experienced locomotive engineers; admitting that many air-brake men who have come up from the work bench, and after riding engines and trains in a semi-official capacity for a while and the engineers have let them make a few easy stops, imagine they are in a position, then, to criticize our best air-brake operators-admitting that they are not to be taken any more seriously than to give their theories a fair try-out, and to help them to understand where the difficulty lies-yet you must concede that many of the air-brake experts have been locomotive engi neers-" "Yes, and good ones, too," Nick rejoined, "and experienced, up to a certain point. But how many of you fellows were running engines after freight trains became 'all air'? Why, Billy, when you was an engineer everybody counted the air cars in the trains that you met on the road; and you'd be willing to miss making a meeting point in taking the time to switch your train so as to get one more air car located where you could work the air brake on it. Why, ten cars of air in one train was something to talk about for a week. Of course, the knowledge gained while you were running an engine is necessary to you now as an air-brake man, in any event, but the different experiences that come to an engineer in braking these long freight trains of today can't just be imagined; circumstances butt themselves in that you wouldn't think of; and the reports that come to you right along prove that every one of those cases of train parting is just a little different from the rest-both as to results and contributory causes. "Let's get down to particulars and figure this process out," Nick suggested. "Quoting a writer in the North American Engineer, we'll assume that we've got a 65-car train-25 loads ahead and 40 empty cars tailing out behind. Now, the idea is to keep the train stretched until the brakes have started to take hold on all of the cars in the train, and this advantage is to be secured by using steam until after the initial reduction has been made. The occasion for our stop is a 'meet' with an opposing train where we take the siding, and as we approach we view the other train coming slowly down the main. "Now, this point is accentuated: that in recommending the use of steam during the beginning of the brake application it is not to be understood as meaning that the throttle can be shut off and reopened, nor be eased off; for in the latter case, and on level track, when the engine has been using steam heavily enough to keep a long train fully stretched, the heavy drawbar springs on the cars are compressed to the limit-under the pull-on all cars in the head portion and the middle of the trainand are in readiness to throw off the same amount of force that it took to compress them; they are loaded; and then, if the steam should be eased down to a slight throttle the slack will come bunching in from behind-pulled along by the expanding drawbar spring coils; and, if just about that time the engineer should make an application of the brakes it will find the conditions of slack between the cars the very worst imaginable, that will permit such a violent stretching of the train due to the higher braking efficiency of the empty cars behind than of the loaded ones ahead-that there can be no doubt as to the train breaking in two. "If steam is used it must be with as full throttle as had been worked for the last mile, for if the attained speed is not maintained until the train brakes are all applied the slack will surely close in. "Next, it is emphasized that the initial reduction must be a light one-not more than 7 or 8 pounds.' "Now, imagine that you are lecturing a class of engineers-wise men, ncar-wise guys, boneheads and all, and are advising indiscriminately to all-as follows: 'Approaching a meeting point you are to continue to use steam under as heavy throttle as had been required to bring your train there, right up to the point where you've got to begin stopping the train, and then you are only to make a 7-pound, or not to exceed 8-pound reduction'; certainly you must not shut off steam, under this method, until the brakes are all on clear back to the caboose, or it would be fatal for the holding together of the trainsome of the rear slack would bunch ahead, and then the brakes on the hind end would go on and rip things apart. I wonder if the men who are putting up this braking proposition know how long it takes before the brakes apply at the rear of a 65-car train with a service reduction! Where are your books, Billy, with the plates that show the lantern slides representing pressure cards taken at brake tests by the air-brake people?" After Nick had glanced hurriedly through a couple of those pamphlets he said he couldn't find any report of tests made on a train of just 65 cars; "but give 'em the benefit of 15 cars less," he proposed, "and let's take this chart here for subject matter: "Slide No. 855; train of 50 cars; engineer makes a 15-pound service reduction. The chart shows that it was 43 seconds before the brake on the fiftieth car had applied with the full power obtainable from that amount of reduction, and it was about 22 seconds after the brake-pipe reduction was begun before the piston started to move in the brake cylinder of the fiftieth car; why, it was more than half a minute-33 secondsbefore the brake cylinder on the first car from the engine had its 31 pounds, the pressure limit for the amount of reduction. This is what we want to show; and with a train of 65 cars we are just commencing to get interested when