THESIS A DESIGN OF AN ELECTRO-DYNAMIC SYSTEM A Design of an Liectro-Dynamic System of Interlocking A Thesis Submitted to The Faculty of MICHIGAN AGRICULTURAL COLLEGE By T. H. Reid Candidate for the Degree of Bachelor of Science June, 1917. THESIS RREFACI The author in the celection of this subject for a thesis dia so with the following objects in mind. First, that by so doing he would become bet'er accuainted with the theo- retical working of a system in which he had some practical ex- pericnoe. Second, that he might leave the institution some compiled form whereby the incentive for further knowledge might be hed by the ctndents, on this cubject. The thesis itself comprises a cystem of interlock- ing which is very important and sho 1d claim the attention of all ctudents interested in slectric Railway or Interlock- ing Systems. It comprises the theoretical part of interlock- ing with drawings, tables of data and caloulatione from these tables as to the size and capacity of a model plant, which was modeled after the one in vce by the iichigan Central Railway in Detroit. | The author expresses his sincere thanks to the Gen- ori “-ilvay Signal Comany of Rochester, New York; the Union Switoh and Signal Company of Swissville, Pa; and the men in charge of the cystem at the Michigan Central in Detroit. Much data wae received from these sources and due acknowledgment ie made hereby. Author T. H. noid. 103419 Contents. Part l. Historical and Explenation of the different kinds of Inter- locking. Part ll. Principies of Eleetrc-" jnamie Interlocking. Part ill. Design of Plant, Switch Board, and Unit Interlocking Systems. Part lV. Eleetro-Dynamic Interlocking Machine, Part V. Model 4 Switching Machine. Part Vl. Model 2 Selenoid Dwarf Signal. Part Vil. Polarised Relay ( Protective Apparatus ) Data and Calculations on Lead Storage Batteries and Design | of Plant. Part 1. Historical and Explenation of the “ifferent Finds of Interlocking. Interlocking is of English origin, and the earliest time for patents having been granted in England was about 1856. In less than twenty years or in 1873 over thirteen thousand me~ chanical interlocking levers were employed on the London and liorthwestern Railway alone, at which time not a single lever was in use in the United States, the firct experimental ine stallation haveing been made in this country by lessers Toucoey and Buchanan at Spuyten Duyvil Junction, New York City in 1°74, and the first important installation on a commercial basis having becn made by the Manhattan Elevated Lines of New York City with machine built by the Jaokson Manufacturing Comeany, of Har: isburg, Pennsylvania in 1877-78, Very soon the railroads eaw that a very econcmic saving could be made by the installation of interloc:ing sys- tems and this gave Bise to the develovment of our modern in- terlocking systems. Five distinct systems of interlooking are in use at the presehS time which are as follows; Nechandeal Uleotro-nechanical Electro-pneumatie Electric D. C, and A. C. sleotré- Dynamie of rechanical interlocking the most commonest at this time end the first in origin, I havo very little to say as everyone is acquainted with this system, its good features and its failures. Lleetro-lMechanical and Zleotro-Pneumatic the next step in the development are very well suited to certain lo- calities, but are not as ccmplcte cs either of the last men~ tioned, It consists of a system in whick the functions are operated by eleotrio currents controlled by leve:s in the ine terlocking plant, The signal or switch is operated by mech- anical energy derived from sir pwessure or other corces, This necessitates, in the case where the energy for the move- ment is derived from compressed air, of having a compressed | air machine and connecting pipes to 211 the different functions, also, batteries whereby indication that the function has per- formed its duty may be received at the interlocking plant, The lnst and most modern of 211 interlocking plants are the electrio and elcutro-dynamic systems. Of the purely electric there are the D, B, and A, C, systems each suited to the conditions under which they may be called upon to operate, but limited to the point that they do not give a positive in- dication thet the finotion has performed ita duties, except thru the breaking of a contact, while the function is in motion, The electro-dynomiso cystem gives an indication when, and only When, the function has comol:.ted ite duties, This is trought about by the reg: nerated energy of the motor, which after producing the cwitch movement acts as a genorator and gives back to the line an indication that the function has com-= pleted its duties, Of the dynamis ryotem much more gan be found in the prececing pages in which I have undertaken to design @ model plant. Part ll. Principles of cleotro-Dynamic Interlocking. In the consideration of a system of interlsc::ing, two features of vital importance must be considered in order to insure reliability and atsolute safety to the eysten. These are os follows; 1. Some means mst be provided to check the correspondence of movement between lever, wwitch, signel or otner function controlled ty it. Ze The mecne for preventing unouthorized movement of switch, cignal or cther controlled funotions,. In the spstem of electro-dynamic interlocking made by the General Railway Signal Commany, these two re- quirements are fully met by teans of dynamic indication, or counter “.U.F. for which, energy is furnished by a mor- netary dynemis current gencrated by the motor of the op- erated function itself when, and only when, the actval op- eration shall have been properly completed, The unauthorized afvement of switch or derails or the improper clearing of signals is prevented by 6 simple and effective means of cross protection whidh I shall de- seribe later. The complete installation of this svstem of inter- locking consists of the following elerents; 1. Source of power, consisting of a storage battery with its charging wit, 2. Power control avparatus introduced between the cource of rower and the interloc ing machine. Se An interlocking machine with levers for the control of the switch end signsl mechanisms, 4. Switch mechanisms, their opereting and indicating oircuits. 