Having had to shovel too much snow this month has caused a question to pop into my mind.
I know most steam engine built from the mid-twenties on all were equipped with mechanical stokers to keep the fire at maximum steaming capacity.
At what point, relatively speaking, was it determined that hand firing was insufficient to keep a proper fire. 2 tons a hour, 4 tons a hour, 6 tons a hour???? Or was the tipping factor the size of the firebox and a man's inability to properly distribute the coal where it was needed in the larger fireboxes?
Never too old to have a happy childhood!
I saw a comment from a British source that the limit seemed to be about 2,000 HP. Exactly why was not reported.
I also saw a statement that it took two men shoveling constantly to keep a Y5 rolling after a stoker failure on the road. I presume that involved some very conservative throttle and cutoff work by the engineer, not full normal steam production.
Chuck
The first Pennsy I1s 2-10-0 was hand fired. It took a couple of days on the test plant to find out it needed a stoker. The old heads thought it was another gadget that needed more maintenance. Some of the K4s and other locos went to the scrap yard with out stokers. On some runs they had 2 firemen to handle the chore. It was the size of the box and the run that determined how many firemen were on board a stoker less loco.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
I'd have rather preferred to fire an oil-burner with a mini-throttle controlling the fuel rate, thus saving the back, spending more attention to the boiler's water level and steam pressure and stack exhaust, and watching the scenery, I mean, keeping an eye on the track ahead.
Mark
If I'm not mistaken in what I've read, it was a USRA rule during WWI that required locomotives with a firebox of 80 sq. ft. or larger to have a mechanical stoker.
TG3 LOOK ! LISTEN ! LIVE ! Remember the 3.
Mechanical stokers became common from the WW1 era on, but they weren't universal. Seems bizarre now, but IIRC the first DMIR Yellowstones in the 1940's didn't have stokers!! However the railroad soon learned that even with two firemen, it was physically impossible to shovel coal in fast enough to keep up with the engine's need for coal to burn.
I had read the rule of thumb was for a man to shovel 5000lbs per hour. When that became a problem due to larger locomotives, etc, then stokers came about. I am sure if a man could not keep up with the required standard his employment then became an issue. The ICC later made into law that any passenger locomotive with 80 ton weight on drivers, or freight locomotives with 87 1/2 ton weight on drivers and built after 15 April 1939 was required to have a stoker unless a reason approved for exemption.
I don't know if this was a required alteration on locomotives built prior to that time but met weight requirements when the mandatory rebuild and inspection was due. Maybe someone can advise.
Coal used in stoker equipped locomotives required a smaller chunks versus hand fired ones, so the crew had to make sure they were using the proper coaling dock chute when refilling.
IIRC, the ICC put out a rule that any locomotive with 160,000# weight on drivers had to have a mechanical stoker. Exactly when that was done, or how long the railroads were allowed to run locos that had not been (or could not be) retrofitted, I don't know.
wjstix Mechanical stokers became common from the WW1 era on, but they weren't universal. Seems bizarre now, but IIRC the first DMIR Yellowstones in the 1940's didn't have stokers!! However the railroad soon learned that even with two firemen, it was physically impossible to shovel coal in fast enough to keep up with the engine's need for coal to burn.
The M3 and M4's always had stokers from the first day they were delivered.
CZ
I had a old retired UP engineer tell me he had the stoker go out on a west bound Big Boy east of Evanston and they hand fired it to Ogden. Some where about 80+ miles. It was down hill except for the 10 miles from Evanston to Wahsatch. At Echo the half way point he rounded the curve and told the fireman to take his seat. He said he lost about 20 pounds mostly in sweat before they got to the Ogden yards. The east bound is a 1.14 % grade. West bound is 1.74 % coming off Whsatch which is 6799' elevation and Ogden is 4298 for a 2501 change in 65 miles or 38.47 per mile. They never would have tried it up hill.
The determining factor is not the horsepower output of the locomotive, but the size of the firebox grate, the thermal and mechanical efficiency of the locomotive, and the use to which the locomotive was applied. In most of the world, the limit for handfiring was considered to be about 50 square feet of grate area. This was the limit used by both the USRA and the British when they designed their standard steam locomotives after the war.
For the record, the French built handfired four-cylinder compound 4-8-2's that produced over 3000 hp (PLM 241C1).
David
Glad to see nobody referred to a stoker as "automatic". I did that ONCE with my Dad who was an engineer on steam towboats in the the Upper Ohio/Monongahela River Pool. Never did that again.
