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Fuel
Systems |
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Aster locomotives
are fired by alcohol, butane gas or coal. Fuel choice is a major factor in
determining what type of boiler will be selected for a miniature
locomotive. While denatured alcohol is probably the most common fuel for
Gauge 1 steam locomotives, gas and coal are viable alternatives. Each fuel
has its advantages and disadvantages. The chart contains
comparisons. A discussion of each system follows. |
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ALCOHOL*
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BUTANE GAS
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COAL
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SAFETY
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Extremely Safe
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Safe
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Extremely Safe
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FUELING
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Not temp. sensitive
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Very temp. sensitive
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Not temp. sensitive
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BURNING
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Irritates eyes
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No eye irritation
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Irritates eyes
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FAN
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Required **
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Not required
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Required
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BLOWER
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Required**
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Not required
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Required
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* 200 proof denatured ethyl alcohol gives the best results when the burner
wicks are in good condition and properly trimmed. It can be purchased from
a chemical / scientific supply dealer. Methyl alcohol vaporizes and burns
at a lower temperature than ethyl alcohol. However, it is also
satisfactory for use in Aster locomotives. The key point is to use a fuel
which is free of water. Ethyl or methyl alcohol purchased in paint or
hardware stores may contain up to 9% water. |
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| ** Not required for a vaporizing alcohol burner system with a pot
boiler. (see Figure 43 in Alcohol section) |
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| Alcohol |
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Most Aster locomotives are fired by
denatured alcohol using either a forced draft wick burner or a vaporizing
burner. USE ONLY DENATURED ALCOHOL. 200 PROOF DENATURED ETHYL
ALCOHOL WILL GIVE THE BEST RESULTS. When adding fuel to a locomotive which
is under steam, close the fuel tank needle valve and extinguish the
burner. After this is done, fuel can be added to the tank
either by means of a funnel or by a squeeze bottle.
TO AVOID INJURY, NEVER ADD FUEL TO AN
ASTER LOCOMOTIVE FIRED BY ALCOHOL UNLESS THE FIRE IS EXTINGUISHED AND THE
FUEL TANK NEEDLE VALVE IS CLOSED. |
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Figure 40 shows a typical forced draft wick burner fitted to a
Gauge 1 locomotive. |
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Figure 41 illustrates the tools required to operate it. |
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This system requires a draft so that there is sufficient oxygen
to maintain combustion. If the boiler should run dry, the draft caused by the
exhaust ceases and the fire will quickly die out. Inspect the wicks and
silicone tube connecting the burner and alcohol tank to insure they are in good
conditions. Replace if necessary.
The needle valve on the fuel tank should be closed, the filter
plug removed and the tank filled to its specified capacity using denatured
alcohol. Be sure to immediately replace the cap on the fuel supply can,
since alcohol will absorb water from the atmosphere. Replace the filler
plug and tighten it unit its O-ring begins to distort. Put a drop of oil
around the plug / O-ring after it is tightened to insure an air tight seal.
The fire is not ready to be started.
1. Place the suction fan in the stack and start it.
2. Make sure the locomotive regulator is closed
3. Open the needle valve on the alcohol tank one turn.
4. As the wicks soak fuel, check for leaks. If the
wicks overflow, close the needle valve and check the filler plug to be sure it
is making an air tight seal.
5. Light the wicks using the igniting bar. The can
be more easily accomplished if a stand is use which raises the locomotive up
about twelve inches and which has a large hole directly beneath the burner
wicks.
6. Check the burner flame by means of a mirror. The
flame color should be predominately blue. If the color is predominately
yellow, the fuel is contaminated and should be replaced.
7. When the pressure gauge reads 2 kg/sq cm, crack open
the blower and remove the suction fan.
8. When the safety valve blows, set the valve gear for
forward running. Wit the regulator slightly opened, roll the locomotive
forward for a few feet to clear the cylinders. KEEP YOUR FACE AND HANDS
AWAY FROM THE STACK AS HOT WATER AND OIL WILL BE EJECTED. Close the
regulator.
9. Couple the train to the locomotive and open the
regulator so that that the load can be pulled at a reasonable speed. Close
the blower. Have people stationed along the track to slow the locomotive
in case it "runs away."
10. When the locomotive is stopped, immediately open the
blower so the fire will have sufficient draft.
11. When operating a compound locomotive, such as the
BR-96, the low pressure cylinders require a brief period of time to warm up and
the locomotive will run somewhat slowly until it begins to
"compound." When the low pressure cylinders are warmed, the
locomotive's speed will suddenly increase for a given regulator setting, so car
must be taken to avoid a derailment. The locomotive should be warmed up on
a straight portion of track, running back and forth, for a few minutes.
