first passing through port K-1, which during service and emergency applicaleads to chamber K-1. Port V is used tions. to vent brake-pipe pressure to port K-1 (To be continued.) MOVEMENT OF TRAINS By G. E. COLLINGWOOD Flag Within Yard Limits. There has been considerable discussion of late as to whether or not a train should flag when it is within yard limits, The following letter from a railroad official will serve as an illustration of the point under discussion: "Let me take an example, in which an extra train is running upon a schedule order, Form-G, Example 3, with right over all trains. The explanation to this example states that trains over which the extra is thus given right must clear permit any train to use the main track without protection within yard limits. Some roads provide for the protection of trains within yard limits with automatic block signals; other roads operate under manual block signals and take advantage thereof to provide protection to trains and engines working within yard limits, upon the main track; still other roads provide semaphores on each side of the yard and secure protection in such manner. "I will appreciate it very much if you will give me the correct understanding of the rule which governs yard limits. The rule that I refer to reads, "Within yard limits the main track may be used, protecting against first-class trains. Rule 93, as quoted, is of little real Second- and third-class and extra trains value in the operation of trains within a must move within yard limits prepared to stop unless the main track is seen or yard, for the reason that it does not actually confer any authority known to be clear.' upon trains within yard limits, except in a very limited manner. The rule clearly authorizes trains and engines within yard limits to use the main track upon the time of first-class trains, by protecting; but it does not instruct first-class trains to proceed through yard limits as the way is seen or known to be clear, nor does it even caution first-class trains that the yard limits will permit trains to hold the main track against them. except by inference. On the other hand, second- and third-class trains and extra trains are instructed to move through yard limits prepared to stop unless the way is seen or known to be clear, and the rule fails to give any authority whatsoever to a train within yard limits to use the main track upon the time of sec the time of the extra five minutes. "I will be pleased to have you state whether or not a train may occupy the main track on the time of this extra train, within yard limits, without flag protection." The above letter is a good sample of many others which have been recently received, and the answer, in brief, is that a train within yard limits may use the main track on the time of the extra train, which is running under the third example of Form-G, the same as it would use the main track within yard limits on the time of any other extra ond- and third-class and extra trains. train. That is to say, an order giving an extra a schedule and right over all trains does not confer any class upon the extra and, therefore, does not give it any more authority within yard limits, under the rules, than any other extra train has. Answering a further insinuation which is contained in the letter, there is no assurance in the rule quoted which will This brings up a condition, under the rules, in which a train can work against a first-class train, under protection, but is required by the rule, as it stands, to clear second- and third-class trains. From this distance it seems that what is to be desired in a yard rule is one that states exactly what it means and fully covers the movements which it becomes necessary to make within yard limits. In this particular case the standard permitted to move through yard limits rule has been twisted to such an extent with the assurance of a clear track. In that it is imperfect in its operation. It the operation of the rule, if there are no will be found that a number of roads are automatic signals or other means of givusing Rule 93 in this imperfect manner. ing protection by fixed signals, then This comes about by reason of the fact trains and engines within yard limits that the Standard Code has left two would be required to work under flag blank spaces in the rule, and in filling protection against second and inferior in these spaces the wrong information has been inserted. The rule should read: "Within yard limits the main track may be used, protecting against second and inferior class trains. Second and inferior class trains and extra trains must move within yard limits prepared to stop unless the main track is seen or known to be clear." class trains and extras. But under the rule as quoted by our correspondent there is no authority conferred on any train within yard limits to use the main track on the time of second- and thirdclass and extra trains. It is suggested to the official making inquiry that the rule should be corrected When the rule is worded as above, or that addtional instructions should be first-class trains, which are usually the issued which will be sufficient for proper most important passenger trains, are operation of trains within yard limits. Questions and Answers Locomotive Running and Repairs. Answers by F. P. Roesch. 