Chapter VI: Part SEVEN (1)

Before taking up the handling of a Traction Engine, we want to tell you of a number of things you are likely to do which you ought not to do.

Don't open the throttle too quickly, or you may throw the drive belt off, and are also more apt to raise the water and start priming.

Don't attempt to start the engine with the cylinder cocks closed, but make it a habit to open them when you stop; this will always insure your cylinder being free from water on starting.

Don't talk too much while on duty.

Don't pull the ashes out of ash pan unless you have a bucket of water handy.

Don't start the pump when you know you have low water.

Don't let it get low.

Don't let your engine get dirty.

Don't say you can't keep it clean.

Don't leave your engine at night till you have covered it up.

Don't let the exhaust nozzle lime up, and don't allow lime to collect where the water enters the boiler, or you may split a heater pipe or knock the top off of a check valve.

Don't leave your engine in cold weather without first draining all pipes.

Don't disconnect your engine with a leaky throttle.

Don't allow the steam to vary more than I0 or I5 pounds while at work.

Don't allow anyone to fool with your engine.

Don't try any foolish experiments on your engine.

Don't run an old boiler without first having it thoroughly tested.

Don't stop when descending a steep grade.

Don't pull through a stockyard without first closing the damper tight.

Don't pull onto a strange bridge without first examining it.

Don't run any risk on a bad bridge.

A TRACTION ENGINE ON THE ROAD

You may know all about an engine. You may be able to build one, and yet run a traction in the ditch the first jump.

It is a fact that some men never can become good operators of a traction engine, and I can't give you the reason why any more than you can tell why one man can handle a pair of horses better than another man who has had the same advantages. And yet if you do ditch your engine a few times, don't conclude that you can never handle a traction.

If you are going to run a traction engine I would advise you to use your best efforts to become an expert at it. For the expert will hook up to his load and get out of the neighborhood while the awkward fellow is getting his engine around ready to hook up.

The expert will line up to the separator the first time, while the other fellow will back and twist around for half an hour, and then not have a good job.

Now don't make the fatal mistake of thinking that the fellow is an expert who jumps up on his engine and jerks the throttle open and yanks it around backward and forward, reversing with a snap, and makes it stand-up on its hind wheels.

If you want to be an expert you must begin with the throttle, therein lies the secret of the real expert. He feels the power of his engine through the throttle. He opens it just enough to do what he wants it to do. He therefore has complete control of his engine. The fellow who backs his engine up to the separator with an open throttle and must reverse it to keep from running into and breaking something, is running his engine on his muscle and is entitled to small pay.

The expert brings his engine back under full control, and stops it exactly where he wants it. He handles his engine with his head and should be paid accordingly. He never makes a false move, loses no time, breaks nothing, makes no unnecessary noise, does not get the water all stirred up in the boiler, hooks up and moves out in the same quiet manner, and the onlookers think he could pull two such loads, and say he has a great engine, while the engineer of muscle would back up and jerk his engine around a half dozen times before he could make the coupling, then with a jerk and a snort he yanks the separator out of the holes, and the onlookers think he has about all he can pull.

Now these are facts, and they cannot be put too strong, and if you are going to depend on your muscle to run your engine, don't ask any more money than you would get at any other day labor.

You are not expected to become an expert all at once. Three things are essential to be able to handle a traction engine as it should be handled.

First, a thorough knowledge of the throttle. I don't mean that you should simply know how to pull it open and shut it. Any boy can do that. But I mean that you should be a good judge of the amount of power it will require to do what you may wish to do, and then give it the amount of throttle that it will require and no more. To illustrate this I will give an instance.

An expert was called a long distance to see an engine that the operator said would not pull its load over the hills he had to travel.

The first pull he had to make after the expert arrived was up the worst hill he had. When he approached the grade he threw off the governor belt, opened the throttle as wide as he could get it, and made a run for the hill. The result was, that he lifted the water and choked the engine down before he was half way up. He stepped off with the remark, "That is the way the thing does." The expert then locked the hind wheels of the separator with a timber, and without raising the pressure a pound, pulled it over the hill. He gave it just throttle enough to pull the load, and made no effort to hurry ii, and still had power to spare.

