Double Firebox Doors

[MidlandMike]

In another thread:

https://cs.trains.com/mrr/f/88/t/292041.aspx

There was a picture of the backhead of a NYC ten-wheeler with what looks like 2 firebox doors.  What is the reason for 2 doors, and was it common?

[tstage]

Mike,

When I read the title of your thread I was wondering if it came from one of my postings today - LOL.

I've only seen single firebox doors - even on large locomotives.  Maybe the design of the firebox for the 4-6-0s required two doors so that shoveling could reach all parts of the firebox that would be difficult with only a single door?  I will also be interested in the answer...

Tom

P.S. I made your link clickable.

[dehusman]

The double firebox doors was an intermediate step as engines became larger and before stokers were widely adopted.

As engines increased in size and power, and as fireboxes became corresponding larger, the engines often required two fireman to keep up with fueling the engine, plus with a larger firebox, reach the entire grate through one door became tough.  Therefore engines were equipped with two firebox doors.  

As stokers became common, they could easily supply all the coal for the biggest fireboxes, so the need for two firebox doors went away.

[gmpullman]

I'm just rambling here and tossing a few ideas out before actually trying to find a documented treatise.

Firebox development took a pretty big leap in the mid-to late 1880s. Prior to this the fireboxes were pretty much restricted to the area between the drivers. Locomotive designers were trying to get a wider firebox in order to increase the heat, thus horsepower.

Fireboxes wider than the frame required smaller drivers or a reliable trailing truck in order to support and balance the weight of the firebox "hanging" behind the last driver.

The Anthracite roads were quick to develop wider fireboxes (Wooten patent) designed to afford the larger grate areas to burn the slower-combusting Anthracite coal. Most of us are familiar with the Camelbacks where the firebox width precluded the location of the cab.

Possibly, too, the slower burning Anthracite was better fired at a slower rate so the designers anticipated the fireman would use a "left-right" firing sequence where each half of the fire could burn in alternate progression.

In my estimation the dual firedoors weren't so much a necessity of firing or getting the coal into the firebox as it was to facilitate the cleaning and removal of clinkers out of the firebox. 

I believe, too, that there might have been a bit of a misconception that the initial designs "required" such a wide firebox would certainly require two openings. After a while in practice it was found to be unnecessary.

Firing a large grate with only a central firedoor can be done with just a bit of finesse and, of course, on-the-job experience. With a quick manipulation of the "scoop" and just the right twist of the wrist a capable fireman can easily hit the inside back corners on even the widest modern fireboxes. The Big Boy's being eight feet wide.

Regards, Ed

["JaBear"]

For a locomotive class that was first built in 1906 (?), and then lasted, with a number of modifications, to the NYCs last days of steam, there doesn’t, unless I’m not “asking” the right question, appear to be not much on-line information on these locomotives.

 

However, it would appear that there was only two crew, engineer and fireman, but to my mind, with firebox grate area of 55 sq. ft, two doors would be rather handy.

 

The NZR Ja class of which I’m most familiar had a firebox area of 39 sq. ft, and whilst cleaning Ja1267, which we had in storage, I often wondered how on earth a fireman managed to maintain a good steam raising fire whilst standing on a moving deck?

 

Listening to the senior drivers, who had gone through the NZR system of starting as locomotive cleaners then progressing up to fireman, then driver, I came to the conclusion that firing a steam locomotive was an art. From what I heard, while each class had a method for efficient firing; for instance, the instructions given to a tyro fireman on a NZR Ab 4-6-2, grate area of 33 sq. ft, was “Grab the shovel, 2 left back, 2 left front, same on the right, 1 down the centre, and 1 up the back”, and besides individual locomotives could have their own idiosyncrasies.

 

The author then described how he missed with the first shovel full, and by the end of the sequence, because he was far too slow had managed to start his left trouser leg smouldering, only to be told “It also needs water you know.”

 

I guess the point I’m, long windily, trying to make, is that to place the coal where required in the NYCF-12s 55 sq. ft grate, especially on the sides and corners would be easier, (???!!!) with two firebox doors. (Even in my younger days, I certainly wouldn’t like to try to arm wrestle a fireman!!!)

 

BTW, I believe that the “Engineers, Fireman’s, and Cleaners Association” regarded the NZR Ka class 47.7 sq. ft grate about the maximum for hand firing.

 

A very nice and interesting acquisition, Tom.

Cheers, the Bear.

[dehusman]

BTW, I believe that the “Engineers, Fireman’s, and Cleaners Association” regarded the NZR Ka class 47.7 sq. ft grate about the maximum for hand firing.

