Rough and Tumble Engineering Part 9

Q. To what cla.s.s does the farm or traction engine belong?

A. To the internally fired.

Q. How would you find the H.P. of such a boiler?

A. Multiply in inches the circ.u.mference or square of furnace, by its length, then multiply, the circ.u.mference of one tube by its total length, and this product by the number of tubes also taking into account the surface in tube sheet, add these products together and divide by I44, this will give you the number of square feet of heating surface in boiler. Divide this by 14 or 15 which will give the H.P. of boiler.

Q. Why do you say 14 or 15?

A. Because some claim that it requires 14 feet of heating surface to the H.P. and others 15.

To give you my personal opinion I believe that any of the standard engines today with good coal and properly handled, will and are producing 1 H.P. for as low as every 10 feet of surface. But to be on the safe side it is well to divide by 15 to get the H.P. of your boiler, when good and bad fuel is considered.

Q. How would you find the approximate weight of a boiler by measurement?

A. Find the number of square feet in surface of boiler and fire box, and as a sheet of boiler iron or steel 1/16 of an inch thick, and one foot square, weighs 2.52 pounds, would multiply the number of square feet by 2.52 and this product by the number of 16ths or thickness of boiler sheet, which would give the approximate, or very near the weight of the boiler.

Q. What would you recognize as points in a good engineer.

A. A good engineer keeps his engine clean, washes the boiler whenever he thinks it needs it. Never meddles with his engine, and allows no one else to do so.

Goes about his work quietly, and is always in his place, only talks when necessary, never hammers or bruises any part of his engine, allows no packing to become baked or burnt in the stuffing box or glands, renews them as quick as they show that they require it.

Never neglects to oil, and then uses no more than is necessary.

He carries a good gauge of water and a uniform pressure of steam. He allows no unusual noise about his engine to escape his notice he has taught his ear to be his guide.

When a job is about finished you will see him cleaning his ash pan, getting his tools together, a good fire in fire box, in fact all ready to go, and he looses no time after the belt is thrown off. He hooks up to his load quietly, and is the first man ready to go.

*Q. When the piston head is in the exact center of cylinder, is the engine on the quarter?

*A. It is supposed to be, but is not.

*Q. Why not?

A. The angularity of the rod prevents it reaching the quarter.

*Q. Then when the engine is on the exact quarter what position does the piston head occupy?

A. It is nearest the end next to crank.

Q. If this is the case, which end of cylinder is supposed to be the stronger?

A. The opposite end, or end furtherest from crank.

Q. Why?

A. Because this end gets the benefit of the most travel, and as it makes it in the same time, it must travel faster.

*Q. At what part of the cylinder does the piston head reach the greatest speed?

A. At and near the center.

*Q. Why?

Figure this out for yourself.

*Note. The above few questions are given for the purpose of getting you to notice the little peculiarities of the crank engine, and are not to be taken into consideration in the operation of the same.

Q. If you were on the road and should discover that you had low water, what would you do?

A. I would drop my load and hunt a high place for the front end of my engine, and would do it quickly to.

Q. If by some accident the front end of your engine should drop down allowing the water to expose the crown sheet, what would you do?

A. If I had a heavy and hot fire, would shovel dirt into the fire and smother it out.

Q. Why would you prefer this to drawing the fire?

A. Because it would reduce the heat at once, instead of increasing it for a few minutes while drawing out the hot bed of coals, which is a very unpleasant job.

Q. Would you ever throw water in the fire box?

A. No. It might crack the side sheets, and would most certainly start the flues.

Q. You say, in finding low water while on the road, you would run your engine with the front end on high ground. Why would you do this?

A. In order that the water would raise over the crown sheet, and thus make it safe to pump up the water.

Q. While your engine was in this shape would you not expose the front end of flues'?

A. Yes, but as the engine would not be working this would do no damage.

Q. If you were running in a hilly country how would you manage the boiler as regards water?

A. Would carry as high as the engine would allow, without priming.

Q. Suppose you had a heavy load or about all you could handle, and should approach a long steep hill, what condition should the water and fire be to give you the most advantage?

