Oil fired locomotives

[Anonymous]

So with a oil fired locmotive. How thick is the fuel when it burns? Does it vaporize, then burn? When more fuel is added what keeps it from just puddleing up on the floor of the firebox? How is the oil added to the fire box, wouldn't just spraying it over the fire smother it slightly? Is it run through some kind of burner system on the floor?

[Big_Boy_4005]

What an interesting question James, well done. I am far from knowledgible on this, but I would have to think it would be something like heating a home with oil. In that situation water is also boiled. Oil certainly has advantages over coal, easier to start, and no cinders.

[TomDiehl]

The earliest ones burned an oil known as Bunker C, a thick, almost tar-like substance that had to be heated with steam so it would flow. Later ones, like the SP GS-4's used a #5 fuel oil (most home heating is #2 or 3, higher numbers being thicker). They were burned much like the home heating oil burners, with a series of jets. which were simply placed in the firebox where the grates would have been for a coal burner. I believe the bottom, where the ash pan is on a coal burner, was open to allow for drafting the fire.

[Anonymous]

Anyone have any pictures of these oil locomotives? Or are these turbine locomotives you are talking about?

[Anonymous]

No they look like a regualr steam loco. So is that why in old pictures you can see the fire glowing under teh engine, is that an indication it is a oil burner? If it isn't open on the bottom of a coal burner, how do you get enough draft to burn, it can't all come throught the cab, or can it?

[Big_Boy_4005]

Didn't UP convert both 844 and 3985 to oil burning? Too many grass fires, and easier to fill with oil instead of coal.

[Anonymous]

That's what I heard.

[Anonymous]

So, what other locomotives used this bunker C fuel? Is it just these oil steamers and UP turbines or some other locomotives used it too?

[markpierce]

Fuel oil was sprayed into the firebox, with the oil being consumed before it could puddle. Bunker C fuel oil was used after gasoline production became important, I think around the late 1920s. Engine fuel oil was lighter before then (lighter than water), but when the petroleum companies changed their production mix to make more gasoline, the railroads had to use a thicker grade (like Bunker C). The oil fuel (both lighter and heavier) had to be heated so it would flow properly, about 100 degrees f. See my Oct. 25 comment in the "Southern Pacific Camelbacks?" topic, discussing the higher energy content of oil over coal.

[Anonymous]

Dear everyone,
I'm not an expert, but I have read a short book on oil burners and volunteer on an oil burner, so I'll share what I know for certain:

1.) The floor of the firebox on an oil buner is solid, there is no gap between the sides and bottom (in practice, small gaps of sunlight can be seen, but it's not a big deal.
2.) As best I know, Bunker C = No. 5, but I've also heard No. 6 was used. Really, anything flamable and liquid can be used, as long as it doesn't burn so hot as to cause problems. For example, because of logistical problems, we usually burn diesel fuel instead of fuel oil (it's harder to fire, but works okay). Gasoline, on the other hand, burns too hot.
3.) Before heating, No. 5 is like jello in consitency. In cold whether it can be one step removed from asphalt.
4.) It is made more fluid by heating it with steam put into the tender (it condenses, and at the end of the day the tank is drained of water). The oil then is gravity fed to the burner at the front of the firebox. On the way, it passes through a larger pipe filled with steam, which increases its fluidity. This is called the oil heater or "superheater" (not to be confused with the superheater in the boiler for steam). "Oil heater" is the more common term by far. Locomotives generally had one burner at the front of the firebox, but a few (NOT necesarily larger) ones had two burners, one at the front and one at the rear. Having the burner at the front works best for drafting purposes.
5.) The oil is made into a fine mist by being sprayed with steam in an arcing fan-shape from the burner (also called the atomizer)
6.) The control of air is accomplished with the damper, which can either be at the front of the firebox (the "throat sheet) on horizontally drafted fireboxes, or up from the floor on vertically drafted fireboxes.
7.) The SP extensively used Von Boden-Ingalls burners, while the AT&SF extensively used Booth burners. There were, as always, certainly exceptions.

I hope this helps a little.

Sincerely,
Daniel Parks

[Anonymous]

Thanks!

[Anonymous]

Just doing my job.

I am needed elsewhere now...wherever members of the public call a freight car a "train"...wherever innocent 3985-like locomotives are excursioning (I want to see it too)...wherever steam locomotives cry out for justice and steamization. My Grand Canyon Limited is about to leave off into the sunset.

Okay, never mind that last part because it would be heading east, but oh well....