we get back to the fiftieth car; about 40 seconds after the engineer's valve was placed in the service position the brakes on the rear 15 cars were starting to apply. "After the train has reached the point where the engineer considers that he should commence to stop it, he is directed to continue using a full head of steam toward the opposing train; he makes a 7 or 8-pound application, and when 43 seconds have elapsed he is still using full throttle instead of really trying to stop, the brakes on almost one-fourth of the cars have not yet applied at any noticeable degree and on 8 or 10 of the rear cars have not yet started to set. It is to be hoped," Nick remarked, "that the engineer of the opposing train is not trying to make his stop also, by this up-to-date method of braking; and that some one will get the switch open in time-at both ends of the siding. "I notice that the exponent of this braking theory doesn't give any instructions as to how close to the objective stopping point an engineer is to chase up toward under a full head of steam, before he starts to make the '7 or 8-pound reduction' (just bear in mind, Billy, that this chart here was taken on a 15-pound reduction). Of course, our up-to-date instructor won't commit himself on that point he says he can't, as differing conditions would fix this point differently; but it is the one vital point that must be considered, and if the proper point is not absolutely known beforehand, one of two things is certain to happen: the train will not be stopped short of the danger zone, or it will be stopped too soon, and the brakes will have to be prematurely released. "It is unnecessary to discuss the possibilities where the train doesn't get stopped in time; and as to the alternative, suppose that with a due regard for safety the engineer applies the air early and heavily enough that if he allows the brakes to stay applied until the train has stopped, he will then have to release, pull ahead and make another stopping application; how should he act in such a case? Instead of allowing the train to stop at first, should he release the air while still moving and using steam and a little later make another application-and if that pinched 'em down too soon, again release, and make his final stop with the air at about the right spot-engine always under a good opening of throttle, but the speed of the train held down as desired by continued reapplications and releases? It-the latter-would be the only way in which this principle of air braking could be made use of with any chances whatever of safety against headon disaster. "So, the engineer puts his brake valve in release position when he realizes that he is stopping too soon; the head brakes release first, and the engine is pulling ahead under heavy steam; of course, we are admitting that the first application while using steam didn't break the train in two, which in many cases would happen, and that the slack of the train is stretched; but it was not stretched heavily enough to fully compress the drawbar springs at the middle and rear of the train-they'll be under stress enough now, though, and when the forward lurch of the engine has gathered up the rest of the spring compression slack in forty or more pairs of drawbars you'll find there's plenty of it, and by the time the stretching event reaches the rearward cars with the unreleased brakes, the train parts. "Suppose, though, the train should not part, and the engineer should let her drag them up under steam and repeated applications and releases as suggested; does the sponsor of this braking method know what it means in the loss of reserve braking pressure, to apply and release the brakes on a 65-car train even but twice, with a very short interval of time between the first release and the second application? And with a modern freight engine under pretty fair throttle, his brake applications have got to be more than 7 or 8pound reductions, too. If the road was slightly down-grade at this point, he would probably not have air pressure enough to stop with at the last application, and this theory and the engineer who was exploiting it, would meet their fate together. No method of braking that proposes releasing and reapplying the brakes on a long train in the near proximity to possible danger ahead is worth its discussion. If the engineer permits the train to be entirely stopped by the first application it is about as bad, for the time of trouble is then only deferred; he will release, pull ahead and again endeavor to make his objective stop, by the modern method of continuing to supply the motive power while the air brakes are being employed to break it down. "The engineer who undertakes a practical demonstration of a stop at a meeting point or railroad crossing, made exactly as has been récommended by our expert herein referred to, and made without killing time when he gets to the point where he has to begin applying the brakes, instead of making a 7 or 8-pound service reduction he will invariably have to throw the brake-valve handle to the emergency position, and jump off the engine. "Let our freight-train braking expert ride one of the cars toward the rear of a 65-car train made up like the one he uses as an example, and he will observe that while the engineer is working the engine as hard as may be necessary to make the time, when the train is on a descending grade-be the gradient so slight as to be hardly noticeable-the slack between the cars will alternately close in and stretch out, and he will feel the jerks and