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?
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.
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.
Anyone have any pictures of these oil locomotives? Or are these turbine locomotives you are talking about?
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?
Didn’t UP convert both 844 and 3985 to oil burning? Too many grass fires, and easier to fill with oil instead of coal.
That’s what I heard.
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?
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.
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 ho
Thanks!
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]
Is the fuel put under pressure to get it to spray out into the firebox?
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.
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.
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.
Some had steam heating coils passing through the oil bunker in the tender.
I suspect there were several variations.
Regards
Ed
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.
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?
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
ed: I see your location as Mexico. Are you ducking a hurricane?
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