tive brakes are thus released without af- their attached valves which is bolted to fecting the train brakes. If desired the locomotive brakes may be graduated off by placing the straight air independent brake valve in locomotive automatic release position and then moving it to running position before exhausting all the control reservoir pressure. The pressure in the brake cylinders will then adjust itself to the pressure remaining in the control reservoir for the pressure in this reservoir now being stationery, the pressure in the locomotive brake cylinders and in chamber B will continue to escape until it is reduced a little below the pressure in chamber D, when the control piston will move towards the lesser pressure until the exhaust valve 7 blanks port N and prevents the further exhausting of brake cyl the second part, this latter part consisting of a reservoir divided into two chambers, one chamber being the control reservoir and the other the auxiliary. This chamber is represented in Fig. 57 by a large circle. All the pipe connections to the control valve are made to the double chamber reservoir which permits the operative parts to be removed without breaking any pipe joints. The small circles shown in Fig. 57 with the exception of one indicate passages in the control valve to which the pipe connections are made. Passage a leads from the divided reservoir through the casting containing the control piston and triple piston and connects to another passage indicated by dotted lines to the graduating spring inder pressure. This can be repeated un- chamber. The purpose of passage a is to til the entire pressure in the locomotive convey brake pipe pressure to the conbrake cylinders is exhausted. If it is de- trol valve which passes by the feed sired to reapply the locomotive brakes groove in the piston valve chamber and with the independent brake valve the charges the auxiliary reservoir. A reducpressure for doing so will be supplied tion of pressure in the brake pipe will through the straight air brake valve to cause the triple piston to move outward. the brake cylinders direct and not through The brake pipe pressure after entering the control valve, the control reservoir the chamber containing the triple slide then remaining without pressure unless valve passes by way of a passage leada further reduction is made in brake pipe ing from it to passage b which leads pressure by the automatic brake valve. out to the auxiliary reservoir in the Up to the present diagrammatic views double chamber reservoir. No pipe conof the control valve only have been con- nection is made to passage b. Passage c sidered. Fig. 57 will serve to give an leads from the control reservoir in the idea of the actual construction of this double chamber reservoir to a passage valve. This view is a sectional cut taken that leads into the chamber in which the through the center of the casting con- control piston operates. Pipe CR containing the triple piston and control nects to the double chamber reservoir of piston. The control valve may be said the control valve and leads into passage to consist of two parts, one part contain- c, so whatever pressure exists in the ing the two pistons above named and control reservoir and passage c will also exist in pipe CR. This furnishes a that connects to the chamber containing means of draining the control reservoir the admission valves. The main reserby means of the straight air independent voir pipe connects to passage d, this pasbrake valve which will cause the locomo- sage then serving to convey main resertive brakes to release after an automatic voir pressure to the admission valves for application without affecting the train applying the brakes. Whatever pressure brakes. The port in the slide valve seat exists in the main reservoir will also be that connects passages b and c or the present in passage d. The brake cylinauxiliary and control reservoirs during der connection to the control valve is applications of the brakes is not shown made at the double chamber reservoir to in the cut as it is not included in this passage e, this passage then serving to section of the control valve. The port convey pressure to and from the locomoshown is port E which leads to the safe- tive brake cylinders. The brake cylinder ty valve while the part of the cavity exhaust port is shown at the left. The under the slide valve seat serves to con- retain pipe connection to the double nect the ports E shown in the diagram- chamber reservoir is not shown in this matic views. Passage d leads from the cut. double chamber reservoir into a passage (To be continued.) MOVEMENT OF TRAINS By G. E. COLLINGWOOD New Proposed Rules. for the train dispatcher to restrict such The Joint Train Rules Committee of automatic movements as may be desired, the American Association of Railroad instead of providing for so many moveSuperintendents and the Train Dis- ments. The fewer orders required to patchers' Association of America have be sent by the train dispatcher and submitted to the American Railway Asso- handled by train crews the better, to say ciation numerous