A locomotive engineer makes a run for a hill in order that the momentum of his train will help carry him over. It is not so with a traction and its load; the momentum that you get don't push very hard.

The engineer who don't know how to throttle his engine never knows what it will do, and therefore has but little confidence in it; while the engineer who has a thorough knowledge of the throttle and uses it, always has power to spare and has perfect confidence in his engine. He knows exactly what he can do and what he cannot do.

The second thing for you to know is to get onto the tricks of the steer wheel. This will come to you naturally, and it is not necessary for me to spend much time on it. All new beginners make the mistakes of turning the wheel too often. Remember this-that every extra turn to the right requires two turns to the left, and every extra turn to the left requires two more to the right; especially is this the care if your engine is fast on the road.

The third thing for you to learn, is to keep your eyes on the front wheels of your engine, and not be looking back to see if your load in coming.

In making a difficult turn you will find it very much to your advantage to go slow, as it gives you much better control of your front wheels, and it is not a bad plan for a beginner to continue to go slow till he has perfect confidence in his ability to handle the steer wheel as it may keep you out of some bad scrapes.

How about getting into a hole? Well, you are not interested half as much in knowing how to get into a hole as You are in knowing how to get out. An engineer never shows the stuff he is made of to such good advantage as when he gets into a hole; and he is sure to get there, for one of the traits of a traction engine is its natural ability to find a soft place in the ground.

Head work will get you out of a bad place quicker than all the steam you can get in your boiler. Never allow the drivers to turn without doing some good. If you are in a hole, and you are able to turn your wheels, you are not stuck; but don't allow your wheels to slip, it only lets you in deeper. If your wheels can't get a footing, you want to give them something to hold to. Most smart engineers will tell you that the best thing is a heavy chain. That is true. So are gold dollars the best things to buy bread with, but you have not always got the gold dollars, neither have you always got the chain. Old hay or straw is a good thing; old rails or timber of any kind. The engineer with a head spends more time trying to give his wheels a hold than he does trying to pull out, while the one without a head spends more time trying to pull out than he does trying to secure a footing, and the result is, that the first fellow generally gets out the first attempt, while the other fellow is lucky if he gets out the first half day.

If you have one wheel perfectly secure, don't spoil it by starting your engine till you have the other just as secure.

If you get into a place where your engine is unable to turn its wheels, then your are stuck, and the only thing for you to do is to lighten your load or dig out. But under all circumstances your engine should be given the benefit of your judgment.

All traction engines to be practical must of a necessity, be reversible. To accomplish this, the link with the double eccentric is the one most generally used, although various other devices are used with more or less success. As they all accomplish the same purpose it is not necessary for us to discuss the merits or demerits of either.

The main object is to enable the operator to run his engine either backward or forward at will, but the link is also a great cause of economy, as it enables the engineer to use the steam more or less expansively, as he may use more or less power, and, especially is this true, while the engine is on the road, as the power required may vary in going a short distance, anywhere from nothing in going down hill, to the full power of your engine in going up.

By using steam expansively, we mean the cutting off of the steam from the cylinder, when the piston has traveled a certain part of its stroke. The earlier in the stroke this is accomplished the more benefit you get of the expansive force of the steam.

The reverse on traction engines is usually arranged to cut off at I/4, I/2 or 3/4. To illustrate what is meant by "cutting off" at I/4, I/2 or 3/4, we will suppose the engine has a I2 inch stroke. The piston begins its stroke at the end of cylinder, and is driven by live steam through an open port, 3 inches or one quarter of the stroke, when the port is closed by the valve shutting the steam from the cylinder, and the piston is driven the remaining 9 inches of its stroke by the expansive force of the steam. By cutting off at I/2 we mean that the piston is driven half its stroke or 6 inches by live steam, and by the expansion of the steam the remaining 6 inches; by 3/4 we mean that live steam is used 9 inches before cutting off, and expansively the remaining 3 inches of stroke.

Here is something for you to remember: "The earlier in the stroke you cut off the greater the economy, but less the power; the later you cut off the less the economy and greater the power."