2424. Starting Fire on Oil Burning Locomotive. Brother H. J. M., of Lodge 691, forwards the following instructions which we believe are worth publishing: Answer. In making a hydrostatic test the Federal Boiler Inspection laws require that the boiler be tested to 25 per cent above the working pressure. This would necessitate a pressure of 125 pounds on a boiler that is to carry 100 pounds. While the same pressure should Answer.-"A good way to start a fire be applied regardless of whether cold with oil burning locomotives. First, water, hot water or air is used, yet as open the blower lightly; second, open the principal object of testing a boiler is atomizer wide and leave it open a min- to determine, first, its ability to carry the ute to free it from water or condensed working pressure, and, second, to find steam, then close it tightly; third, light and correct any leaks that might exist in a piece of waste saturated with oil and the boiler, it is always preferable to use throw it in the firebox. Be sure that hot or warm water. In fact, the use of you have closed atomizer. Fourth, open oil valves just a little, and as soon as you see oil at the mouth of the burner, get away from fire door and turn on the atomizer lightly. With a little practice anyone can light fires and never make any smoke or noise, or lay himself liable to injury by back-flashing or exploding of the gas in the firebox, if he will follow these rules as laid down." 2425. Testing Boilers.-"In testing a boiler that is to carry say 100 pounds of steam, what pressure should be applied when cold water is used and what pressure when air is used?"-M. M. air to test a boiler would not be considered satisfactory by the Federal Inspection Bureau. The only time that air should be used is when applying pressure to a boiler in order to test flexible staybolts under the hammer. This because a certain type of flexible staybolt can not be accurately tested with a hammer test unless a pressure equal to the working pressure is applied to the boiler in order to separate the two ends of any bolt that should happen to be broken. Answer. This question was referred to Mr. J. Will Johnson, General Manager of the Pyle National Electric Headlight Co., who replies as follows: "We will not give you the answer in short terse terms, but will cover this particular point as thoroughly as possible. "When the headlight burns poorly, it will be found that this is due to either too low speed of armature (speed should be 2800 R. P. M. no load), poorly focused lamp or dirty reflector. When the carbon continues to jump up and down on the electrode, it will be found that either the speed of the armature is too low, which would not generate current enough to energize the solenoid of the lamp to a strength sufficient to grip the solenoid plunger 64 and hold same steady, or the 2427. Type of Valve. "Is there any set rule to be applied in choosing a valve for a slide valve engine when the size of the seat and ports are known?"-M. M. Answer. While there is no set rule as to the type of slide-valve to be used, which can be of either inside or outside admission on a stationary engine, depending, of course, upon the manner in which link that connects the solenoid plunger the ports are cut into the valve seat, yet there are other things to be considered besides the size of the seat and ports; as, for instance, the travel of the valve, which, of course, would be regulated by the throw of the eccentrics, lengths of the rocker arms, if used, etc., this determining the amount of lap or the distance that the valve edges governing the admission of steam should project over the ports when the valve is centralized on its seat. In fact, the lap of the valve is one of the prime essentials, as economy in fuel and water usually depends in a large measure upon the lap. 2428. Intercepting Valve. "Will you please give a brief description, through the columns of the Magazine, of the intercepting valve on a Mallet compound engine? How would you determine if it was stuck open or closed?"-G. E. R. Answer.-For a full description, together with illustrations of the intercepting valve as used on the American locomotive type of Mallet engines you are referred to "Our Special Study Course" as published in the November, 1913, issue of the Magazine, beginning on page 629. For short answers to your questions we would refer you to questions 43, 51 and 53, together with their answers, on page 651 of the same issue. 64 to solenoid plunger yoke 90 is too short, which causes the lamp to jump. In this case, of course, you would drop the plunger 64 in the solenoid a short distance, which would stop the jumping and jigging of the lamp." 2430. Movement of Crosshead. "Please explain the to and fro movement of the crosshead in the guides. I am having an argument with an engineer. He claims that the crosshead does not move in the guides."