Straw Spark Arresters and Firing with Straw

an ad for the ‘United States Spark Arrester,’ K. M.
Colquhoun, Box 359, Minneapolis, Minn. ‘The only arrester made
that in no wise stops the draft.’ Made in twelve styles and
sizes.

The picture of it is enough like the one in the ALBUM that I am
sure it must be one of the twelve models, this one is larger in
diameter in relation to its height than the one in the ALBUM. It
has the same kind of hinged cap in the center, only it looks
smaller in relation to the whole arrester.

I have burned straw in engines more than coal, have seen many
types of spark arresters but never one like this one. The ones that
I have used were just screen caps of various shapes, and unless
conditions were very dry a lot of the time we did not have one at
all, in fact the Advance 30 hp. cross compound did not have one at
all, and a 35 hp. Advance tandem-compound had only the cylindrical
part, the top was wide open. Of course compound engines with a
milder exhaust did not throw sparks too bad. But to see them
working after dark you would think there was great danger of
setting fire.

After receiving the above letter I wrote to Mr. Aslakson with
the explanation the folks were not so much interested in the make
of the spark arrester but why they had such a ‘Bogwamus’ of
a thins: on a smoke stack. I asked him if he would not give us a
letter on straw spark arresters or something on firing with
straw.

I think the majority of ALBUM readers have little, or only a
hazy idea about firing with straw. Here in the East we only heard
about it and from what I have learned since if we would have had a
straw burner we would never have gotten steam up in it. We would
have put a fork full of straw in the thing and waited 15 or 20
minutes for that to have burned up. Mr. Bontreager of Belleville,
Pa., had a nice article some years ago and now this one makes our
knowledge more complete.

We thank Mr. Aslakson for his very informative article on this
little known business.

(Mr. Aslakson invited us to spend our winters in North Dakota.
He said they had very little snow this winter. This will interest
all Pa., N. J., Md., and Dela., folks). ELMER

THOSE OLD STRAW BURNERS

For the benefit of those who have never burned straw in a
threshing engine, or have never seen it done, I will try to give
some information on it.

Most of the manufacturers made their engines so straw could be
used, with special grates and brick arch.

Or they made special boilers, such as the LeFever boiler used by
Advance, or the water leg boiler used by Russell. My own experience
has been with direct-flue engines, but return flue engines were
used a lot too, especially those with firebox boilers such as
Avery, Gaar Scott, Buffalo Pitts, etc. I knew of one Minneapolis
return-flue that was fired with straw for years, I would think the
small fire space in the main flue would not be so good for
strawburning.

Here are some of the features that I like in a strawburner. The
firebox should be large. I like 2 or 3′ flues because they are
not so apt to be clogged at the firebox end by fine straw or chaff
drawn over the arch, with the larger flues this can be drawn
through and burned before reaching the stack. I like the fire door
low, just on the grate line. This low door and larger flues help
prevent the common trouble of straw being drawn over and deposited
on the flue ends. I like a large steam space and a boiler that does
not prime easily, we like to keep the water high enough in the
glass so that if we have a bad spell of steaming due to clinkers
forming, etc., we can slow up on the feed-water for a while till we
get our firing back in rhythm.

Good burning straw can make large and hard clinkers both at the
grates and on flue ends. Sometimes the straw drawn over the arch
onto the flue ends will form a ‘carpet’, nearly closing the
flues, and while very hot may be so tough and flexible that a poker
could be hooked in one corner and the whole mass twisted together
and pulled out through the peep-hole.

The straw chute has a hinged door that will drop down after each
forkfull but usually the chute is kept full and each forkfull
pushes in the one ahead of it. Quite often you can feel the draft
of the engine pull the straw in the chute. Most engines can use a
larger exhaust nozzle for straw than for coal, we always used one
as large as we could get along with.

Because of the danger of the light straw coming out the stack
still burning, spark arresters of some kind were usually used. Some
had a hinged lid or cap that could be opened, mostly for
‘firing up’ or other times when a few sparks would not be
dangerous. Some tilted the whole cap to leave the top of the stack
wide open. They were usually controlled by a rod or chain within
reach of the engineer, sometimes from the engine platform.

Some spark arresters worked on the simple principle of stopping
the larger particles and letting the smaller ones go through,
others had a more complicated design, such as a flat plate or
inverted cone at the top designed to deflect the burning sparks out
and down through the screen on sides. Some directed the sparks down
through a tube at the side of the stack..

Sometimes the combination of soot, oil and water would more or
less clog the screen, and would be about the first thing the
fireman would blame if the engine did not steam well, and would
open it wide if conditions were not too dangerous for fire.

Simple engines with a sharp ‘bark’ were of course the
worst offenders, compound engines usually not so bad. I must have
threshed ten or twelve falls burning straw and never had to till a
separator out. But we always were careful to have a chain stretched
out from the separator pole so we could hook up quickly to the
front of the engine. We tried to avoid setting dead in line with
the wind, but especially with an early morning set the wind could
easily change after setting. Another safety measure found in almost
all straw burners is a sprinkling hose connected to the feed water
delivery pipe, so any time the injector or pump is running you can
have a stream of water by opening a valve. When pulling a lot of
hot ashes out of the ash pan onto flam-able stubble a hose was
often needed.

For carrying straw while on the move, if the engine had large
water supply tanks usually a rack was hung back of the platform
carrying enough straw to run quite a ways. If the engine did not
have much of a water supply a four-wheeled tender would probably be
used, with a large water tank and a straw rack on top of it. This
would usually carry enough straw for a fairly long move. The first
method had the advantage of allowing the engine to back up at will.
With the wheeled tender a large circle was needed to ‘line
up’ to the separator, and when hooking up for a move the
separator was quickly hooked to the back of the tender with a chain
and then if a shorter hookup was wanted the rig would be pulled out
straight and then the engine and tender backed up to the pole of
the separator.

For bringing the straw up to the engine while threshing several
methods were used. Some used a separate team and rack, probably
driven by a boy too young to do a man’s work. Others had one of
the bundle haulers miss his turn at the feeder to fill his rack
under the blower and unload it at the engine. Some used a
‘bucking pole’ and a team of horses. With our rig we used a
dump rack. This was just a rack open at the rear end, with a smooth
bottom, balanced near its center so it could easily be tilted up
and the load dumped in a neat pile just back of the engine. This
rack had a long cable with a hook and when straw was needed a
bundle hauler that had just unloaded drove past the front of it and
the cable hooked to the rear axle of his wagon, he then drove past
the rear of the engine, the load dumped on the run and he put the
rack back near the strawstack so it could be refilled under the
blower.

In a good strawburner straw was a satisfactory fuel. Firing was
not hard work but rather steady and the hours long. Most engineers
would ‘spell off’ the fireman once in a while.

I think straw is easier on the firebox sides than coal, possibly
a little harder on the flues.

At least three firms made stokers for straw firing. I never saw
one.