Suppose we go into this a little farther. If you are carrying I00 pounds pressure and cut off at I/4, you can readily see the economy of fuel and water, for the steam is only allowed to enter the cylinder during I/4 of its stroke; but by reason of this, you only get an average pressure on the piston head of 59 pounds throughout the stroke. But if this is sufficient to do the work, why not take advantage of it and thereby save your fuel and water? Now, with the same pressure as before, and cutting off at I/2, you have an average pressure on piston head of 84 pounds, a loss of 50 per cent in economy and a gain of 42 per cent in power. Cutting of at 3/4 gives you an average pressure of 96 pounds throughout the stroke. A loss on cutting off at I/4 of 75 per cent in economy, and a gain of nearly 63 per cent in power. This shows that the most available point at which to work steam expansively is at I/4, as the percentage of increase of power does not equal the percentage of loss in economy. The nearer you bring the reverse lever to center of quadrant, the earlier will the valve cut the steam and the less will be the average pressure, while the farther away from the center the later in the stroke will the valve cut the steam, and the greater the average pressure, and, consequently, the greater the power. We have seen engineers drop the reverse back in the last notch in order to make a hard pull, and were unable to tell why they did so.

Now, as far as doing the work is concerned, it is not absolutely necessary that you know this; but if you do know it, you are more likely to profit by it and thereby get the best results out of your engine. And as this is our object, we want you to know it, and be benefitted by the knowledge. Suppose you are on the road with your engine and load, and you have a stretch of nice road. You are carrying a good head of steam and running with lever back in the corner or lower notch. Now your engine will travel along its regular speed, and say you run a mile this way and fire twice in making it. You now ought to be able to turn around and go back on the same road with one fire by simply hooking the lever up as short as it will allow to do the work. Your engine will make the same time with half the fuel and water, simply because you utilize the expansive force of the steam instead of using the live steam from boiler. A great many good engines are condemned and said to use too much fuel, and all because the engineer takes no pains to utilize the steam to the best advantage.

I have already advised you to carry a "high pressure;" by a high pressure I mean any where from I00 to I25 lbs. I have done this expecting you to use the steam expansively whenever possible, and the expansive force of steam increases very rapidly after you have reached 70 lbs. Steam at 80 lbs. used expansively will do nine times the work of steam at 25 lbs. Note the difference. Pressure 3 I-5 times greater. Work performed, 9 times greater. I give you these facts trusting that you will take advantage of them, and if your engine at I00 or I00 lbs. will do your work cutting off at I/4, don't allow it to cut off at I/2. If cutting off at I/2 will do the work, don't allow it to cut off at 3/4, and the result will be that you will do the work with the least possible amount of fuel, and no one will have any reason to find fault with you or your engine.

Now we have given you the three points which are absolutely necessary to the successful handling of a traction engine, We went through it with you when running as a stationary; then we gave you the pointers-to be observed when running as a traction or road engine. We have also given you hints on economy, and if you do not already know too much to follow our advice, you can go into the field with an engine and have no fears as to the results.

How about bad bridges?

Well, a bad bridge is a bad thing, and you cannot be too careful. When you have questionable bridges to cross over, you should provide yourself with good hard-wood planks. If you can have them sawed to order have them 3 inches in the center and tapering to 2 inches at the ends. You should have two of these about 16 feet long, and two 2x12 planks about 8 feet long. The short ones for culverts, and for helping with the longer ones in crossing longer bridges.

An engine should never be allowed to drop from a set of planks down onto the floor of bridge. This is why I advocate four planks. Don't hesitate to use the plank. You had better plank a dozen bridges that don't need it than to attempt to cross one that does need it. You will also find it very convenient to carry at least 50 feet of good heavy rope. Don't attempt to pull across a doubtful bridge with the separator or tank hooked directly to the engine. It is dangerous. Here is where you want the rope. An engine should be run across a bad bridge very slowly and carefully, and not allowed to jerk. In extreme cases it is better to run across by hand; don't do this but once; get after the road supervisors.

SAND.