recommendations for changes in the present Standard Code of Train Rules. It will be understood that these proposed changes may, or may not, be accepted by the Association. The proposed rules in some cases are new to the Standard Code, but are held to be desirable adjuncts. In other cases the proposed rules simply amplify, or make the rule more easily understood. The Joint Committee claims that the proposed rules provide for the utmost elasticity of movement consistent with safety and avoid the possibility of many delays which would otherwise occur in case of circuit failure. It is proposed on single track that freight trains in the same direction may run irrespective of class superiority unless otherwise directed, the principle being identical with that in common practice on double track, and equally applicable and safe in either case. Instead of placing so many trains in a position where they will be entirely dependent upon the train dispatcher, they are permitted more or less to run automatically, and it will only be necessary nothing of the time saved to trains getting orders and to train dispatchers, which can be used to the benefit of other trains. Movement is provided for extra trains similar in principle to that already provided for regular trains, and, it is claimed, such movement is provided fully as safe as for regular trains. It provides for giving the train dispatcher more complete control over trains by the use of clearance cards, but does not hamper train movement, since the clearance card may be issued without the authority of the train dispatcher in case of wire failure. In the interest of uniform practice, proper train order forms are provided for many movements, which are of daily occurrence, to be used in the place of various unauthorized forms now in common use, some of which are not sufficiently specific, or clear in wording. The most important of the proposed rules will be shown in this department, and whether or not the rules become a part of the Standard Code they are instructive. Under the heading, "Movement of to issue a clearance card until he has Trains" which appears in the Standard secured a number from the dispatcher, Code of Rules, it is proposed to add the which is the next train order number, and following explanation: the dispatcher makes record of this in its order sequence. register stations. "These rules and forms, for the purpose of illustration, deal with passenger It is a matter of general practice to trains as first class and fast freight trains as second class, but they will be used for authorize a train to assume a schedule all classes of trains and extras when ap- at its initial station It is customary to plicable. See Rule 85, second paragraph. require trains to obtain clearance cards It is permissible to schedule passenger at certain intermediate stations and at trains as first, second and third class (and so on), and when so scheduled, the rules and forms should be amended ac- A train on a siding should be required cordingly. Freight trains may be sched- to receive a clearance card before prouled in the same class with passenger ceeding, because a dispatcher frequently trains." wants such train for orders but before The writer does not concur with the he can get to them he finds the train at spirit of the above note, or explanation. the opposite end of the siding and may be He prefers that the rules be so worded a mile from the station. The proposed as to protect each class of trains irre- rule keeps them under the control of the spective of whether or not they are pas- dispatcher while at a station, which is senger trains, and in cases where some greatly to be desired. This is somewhat special protection is required the rule in the nature of block control under should refer to the case by using the term, "Passenger Trains." The definitions should then show the term, defining its limits of meaning. Proposed new Rule 80, reads as follows: "80. Clearance cards (Form A) will be issued by operators upon authority from the train dispatcher. They must be without erasure, alteration or interlineation. They may be numbered if desired. "A train may be authorized to use a schedule at its initial station on any division (or subdivision) by a clearance card (Form A), properly addressed, upon permission from the train dispatcher. "A train, except a detoured train as provided in Rule 83 (Rule 83 referred to is an amended rule), must not assume a schedule at an intermediate station unless directed to do so, as prescribed by Forms For I, nor leave its initial station, or other prescribed stations, on any division (or subdivision) without a clearance card (Form A). "A detoured train, returning to its own rails, must secure a clearance card before proceeding. "A train taking siding at an open train order station to be met or passed by another train, must secure a clearance card before proceeding. "If the circuit fails, the clearance card may be issued by the operator, who will endorse on same circuit has failed." Manual Block Signal Rules. One of the weaknesses of the train dispatching system has been the fact that dispatchers