Why was the firebox in the front and the smokestack in the rear on cab-forward locos

These war planes were steam powered? I had no idea? Did they fly through tunnels as well?

To keep the heat and exhaust smoke OUT OF THE CAB when working up-grade through snow sheds and tunnels. You haven't lived until you have been in the cab of a "conventional" steam locomotive working hard thru a 2 mile tunnel/snow shed! The heat alone exceeds 200 degrees.

There are all sorts of steam operated appliances that come off the top of the firebox/backhead. (Lubricators, injectors, steam for the compressor, generator, blower, oil nozzel, plus a valve to shut down each.)  Like the throttle, these appliance like nice "dry" steam from above the water level.  It's all nice and handy on a turret on or near the backhead.

All that would have to be plumbed and levered the length of the boiler, past the smokebox and into the cab, plus there would still have to be some kind of enclosure in back for a fireman to monitor the water glass (probably THE most important indicator on a steam locomotive) tri-cocks (in case the water glass blows out or gets clogged) and monitor the fire and be able to operate the blow-down valves.

Steam locomotives are also noisy beasts, a speaking tube, telephone or telegraph would make communication between the fireman and engineer that much more difficult.

Plus, the engineer and fireman work best when in the same location.

Rusty

10 seconds in a steam locomotive working upgrade in a long tunnel and you would CLEARLY understand why the cab-forward design came to be. Nice to have the stack BEHIND you.

Been there. Done that. Many times. It wasn't enjoyable and I don't want to do it again.

Rich, I didn't ask about why the cab was put forward.  THAT is obvious, and a given.  What I asked was why, when the cab was moved forward, the firebox had to also be moved forward.  It made sense to do that on the SP cab forwards - they were an existing design and so the easiest step was to expeditiously just turn the entire loco around and run it cab forward.  The firebox, etc., ends up in front.  But if you were designing a new, cab-forward loco from scratch, is there any reason why you can't locate the cab at the front and the firebox at the rear, and engineer all those "steam operated appliances" Rusty Traque mentions to the rear, keeping tender to fuel lines short, etc.  

These war planes were steam powered? I had no idea? Did they fly through tunnels as well?

Well not for long. 

Lee,

The distance from the tender to the cab forward's firebox doesn't matter since they were ALL oil fired. Also, if the firebox was placed next to the tender, then the exhaust is IMMEDIATELY right behind the "cab" and its crew,,,,,,so what would be the point? 

I think another reason was why the camelback locomotives were banned.  It was because the engineer and fireman were in two different locations and not able to communicate with each other.  I believe there was at least one occurrence  where the engineer had a heart attack and the train jumped the rails.  As long as they're together they can monitor each other.

If the cab forward had the firebox in back that's where the fireman would be and you'd have the same situation.

This is a fairly good point and the first practical reason I see for putting the smokestack at the rear (which pretty much means the firebox has to go forward).  Thank you very much, Hot Water!!!!!

I rode through Raton Pass awith my uncle in the early '50s.  It was a big adventure for a seven year old.  By then he was driving F3s, but two helper locos were steam, and it was bad in the tunnel even with the windows and vents shut tight.  the air got "thick" so to speak.  And it was the peak of the adventure, so to speak.  

I should think the engineer and firemen would want to be close by the firebox and boiler with some means of visually inspecting levels, pressures and the fire regardless of whatever automated controls there might be. I certainly would.

Would it not stand to reason to have the firebox near the crew to watch all of the gauges, valves, and things going on? I am also thinking that the economy of manufacturing essentially a reversed conventional locomotive would be the least expensive alternative. Thoughts?

Plus with the cab by the stack, the cab would have to be removed to access the smokebox for maintenance and cleaning.

It's all very simple really:  All the stuff needed to make a steam locomotive go is located on the backhead behind the firebox (or in front of in the case of a cab-forward.)

Rusty

Well, as I observed earlier, by the time this loco was built, we were routinely building bombers and such with instrumentation and controls that were "remote" from the operators via mechanical/electrical systems.  RickO's joke about steam powered bombers aside, it definitely could have been done and it actually was in fact with diesels.   

xxx - this is another good practical reason for a firebox-forward design, which I have decided to build on my model.  

-------------------

Hot Water and Rusty Traque, I appreciate your treating my question seriously and the information you have given me.  My conclusion is that while there was no engineering reason why the firebox could not be located at the rear of the loco whenever the cab was at the front, there were abiding practical reasons.  This is why I asked this question here: with 44 years as an engineer I pretty much felt I understood the engineering, but the "product performance specification" was what concerned me - I have zero experience running railroads bigger than 1:48, as not having thought of these issues proves.  Thank you!!!

Why did we not see CF's on other railroads?  At least those which burned oil on hilly routes?

No other railroad had the profile, number of tunnels and snowsheds the SP had.