The majority of P&R steamers from the 1880's, 1890's had fireboxes upwards of 70-80 sq ft.  By the end of steam the RDG fireboxes were 9x12 or 108 sq ft.

[dehusman]

gmpullman

Most of us are familiar with the Camelbacks where the firebox width precluded the location of the cab.

That is not the reason the camelback cab is ahead of the boiler.  Actually width is what stopped camelbacks from being built.

Camelbacks were created to reduce the height of the engine.  Originally Wooten firebox engines had the cab on top of the firebox in the rear.  Which put the cab up high.  While on a demonstration run in Italy the engineer and fireman moved the cab from the top of the firebox and put it on the running boards to lower the height of the engine so it would fit through Italian tunnels, thus creating the first "camelback".  When the engine returned here the P&R copied the design so they could build bigger fireboxes and bigger engines without enlarging tunnels.

After about 30 years the boiler diameters became so large that threre really wasn't room for the engineer to be on the running boad, they went back to end cab designs.  The camelback was never actually banned by the ICC, it just became obsolete.

Since there were hundreds, if not thousands of Wooten firebox engines built with end cabs (pretty much all Wooten firebox engines after about 1915), the "firebox is too wide for an end cab" reason is inaccurate.

[wrench567]

Without seeing a drawing of the firebox, I can see no reason why two smaller doors instead of one larger central opening. Could there be some sort of crown sheet support in the center or even piping from the crown sheet to below the firebox like a feed water or super heat piping?

 The PRR considered stokers as fancy unnecessary gadgets and elected to build their best locomotives without them. The K4s and I1s had nearly 70 square feet of grate. Many eventually reciever stokers but a great amount of them went to the scrappers still hand fired. It was not uncommon to assign two firemen to a job or even enlist the help from the front brakeman. You can't expect one man to shovel 20 tons of coal, look out ahead, and maintain water. Hence the old saying " There were no fat firemen on the Pennsy." It wasn't until WW2 and a shortage of experienced men that stokers were looked at in the non experimental locomotives such as the T1, S1, and S2. The two K5s pacifics reciever stokers in 1937. I believe there was an agreement between the railroad and the fireman's union on grate size or tonnage of passenger trains.

  Pete.

[gmpullman]

dehusman

That is not the reason the camelback cab is ahead of the boiler.  Actually width is what stopped camelbacks from being built.

I agree that I oversimplified that statement. Should have left it out as it doesn't add anything to the two-door discussion. 

A good portion of chapter two is devoted to the firebox designs of the late 1800s and early 1900s in William L. Withun's book. 

dehusman

Since there were hundreds, if not thousands of Wooten firebox engines built with end cabs (pretty much all Wooten firebox engines after about 1915), the "firebox is too wide for an end cab" reason is inaccurate.

To quote Withun: "On a 4-4-0 or 4-6-0, however, the firebox was immense in relation to the remainder of the boiler. With adjustments to grates and draft, such engines could burn culm or regular anthracite. A more pressing problem was created, though. Now there was no room at the back of the boiler for a cab. The primary difficulty was not the width of the firebox but the extreme rear-end overhang.

No matter. Put the engineer's cab in front of the firebox, astride the boiler. As in Winan's old Camels, the fireman could shovel from a position at the front of the tender."

I didn't intend for the conversation to drift toward the Camelback. Sorry.

wrench567

The PRR considered stokers as fancy unnecessary gadgets and elected to build their best locomotives without them.

The PRR's very own Crawford Stoker was a 1905 design, but, you're right, the PRR was mainly looking at cost effectiveness and firemen at the time were cheaper than the cost of buying and maintaining the stoker.

Regards, Ed

[dehusman]

Withun needs to:

a) Look at a picture of an early Wooten firebox engine, they were all essentially end cab engines.  The original Wooten firebox engines were not built as camelbacks, they didn't start building camelbacks until Eng P&R 412 returned from a demo trip to Europe (and it left the US as an end cab engine and returned as a camelback).

b) Read chapter 8 "The Saga of Engine 412" of James Holton's "The Reading Railroad: History of a Coal Age Empire, Vol 1" in which he describes in great detail how the first camelback was built in France for use in Italy.

c) Explain how some engines were built with Wooten fireboxes as camelbacks and then later, end cab engines were built with a virtually identical firebox.  If there was no room at the back of the Wooten firebox for a cab how did they build engines with a cab at the back of a Wooten firebox?

The Wooten firebox being too wide and camelbacks being banned are kinda "urban legends" the same as the ICC banning billboard reefers.   

 

[ndbprr]

I have been under the impression that the  Wooten firebox was used on Reading engines so they could burn the anthracite fines. The additional size limited the draft that would blow the fines up the stack otherwise.