An engineer wants a sufficient amount of "sand," but he don't want it in the road. However, you will find it there and it is the meanest road you will have to travel. A bad sand road requires considerable sleight of hand on the part of the engineer if he wishes to pull much of a load through it. You will find it to your advantage to keep your engine as straight as possible, as you are not so liable to start one wheel to slipping any sooner than the other. Never attempt to "wiggle" through a sand bar, and don't try to hurry through; be satisfied with going slow, just so you are going. An engine will stand a certain speed through sand, and the moment you attempt to increase that speed, you break its footing, and then you are gone. In a case of this kind, a few bundles of hay is about the best thing you can use under your drivers in order to get started again. But don't loose your temper; it won't help the sand any.

Now no doubt the reader wonders why I have said nothing about compound engines. Well in the first place, it is not necessary to assist you in your work, and if you can handle the single cylinder engine, you can handle the compound.

The question as to the advantage of a compound engine is, or would be an interesting one if we cared to discuss it.

The compound traction engine has come into use within the past few years, and I am inclined to think more for sort of a novelty or talking point rather than to produce a better engine. There is no question but that there is a great advantage in the compound engine, for stationary and marine engines.

In a compound engine the steam first enters the small or high pressure cylinder and is then exhausted into the large or low pressure cylinder, where the expansive force is all obtained.

Two cylinders are used because we can get better results from high pressure in the use of two cylinders of different areas than by using but one cylinder, or simple engine.

That there is a gain in a high pressure, can be shown very easily:

For instance, 100 pounds of coal will raise a certain amount of water from 60 degrees, to 5 pounds steam pressure, and 102.9 pounds would raise the same water to 80 pounds, and 104.4 would raise it to 160 pounds, and this 160 pounds would produce a large increase of power over the 80 pounds at a very slight increase of fuel. The compound engine will furnish the same number of horse power, with less fuel than the simple engine, but only when they are run at the full load all the time.

If, however, the load fluctuates and should the load be light for any considerable part of the day, they will waste the fuel instead of saving it over the simple engine.

No engine can be subjected to more variation of loads than the traction engine, and as the above are facts the reader can draw his own conclusions.

FRICTION CLUTCH

The friction clutch is now used almost exclusively for engaging the engine with the propelling gearing of the traction drivers, and it will most likely give you more trouble than any one thing on your engine, from the fact that to be satisfactory they require a nicety of adjustment, that is very difficult to attain, a half turn of the expansion bolt one way or the other may make your clutch work very nicely, or very unsatisfactory, and you can only learn this by carefully adjusting of friction shoes, until you learn just how much clearance they will stand when lever is out, in order to hold sufficient when lever is thrown in. If your clutch fails to hold, or sticks, it is not the fault of the clutch, it is not adjusted properly. And you may have it correct today and tomorrow it will need readjustment, caused by the wear in the shoes; you will have to learn the clutch by patience and experience.

But I want to say to you that the friction clutch is a source of abuse to many a good engineer, because the engineer uses no judgment in its use.

A certain writer on engineering makes use of the following, and gives me credit: "Sometimes you may come to an obstacle in the road, over which your engine refuses to go, you may perhaps get over it in this way, throw the clutch-lever so as to disconnect the road wheels, let the engine get up to full speed and then throw the clutch level back so as to connect the road wheels." Now I don't thank any one for giving me credit for saying any such thing. That kind of thing is the hight of abuse of an engine.

I am aware that when the friction clutch first came into use, their representatives made a great talk on that sort of thing to the green buyer. But the good engineer knows better than to treat his engine that way.

Never attempt to pull your loads over a steep hill without being certain that your clutch is in good shape, and if you have any doubts about it put in the tight gear pin. Most all engines have both the friction and the tight gear pin. The pin is much the safer in a hilly country, and if you have learned the secret of the throttle you can handle just as big load with the pin as with the clutch, and will never tear your gearing off or lose the stud bolts in boiler.

The following may assist you in determining or arriving at some idea of the amount of power you are supplying with your engine:

For instance, a I inch belt of the standard grade with the proper tention, neither too tight or too loose, running at a. maximum spead of 800 ft. a minute will transmit one horse power, running 1600 ft. 2 horse power and 2400 ft. 3 horse power. A 2 inch belt, at the same speed, twice the power.