Rusty

Northern Pacific considered a cab forward Challenger for the Stampede Tunnel.  They went so far as to test run a Challenger in reverse to see if it would be possible.  The biggest problem was the size of the locomotive (big) and the size of the tunnel (tight).  They were afraid for two things.  First was the exhaust hitting the roof of the tunnel at close range causing damage.  Second was that if the locomotive derailed it would be very difficult rerailing it in the tunnel.  Normally the NP ran its old compound 2-8-8-2's through the tunnel.  These locomotives were smaller than the Challengers, and being compounds the exhaust blast was less intense, so the railroad decided to just keep running things they way they were until diesels came and made the whole point moot.

Stuart

CP and the Sprial Tunnels in the Rockies?

You'll also notice CP had no articulated locomotives to speak of. (Two 0-6-6-0's if I recall correctly.)

There are only 3 tunnels on the CP between Field and Hector, the shortest being about 180', the longest about 3/4 of a mile with a fair amount of "breathing room" inbetween.

SP had more tunnels, a stiffer profile, plus multiple snowsheds to contend with.  Plus the AC's were not only road power, but helpers also.

Rusty

(It is) easier to move signals than oil, I think.

Lee

What "signals" do you need to send?  How do you propose to send them?  Remember, it is 1940 and you have no solid state electronics.  Instrumentation and control is an entirely different world from 1970, let alone today.  Moving oil hasn't changed too much since 1940.  Everything else has.

My wife and I rode the Clinchfield RR from Elkhorn City KY to Spartansburg SC.

At Erwin TN, we picked up "One Spot" (a 4-6-0 steamer) accompanied by 2 B unit diesels. We decided to ride the open air Gon on that leg of the trip.  Well the Clinchfield is famous for all the tunnels and when we got to Spartansburg SC, it took 3 showers to get all the soot and cinders out of our hair.  But it was worth it!

Larry

As a mechanical engineer I can tell you yet another reason, and it may of been one of the big ones for management and the bean counters, and that is cost!  Yes, a locomotive could easily be designed as Lee proposes, but the cost difference between doing a new design and building it versus tweaking an existing design and turning it around is great.  Many people don't realize that a cost analysis is also part of design engineering and should always be part of the process.

This is not to say that Rusty and Hot Water aren't right, because they are right, but those aren't the only reasons that I'm sure of.  I've been reading lately several books about railroad history in the USA in general as well as specific roads, and money making and cost of things are common themes in the actions and choices roads made.

This is a very good point.  Even though the Santa Fe 6-4-4-4 was ostensibly a "clean sheet" design, it was probably based upon/going to use a great many components and already engineered "modules."  I read one discussion of it that said it was to have a boiler, etc., derived from Madam Queen, so this makes sense, too.  

-------------------------

Originally posted by Ted Hikel

The signals are from sensors, such as for temperature, pressure, fuel flow, etc., etc., etc., for each instrument, and for control, such as throttle position, air flow dampers, back to instruments and machinery located where needed, etc.  All of these were used - standard off-the shelf components in many cases -  in bombers, diesel locomotives, and ships, etc., long before the solid-state electronics world.  About forty years ago I helped re-wire and re-fit an old (then) B-17: amazingly clever, innovative analog machinery.  If you could monitor and operate over 4000 HP in four engines forty to fifty feet away as the wire runs from the cockpit of an aircraft you could certainly monitor and operate one big steam engine forty to fifty feet away from the cab at the front of a locomotive.  that doesn't mean you would want to, as several considerations discussed above have made clear, but you certainly could.

Even ships of the time still had an engineer down in the engine room doing the actual control of the engine. You didn't want to trust a hydraulic or electrical system of the time to control what amounted to a giant pipe bomb.

The firebox was likely placed up front so that the engineer could have direct hands-on interaction with the engine for that very reason.

Plus, like old men of any era, the engineers of that time did not like change. Having the engine cab forward was surely bad enough. Expecting them to trust remote gauges and hydraulic systems when they had always been hands-on with their locomotives was simply too much to ask.

 With respect to CPR's Spiral Tunnels, the big one was the Connaught tunnel, that basically went under Rogers Pass. There are still SnowSheds today thru Rogers Pass.

  The orginal CPR mainline thru Rogers Pass had even more I believe.

I will have to consult my library to confirm lol

Al

When you fire, you don't just rely on gauges. You can't really do it "from a distance." You need to be able to see things like the fire color/intensity. You need to be able to physically see the water over the crown sheet, either by glass or by trycock. You need to physically be able to check the glass drains. You need to be able to sand the flues--a complately manual operation that has to be done from the backhead.

So many of the things the fireman does need to be done at the backhead. Perhaps the engineer could control the engine far more remotely, but that's not the case on the left side. Lee, you may think a steam locomotive can be made to "fly by wire," but it's a lot more difficult than that.