bumps if riding in the caboose-this without the engineer easing off the throttle at all; the effect is greater when the engine and forepart of the train is upon a level or rising portion of the track at the same time, and is increased by the pull of the drawbar springs which are now throwing off the force that had compressed them during the harder pull coming up the preceding grade as these springs are compressed under a pull as well as under a butt. So you see, Billy, that when the track ap proaching a stopping point is altogether or partly of a descending gradient, even a dangerously wide open throttle would not keep the train fully stretched; but brakes on the rear cars took hold-engine when the application was made and the using steam toward the enemy-there's no doubt of the heap big stretching then, and the dissolution of the consist of that there train. "Then, I want to refer back again to that 7 or 8-pound' initial reduction made while the engine is forging ahead; the engineers trying this had better get their first experience with that kind of a stunt somewhere away from any meeting point, or where other trains might be delayed. Without a lot of 'K' triple valves, anything less than 10 pounds is too light a reduction to set all brakes in a 65-car train-productive of rough effects itself; but when a 7-pound reduction is followed by the second movement of the brakevalve handle to the service position, the delinquent brakes will quite often go on with an emergency application. "Well!" Nick looked at his watch"I've did all of the arguing, and haven't given you a chance to put up any talk in favor of the new theory-if you have any to put up. But let me conclude with this advice: If you tell your fellows to use steam-heavy throttle or otherwise-until after the brakes are all on, at all service stops with long freight trains, and if they are pinheads enough to take you at your word, your company had better borrow a few more wrecking outfits, and prepare to turn,most of your freight and passenger business over to our road; for you'll have trains straddling the track at every derail and engines Malletted together at every meeting point. It's about as safe to give your baby an automatic pistol to play with, as to demand that the engineers shall use this method of braking in general. It must be," he mused, "sort of a theory on. the antitoxin principle that 'like cures like.' If you was running an engine, Billy, would you give the new method a trial?" "Not even a trial, Nick, unless I was instructed and ordered to," I replied. "I am a member of the Board of Health." WHAT TO DO IN CASE OF BOILER TROUBLES ON THE ROAD (Copyright 1911) BY FREDERICK J. PRIOR Author's Note.-This article is divided into paragraphs, each bearing a number. Review ques tions at the end bear corresponding numbers, so in reviewing the subject immediate reference may be had to the subject-matter in which the answer may be found. In locomotive operation the difficulties that are continually met with are numer ous. Boiler troubles in road service are, perhaps, the most frequent source of difficulty, certainly the most vital. What is the nature of the boiler troubles most likely to be encountered, and what should be done in each instance, forms the basis of important and practical information for firemen and engineers. The most pronounced troubles, with suggestions in regard to them, are therefore tabulated as follows: 1. Priming and foaming are the chief causes for the carrying of water from the boiler into the cylinders. 2. The cause of foaming is the presence of foreign matter in the water, such as alkali or oil, forming a light, soapy mixture. Corn meal, used to stop leaks, and other substances also cause foaming. 3. The cause of priming is usually traced to forcing the boiler, or because the steam space is too restricted to care for the steam being generated. Defective circulation is also a cause, with the steam driving the water ahead of it through restricted spaces. In any event, water is carried into the cylinders in conjunction with the steam. 4. Foaming is usually detected by the appearance of water at the top of the stack. The steam should then be shut off gradually and the water be permitted to settle. If there are three gauges of water the trouble is usually too much water in the boiler. If the water settles down so there is only one gauge, foaming is the trouble. The whitish appearance of the steam escaping from the stack also indicates foaming. The same appearance of the steam in escaping from cylinder cocks and water gauges, and the noise made in escaping-a sort of flutter-also indicates foaming. 5. With the detection of, and proof of, foaming, the cylinder cocks should be opened, thus preventing the knocking out of cylinder heads. If there is a surface blow-off it should be opened. The left and right injectors should be put to work to raise the water level. At frequent intervals the steam should be gradually shut off and the water permitted to settle. This will determine the true levelwhich should be neither too high nor too low. Reduction of speed may also be necessary. At the first stop there should be enough solid water in the boiler to permit its being blown down for two gauges. 6. When a boiler is priming the injector should be shut off, the water level lowered and the fire checked, thus reducing the rate of evaporation. 