Now if you know the circumference of your fly wheel, the number of revolutions your engine is making and the width of belt, you can figure very nearly the amount of power you can supply without slipping your belt. For instance, we will say your fly wheel is 40 inches in diameter or 10.5 feet nearly in circumference and your engine was running 225 revolutions a minute, your belt would be traveling 225 x 10.5 feet = 2362.5 feet or very nearly 2400 ft. and if I inch of belt would transmit 3 H. P. running this speed, a 6 inch belt would transmit 18 H.P., a 7 inch belt, 21 H.P., an 8 inch belt 24 H.P., and so on. With the above as a basis for figuring you can satisfy yourself as to the power you are furnishing. To get the best results a belt wants to sag slightly as it hugs the pulley closer, and will last much longer.

SOMETHING ABOUT SIGHT-FEED LUBRICATORS

All such lubricators feed oil through the drop-nipple by hydrostatic pressure; that is, the water of condensation in the condenser and its pipe being elevated above the oil magazine forces the oil out of the latter by just so much pressure as the column of water is higher than the exit or outlet of oil-nipple. The higher the column of water the more positive will the oil feeds. As soon as the oil drop leaves the nipple it ceases to be actuated by the hydrostatic pressure, and rises through the water in the sight-glass merely by the difference of its specific gravity, as compared with water and then passes off through the ducts provided to the parts to be lubricated.

For stationary engines the double connection is preferable, and should always be connected to the live steam pipe above the throttle. The discharge arm should always be long enough (4 to 6 inches) to insure the oil magazine and condenser from getting too hot, otherwise it will not condense fast enough to give continuous feed of oil. For traction or road engines the single connection is used. These can be connected to live steam pipe or directly to steam chest.

In a general way it may be stated that certain precaution must be taken to insure the satisfactory operation of all sight-feed lubricators. Use only the best of oil, one gallon of which is worth five gallons of cheap stuff and do far better service, as inferior grades not only clog the lubricator but chokes the ducts and blurs the sight-glass, etc., and the refuse of such oil will accumulate in the cylinder sufficiently to cause damage and loss of power, far exceeding the difference in cost of good oil over the cheap grades.

After attaching a lubricator, all valves should be opened wide and live steam blown through the outer vents for a few minutes to insure the openings clean and free. Then follow the usual directions given with all lubricators. Be particular in getting your lubricator attached so it will stand perfectly plum, in order that the drop can pass up through the glass without touching the sides, and keep the drop-nipple clean, be particular to drain in cold weather.

Now, I am about to leave you alone with your engine, just as I have left any number of young engineers after spending a day with them in the field and on the road. And I never left one, that I had not already made up my mind fully, as to what kind of an engineer he would make.

TWO WAYS OF READING __________

Now there are two ways to read this book, and if I know just how you had read it I could tell you in a minute whether to take hold of an engine or leave it alone. If you have read it one way, you are most likely to say "it is no trick to run an engine." If you have read it the other way you will say, "It is no trouble to learn how to run an engine." Now this fellow will make an engineer, and will be a good one. He has read it carefully, noting the drift of my advice. Has discovered that the engineer is not expected to build an engine, or to improve it after it has been built. Has recognized the fact that the principle thing is to attend to his own business and let other people attend to theirs. That a monkey wrench is a tool to be left in the tool box till he knows he needs it. That muscle is a good thing to have but not necessary to the successful engineer. That an engineer with a bunch of waste in his hand is a better recommendation than an "engineer license." That good common sense, and a cool head is the very best tools he can have. Has learned that carelessness will get him into trouble, and that to "forget" costs money.

Now the fellow who said "It is no trick to run an engine," read this book another way. He did not see the little points. He was hunting for big theories, scientific theories, something he could not understand, and didn't find them. He expected to find some bright scheme to prevent a boiler from exploding, didn't notice the simple little statement, "keep water in it," that was too commonplace to notice. He was looking for cuts, diagrams, geometrical figures, theories for constructing engines and boilers and all that sort of thing and didn't find them. Hence "It is no trick to run an engine."

