Straw Spark Arresters and Firing with Straw

4 hp. steam saw rig

4 hp. steam saw rig. Owned by O. W. Nord and son Peter, R. D. 1, Savage, Minnesota. Looks like a clever outfit. Elmer would be happy play with this one

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New Rockford Flying Service, New Rockford, North Dakota

I DO NOT REMEMBER seeing more than one reply to your question on page 8 of the March-April ALBUM about the big spark arrester on the Case engine. The letter of Harry G. Yates did not give much information on it.

I have a copy of American Threshermen, October, 1907, in it is 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


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.