A. A moderately low gauge of water and a very hot fire.

Q. Why a moderately low gauge of water?

A. Because the engine would not be so liable to draw the water or prime in making the hard pull.

Q. Why a very hot fire?

A. So I could start the pumps full without impairing or cutting the pressure.

Q. When would you start your pump?

A. As soon as fairly started up the hill.

Q. Why?

A. As most hills have two sides, I would start them full in order to have a safe gauge to go down, without stoping to pump up.

Q. What would a careful engineer do before starting to pull a load over a steep hill?

A. He would examine his clutch, or gear pin.

Q. How would you proceed to figure the road speed of traction.

A. Would first determine the circ.u.mference of driver, then ascertain how many revolutions the engine made to one of the drivers. Multiply the number of revolutions the engine makes per minute by 60, this will give the number of revolutions of engine per hour. Divide this by the number of revolutions the engine makes to the drivers once, and this will give you the number of revolutions the drivers will make in one hour, and multiplying this by the circ.u.mference of driver in feet, and it will tell you how many feet your engine is traveling per hour, and this divided by 5280, the number of feet in a mile, would tell you just what speed your engine would make on the road.

THINGS HANDY FOR THE ENGINEER

The first edition of this work brought me a great many letters asking where certain articles could be procured, what I would recommend, etc.

These questions required attention and as the writers had bought and paid for their book it was due them that they get the benefit of my experience, as nothing is so discouraging to the young engineer as to be continually annoyed by unreliable and inferior fittings used more or less on all engines. I have gone over my letter file and every article asked for will be taken up in the order, showing the relative importance of each article in the minds of engineers. For instance, more letters reached me asking for a good brand of oil than any other one article.

Then comes injectors, lubricators have third place, and so on down the list. Now without any intention of advertising anybody's goods I will give you the benefit of my years of experience and will be very careful not to mention or recommend anything which is not strictly first cla.s.s, at least so in my opinion, and as good as can be had in its cla.s.s, yet in saying that these articles are good does not say that others are not equally as good. I am simply antic.i.p.ating the numerous letters I otherwise would receive and am answering them in a lump bunch. If you have no occasion to procure any of these articles, the naming of them will do no harm, but should you want one or more you will make no mistake in any one of them.

OIL

As I have stated, more engineers asked for a good brand of oil than for any other one article and I will answer this with less satisfaction to myself than any other for this reason: You may know what you want, but you do not always get what you call for. Oil is one of those things that cannot be branded, the barrel can, but then it can be filled with the cheapest stuff on the market. If you can get Capital Cylinder Oil your valve will give you no trouble. If you call for this particular brand and it does not give you satisfaction don't blame me or the oil, go after the dealer; he did not give you what you called for. The same can be said of Renown Engine Oil. If you can always have this oil you will have no fault to find with its wearing qualities, and it will not gum on your engine, but as I have said, you may call for it and get something else. If your valve or cylinder is giving you any trouble and you have not perfect confidence in the dealer from whom you usually get your cylinder oil send direct to The Standard Oil Company for some Capital Cylinder Oil and you will get an oil that will go through your cylinder and come out the exhaust and still have some staying qualities to it.

The trouble with so much of the so called cylinder oil is that it is so light that the moment it strikes the extreme heat in the steam chest it vaporizes and goes through the cylinder in the form of vapor and the valve and cylinder are getting no oil, although you are going through all the necessary means to oil them.

It is somewhat difficult to get a young engineer to understand why the cylinder requires one grade of oil and the engine another. This is only necessary as a matter of economy, cylinder or valve oil will do very well on the engine, but engine oil will not do for the cylinder. And as a less expensive oil will do for the engine we therefore use two grades of oil.