The 1905 DL&W Camelback 4-4-0 at the National Museum of Transportation near St Louis only has a single fire door, so you really can't generalize when discussing these locos.

Intetesting. Thanks, Ron.

RDG 0-4-0 1187/CF&I 4/SRC 4 has one firedoor. The firebox is narrow enough the walkway is level with the cab floor. It's not a big engine but the class was superb at wiggling around street trackage in Reading, Philadelphia and Wilmington.

RDG 0-6-0T 1251 also has one firedoor but is an end cab saddletank engine.

As far as I know CNJ 4-4-2 592 has two firedoors.

Phil Mulligan

Greetings:
Another existing locomotive with two firedoors is former Lehigh & New England 0-6-0 No. 207 built by Baldwin (c/n 61922) in June 1936, owned by Illinois Railway Museum, currently in storage (Barn 13(?).
J.David

So fair question, but was there a point to double firedoors in a backhead? To my simple mind, it seems that it would add more complexity for limited benefit.

Daylight: in coal fired applications; whether it be marine, locomotive or stationary; an even bed of coals results in evenly distributed heating. This is not only more efficient but reduces uneven heating of the firebox, which can lead to metallurgical weakness, buckling and / or catastrophic failure.

The two doors on Wootten fireboxes allows the fireman to access hard to reach locations or "blind spots" in the firebox, usually the rear corners along the wall of the backhead.



Here's an automotive analogy: most two door coupes could seat four people (2 in the front and 2 in the back); but the people in the back had to fold the front seat down to get in and out. In a four door sedan; the rear passengers had their own doors. Easier access.

Regards,

On another note, for all of those interested:

In January 2022; I ordered a copy of the 1908 thesis as submitted by Charles R. Cullen and Sidney Dias Gridley to Cornell University for their senior engineering class thesis.

These thesis was written in conjunction with the Erie Railroad Dynamometer Car Test the year before, and that both Messrs. Cullen and Gridley were present for.

I have now received that thesis from the RareReference division of Cornell University.

This thesis holds very interesting information over and above the The Erie Test findings, which I also have a copy of.

For one, I immediately took note that it is now confirmed that bituminous coal was used in the L1's, not just anthracite culm as would be expected by the presence of the Wootten firebox. Since no special preparations were made for test, therefore this use of bituminous was normal. The thesis goes into such detail as to include the source of the coal used: Dagus Mine of the Erie RR, located in Elk County, PA, its moisture content, volatility, etc (p.38)

We also now know the test utilized Locomotive #2602 (p. 15).

Other interesting reading is the calibration of tenders water capacity. The tender was unhitched from the locomotive, and emptied of coal. Water was filled to top of tank and tender was weighed. Water was drained an inch at a time, and tender weighed at each inch and once more when empty. (p.16)

For the coal, a partition was built in the tender diving up the coal bunker and a platform built on the partition that held a scales. Cans were placed on the scales, men shoveled coal in the cans on the scales, their weight recorded and then dumped out for the use of the "fireman"; speaking of which (and most importantly) we also have another confirmation that a single fireman was used (p. 18).

The amount of men present and on the locomotive during the test (in addition to the engineer and fireman): Eighteen! (p. 24)

Platforms and handrails were attached to the locomotive at the various locations for "indicator men" observing the respective measurement recorders and to be analyzed while the locomotive was in use. Some indicator men sat on the low pressure (front) cylinders themselves (!), and platforms were built on the front of the high pressure cylinders for those men. Since the locomotive was traveling under 7 mph for the test, the men were in "no danger" (p. 22-24).

In all, this thesis is 115 pages long, and while it contains some duplicates of the graphs from dynamometer car test, it also includes others that are not, as well as calculation tables. I have simply put a link to the .pdf file here,

http://members.trainweb.com/milepost51/rrmem/Test%20of%20Mallet%20Articulated%20Compound%20Locomotive%20-%20Thesis%201908%20-%20watermarked.pdf

That is correct. Probably mentioned elsewhere in this thread, but see ex-CNJ #592 at the B&O museum for an example.

I recall ex-RDG #1187/CF&I #4 even had a variation on this, despite the relatively small size of her Wootten firebox. Her box is not necessarily big enough to warrant two fire doors, but she does have a single extra wide door hole, and an extra wide set of Franklin doors to make the sides and corners easier to reach.

See also Charlie Kachel's quote from the early 1990's BM&R video, in his thick Penn Dutch accent - "When I hired out everything except mainline engines was hand fired. Two fire doors - One side when you got weak, the other side when you got strong." I always wondered just exactly what he meant by that last comment....

-Erich Armpriester

Erich,

Dick Leonhardt was gracious enough to allow me to use his rear 3/4 image of Reading 1187
just last month, and showing the wide firebox door you mention.

Note also the firebox is narrow enough the walkway is next to it and level with the cab floor. Larger Camelbacks have the walkway mounted high enough to clear the loading gauge with steps up and down.

Phil Mulligan

Without providing examples, some European locomotives used a wide, relatively low door to provide a kind of 'slot' access, which I believe was top-hinged.

The 15mph and Flaman recorder was in some kind of contemporary trade-press description, which I can not now find on Ms. Google. I believe part of the 1921 rebuild was to improve drifting bypass on the LP cylinders (some very good approaches, like the devices applied on recently restored C&O 1309, were described mechanically both at the time and are covered a couple of websites) which along with a pony truck would greatly reduce the augment problem going downhill.

Finding the thesis was a masterstroke; posting access to it is wonderful.

.

Excellent post Kelly!

While we are on the general subject of Vauclain compound cylinders:

You can tell the Erie locomotive doesn't have them because you can see the outside valve gear. The original 'outside cylinder' Vauclain Compound used an insanely-clever common piston valve to govern admission and exhaust from both cylinders. There was a good ¾ cutaway drawing that showed this on the same catskillarchives site that had the LP bypass-valve discussion -- see here and scroll down:

http://www.catskillarchive.com/rrextra/busa01.Html

Note that the exhaust from this arrangement would likely already be at too low a pressure for use in anything but a ship engine with reliable and cheap subatmospheric condensation, and even then the likelihood that mass flow sufficient for the LP engine of a Mallet this size would be provided from a Vauclain LP exhaust is... let's say highly unlikely.