7. Should the level of the water in the boiler fall so low as to leave the crownsheet uncovered the engine should be stopped and the fire banked with earth, thereby preventing the burning of the crownsheet. When the boiler has cooled and the steam pressure has fallen, the injector should be started and the water level raised. With the appearance of water at the first gauge, the fire may be cleaned and the locomotive is again ready for the run. 8. Where boilers are fitted with a fusible plug, which has melted because the water has fallen too much, the engine is generally disabled and has to be towed in. Should another fusible plug be available, this may be inserted after the steam pressure has been lowered. The boiler can be refilled through the safety valve opening and the fire may be rekindled. This generally involves too much time to make it practicable. 9. If a flue is leaking badly, nothing can be done if the leak is at the tubesheet where the tube has been expanded into place. Should the cause be a defective tube so that the water is blowing through to the firebox, the tube may be plugged. A wooden plug, hammered in and broken off, will usually suffice to complete the run. While the end will be burned off, the part within the tube will usually be protected. There are plugs made especially for this purpose, but they are rarely supplied to locomotives. 10. Should the blow-off cock become clogged in blowing down the boiler so that it can not be closed, the result will usually be the emptying of the boiler to such a degree that the crown-sheet will be bared. The fire, in this case, should be drawn without delay. If the fire is light it may be possible to bank it up with earth, thus keeping the heat away from the crown-sheet. 11. Where a locomotive has a shallow ashpan, and the drop-grate should become broken or burned out, the fire should be drawn back from the broken part and the space beneath filled with stones to the top of the grates. Coal should be thrown over it, so as to prevent the drawing up of an excessive amount of air. 12. Where a locomotive has a deep hopper. ashpan, and the drop grate becomes broken or burned, the locomotive should be run to the first place where splice bars or other pieces of iron or steel of suitable length can be secured. After pulling back the fire the break can be bridged with these pieces of iron. 13. Locating leaky joints in an exhaust pipe, where the air brake pump exhausts into the passages of the saddle, is accomplished by plugging the nozzle and starting the pump with an angle-cock opened to prevent accumulation of pressure in the main reservoir. This will cause the escape of steam from any joints that may be leaking. If the air pump does not so exhaust, the locating of the leak is more difficult, unless the steam pressure is low-around 25 or 30 pounds. In this event, the nozzle may be plugged and the wheels blocked. The throttle may be opened slightly and the reverse lever moved backward and forward. This will cause a pressure in the exhaust pipes and passages. 14. The best time for the inspection of a locomotive for leaky steam pipes in the front end is after the fire has been drawn and the boiler has been permitted to cool. 15. Boilers that have been standing some time under pressure have been known to explode with the opening of the throttle, caused, it is believed, by the superheating of the water. The opening of the throttle causes the outflow of steam and the liberation of the steam from the water, with a sudden increase in pressure. The danger seems to exist mostly in boilers having some weakness. 16. The form of boiler seams sometimes has a deteriorating effect on the sheets. The application or removal of pressure should in no wise affect the shape of the metal. This weakness leads to grooving and eventually to fractures. 17. There is danger in making repairs on a boiler under pressure, because if there is any grooving or weakness anywhere in the metal the disturbance is apt to cause an explosion. 18. Cracked sheets occur frequently, and generally at the throat-sheet, the tube-sheet or the side-sheets of the firebox, but this does not imply an explosion will follow. If an explosion were going to occur, it would be simultaneous with the cracking. The pressure should be reduced immediately, as by throwing earth on the fire or starting the injector. The movement of the train should not proceed without a careful inspection, so as to determine the extent of the injuries. 19. While blistered sheets are not as frequent in steel as they were in iron, they sometimes occur, and usually in the firebox where the greatest heat is exerted. In size they vary from a small spot to more than a foot in diameter. The same precautions should be taken as in the case of a cracked sheet, and if the blister has not raised away from the sheet more than two or three inches across, the locomotive may move under reduced pressure. Repairs are necessary before it is again fit for service. 20. In the explosion of a boiler, the first break occurs at some point of weakness. Through this vent the onrush of the steam tears the materiale asunder, accomplishing the complete explosion in a remarkably short space of time. Grooving along a lap, lines of rivet holes or the edge of a welt is generally the place of the initial rupture. 21. The source of energy in boiler explosions is the heat in the water. Thus, the more water in the boiler, the worse the explosion will likely be. This force is sometimes over 2,600,000,000 foot pounds, or a force sufficient to lift a 190,000-pound locomotive to a height of two and one-half miles. The energy, however, is spread in all directions. 22. While a boiler may not burst |