have had no effective control of the train movements they directed. The aim of the committee throughout these rules has been to strengthen this weakness by control of the issue of clearance cards. Since the A. R. A. has ruled that a detoured train may assume or resume its schedule at an intermediate point, it should be required to receive a clearance card because it may be necessary to issue orders to it. The dispatcher must, in the interest of safety, have control over such a train, and if it is to return at a nontrain order station the dispatcher may authorize the clearance card issued before it leaves its own rails, or give it an order releasing it from the rule requiring a clearance card. The committee points out that it is a recognized principle that a regular train may be authorized to assume a schedule (or its schedule) at its initial station on any division or subdivision, but such a procedure is generally prohibited at any other point, the committee asserts, because it would be unsafe to thus assume a schedule without authority from the train dispatcher. The writer agrees that a train should The argument of the Joint Committee not be permitted to assume a schedule at in favor of the rule quoted above is that any point except its initial station withclearance cards are used for different pur- out orders to do so, but objects to the poses and should not be issued without illogical statement in the rule that, "a the authority of the train dispatcher. It train, except a detoured train as provided claims the practice of permitting opera- in Rule 83, must not assume a schedule tors to issue clearance cards without such at an intermediate station unless directed an authority is illogical, since they are to do so." In the case of a detoured train more or less in the nature of train orders. it does not "assume" but it "resumes" its Some roads do not permit an operator schedule. And a train which has assumed a schedule at A, its initial station, to Z, its terminal station, has a clear title to that schedule from A to Z and in case it should be run extra from B to C, ahead of time, and the schedule annulled from B to C, it would be at liberty to resume its schedule at C and proceed thereon to Z, as that portion of the schedule would still remain in effect and would properly belong to the train which assumed it at A. This practice is as safe and as clearly warranted as in the case of a detoured train. The claim that the dispatcher, under standard rules, has not had effective control over the trains which he directs does not seem to be substantiated by the fact of actual operation under such rules. The requirement that a train taking siding at an open train order station to be met or passed must secure a clearance card It before it can proceed is sure to cause Questions and Answers Locomotive Running and Repairs. Answers by F. P. Roesch. 2351. Lead and Pre-Admission. "Would you please explain through the columns of the Magazine a few questions concerning an engine, or rather operation. I will give you what information I have; if you need more than I send, please let me know and I will get what else you may need. that is, would it have a tendency to hold the lead constant, or would it decrease the lead? Now, there was an engine here of the same class as I mention, and with the right side spotted on the house track 1/16 or the crosshead being about 3 inches from the completion of its back stroke, engine moving ahead, the reverse lever in front corner, steam was admitted to front end of cylinder, and "The engine that I have reference to would get steam in back end of same when hitched up to the tenth notch, has a Stephenson valve motion; the cylinder. Seems to me engine got steam valve has a 5-inch travel; outside lap too soon when in this notch. I trust you -inch, inside lap line and line; lead will be able to understand what informaahead 1/32-inch; lead back-up -inch tion I am seeking."-H. J. B. (blind). The cylinders are 19 inches by 24 inches; the engine is right lead. There are 24 notches in the quadrant that the reverse lever latch can be put in. The engine works in the tenth notch from the corner going ahead. Now, I understand that to hitch up an engine with a Stephenson valve motion increases the lead. What I want to know be about in the second notch from the is what will be the position of the main center, or working in about a 6-inch cutpins when the engine gets steam working off. Hooking engine up with the Stephenin the cut-off I mentioned? I would also son gear always increases the lead, the like to know if on account of this engine amount of increase, however, depending being set -inch blind in the back-up motion it would have any effect on the motion of the back-up eccentric. In this on the length of the blades and the position of the valve when engine was going ahead being worked in the tenth notch? particular instance, the back-up gear unI mean would it affect it in the lead; doubtedly was set blind in order to over Answer. The fact that there are 24 notches in the quadrant, and assuming that there are as many notches for the back