ChuckAllen, TX
In 1973 a test conducted in New South Wales, Australia with a 460 ton load on a 1% grade by a 38 class PACIFIC type locomotive averaging 29mph required 1600 indicated horse power (IHP). Taking a figure of 2.7lbs per IHP this was 4300lb per hour or 150lbs per mile. the firebox had a grate area of 47sq ft. This was the largest hand fired firebox in New South Wales.
The conclusion was: for the largest Australian hand fired locomotives having grate areas 42 to 50 sq ft, the average maximum sustained firing rate for a single fireman for periods of 60 to 75 minutes appears to be about 4200lb per hour, or seven 10lb scoopfuls of coal per minute.
flare40xFor the record, the French built handfired four-cylinder compound 4-8-2's that produced over 3000 hp (PLM 241C1). David
But like you said: that is a compound engine and therefore much more different / efficient in the way it used steam
Paul
cefinkjr Glad to see nobody referred to a stoker as "automatic". I did that ONCE with my Dad who was an engineer on steam towboats in the the Upper Ohio/Monongahela River Pool. Never did that again.
Also, on p. 447: "No locomotive stoker is automatic. The fireman with any successful stoker must regulate its firing and have absolute control of distribution to the firebox in order to take care of the fire's varying needs."
Now, as to what engines should have stokers, the author states, on p. 448: "Any locomotive which cannot be fired to maximum capacity by hand over an extended period of time is a proper engine for stoker application. In temperate climates where grades are not excessive this includes all engines of 50,000 pounds tractive effort and over, both freight and passenger. In regions subject to excessive heat and extremely heavy service, stokers have been found necessary on engines of 35,000 pounds tractive effort."
Johnny
Deggesty Ah, yes. From The Locomotive Up to Date, 1922 Edition, p. 445: "The term automatic, however, is perhaps misleading, for it must be remembered that the mechanical stoker does not dispense with the fireman. He must attend to the firing of the stoker, and must occasionally make use of the shovel, and the rake as well." Also, on p. 447: "No locomotive stoker is automatic. The fireman with any successful stoker must regulate its firing and have absolute control of distribution to the firebox in order to take care of the fire's varying needs."
Ah, yes. From The Locomotive Up to Date, 1922 Edition, p. 445: "The term automatic, however, is perhaps misleading, for it must be remembered that the mechanical stoker does not dispense with the fireman. He must attend to the firing of the stoker, and must occasionally make use of the shovel, and the rake as well."
I would agree with the automatic stoker statement except for the N&W M2 Automatic locomotive. Two were built to eliminate the fireman in switcher service and were number 1100 and 1112. They ran for four years but no more were built since the N&W purchased the C&O 0-8-0's in the 1950. From the article I have in a N&W book, it had automatic boiler pressure controls and safety devices to minimize the need for human attention. From what I know, this locomotive could be used for switching service without a fireman. I am not sure of the technology they used for operating the stoker, but it is listed as a low-speed stoker and turbine driven draft fan to increase thermal efficiency.
It sounds like the experiment worked to some degree, but it was probably hard to maintain.
CAZEPHYR I would agree with the automatic stoker statement except for the N&W M2 Automatic locomotive. Two were built to eliminate the fireman in switcher service and were number 1100 and 1112. They ran for four years but no more were built since the N&W purchased the C&O 0-8-0's in the 1950. From the article I have in a N&W book, it had automatic boiler pressure controls and safety devices to minimize the need for human attention. From what I know, this locomotive could be used for switching service without a fireman. I am not sure of the technology they used for operating the stoker, but it is listed as a low-speed stoker and turbine driven draft fan to increase thermal efficiency. It sounds like the experiment worked to some degree, but it was probably hard to maintain. CZ
Obviously, the N&W design engineers were better than the design engineers used by Hanna, Standard, Duplex, Crawford. and Street (the brands mentioned in The Locomotive Up to Date). I am sure that they were endeavoring not to simply reduce the amount of coal shoveled by the fireman (the advantage of the above-named stokers) but to reduce the man-hours spent in switching.
As I recall, the N&W regularly used one of the former C&O switch engines to work the passenger trains in Bristol. I have a memory, though, of seeing one of the unreworked 4-8-0's switching the passenger cars on one occasion.
Deggesty As I recall, the N&W regularly used one of the former C&O switch engines to work the passenger trains in Bristol. I have a memory, though, of seeing one of the unreworked 4-8-0's switching the passenger cars on one occasion.
I thought that all the N&W's 4-8-0s were "hand bombers", and remained so because they were built before the rule about mechanical stokers went into effect. I seem to remember hearing the engines were called "outlaws" as a result.
Dan
Our community is FREE to join. To participate you must either login or register for an account.