[dehusman]

It was originally designed to burn "culm" which are fines and waste from anthracite mines.  In practice, the RDG tended to burn a mix of bitumonous and anthracite.

[Overmod]

A major issue with culm -- probably far more significant than the fines content -- was the broken and weathered slate and other dirt content, which might have been addressed with rocking grates, but there are reasons those are difficult (at best!) to use with the fuel.  There are some discussions of its use as an 'economy' fuel in Sinclair's history of the locomotive engine.

What I think you're looking at on the NYC engine is a combination of an early wide firebox and an extremely steep grate angle.  With the poor riding at the rear of the 4-6-0 chassis, you'd have an evil time trying to maintain a heel at the back of the grate with just one door.

Something I'd like to see from Ed -- as I recall, some of these 4-6-0s were oil-fired for use in the Adirondacks.  I have not seen their firebox construction or 'special' backhead arrangements.  (The double-firedoor locomotive would not be oil-fired because the doors have treadles...)

[BEAUSABRE]

wrench567

 The PRR considered stokers as fancy unnecessary gadgets

When the unions were negotiating with the D&H (in the Twenties?) the firemen requested stokers. President Lenore Loree replied, "You've got the best stokers money can buy, Red Edges!" Which was a brand of shovel. 

AS far as the application of stokers, I thought there was an ICC edict requiring stokers on all locomotives above a certain weight on drivers. I think the Depression and the War prevented the railroads from completing the process by the ICC's end date

[PM Railfan]

I wonder if anyone has given consideration to the added access 2 doors provide for such a 'wide' firebox during the maintenance cycles when shes in the shed, dry and cold. Not really a design feature in as much as is an unexpected benefit, i bet.

 

PMR

 

[wrench567]

BEAUSABRE

 

 

wrench567

 The PRR considered stokers as fancy unnecessary gadgets

 

 

When the unions were negotiating with the D&H (in the Twenties?) the firemen requested stokers. President Lenore Loree replied, "You've got the best stokers money can buy, Red Edges!" Which was a brand of shovel. 

AS far as the application of stokers, I thought there was an ICC edict requiring stokers on all locomotives above a certain weight on drivers. I think the Depression and the War prevented the railroads from completing the process by the ICC's end date

 

  I don't think it was the weight on driver's in as much as area of grate and tonnage of coal used/ carried.

   Pete.

[gmpullman]

INTERSTATE COMMERCE COMMISSION

BUREAU OF

LOCOMOTIVE INSPECTION

LOCOMOTIVE INSPECTION LAW AS AMENDED

MARCH 4, 1915, JUNE 7, 1924, APRIL 22, 1940, AND MAY 27, 1947

WITH RULES AND INSTRUCTIONS ESTABLISHED IN CONFORMITY THEREWITH

ALSO SAFETY APPLIANCE STANDARDS FOR STEAM LOCOMOTIVES
AS FIXED BY ORDERS OF THE COMMISSION DATED

MARCH 13, 1911, AND DECEMBER 11, 1943

(c) Mechanical stokers.-All coal-burning steam locomotives which weigh on driving wheels 160,000 pounds or more to be used in fast or heavy passenger service, built on or after April 15, 1939, shall be equipped with a suitable type of mechanical stoker, and all coal-burning steam locomotives which weigh on driving wheels 175,000 pounds or more to be used in fast or heavy freight service, built on or after April 15, 1939, shall be equipped with a suitable type of mechanical stoker and such stokers shall be properly maintained.

Each railroad which operates coal-burning locomotives of the above weights shall file with the director of the Bureau of  Locomotive Inspection as of April 15, 1939, a list of all hand-fired coal-burning locomotives of the above weights built prior to April 15, 1939, which will in the future be used in fast or heavy service on its line, and mechanical stokers will be applied each 12-month period to not less than 20 per cent of the total number so listed, and all locomotives included in said list shall be so equipped before April 15, 1944, and such stokers shall be properly maintained. * 119. Cylinder cocks.--Necessary cylinder cocks, opera tive from cab of locomotive, shall be provided and maintained in a safe and suitable condition for service.

*NOTE.-Order No. 24049, dated March 18, 1939, provides: “That for the present rule 118(c) shall not apply to deckless locomotives equipped with two cabs, which are generally known as the 'Mother Hubbard type,' built prior to April 15, 1939."

[BEAUSABRE]

gmpullman, Thank you!

[gmpullman]

BEAUSABRE

Thank you!

Glad it helped.

Tom might want to reference the NYC diagram sheets for his F-12e. I have reproduced them below. I'm not sure which tender his model has.