[:)][:D][8D][:-,][swg][swg]

[Murphy Siding]

Is the fuel put under pressure to get it to *spray* out into the firebox?

[markpierce]

I believe the cab-forwards pressurized the fuel tanks to move the fuel to the front of the locomotive (the firebox was at the extreme front end of the train) because it was such a long way. Otherwise, it was gravity fed.

[egmurphy]

As Daniel mentioned, they inject the oil using steam to force it through the spray heads. So it's under pressure only at the final point. It flows from the tender by gravity.

QUOTE: Daniel: 1.) The floor of the firebox on an oil burner is solid, there is no gap between the sides and bottom (in practice, small gaps of sunlight can be seen, but it's not a big deal.

Could be, but not necessarily all of them. The one oil burner (actually converted to diesel) I am aquainted with does have a large opening in the bottom of the fire box, or maybe they're just huge dampers.

QUOTE: 4.) It is made more fluid by heating it with steam put into the tender (it condenses, and at the end of the day the tank is drained of water).

Some had steam heating coils passing through the oil bunker in the tender.

I suspect there were several variations.

Regards

Ed

[markpierce]

I believe all of the tenders of oi-fired locomotives had steam coils in the tender to warm up the fuel. The burners (fuel sprayers) also included a steam pressure passage to help atomize the fuel.

[Murphy Siding]

If the fuel oil is being sprayed, or atomized,then is it burning in the air,between the orifice and the floor of the firebox? Or, does it also burn on the floor of the firebox too? For example,what happens if the fireman has too much fuel pumping to the firebox for the fire to consume at the moment?

[egmurphy]

QUOTE: For example,what happens if the fireman has too much fuel pumping to the firebox for the fire to consume at the moment?

Lots of black smoke, waste of oil, and in extreme cases a danger of explosion. One of the fireman's most important jobs on an oil burner was to carefully control the flow of oil to match the throttle setting. I believe the engineer and fireman kept a dialogue going when making significant changes in the throttle so as to avoid catching the fireman unaware.

Regards

Ed

[Murphy Siding]

ed: I see your location as Mexico. Are you ducking a hurricane?

[egmurphy]

Fortunately, no. The hurricane just finished blasting the far eastern part of the country, including Cancun and Cozumel. I'm on the Gulf Coast, but in the state of Veracruz, about 300-400 miles south of Brownsville, TX. But thanks for asking.

Regards

Ed

[Anonymous]

I don't believe the fireboxes of oil burners had floors. They sure didn't need grates, or ashpans.

Old Timer

[Murphy Siding]

QUOTE: Originally posted by Old Timer

I don't believe the fireboxes of oil burners had floors. They sure didn't need grates, or ashpans.

Old Timer

Wouldn't they have to have *something* to form the bottom of the firebox?

[Big_Boy_4005]

I'm with you Murph, it doesn't seem right to have the burners open to a major draft. Yes, you need combustion air, but you also want to transfer the heat to the water efficiently and not worry about the fire blowing out at running speed.

[Anonymous]

QUOTE: Originally posted by egmurphy

As Daniel mentioned, they inject the oil using steam to force it through the spray heads. So it's under pressure only at the final point. It flows from the tender by gravity.

QUOTE: Daniel: 1.) The floor of the firebox on an oil burner is solid, there is no gap between the sides and bottom (in practice, small gaps of sunlight can be seen, but it's not a big deal.

Could be, but not necessarily all of them. The one oil burner (actually converted to diesel) I am aquainted with does have a large opening in the bottom of the fire box, or maybe they're just huge dampers.

I would guess that it's the damper, but you've seen it, I haven't. On vertically drafted locomotives, like the one I work on, there is a square hole in the floor, which opens into a "box" of which one side is the damper door.

QUOTE: Originally posted by egmurphy

QUOTE: 4.) It is made more fluid by heating it with steam put into the tender (it condenses, and at the end of the day the tank is drained of water).

Some had steam heating coils passing through the oil bunker in the tender.

I suspect there were several variations.

You're absolutely right, I was keeping things simple. This teaches me to be mindful though that for every "fact" about steam locomotives, there are 17 railroads with different practices.

[Anonymous]

Dear Old Timer,
As Elliot pointed out, without a floor there would be an uncontrolled and massive amount of air coming in, and at high speeds the oil would quite easily be blown out.

The locomotive I volunteer on has a flat floor of steel which I assure you is quite thick. Other locomotives sometimes have a V-shaped floor with a flat bottom (SP 1795, for example).