Probably one more reason diesels took over.  I remember riding through Raton Pass with my uncle in an F3.  It was an A-B-B-A set and they could read and operate all four units from the lead cab.  Steam served the industry for over a hundred years quite well, and steam locos were glorious and romantic, but hardly competitive - probably one more reason why Santa Fe never built that 6-4-4-4.  Pity.

When you fire, you don't just rely on gauges. You can't really do it "from a distance." You need to be able to see things like the fire color/intensity. You need to be able to physically see the water over the crown sheet, either by glass or by trycock. You need to physically be able to check the glass drains. You need to be able to sand the flues--a complately manual operation that has to be done from the backhead.

Lee

You seem to be a little slow on the uptake here.  Hopefully Steve is finally getting the point across that the engineering challenges involved in providing instrumentation and control for firing a boiler are vastly different than for monitoring and controlling internal combustion engines. Given 1940s technology and even today's practical and regulatory requirements the fireman has to be present at the backhead.  In addition to the physical tasks he must perform at the backhead his eyes and ears are critical sensors and his brain is the PID controller in several essential feedback loops. 

Ted, maybe I should take offense at that but I won't.  You're probably a good guy . . . 

For the past forty-four years, I've specified, engineered, designed, and worked with control systems for internal combustion, reciprocating steam, steam and gas turbine, and other types of distributed power plants and prime movers.  I've worked on all-manual steam plants as old as 1911, post-WWII steam and diesel and gas turbines with analog metering and controls, and very modern digital stuff all over the world.  

I assure you I understand gauge glasses, trycocks, sanding the flues, and judging the fire's color, intensity and evenness well.  They were victorian-era "technologies" used in both steam locomotive and stationary power plants well into the 20th century because they were cheap, effective, proven and familiar to the generation of personnel the designer's knew would be operating those systems. But the fact that those methods were used and worked does not mean that they were the only methods that could be used to operate and control reciprocating steam.   I've retrofitted oil-fired boiler steam for not with remote control but with automated control (no humans even watched the dials unless there are alarms), so I know it can be done.  And I've taken apart and worked on analog systems from the war and postwar era so I know remote control could have been done in the '40s, too. 

By 1939, all the measurement, meter, and control equipment needed to remotely control oil-fired combustion existed and was in both military and civilian use.  My example of bombers was not used to imply steam and internal combustion were equivalent, but to make the point that if we could "remotely" control 5,000 HP in a high-speed bomber of that e period - a much more difficult job that any steam locomotive given the speeds involved, the altitude differences over which combustion had to be controlled, and the fact that things had to be kept as light as possible while being somewhat capable of surviving battle damage - then we certainly could have built a firebox-to-the-rear oil-fired locomotive in the WWII/postwar era.  I have absolutely no doubt about that.   

What I came to this particular forum to ask was despite the fact that that could be done, were there reasons a RR would not want such a design?  I got very practical compelled reasons why from Hot Water and sinclair, and some interesting and useful observations from several others, so I have what I want - enough to convince me that Santa Fe would never have accepted such a design and that their cab-forward6-4-4-4 would have had the firebox up front and the smokestack at the rear, which is how I shall model it.  

------------------------------------------------------

TO EVERYONE, including you Ted, I appreciate each of you taking the time to read and consider my question and provide your thoughts.  I read everything you wrote. I have what I want and this thread seems to be both straying off topic and devolving into something a bit mean spirited at times, so I won't be back to it.  So thank you, all, very much!!!! 

The power requirements you are used to dealing with on package boilers, which are fairly constant, are FAR different than what's required of steam locomotive boilers. Package boilers CAN be automated. I've yet to see that happen with a steam locomotives. Maybe not because it can't be done. But because it would just be plain inefficient to do so.

Lee, We all know you take a great deal of pride in your profession. Remember, it's your brethren that helped develop the steam locomotive. If they had determined that remote firing and operating of the steam locomotive was practical or worth looking into, they would have.

Granted, in this instance the crew still didn't survive.  You certainly wouldn't want a cab right behind the smokebox in case you ran out of water and didn't know it because you were on the wrong end:

I've retrofitted oil-fired boiler steam for not with remote control but with automated control (no humans even watched the dials unless there are alarms), so I know it can be done.  

Gee Lee, that is great.  I would think that your experience would help inform your understanding of why it was not done.  As Steve points out.....

The power requirements you are used to dealing with on package boilers, which are fairly constant, are FAR different than what's required of steam locomotive boilers. Package boilers CAN be automated. I've yet to see that happen with a steam locomotives.