NYC_Diagram_F-class by Edmund, on Flickr

NYC_Diagram_F-12e-5K tender by Edmund, on Flickr

NYC_Diagram_F-12e by Edmund, on Flickr

The NYC roster books make no mention of which specific locomotives were converted to oil burners. Did they consider it a temporary application? I know there were twenty K-11s adapted to oil fuel but my information on other classes is sparse.

Of course the "Rexall" Mohawk L-2c 2873 was temporarily outfitted with oil burners for its U.S. Tour in 1936.

I still regard the idea behind the twin firedoors was to facilitate cleaning the fire and breaking up and removing clinkers. The designers and builders probably came to the conclusion that it wasn't worth the effort.

Considerable design work went into forming and joining the inner and outer sheets at the fire door opening. Stress at this seam was a consideration and apparently some designs were prone to cracking and leaking. A locomotive I'm familiar with features a bit of a "bulge" on the inside sheet around the firedoor opening which forms a bit of a reverse curve which would allow expansion and contraction of the inner sheet as opposed to having a sharper right-angle.

The only information I have is "Syracuse" penciled on the back of this print.

NYC_Consolidation by Edmund, on Flickr

Sure wish photographers (or whomever does the darkroom work) would record a little more info on prints.

If I were the engineer in charge of this engine, the deck certainly wouldn't be scattered with all that loose coal! Doesn't take much to twist an ankle. Add a little rain water and you have a real mess.

Regards, Ed

 

[wrench567]

   I stand corrected. Reading the rule, the railroads had five years to change over each class of locomotive. I wonder what they considered heavy freight service? Pushers and yard humppers might be the reason so many of the PRR decopods didn't receive stokers. I'm not sure how many of the K4s got stokers.

    Pete.

[dehusman]

Let's see, the order was instituted in 1939 and was supposed to be completed by 1944.

Was there anything that happened between 1939 and 1944 affecting the railroad industry and locomotive maintenance schedules that could have delayed or extended the implementation of this order?

[tstage]

gmpullman

Tom might want to reference the NYC diagram sheets for his F-12e. I have reproduced them below. I'm not sure which tender his model has.

Ed,

Thank you for the info.  My brass NYC F-12e 4-6-0 came with the 5K-gal tender.  I knew about the 7.5K tenders.  I didn't realize there was also a 6K, 7K, and 8K tender, as well.

After receiving the locomotive I went through 16 pgs of F-12e (233) photos in the online NYCSHS archive and found five with similar looking 5K-gal tenders.  Two of those - #831 & #833 - are confirmed in your table above.  The other three - #825, #839, and #842 - are stated as having 7K-, 7.5K-, and 7K-gal tenders, respectively.

The 6K-, 7K-, and 7.5K-gal tenders in the 2nd diagram are very destinctive from the 5K-gal tenders in the 1st diagram.  NYC #1238 (ex #825) in Apr '50 appears to be outfitted with a 5K-gal tender:

Over time would larger/smaller tenders be swapped in/swapped out on the F12s - perhaps depending on the duty that they had for a given time frame?  Most tenders generally had the locomotive cab number on the back end so I wouldn't think it would be a temporary situation.

Tom

[PM Railfan]

dehusman

Let's see, the order was instituted in 1939 and was supposed to be completed by 1944.

Was there anything that happened between 1939 and 1944 affecting the railroad industry and locomotive maintenance schedules that could have delayed or extended the implementation of this order?

Im thinking WWII.... maybe?

PMR

[tstage]

Just a slight diversionary question: Is that a small rear headlamp on the end of the tender?

[PM Railfan]

Yep, and two tiny marker lamps too. Thats what im seeing.

 

PMR

 

[gmpullman]

PM Railfan

Yep, and two tiny marker lamps too.

Or just the electrical sockets to plug in the electric marker lamps.

The PRR was a big adopter of the little "cat-eye" markers, the lens IIRC was only 1¼" in diameter. Those would be seen on the backs of passenger cars and some locomotive tenders.

I believe in the case of Tom's model those are Pyle-National sockets where electric markers could be plugged in if needed.

NYC_Tender_1234 by Edmund, on Flickr

The white lamp in the center wasn't so much as a lamp for illuminating the path for the engineer, although it did serve this purpose to a degree, as it was to aid the brakeman or fireman while working around the rear of the tender. I've seen some of these lamps with the fresnel ridges molded in the glass so light would be deflected downward to illuminate the ground around the end of the tender.

Engines assigned to work where longer backup moves were common would be equipped with regular headlight assemblies specifically for the engineer's vision and visibility of the oncoming train at crossings and such.