-D. R. P. Answer. The engineer is but half ight. When the piston is traveling from the back end to the forward end of the cylinders the crosshead is also traveling from the back end to the forward end of the guides. On the return movement, however, the crosshead would be practically stationary with relation to a fixed point on the ground, the guides traveling forward over the crosshead. In other words, if with the engine standing on the back center you were to place a stick in the ground opposite the crosshead and then move the engine, you would find that the crosshead traveled forward or beyond the stick, the entire engine being carried forward at the same time. If, however, you were to place a stick in the ground opposite the crosshead when the crosshead was on the forward center, you would know that the crosshead practi2429. Trouble with Pyle Headlight.- cally remained stationary with relation "Recently our locomotives have been to the stick while the entire engine was equipped with Pyle National Electric carried forward again as before. ConseHeadlights (Equipment E). Some of quently, during what might be termed them burn very poorly, the carbon keeps the forward movement of the crosshead jumping up and down on the electrode, and the lamp burns green and does not give much light or goes out entirely; what is wrong?”—J. D. the crosshead moves forward on the guides, and on the return movement the guides move forward over the crosshead. 2431. Tractive Power of Mallet Com- 2433. Blocking Crosshead. "In case pound Engine.-"Will you kindly advise, it is necessary to take down the main rod through the columns of the Magazine, the and block crosshead and valve, how correct formula for figuring the tractive would you proceed?"-J. W. G. power of a Schnectady articulated Mallet compound locomotive, with cylinders of the following dimensions? Low-pressure cylinders 23 x 32 inches, high-pressure with the crosshead at the rear of the cylinders 34 x 32 inches."-C. H. K. Answer.-You did not give sufficient data covering the locomotive in question for us to calculate the tractive power or show you by means of an example. Therefore, we can simply furnish you with the formula. We are also inclined to believe that you have the cylinder dimensions reversed, in that the high-pressure cylinders are 23 x 32 inches, and the low-pressure cylinders 34 x 32 inches, instead of as stated in your letter. In order to calculate the tractive power it would be necessary for you to furnish in addition to the cylinder dimensions, the diameter of the drivers and the steam 2432. Sprung Intermediate Axle.-"If the intermediate axle of a consolidated engine should become so badly sprung that the wheels would not turn, what action would you take?"-J. A. G. Answer. Two methods are commonly used, depending upon whether or not guides it will clear the front crank pin. If with the crosshead blocked back it will clear the front crank pin, it is preferable, after pushing crosshead back to the rear of the guides, to block the valve central on its seat and fasten it there, either by clamping the valve stem with the set screw provided for that purpose, valve stem key and stuffing box and wirif any, or by placing a block between the ing it there, or by driving wedges between the valve stem hole through which it passes in the guide yoke, providing the engine is so constructed. Then either get a block to fit between the front end of the crosshead and the front guide block, tying it securely to the guide, or else, if there are liners between the front end of either top or bottom guide and the guide block, remove the liners and tighten up on the front guide bolts so as to make the guides pinch the crosshead so that it could not move. The object in placing the crosshead at the back end of the guides when it can be done is, in case the valve should shift and admit steam to the cylinder and cause the piston to move, the piston would move forward and so simply knock out the front cylinder head, thereby doing considerably less damage than if it moved back and broke the back cylinder head. If the crosshead will not clear the front crank pin when blocked at the rear of the guides, it is, of course, necessary to block it forward; and in this case, if secure blocking can not be placed back of the crosshead, as is the case on many of Answer.-In this case it would first be our modern locomotives, and the crossnecessary to disconnect all side rods, head can not be clamped securely with then place blocks or wedges on the rail the guides by removing some of the liners, ahead of the intermediate wheels, and it should be fastened as well as possible move your engine forward so as to raise so that it could not jar back, but the the intermediate drivers clear of the rail. Valve, instead of being placed central on Then block up between the bottom of the its seat, should be clamped forward so as driving boxes and the pedestal or binder to leave the back steam port slightly braces. At the same time, insert blocks open, admitting sufficient steam to hold between the spring saddles and top of the piston forward while working steam. frame over the same wheels. Then run wheels off the wedges and proceed with only the main rods up. By blocking the intermediate wheels to clear the rail you will avoid damaging the tires, as would otherwise be the case if the wheels were allowed to rest on the rails and the axle was so badly sprung that the wheels could not turn. 2434. Locating Loose Piston Head."How would you locate a loose piston head, and when you were satisfied that you had located it what would you do?" J. W. G. Answer.