If this has been your idea of "Rough and Tumble Engineering" forget all about your theory, and go back and read it over and remember the little suggestions and don't expect this book to teach you how to build an engine. We didn't start out to teach you anything of the kind. That is a business of itself. A good engineer gets better money than the man who builds them. Read it as if you wanted to know how to run an engine and not how to build one.

Study the following questions and answers carefully. Don't learn them like you would a piece of poetry, but study them, see if they are practical; make yourself thoroughly acquainted with the rule for measuring the horse-power of an engine; make yourself so familiar with it that you could figure any engine without referring to the book. Don't stop at this, learn to figure the heating surface in any boiler. It will enable you to satisfy yourself whether you are working your boiler or engine too hard or what it ought to be capable of doing.

SOME THINGS TO KNOW

Q. What is fire? A. Fire is the rapid combustion or consuming of organic matter.

Q. What is water? A. Water is a compound of oxygen and hydrogen. In weight 88 9-I0 parts oxygen to II I-I0 hydrogen. It has its maximum density at 39 degrees Fahr., changes to steam at 2I2 degrees, and to ice at 32 degrees.

Q. What is smoke? A. It is unconsumed carbon finely divided escaping into open air.

Q. Is excessive smoke a waste of fuel? A. Yes.

Q. How will you prevent it A. Keep a thin fire, and admit cold air sufficient to insure perfect combustion.

Q. What is low water as applied to a boiler? A. It is when the water is insufficient to cover all parts exposed to the flames.

Q. What is the first thing to do on discovering that you have low water? A. Pull out the fire.

Q. Would it be safe to open the safety valve at such time? A. No.

Q. Why not? A. It would relieve the pressure on the water which being allowed to flow over the excessive hot iron would flash into steam, and might cause an explosion.

Q. Why do boilers sometimes explode just on the point of starting the engine? A. Because starting the engine has the same effect as opening the safety valve.

Q. Are there any circumstances under which an engineer is justified in allowing the water to get low? A. No.

Q. Why do they sometimes do it? A. From carelessness or ignorance.

Q. May not an engineer be deceived in the gauge of water? A. Yes.

Q. Is he to be blamed under such circumstances? A. Yes.

Q. Why? A. Because if he is deceived by it it shows he has neglected something.

Q. What is meant by "Priming." A. It is the passing of water in visible quantities into the cylinder with the steam.

Q. What would you consider the first duty of an engineer on discovering that the water was foaming or priming A. Open the cylinder cocks at once, and throttle the steam.

Q. Why would you do this? A. Open the cocks to enable the water to escape, and throttle the steam so that the water would settle.

Q. Is foaming the same as priming? A. Yes and no.

Q. How do you make that out? A. A boiler may foam without priming, but it can't prime without first foaming..

Q. Where will you first discover that the water is foaming? A. It will appear in the glass gauge, the glass will have a milky appearance and the water will seem to be running down from the top, There will be a snapping or cracking in the cylinder as quick as priming begins.

Q. What causes a boiler to foam? A. There are a number of causes. It may come from faulty construction of boiler; it may have insufficient steam room. It may be, and usually is, from the use of bad water, muddy or stagnant water, or water containing any soapy substance.

Q. What would you do after being bothered in this way? A. Clean out the-boiler and get better water if possible.

Q. How would you manage your pumps while the water was foaming. A. Keep them running full.

Q. Why? A. In order to make up for the extra amount of water going out with the steam.

Q. What is "cushion?" A. Cushion is steam retained or admitted in front of the piston head at the finish of stroke, or when the engine is on "center."

Q. What is it for? A. It helps to overcome the "inertia" and momentum of the reciprocating parts of the engine, and enables the engine to pass the center without a jar.

Q. How would you increase the cushion in an engine? A. By increasing the lead.

Q. What is lead? A. It is the amount of opening the port shows on steam end of cylinder when the engine is on dead center.