Some switchers had auxiliary lamps on the front, in addition to the usual headlight, as well.

Cheers, Ed

[Overmod]

PM Railfan

dehusman

Let's see, the order was instituted in 1939 and was supposed to be completed by 1944.

Was there anything that happened between 1939 and 1944 affecting the railroad industry and locomotive maintenance schedules that could have delayed or extended the implementation of this order?

Im thinking WWII.... maybe?

Sometimes Captain Rhetorical Question goes unrecognized when in civilian dress!!! 

Something that may be far more interesting is the front-end stoker development that... I strongly suspect... was timed to coincide with the ICC 'ukase', to be ready for deployment when the mandated applications had to be made.

As some of us already know, a 'preferred' location for oil burners is up at the throat sheet, at the front of the firebox space, with a heavy refractory structure taking the place of a brick arch to enlarge and shape the flame plume in the radiant-uptake section.  "What if..." some inquiring minds thought, "we could arrange a stoker to supply coal in this location?"

You might already be running out of fingers counting the likely showstopping issues with this sort of arrangement, even if you fed it with 2" sized washed passenger gas coal.  And judging by how well the thing has disappeared from view, you'd probably be justified.  I have fragmentary reports at second- or third-hand that indicated B&O, arguably the greatest early adopter of the things, had as many as 74 actually installed on road power, some by... a few months before America's unwilling injection into the War, before railfan photography was treated the same as espionage, and the removal and agreement never to talk about the result seems to have been orchestrated well before the cessation of hostilities.

I'll be interested to see what Ed comes up with to document this; it was mentioned a number of times in the trade press in the late 1930s.  Interestingly, the whole of the B&O Yahoo (now groups.io) Group knew nothing of any substance about the actual machinery B&O utilized...

Had it succeeded, it would have been a well-touted alternative in the Locomotive Cyclopedia for railroads desiring to comply with the new Federal law.  I still find it 

[gmpullman]

Something that may be far more interesting is the front-end stoker development that... I strongly suspect... was timed to coincide with the ICC 'ukase', to be ready for deployment when the mandated applications had to be made.

 

From what I gathered, B&O's Colonel Emerson, in November of 1939, had devised the front-delivery stoker and I believe his ultimate goal was smoke abatement (complete combustion) . After 80 locomotives were fitted with the contraptions it was determined that they were more trouble than necessary.

Overmod

Something I'd like to see from Ed -- as I recall, some of these 4-6-0s were oil-fired for use in the Adirondacks.  I have not seen their firebox construction or 'special' backhead arrangements.

Why not open a separate thread on oil burners? We can then keep this one more focused on double firedoors.

---

 

 

While sorting through drawings and photos of other NYC locomotives of the period I found that the twin-doors were more prevalent on the Railroad than I had previously realised.

NYC_K-3p-backhead by Edmund, on Flickr

The above is a K-3 Pacific of which there were 45 delivered in this order. In addition I found some of the L-2 Mohawks were similarly equipped with two firedoors.

NYC_4-8-2_Backhead by Edmund, on Flickr

There were some 429 L-1 and L-2 classes built. I don't know exactly how many of these may have had the double doors as that was not mentioned in the specifications.

NYC_4-8-2_Elevation by Edmund, on Flickr

The Ks had 75¼" wide fireboxes and the L's were 84½. Not notably "wide" by any stretch. It would seem that for some reason the NYC's Chief Engineer of the day (W.D. Carlton?) determined that two were better than one. Not until reasonably reliable stokers came about that seems to have changed the thinking behind the two roors, at least on the NYC.

NYC_K2_Backhead by Edmund, on Flickr

Regards, Ed

[Overmod]

Remember also that to 'frame' in the double doors requires an enormous amount of additional fabrication by the firebox/boilermaker shop, and it really screws up vertical water circulation and perhaps water-gauge reading if there is any substantial heat uptake by the rear firebox sheet... which is where the flame plume from the arch reverberates.

Just for grins, look up the advent of NYC use of the Butterfly fire door (which may have obviated the need for two doors to build heel or easily access thin spots).  Ed might check with the NYCSHS to see if there are records of two firemen on very fast trains or heavy consists with the early Mohawks... I suspect we will find there were none on a regular basis.

Certainly a stoker with distribution table solves much of other 'reasons' for two doors.  According to Staufer, though, you still needed some hand bombing in the rear corners...

[SeeYou190]

Fellows,

This has been a great thread to read. It is a breath of fresh air to see such informative conversation on these forums again.

While I almost never contribute to the Prototype Information threads, I sure do get a lot of enjoyment from them.

-Kevin