5. ‘ignal mecheniems, their overating and incicating circuits. 6. Kcans for the nrevention of unauthorized movement of any function. fhe source @f power from which the syetem is op- erated is a stor:ge battery with a working potential of 110 volte. This battery being charged by a motor gencrator, rotary convertor or reotifier, Power is delivered to the interlocking machine under control of nrotective apvaratus located on the switBh board. Interlocking liachine, The operation of each gwiteh and signal function 1s controlled by levers, wnich rith their respective loc ing tappets indicntions magnets, and circuit controllers are mounted in a common frene, the whole being know as a inter- locking machine. ‘Starting with the lever in cither of ite extreme poritions, the atroke of the lever is divided into two movements. The first movement locks all lovers conflict- ing with ite new position and oneretes the function, THe second and final movement of the ctrol:e relesses such levere, hitherto locked as do not conflict with ite new position. Except in the reverse po ition of a cignal lover, this final A- At Rest-No Corrent aA TEd Mears et a Nv ia la wet pat Ye) NermalContro/ b od fl ‘Reverse Contre/ S > ; , witch Fe Ul Meshal iii Wt eT PT a “B- Opera ray ah of cad Switch Lea a Norma’ Pesitien Ae@ver at Neverse Tnoficatiern Postion a _Indice ting switch Weverse Lever at ffeverse Tncdheatior Fes: tien 7 oie AM tee aaa Te) APC NE Levéerat Full Trererse Switch Reverse movement cannot be made, until tne Gncmio indication hzs been received certifing that the onerated Punsction has as- srred a pocition corresponding vith th t of its lever, switch Mechanicm -e-<----s8=— operating and indicating. wach switch and derail is throvm and locked by a switBA and lock movenent driven by a series wound direot urrent motor. Two wires are usei for its control, one for the rorral and the other for the reverse operation, The same wires are used for indiie&ting purposes, the normal con- trol wire bcing ueed for reveree indicetione and the reverse control wire for normel indiostions, The cirouit is connect- ed to the main contion at the switch loc:tion. The oircrits for the switch are chown in the fol- lowing dravinge, the opersting erd indicating currents in the different diagrams being shorn by red lines. ‘When the svitch is to be operated, the Tiret movement of the stroke of the controlling lever carricgs it as far asthe reverse indication position anc permits crrrent to flow ag chown in Fig. 2., which cauees the mechanism to move the switoh points to the revorse position and locks them in that pos- ition, hen this movement has been comnicted, the circuit thru the switch motor is automatically changed, disconnect~- ing the motor from the battery and connecting it in a closed circuit inoluding the indlostion magnet, Big. C., at the game time the armature temiinzls are reversed for indication purvocea, thus, leaving the motor connections in the proper porition for the next operation. The motor (now a generator) a lah . « Bee 2A 2h Wl dod ae Com trol e Indicgtion te - x Oy de hs deed = Py Tas a a7, RE LVaG7ET Fond ll pO ea ee Bo a ee Be hever Fels We wrerse = — Vil 22, Ma Necdcal é Signal af ear re aed 2 ea \ a AS ee a ra 5S ae Tee Ee) AA EARL) oe MEL) ay ene a a ere ie =< eg ; y : F ve PTT ae ei as AZever Fuss PF ceguis Hy ee eed yea 7 ae ie IEP: ene de aa Set at Va iad D- Ind: Cele > ue 2a | S:onal 10° (apgror) Fromm Stop pesiTor ae a aaa ok now & gcneretcr «ith 2a monentum accuirod duming the operation of the cwitoh movement, generetes 2a mementary current which energizes the indicetion mignet thus vermitting the final movement of the lever to he comnl:ted, Fig. D. The operetion of the lever end function from the reverse to the nérmal position is accommliched in the came manner. The gomplete: switch moverent and final déperation of the lever may be accomplished in from two to two and a half seconds, the indicstion being practicnlly iuastantaneous with the completion of the switch operation. Sienai Orercticn. The signal is operzted by 8 rechanism in which the motor is directly connected to the sera-phore chaft thru a Low reduction gearing, The eignal is held aB proceed during snoh time as its controlling lever is in the reverse position, soley by means of a dense magnotis flux throw across the air go> between the motor armature and the ficsld pole vieces, by eutting the windings on ‘he holding field poles in series with the oper&ting field windings. Zach signal recuires for 4te operation and indicntion, one wire and 2 connection to the common return wire, Diagrammatic cirevite sre chon in the fol‘ owing dravings, the path takon by the operating, holding, and in- dicating enrrent in the diffsrent diagrams being shown by red Llinss, Upon reversal of the controlling lever, the sig- nal mechanism