then, everything was overdesigned, so the boiler will be OK..." It is inspections, UT readings, and "hard numbers" to back up any boiler that is either is up to having its certification renewed, or is being put back into steam after years of sitting around on static display or similar.

I run into men who have shipped in the Merchant Marine or come out of steam powerplants, and when I tell them the firetube boilers carry 200 psi steam, many of these guys will dismiss it as "low pressure". I waste no time in telling them otherwise. The pictures in this thread of the exploded boilers tell the tale of what that "low pressure" can do.

I read the report of the Ohio Fair Case engine explosion....two investigations ...the second one done by a steam expert ,not cops.........It showed the engine was being run on approx 30lbs pressure because of the condition of the crownsheet.....stays rusted off and welded in ,crown sheet something like 1/8"thick in places ....expert estimated pressure at 50psi when it blew...seems two cops decided to ticket the driver for iron wheels ,while they distracted his attention,pressure rose ,and crownsheet tore out,down thru the grate ....Surprising the cops survived ,as they were walking back to the car.

I run into men who have shipped in the Merchant Marine or come out of steam powerplants, and when I tell them the firetube boilers carry 200 psi steam, many of these guys will dismiss it as "low pressure". I waste no time in telling them otherwise. The pictures in this thread of the exploded boilers tell the tale of what that "low pressure" can do.

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My steam career peaked out at Canal Electric Unit No. 1 which was a 1960s attempt at greater thermal efficiency. The plant had some (for then) remarkable adaptations including a four cylinder turbine (VHP, HP, IP, 2x LP) double reheat, main steam pressure 3450psi and 1000F, and a "once through" boiler.

Start of the unit was accomplished by bypassing the turbine entirely and until about 30 percent boiler load, everything was blown down to the condenser. The unit was designed to be "base loaded" and a typical startup to full load was minimum 14 hours. For its time it was very efficient and won the Electric Light & Power Magazine award for most efficient fossil fired plant in the nation a couple of times. (The Liars List as the award was affectionately known in the industry.)

As once-through at supercritical steam, there was no established water line or gauge glass on the boiler. As the Chief Engineer said to me "pump for pressure - fire for temperature." The plant burned No. 6 oil, now converted to natural gas. At its pre-precipitator peak, it would make electricity at about 7900btu/kwhr, about 43 percent thermal efficiency. Addition of TWO precipitators over the years reduced this below 40 percent.

And the Tandem Compound Westinghouse Turbine incorporated "Chromarc" pipe which was thought an advancement in piping cost savings and material efficiency, until the pipe blew off one night, went through the turbine hall roof, and was found alongside the railroad tracks paralleling the Cape Cod Canal about 3/4 mile away.

Funny though - natural gas combined cycle units now CAN have a thermal efficiency in the high 50s - what technology and ingeniousness can offer. The 800MW combined cycle unit in Portsmouth, NH can do this and be at full load in 15 minutes. With a plant staff of 20 people!

My low in steam pressure was the trash burner in Lawrence, MA which operated at 800psi and 725F. Single flow Hitachi turbine with one cylinder. Two gravity fed grate style boilers. Efficiency was NOT their objective, rather to get rid of and consolidate the trash. Trash burning reduces disposal volume by 90 percent - but what to do with the 10 percent remaining? The plant still operates and currently they're building "trash mountain" in a horseshoe shape around the plant. When the horseshoe is at maximum, the plant will be dismantled and moved nearby, and the center of the horseshoe filled to make a true conical "trash mountain" and probably the highest land point within 150 miles.

And then the trash mountain and its resulted percolated rain water will be captured and treated for eons to come. And people think nuclear waste is a continuing problem?

And - in the plant management wisdom, the boilers were operated with a tube leak, the managers hoping to "squeak it through" to the next planned outage - as long as the water treatment system could keep up with it. I was on the Control Board the night the water level of that boiler disappeared, the water wall blew out of the boiler and bent a 12x12 main carrying post of the boiler building. After recovering the plant at half-load I was instructed to "Make a call on the PA to have any survivors come to the Control Room for a head-count." The boiler and personnel risk must have been worth the 12 week outage to repair the boiler - and truck all that unburned trash to the nearest sister plant in New Jersey. I didn't own stock in the company. Fortunately nobody was hurt

Life of a power plant operator - at least while they're still alive: 90 percent sheer boredom followed by 10 percent sheer terror.

And: "Always eat dessert first as you never know what is going to happen."

Joe in NH