as for the forward motion, it would in the tenth notch from the corner it will indicate that when the engine is worked constant, because the lead will increase as the reverse lever is hooked up, but the increase will not be the same as though the back-up eccentric were set for line and line or with 1/32-inch lead, same as the forward eccentric. come excessive lead in the forward gear set blind. It would not hold the lead when the engine was hooked up close. Excessive lead with the Stephenson gear always results in a certain amount of preadmission; pre-admission meaning that the steam port is open to the admission of steam before the piston has entirely completed its stroke, and this was the case with the engine you mentioned, where the engine took steam at the back end of the cylinder with the reverse lever in the tenth notch, when the crosshead lacked about 3 inches of completing its back stroke. We question very much, however, your assertion that with the reverse lever in full forward gear steam was admitted to the front end of this cylinder, as with the crank pin in the position mentioned; that is, the crosshead lacking but 3 inches of completing its stroke, there would not be sufficient movement given to the valve by moving the reverse lever from the forward corner to the tenth notch, or even into full back gear to change the admission of steam from one end of the cylinder to the other. As stated before, the increase in lead is due altogether to the length of the blades; that is, the radius of the link and the position of the eccentrics in relation to the main crank pin. Ordinarily, if both eccentrics were set so that the engine forward and back gears, you would have would have about 1/32-inch lead in both from 4-inch to 5/16-inch lead with the reverse lever hooked up in the tenth notch. Setting the backing eccentric inch blind much; or, in other words, would give you would reduce this by that 3/16-inch lead in the tenth notch. 2352. "Please furnish the principal dimensions Erie Type Mallet Engine.— of the large Mallet type freight locomotive now being constructed by the Erie Railroad."-Subscriber. we Answer. As others of our readers may be interested in this locomotive, furnish herewith a cut as well as description. As can be seen from the illustration, this locomotive embodies an entirely new design, in that the adhesive weight of the tender is utilized for the purpose of pulling cars. In other words, a complete engine is mounted under the tender, including frames, cylinders, driving wheels, etc., and the weight of the tender is thus utilized to increase the tractive effort of the locomotive without any increase in the total weight of the locomotive and tender itself. Of course, it is understood that the tractive effort of a locomotive depends as much on the adhesion as it does on the size of cylinders, steam pressure, etc., and were the adhesive weight of the locomotive alone utilized it is plain that the tractive effort cannot be much above one-fourth of the weight of the locomotive, as it is necessary to have at least four pounds of adhesive weight for each pound of tractive effort in order to prevent slipping. With reference to your question as to what the position of the main pin will be when the engine gets steam with the reverse lever in the tenth notch from the forward corner, would advise that this cannot be answered definitely unless the radius of the link were known, and also the exact position of the eccentrics in relation to the crank pin. We would judge, however, that with the eccentrics set as stated, namely, the go-ahead 1/32-inch lead in full gear and the back-up -inch blind, that steam would be admitted to the front end of the cylinder with the cross-head lacking about 2 inches of having completed its stroke; that is, the engine would have about 2 inches pre-admission. This, however, would be nothing serious, as there would be practically no pre-admission with the reverse lever down in the corner, and it is only when the engine is moving at very slow speeds that pre-admission is objectionable. The fact that the engine is worked in the tenth notch from the corner indicates that it must be in passenger service, and usually run at high speed; consequently, the pre-admission would simply serve to act It was to obtain an increased tractive as a cushion for the reciprocating parts, effort, as well as increased flexibility, that and would not in any manner retard the the Mallet type of locomotive was first speed or power of the engine. So far as designed. Mr. George R. Henderson, the position of the back-up eccentric af- Consulting Engineer of the Baldwin Locofecting the motion of the valve with en- motive Works, however, realized that by gine in forward gear is concerned, would taking advantage of the weight of the advise that it will affect the motion when tender and placing another driving unit the engine is hooked up, in that the under it, instead of the usual tender amount of lead will be decreased practi- truck, increased power could be obtained cally as much as the back-up eccentric is without a further increase in total |