Then it can be connected to its train and the proper regulator setting selected
for the load to be hauled.
It is always necessary pull a heavy train other wise the locomotive
will accelerate to a high speed and derail. The track's curves should be
slightly banked and the rust must be free of grease and oil. Freight cars
can car loads, such as small castings or electric motor armatures, which will
increase the train's weight as well as add realistic detail. The heaviest
cars should be coupled nearest to the locomotive. Be sure all cars
couplers are in good condition and will not come open or fail during operations.
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A
vaporizing burner, as show in Figure 42, is used on some Aster models,
which utilize pot boilers such as the BR-86.
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Operation of this system is very simply since a forced draft is now required.
The pilot light heats the nozzle tube and vaporizes the alcohol, which then
burns with a very hot flame. A vaporizing burner does not have the
automatic fire extinguishing feature, as does a forced draft system. Care
must be taken to prevent the boiler from running dry. If it should,
immediately close the fuel tank needle valve. The burner will be
extinguished in a minute or so. NEVER ADD WATER TO AN OVERHEATED BOILER.
Let the boiler cool for about 20 minutes before refilling it. |
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Another style of vaporizing burner, which is also called a blow lamp, is show in
Figures 43. It consists of two major parts, the main blow lamp
burner and the preheating burner. The alcohol tank becomes pressurized
after being heated by the preheating burner and blows a stream of vaporized fuel
through the nozzle where it is ignited by the preheating burner. This type
of burner is most suitable for a center flue boiler. Both the main and
preheating burner tanks should be filled to no more than 80% of their respective
capacities to avoid fuel waste and spillage. The main tank is fitted with
a safety valve to limit pressure. The performance of this system varies
with ambient conditions.
Figure 44 shows different nozzle settings which result in
different flame intensities. The position of the nozzle determines how
much air mixes with the vaporized alcohol and the temperature of the resulting
flame. In general, the greater amount of air in the mixture, the hotter
the flame of will be.
NEVER USE GASOLINE OR PAINT THINNER AS FUEL SINCE THEY COULD
EXPLODE AND CAUSED DAMAGE AND INJURY. USE ONLY DENATURED ALCOHOL.
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| Butane Gas |
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Butane gas is sometimes used as fuel for Gauge 1 locomotives and
several Aster locomotives, such as the C&S Mogul and Climax, employ it.
Figure 45 shows the typical butane gas system. It is most suitable for a
center flue boiler.
ASTER LOCOMOTIVES WHICH ARE GAS FIRED, ARE INTENDED TO BE FIRED
ONLY BY BUTANE GAS. NEVER USE PROPANE GAS OR A PROPANE / BUTANE MIXTURE AS
A SUBSTITUTE SINCE AN EXPLOSION CAUSING SERIOUS DAMAGE AND INJURY COULD
RESULT.
Gas
fired locomotives are sometimes fitted with an axle driven feed water pump and a
bypass valve, which when properly adjusted, keeps the boiler water at a constant
level. If the water level falls below the flue level, the boiler will be
seriously damaged. The water level should be constantly checked to assure
the proper level is maintained.
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A butane tank pressurizes when it is filled. The pressure
of the gas is a function of the temperature of the fuel tank. When the
tank is first filled, the pressure may be quite low if the fuel system is
relatively cold. When the regulator valve is opened, butane gas flows
through the nozzle mixes with air and flows to the burner. Aster locomotives
situate the main fuel tank in the water reservoir.
For the day's first run, the proper amount of butane should be
added to the tank before any water is added to the reservoir. Next, fill
the reservoir with WARM (NOT HOT) water. This will cause the butane in the
main tank to pressurize so that the burner can be easily lit and will remain lit
while the fuel system "warms up." Once the fuel system is warm it
will provide a stabilized flow of butane to the main burner. Any
additional water added to the reservoir can be cold.
The tiny jet in the main burner should be frequently cleaned by
means of a small wire "pricker." Care should be taken not to enlarge
the diameter of the jet. The burner is usually lit through the smoke box
or the stack. The burner must be correctly adjusted to assure proper
combustion. A reduction of intake air will reduce noise, but may not
result in proper combustion. If butane an be smelled, the intake air flow
must be increased. Correct adjustment will maximize heat generation.