Since it was brought up, here are some fineries of firing oil burners (random points):
1.) The fireman must increase the firing valve as the Amount Of Steam Used is increased (it's not just the throttle--it's the reverser). If the fireman doesn't, the fire could be blown out because of a large draft (gives you a new appreciation of the exhaust nozzle that it could put out a locomotive's fire). But, open it too much and you will be "forcing the fire," which can cause leaky tubes and flues, and waste fuel. The engineer will tell the fireman when he plans to change the amount of steam used (like leaving the station). The firing quadrant (on which the firing lever is mounted) usually has a spot for an adjustable marker/stop for the "drifting fire"--the lowest amount of oil which can maintain full steam pressure when drifting. (The one I work on was converted to oil on the cheap in 1941, and doesn't have a nice quadrant like that.)

2.) To keep the fireman entertained, he also has two other controls which require his constant attention--the atomizer and the damper. The atomizer valve controls how much steam is used at the burner.

Too little atomizer and the oil won't atomize (what a surprise), too much and you're wasting steam, and worse, making the fire burn cooler, and wasting oil. Either way leads to black smoke.

Too little damper and the oil won't burn all the way--black smoke, wasted oil, colder fire. Too much damper and the fire can get too cold--black smoke, wasted oil (burning more to keep the same temperature); worst, too much damper and the flues will contract and leak.

3.) The blower control can be turned on to increase draft. Have fun.

4.) Whenever possible, only use the injector when running. If necessary to use it while stopped, increase the firing valve above the drifting stop to prevent losing steam pressure. Alternate which injector is used to minimize wear on the nozzles.

5.) Sand the flues regularly.

6.) Oil can burn with up to 50% more heat/time than coal.

You might not have to shovel oil, but it does require constant vigilance, and balancing the firing valve, damper, and atomizer is definitely an art.

Sincerely,
Daniel Parks

[markpierce]

Oh Murphy Siding!! Yes, the atomized oil burns in "mid air" and does not puddle in the bottom of the firebox. When I guest-engineered (drove) a small oil-fired Shary in 2002, I observed that the atomizer was in the back of the firebox, blowing forward. However, a current article on oil-fired Southern Pacific locomotives stated that was its practice then, but by 1905 it was changed to the opposite with the burner in the front of the firebox facing the rear.

[Anonymous]

QUOTE: Originally posted by markpierce

I believe all of the tenders of oi-fired locomotives had steam coils in the tender to warm up the fuel. The burners (fuel sprayers) also included a steam pressure passage to help atomize the fuel.

Firstly, about the pressure gauge, I've never seen one on any locomotive (didn't mean it didn't happen though). The locomotive I volunteer on (Ventura County Railway no. 2) doesn't have one, and neither does AT&SF 2926 to my knowledge. It really wouldn't do you much good except in finding leaks (which is easy enough with the atomizer steam pipe).

Some had heating coils, but the old system of putting steam right into the oil worked pretty well. The oil pipe in the tender tank would rise up about 2", so that the heavier condensed water would fall below it, and only oil would be taken.

Not trying to be condescending, just helpful [:)].

Sincerely,
Daniel Parks

[Murphy Siding]

QUOTE: Originally posted by markpierce

Oh Murphy Siding!! Yes, the atomized oil burns in "mid air" and does not puddle in the bottom of the firebox. When I guest-engineered (drove) a small oil-fired Shary in 2002, I observed that the atomizer was in the back of the firebox, blowing forward. However, a current article on oil-fired Southern Pacific locomotives stated that was its practice then, but by 1905 it was changed to the opposite with the burner in the front of the firebox facing the rear.

Cool! It kind of sounds like a tamed dragon.[:)]

[nanaimo73]

QUOTE: Originally posted by trainjunky29

5.) Sand the flues regularly.
Sincerely,
Daniel Parks

Daniel,
I thought oil fired steam locomotives needed less sanding than coal fired locomotives ?


Some railroads put lights on the top of their locomotives so the fireman could see the smoke at night and adjust his fire.

[Murphy Siding]

QUOTE: Originally posted by nanaimo73

QUOTE: Originally posted by trainjunky29

5.) Sand the flues regularly.
Sincerely,
Daniel Parks

Daniel,
I thought oil fired steam locomotives needed less sanding than coal fired locomotives ?


Some railroads put lights on the top of their locomotives so the fireman could see the smoke at night and adjust his fire.

? Can someone explain sanding the flues? For better *traction* of the smoke? I'm lost.

Thanks