I have a question for Hot Water or anyone else who has an answer to this question. On the UP and SP steam engines there was usually two small hoses usually laying in the floor and connedted to the backhead for which I contend they were air for the crew when in a tunnel of breathing if necessary but a friend contends that they were for water (squirters he called them) for washing down the cab floor. Anyone have the facts and not just an opinion? Thanks Ed

First,

The UP locomotives, 844 and 3985 specifically, do have deck hoses,i.e water under pressure from the cold water turbine pump, used for WASHING out the cab. Virtually ALL coal burning steam locomotives have/had water deck hoses for washing out the cab. Another use for the Fireman's water hose, on coal burners, was/is to wet down the coal pile to keep the dust to a minimum. I have also used the water deck hose to add water to the coal going through the auger tube on 3985 when I wanted as much heat in the firebox as I could get going up Sherman Hill. Adding some water to the coal adds extra oxygen (H2O remember).

Some steam locomotives also have air hoses in addition to the water deck hoses. Naturally the air pressure comes off the main reservior and be regulated to blow dust off the back head, gauges, etc. As best as I can remember UP engines (844 & 3985) have both.

Second,

SP 4449 has no water deck hose nor air hose. We use a broom! I can't speak for other SP locomotives, but I doubt that the GS class would have had them, since they simply didn't get that dirty in the cabs (that simple sweeping wouldn't take care of).

quote:

Adding some water to the coal adds extra oxygen (H2O remember).

Physics doesn't work quite that way. Coal is a Hydro-Carbon, meaning it is made up of compounds of hydrogen atoms and carbon atoms. To make use of the oxygen in water you have to first split the water molecule into hydrogen and oxygen. That takes energy, lots of energy. Assuming the extreme heat of the fire could actually do that, then these free oxygen atoms are going to recombine with an atom of carbon from the coal to make Carbon Dioxide (CO2) or Carbon Monoxide (CO) or combine with the hydrogen atoms in the coal to make water again (H2O) or with the free hydrogen that you just separated from water to remake water (H2O). The energy needed to split the water into hydrogen and oxygen would come from the fire in the firebox, thus that process CONSUMES ENERGY instead of producing it. When the oxygen atoms recombine with carbon or or oxygen there is no net gain of energy. None. You are better off simply using the "free" oxygen from the air that is sucked into the firebox.

Furthermore, there will be a net loss of energy burning wet coal vs dry coal because you have to heat the water sprayed on it, from what ever temperature that water is, up to the boiling point of water (212 F at sea level) then you have to boil that water into steam. All of that consumes energy. That steam simply goes up the stack with the exhaust gases and does no work so all of that energy is wasted which would not be the case with dry coal.

If in your experience you found that you got more steam by watering down your coal the only scientific answer I could give for that phenomenon is that the wet coal packed tighter (denser) in the stoker thus the stoker delivered more coal to the firebox than if it were dry.

Wyhog

Don't know nuthun about that physics stuff! I learned that trick from an old head back in the 1950s on the PRR New york & Long Branch. Also was reinforced by the late Tom Stewart on the UP back in the early 1980s. He showed me how to "boost the fire" on 3985 (when still a coal burner using Hanna Coal) on Sherman Hill, while doing all those photo run-bys. I've even done it once on NKP #765. Maybe it was just physiological!

Rich Melvin may have some additional input, as he has spent much more time with the 765 than I did in the late 1970s

Wyhogg's got it right. Water can not and will not supply more O2 to boost a fire. If that were so, every fire engine in the world that pumps water would be adding O2 to the fire, and not putting it out.
What is more likely happening is that the water is vaporizing to steam which increases the density of the fumes coming off the fire, which in turn boosts the heat capacity the fumes and transfer rate of energy to the boiler tube walls. The trick is to use the "right" amount of water, such that the transfer rate is improved, but the fire is only minimally hindered.

Chris
LVHR

Hot Water

Wyhog is correct about the physics (actually chemistry). The H2O you were putting on the coal did not disassociate. My fireman's training, the red lights and siren kind, tells me that only a flammable metals fire reaches high enough temperatures to split the hydrogen atoms from the oxygen in water. And as someone who has hit the magnesium in a burning Volkswagen with a 1 3/4 line, trust me, if you had a fire that hot you would have known it!

However, I think your practice of wetting the coal for periods of high demand has a scientific basis and could indeed have been beneficial. Some of L.D. Porta's refinements to existing locomotives like the South African Red Devil 4-8-4 were aimed at LOWERING the temperature of the fire bed by injecting steam at the grate level. This reduced the formation of cinders and produced flammable gases which were burned completely higher up in the fire box after swirling and mixing with oxygen. By absorbing some heat and slightly lowering the temperature at the fire bed you can get a net increase in the total energy produced by the fire and get cleaner combustion to boot. You might not have been doing it in as controlled a way as Porta, but I do think you were accomplishing the same thing.

Kanasket,

Good explanation. Thanks. That also explains the effective use of "over-fire jets" added on many more modern locomotives for smoke consuption (sometimes referred to as "smoke eaters"). Over-fire jets, when turned on by the Fireman, inject steam jets from tubes placed thru the firebix side sheets, into the fire, just above the bed of burning coals.

By the way, did Brasman get the answer he was looking for?

Thanks all for your answers. I do recall hearing and seeing pictures of cab crews using air hoses to assist in their breathing in tunnels using a towel or bandana to direct the air. Any comment ot that? They would need two hoses with air. Ed

Brasman,

Yes, you're correct about the breathing hoses. I know the C&O and NP used that method because of their tight tunnels. Both Engineer and Fireman (don't know about the headend brakeman) had air hose with funnels on the ends. They would take clean cotton waste, moisten it with water, place the waste over the nose & mouth, put the air funnel up to the waste, and regulate the air pressure for breathing.

Since cotton waste isn't all that common around the UP, I just use clean cotton rags, moistened with drinking water and breath thru that going eastbound through Hermosa Tunnelon the UP. I had a buddy who started out working as a Fireman on the NP, befor WWII, out in Tacoma. He told be about goig thru Stampede Tunnel, laying on the cab floor, while breathing thru the "air funnel".

What was at the other end of the air hose, ie what was the air source?? Ambient air from somewhere forward? Pressurized? Filtered? Who maintained it??

The "breathing air" came off the number 2 main reservior, same as the air for the air brakes. The number 2 main res. is the coolest & driest compressed air on any locomotive. The hot compressed air comes out of the compressors, thru cooling coils and into the number 1 main res. where moisture is condensed out of the cooling compressed air. The air then continues into more cooling coils and into the number 2 main res. Makes for ok breathing air but smells a little oily. Thus the moisture soaked clean cotton waste or rags.

If I am not mistaken, arent steam jets used to distribute the stoker coal around in the firebox. What effect does that steam have on the fire?

Winky

Yes steam jets were used to distribute stoker fed coal around the fire box. Those type of steam jets likely had little effect on the fire.

In the Porta system the jets down at the fire bed level were used in conjunction with a restriction in the volume of air allowed through the grates to keep the fire bed temp slightly lower and allow the flammable gases which are a result of incomplete combustion to rise up in the fire box where they are mixed with more air and then burn completely and cleanly.