Not
all Aster burners allow for adjustment with the burner on the C&S Mogul being an
example. If the burner lights but will not stay lit, the problem is
most likely a cold fuel system. On locomotives which are fitted with a
preheating tank, such as the C&S Mogul, it is best to first open the valve
between the preheating tank and the burner. This is done when the
locomotive is initially steamed and before opening the main fuel supply valve on
the tender. After the preheating tank has had a chance to "warm up," its
valve can be use to control the fuel flow. If the burner goes out
immediately shot off the fuel supply and let any gas dissipate.
Keep
spectators, especially children away from the locomotive. Add warm water
to the water reservoir, as described above, and re-light the burner.
When butane tanks are filled, it is common for a small amount of gas to escape
and surround the locomotive. For this reason, never attempt to fill a tank
unless the fire has been extinguished and the locomotive is situated away from
the main line where other locomotives are operating. thereby preventing flash
burning.
Prior to filling the main fuel tank, inspect the system for
damaged hoses and /or O rings. Replace as necessary. If there is
evidence of frost on the hose or fitting this is an indication of a leak.
DO NOT ATTEMPT TO STEAM THE LOCOMOTIVE UNTIL THE LEAK HAS BEEN LOCATED AND
ELIMINATED. OTHERWISE, A FIRE COULD OCCUR.
Hose replacements should be rated for high pressure. Aster
recommends only the use of Aster replacement hose with wire shielding. The
vapor pressure of commercial butane gas varies from 7 psi at 10 degrees C; to 31
psi at about 21 degrees; to 97 psi at about 54 degrees C; to 180 psi at
100 degrees. Butane is a safe efficient fuel, but like any fuel, whether
solid, liquid or vapor, it must be handled with respect and care.
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| Coal Firing |
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Some Aster locomotives, such as the JNR
C62, are fitted with locomotive type boilers, which may be fired by coal
or alcohol. When fired by coal, the alcohol burner is removed and
grates are installed at the bottom of the fire box. The figure below
shows the typical equipment and tools need to fire a locomotive type
boiler |
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Firing such a small boiler is quite interesting and challenging,
since grate area may be as small as 47 mm by 64 mm, while the fire hole is only
about 20 mm in diameter. If low quality bituminous coal which is
used to heat houses, is burned in a small fire box, the tubes will soon become
plugged and clinkers will form on the grates. The fire will be weak and
unable to generate steam in the boiler.
The best coal for small seam locomotives is Welsh steam
coal. If it is not available, anthracite coal or hard charcoal, known as
"Bincho" in Japan, can be used. Hard charcoal will supply
sufficient heat to steam the boiler. If a little coal is also added to the
fire, the aroma of a coal fire will be simulated. The charcoal should be
broken into small pieces about the size of a fingernail. The pieces must
not be too small or they will fall through the grates. Lighting a hard
charcoal fire may be difficult. After the locomotive's bearings are
lubricated and the lubricator and boiler filled to the specified limits, the
following procedure can be used to start the fire.
1. Place the charcoal bits evenly on the grates to a
height of about 2 cm. Pace a suction fan in the stack and turn it only.
2. Ignite an alcohol blow lamp burner and play the flame
on the charcoal and the smoke tubes. Continue to do this until the
pressure gauge shows 1 kg/sq cm and the charcoal glows red.
3. Close the fire box door and crack the blower
valve. Remove the suction fan from the stack. After a few minutes,
steam pressure should be rising.
4. Open the fire box door and add additional charcoal
evenly to the fire. Close the door and listen for the fire to make a
cracking sound.
5. When operating pressure has been reached, the safety
valves will blow. The color of the fire should be yellow, which signifies
excellent combustion. The locomotive can be connected to the train and
operated.
There are other methods of starting a fire, such as the use of an
extension chimney and a foot operated bellows. Soft charcoal pieces can be
lit on a outdoor grill and then even placed on the grates in the fire box.
The door should be closed and bellows operated until the pressure gauge shows 1
kg/sq cm. The blower should be cracked open and hard charcoal added evenly
to the fire. Remove the bellows and extension chimney and wait for the
safety valve to blow. Add additional charcoal as necessary.
Experienced operators can start a charcoal fire directly in the
fire box by stacking soft charcoal evenly on the grates and laying oil soaked
wood chips on top. Once the fire is burning, hard charcoal is added.
A coal fire in a Gauge 1 locomotive does not yield constant heat, as does an
alcohol or gas fire, because the heat release of the burning coal follows a
cycle. Firing the locomotive, so that long runs can be made, is an
indication of the operator's skill and provides a significant challenge to both
the beginner and the experienced live steamer.
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