Perhaps you are incorrectly extrapolating from your experience with steam and other power sources for particular uses to different applications.  Have any of your boiler control installations had to work under conditions where one end of the boiler could suddenly be a foot or two above or below the other end?  Have any of your boilers had the water inside them slosh under acceleration or braking? Have you ever installed a boiler on a bed that could be flat one moment and suddenly superelevate one side or the other?  How much have the loads you have designed for changed in less than a minute?  Have you ever automated a boiler with vintage instruments?  Have you ever installed them in a environment where they were exposed to soot, lubricants, dust, rain and snow?  How reliable were those vintage instruments under those kind of conditions?

I assure you I understand gauge glasses, trycocks, sanding the flues, and judging the fire's color, intensity and evenness well.  They were victorian-era "technologies" used in both steam locomotive and stationary power plants well into the 20th century because they were cheap, effective, proven and familiar to the generation of personnel the designer's knew would be operating those systems. But the fact that those methods were used and worked does not mean that they were the only methods that could be used to operate and control reciprocating steam.

Ok Lee.  What special knowledge are you holding back on?  Do you have a treasure trove of 1940s I&C catalogs?  Do you have a period paper presented to the ARA or other rail professional group on steam locomotive automation?  Any patent Drawings?  If remote control or automation of steam locomotive boiler firing was practical in the 1940s I think Alco, Baldwin or Lima would have been working on it and trying to sell it to the railroads.  That would have made multiple unit steam locomotive operation possible with one crew.  And that would have been a good response to the sales guys from EMD.

So what info do you have?  I'm sure all us good guys here would be interested in whatever historic and technical information you have to share. 

Lee, I have really enjoyed your starting this topic. Have learned so much from the

comments (abrasive and friendly).

Would you consider posting some pictures of your undertaking at some point down the

road please? I am certain it would be most interesting.

thanks again, Lee. Well Done.

Perhaps you are incorrectly extrapolating from your experience with steam and other power sources for particular uses to different applications.  Have any of your boiler control installations had to work under conditions where one end of the boiler could suddenly be a foot or two above or below the other end?  Have any of your boilers had the water inside them slosh under acceleration or braking? Have you ever installed a boiler on a bed that could be flat one moment and suddenly superelevate one side or the other?  How much have the loads you have designed for changed in less than a minute?  Have you ever automated a boiler with vintage instruments?  Have you ever installed them in a environment where they were exposed to soot, lubricants, dust, rain and snow?  How reliable were those vintage instruments under those kind of conditions?

I don't know but it seems to me that aircraft carriers esp. the Nimitz Class will do more than the above anyday of the year. It's boilers has to produce over 140,000 shaft horsepower to move a 97,000 ton ship at a classified speed. Then at full steam they give the 35 deg. right/ left full rudder order and the ship will keel at 15+ degrees...I never heard of a 15 degree superelevation. Or how about being in rough seas with 25' waves heaving the ship up & down under full steam..the bow will raise & drop at least 30' but the boilers remain supplying steam for the shafts & electric..even the catapults if they decide to launch.  

There's something to consider here... 

Now, I don't know if there were ever any experiments with running a steam locomotive by wire (for lack of a better term,) but when the world was on the steam standard, design and mechanical engineers, railroads big and small worldwide had pretty much decided that the engineer (or driver if you prefer) and fireman be located "where the action was," behind the firebox.  (Yes, I'm aware of the few exceptions like camelbacks...)

Now, if we extrapolate this up into the 21st century, do you think folks would accept unmanned trains using drone technology operated by "enginemen" tucked safely away in bunkers under corporate headquarters?

Rusty

I am surprised the SP did not considered the CF concept for their 4-8-2 and 4-8-4's!  The CF concept did not have be only an oil artic platform!

Horsepower; weight of ship; blah blah blah....None of your scenarios come close to describing the demands placed on a locomotive boiler. They're DIFFERENT. DIFFERENT!

Why is it that some folks cannot make a point without insulting others?  I expect it when I read web pages with content provided by teenagers and other socially inept folks.  I kind of expect more in the train hobby, which in my experience is comprised of gentleman who can comfortably do business on a handshake.  Moreover, what is particularly interesting, and dumbfounding at the same time, is that Hikel is a sponsor here and in the business, presumably, of selling train-related goods to folks.  Is that the foot you want to put forward to customers?

Time to get out of the train room and spend some time with live humans. 

"In May, 1954 Baldwin built a 4,500 horsepower steam turbine-electric locomotive for freight service on the Norfolk and Western Railway, nicknamed the Jawn Henry after the legend of John Henry.  Length including tender was 161 ft 1-1/2 inches, probably the record for a steam locomotive; engine-only length was 111 ft 7-1/2 inches, perhaps the record for any single unit.

The unit was a C+C-C+C with a Babcock and Wilcox water-tube boiler with automatic boiler controls.  The Jawn Henry was retired from the N&W roster on January 4, 1958."