Q. Is there any rule for giving an engine the proper lead? A. No.

Q. Why not? A. Owing to their variation in construction, speed, etc.

Q. What would you consider the proper amount of lead, generally. A. From I/32 to I/I6.

Q. What is "lap?" A. It is the distance the valve overlaps the steam ports when in mid position.

Q. What is lap for? A. In order that the steam may be worked expansively.

Q. When does expansion occur in a cylinder? A. During the time between which the port closes and the point at which the exhaust opens.

Q. What would be the effect on an engine if the exhaust opened too soon? A. It would greatly lessen the power of the engine.

Q. What effect would too much lead have. A. It would also weaken the engine, as the steam would enter before the piston had reached the end of the stroke, and would tend to prevent it passing the center.

Q. What is the stroke of an engine? A. It is the distance the piston travels in the cylinder.

Q. How do you find the speed of a piston per minute? A. Double the stroke and multiply it by the number of revolutions a minuet. Thus an engine with a 12 inch stroke would travel 24 inches, or 2 feet, at a revolution. If it made 200 revolutions a minute, the travel of piston would be 400 feet a minute.

Q. What is considered a horse power as applied to an engine? A. It is power sufficient to lift 33,000 pounds one foot high in one minute.

Q. What is the indicated horse power of an engine? A. It is the actual work done by the steam in the cylinder as shown by an indicator.

Q. What is the actual horse power? A. It is the power actually given off by the driving belt and pulley.

Q. How would you find the horse power of an engine? A. Multiply the area of the piston by the average pressure, less 5; multiply this product by the number of feet the piston travels per minute; divide the product by 33,000; the result will be horse power of the engine.

Q. How will you find the area of piston? A. Square the diameter of piston and multiply it by .7854.

Q. What do you mean by squaring the diameter? A. Multiplying it by itself. If a cylinder is 6 inches in diameter, 36 multiplied by .7854, gives the area in square inches.

Q. What do you mean by average pressure? A. If the pressure on boiler is 60 pounds, and the engine is cutting off at 1/2 stroke, the pressure for the full stroke would be 50 pounds.

Q. Why do you say less 5 pounds? A. To allow for friction and condensation.

Q. What is the power of a 7 x 10 engine, running 200 revolutions, cutting off at 1/2 stroke with 60 pounds steam? A. 7 x 7 = 49 x .7854 = 38.4846. The average pressure of 60 pounds would be 50 pounds less 5 = 45 pounds; 38-4846 x 45 = 1731.8070 x .333 1/3, (the number of feet the piston travels per minute) 577,269.0000 by 33,000=17 1/2 horse power.

Q. What is a high pressure engine? A. It is an engine using steam at a high pressure and exhausting into the open air.

Q. What is a low pressure engine? A. It is one using steam at a low pressure and exhausting into a condenser, producing a vacuum, the piston being under steam pressure on one side and vacuum on the other.

Q. What class of engines are farm engines? A. They are high pressure.

Q. Why? A. They are less complicated and less expensive.

Q. What is the most economical pressure to carry on high pressure engine? A. From 90 to 110 pounds.

Q. Why is high pressure more economical than low pressure? A. Because the loss is greater in low pressure owing to the atmospheric pressure. With 45 pounds steam the pressure from the atmosphere is 15 pounds, or 1/3, leaving only 30 pounds of effective power; while with 90 pounds the atmospheric pressure is only 1-6 of the boiler pressure.

Q. Does it require any more fuel to carry I00 pounds than it does to carry 60 pounds? A. It don't require quite as much.

Q. If that is the case why not increase the pressure beyond this and save more fuel? A. Because we would soon pass the point of safety in a boiler, and the result would be the loss of life and property.

Q. What do you consider a safe working pressure on a boiler? A. That depends entirely on its diameter. While a boiler of 30 inches in diameter 3/8 inch iron would carry I40 pounds, a boiler of the same thickness 80 inches in diameter would have a safe working pressure of only 50 pounds, which shows that the safe working pressure decreases very rapidly as we increase the diameter of boiler. This is the safe working pressure for single riveted boilers of this diameter. To find the safe working pressure of a double riveted boiler of same diameter multiply the safe pressure of the single riveted by 70, and divide by 56, will give a safe pressure of a double riveted boiler.