-A loose piston head will cause a pound on that side, both when working steam and when the engine is shut off. Consequently, if the engine de- to its seat by means of a block placed velops a pound at each end of the stroke between the valve and the cap. If the when working steam, shut the engine off, circulating valve is of the type that does and if the pound still continues you can not depend upon the steam from the be satisfied that the piston head is loose. steam pipe to seat it, a blind gasket could The pound will, of course, take place at be placed in the circulating pipe conneceach end of the stroke, and in this man- tion at its upper end. In either case the ner you can readily determine which side circulating valve at that end of the cylit is on. If the piston head is quite inder would be out of commission and loose it will cause it to strike the front would probably cause the engine to cylinder head and the blow can plainly be felt by placing your foot on the cylinder head when the engine is drifting. pound considerably on that side, especially when drifting at a high rate of speed. After the loose piston head is located, 2436. Broken Circulating Valve. if the engine is not fitted with extended "What would you do in case a circulatpiston rods, or the cylinder head is not ing valve broke? Explain fully.”— so large as to be unmanageable, the front J. W. G. cylinder head should be removed, after Answer. This, as in the question first placing the engine on the front center on that side. An effort can then be made to correct the trouble by tightening the nut which secures the piston head on the piston rod. If this is not practicable, however, or if the nut can not be tightened, the only thing that can be done is to cushion the piston head with a little steam while drifting and not indulge in any excessive rate of speed. Of course, there is a possibility with a loose piston head of the head being pulled off the rod entirely by the pressure of the steam while working. Yet, as it is seldom practical with a modern engine to make any repairs on the road, the only thing that can be done is to be governed by circumstances; that is, if the head is so loose that there is a greater possibility of it coming off than there is of it staying on until the end of the division has been reached, the main rod and valve stem should be disconnected and the valve clamped to cover the ports. This in order to avoid damage that might ensue were the piston head pulled off. If the head is only loose enough, however, to cause a slight pound and the distance to the terminal is not too great nor the train too heavy, the engine might be brought in by cushioning on descending grades as stated above. 2435. Defective Circulating Valve Steam Pipe. "If the circulating valve steam pipe became broken or defective, what would you do?"-J. W. G. above, would depend altogether upon the type of circulating valve used. Assuming in this case the circulating valve is of the type used in connection with the new superheated locomotives; that is, a circular valve placed in a cavity cored through the cylinder casting and having a valve in each end of the cavity, which seats when the throttle is opened and opens when the throttle is closed and the engine drifting, in case one of the valves became broken in such a manner that the valve, if seated, would no longer make a steam-tight joint on its seat, the only thing that could be done to prevent too much loss of steam would be to block the valve on the opposite end of the cylinder to closed position. This would then have the same effect as a stuck-shut circulating valve, in that it will cause the engine to pound when drifting, but there would be no loss of steam, as both valves must be open before steam when admitted to one steam port can flow through the circulating valve chamber and pass out through the other steam port, which is in communication with the exhaust. Therefore, if in a case of this kind the good valve could be blocked shut no steam can pass through the circulating valve chamber and to the exhaust in either direction. 2437. Reducing Lead. "I am running a Shay engine and want to reduce the lead as it now has inch lead. The eccentrics are milled or forged solid on the crank shaft. How shall I proceed?" -H. P. C. Answer.-We would suggest that you do not attempt to alter the lead on this engine, as undoubtedly the manufacturers had good reasons for giving the engine Answer. This would depend largely upon the type of circulating valve used. If the circulating valve is of the type that depends upon the steam admitted through the circulating valve steam pipes to force it to its seat, it would be neces- the amount of lead it has.” Again, with sary, after removing the circulating pipe and placing a blind gasket between one of the connections, to also remove the circulating valve cap and block the valve the eccentrics forged solid on the crank shaft it would be a very hard matter to reduce the lead, as the amount of lead is usually governed by the position of the |