Q. Why is a steel boiler superior to an iron boiler? A. Because it is much lighter and stronger.

Q. Does boiler plate become stronger or weaker as it becomes heated? A. It becomes tougher or stronger as it is heated, till it reaches a temperature Of 550 degrees when it rapidly decreases its power of resistance as it is heated beyond this temperature.

Q. How do you account for this? A. Because after you pass the maximum temperature of 550 degrees, the more you raise the temperature the nearer you approach its fusing point when its tenacity or resisting power is nothing.

Q. What is the degree of heat necessary to fuse iron? A. 2912 degrees.

Q. Steel? A. 2532 degrees.

Q. What class of boilers are generally used in a threshing engine? A. The flue boiler and the tubular boiler.

Q. About what amount of heating and grate surface is required per horse power in a flue boiler. A. About 15 square feet of heating surface and 3/4 square feet of grate surface.

Q. What would you consider a fair evaporation in a flue boiler? A. Six pounds of water to I pound of coal.

Q. How do these dimensions compare in a tubular boiler. A. A tubular boiler will require I/4 less grate surface, and will evaporate about 8 pounds of water to I pound of coal.

Q. Which do you consider the most available? A. The tubular boiler.

Q. Why? A. It is more economical and is less liable to "collapse?"

Q. What do you mean by "collapse?" A. It is a crushing in of a flue by external pressure.

Q. Is a tube of a large diameter more liable to collapse than one of small diameter? A. Yes.

Q. Why? A. Because its power of resistance is much less than a tube of small diameter.

Q. Is the pressure on the shell of a boiler the same as on the tubes? A. No.

Q. What is the difference? A. The shell of boiler has a tearing or internal pressure while the tubes have a crushing or external pressure.

Q. What causes an explosion? A. An explosion occurs generally from low water, allowing the iron to become overheated and thereby weakened and unable to withstand the pressure.

Q. What is a "burst?" A. It is that which occurs when through any defect the water and steam are allowed to escape freely without further injury to boiler.

Q. What is the best way to prevent an explosion or burst? A. (I) Never go beyond a safe working pressure. (2) Keep the boiler clean and in good repair. (3) Keep the safety valves in good shape and the water at its proper height.

Q. What is the first thing to do on going to your engine in the morning? A. See that the water is at its proper level.

Q. What is the proper level? A. Up to the second gauge.

Q. When should you test or try the pop valve? A. As soon as there is a sufficient pressure.

Q. How would you start your engine after it had been standing over night? A. Slowly.

Q. Why? A. In order to allow the cylinder to become hot, and that the water or condensed steam may escape without injury to the cylinder.

Q. What is the last thing to do at night? A. See that there is plenty of water in boiler, and if the weather is cold drain all pipes.

Q. What care should be taken of the fusable plug? A. Keep it scraped clean, and not allow it to become corroded on top.

Q. What is a fusible plug? A. It is a hollow cast plug screwed into the crown sheet or top of fire box, and having the hollow or center filled with lead or babbit.

Q. Is such a plug a protection to a boiler? A. It is if kept in proper condition.

Q. Can you explain the principle of the fusible or soft plug as it is sometimes called? A. It is placed directly over the fire, and should the water fall below the crown sheet the lead fuses or melts and allows the steam to flow down on top of the fire, destroys the heat and prevents the burning of crown sheet.

Q. Why don't the lead fuse with water over it? A. Because the water absorbs the heat and prevents it reaching the fusing point.

Q. What is the fusing point of lead? A. 618 degrees.

Q. Is there any objection to the soft plug? A. There is, in the hands of some engineers.

Q. Why? A. It relieves him of the fear of a dry crown sheet, and gives him an apparent excuse for low water.

Q. Is this a real or legitimate objection? A. It is not.

Q. What are the two distinct classes of boilers? A. The externally and internally fired boilers.

Q. Which is the most economical? A. The internally fired boiler.

Q. Why? A. Because the fuel is all consumed in close contact with the sides of furnace and the loss from radiation is less than in the externally fired.

Q. To what class 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 circumference or square of furnace, by its length, then multiply, the circumference 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 circumference 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 circumference 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 ____________