vill receive current os shorm in Fig. B., this casing 4% to move tno tlade to the nrececd position. ivhen the cipnal blede has esewed this nocition tre circuit bres.c- er ents in eceries with the op rating ficld and armature, the high resistance holding ficld, rcléding the cignal arm at pro- cecd Fig. C. Tne hrolidize field tindcings have a high resicte ence, .sich reduces the crr:ext to that emmnloyed for holding the -ignal at proceed. “hen tke clenal lever is pleged in the nornel indile&ting position,cnergy, is cut off from the motor and the tinde retvrens to the ctes position by rravity, Guucing the ciprn.l iechenicn snd netaeyp arnature to revolve backwards to the criginal pn sition, Just as the blade reaches the stop position the action of the @ircuit breaker connects the motor armature and operating field into thelr original Closed circuit Fig. D., in which ig included the ladication napnot. Do to its ec.uvired momcnutum the motor (now 2 ganer- ator) produces an indicsting current in this clireuit which permite the controlling lever to be moved to the fu:l nore ral position Fire oe Dynamic Indisetion.-----s--< Advantages. 1. The indication te not cecured from energy existent at the S:netion vrior to the movement of the fun-= ction, and depentent only on tne closing of <¢ single brake in the indicetion oirevit, as in the 4.C, end battery in- disation systeme, but being a G@ynomic durrent generated by the moncutum of the motor, it can be cecured only after ac- tue] operating of tie function. 2e The energy for the indication is develop- ed at one ond of the strenit and the tnifeation magnet is located at the other, hence, 3s cross betw'cn wires prevents indicetion, while in a svstem whera a battery is used a crose in wires vould eause an indication, 5. ‘No extra power for indicetion, 4. Indication current seases sutémeticallg vith the stopving of the movér, 5. No sddittioncl] wires ere recvirec for ine dication. Cross Protection. The cross vrotedtion system prevents the unauthor= ized movement of any svithe, simmel, or cther function dune to energy improperly applied to its olrcult thru a erose between wires, by cutting off the current from the function inthe event of cuch an occurence, ALL functions are normally on a olased circuit of low resistance, Connected rith each of thease circuits is a small polarized releay thru which all operating and indio~ ating currents must pass in a direction to maintain the relay's contact closed, while all currents from an anauthore ized souroe must pess in the dvposite direction thus inetant- ly opening the contact. ( Part V1l explains the action of the relay more fully) Thru all the cortacts in series is controlled the retcining mognet of an elcoctro-mechanical circuit breaker. ence a cross on the circuit of the 2imcte ion at rest, by opening the contact of its polarized relay, opens the circuit breaker nnd cuts off power from the inter- losking michines, thereby rrevonting any imrreper move- ment of the function. Pert 111, Desten of Plont, Switoh Poard Cirenit and Unit Inter- looking System, Drawing l,. Tig. 1., shows how a svstem of slectrisc inter- locking can be applied to a railroad terminel. The erve- tem I heve undertaken to Gesien consists of five (EF) Model 4 G@witoh Machines and three (2) Model 2 Dwerf Solenoid Sigenmel Machines. The fecien iteel? is texen uv further -under the read of Be@ign of Piant. Operetine Svitch Roard, Fig. 2., on this draving shows the overnting switeh board for an interlocking pliant and consists, of a ewitch board on which are morntsd ocly the apreratus er- sential to the ofrenit breaker control, chows tre retein-e ins magnet of the circuit breaker controlled thrn the pol- arized relay on the ewiteh doawd and those on the inter- locking rachine in such & ni aner, that, should any of them reverse their pocition the clronit breceker will AImnedisate- ly open. The polarized rolay on the cwitch bewera is to guard arainst the eftect of an accidental oross between the positive and indicating bres bars on the interlocking mnach- ines Figs 56, on the sane drawing shows the circuits for the operating switch board, interlocking machine, switch and seiznal function and gives © clear idea how the wiring drawing for a two lever plant would be. From thie drawing a coneise conception can be had of an interloc:ing plant consisting of sight (8) levers Fart 1V. sLeotre=-Dynamic Interlocking lachine. The interlocking machino is ucunlly @ccipned co thet each lever controls a fign.:l or switch mechinism. Put in some Gates machines are made in which one lever opors:tcs both the ewltoh and cignel function. The design of an in- .terlocking mechine necessitates, that 1t be absolutetly enfe in operstion «nd indicntion of the differcnt function movemcnts, The raghinca are co decif¢ned thot; » No lever o:n be moved from any given pos- ition, if .ny other lcver rechonically interlocked with, is in such ca pocition that its controlled function should conflict with the function of the lever itcolf, ee The full movemcnt of the lever cannot be commleted until the function controlled by the lever itself hes moved. fodel ¢ Unit Intcriocking lt achine. Drawing Ilo. & The machine comyriscs the frame, levore with guides indio tion msagnots, and circuit ocontrolilcrse. The locking phates and locking, the terminsl bosrd and e machine cabinet. Levers. nch lever with ites guide, indic tion -mepgnet controllers, etc., commriscs 2 commicte unit in the interlociing ro chine which ¢e-n be r moved and replaced in the machine vithort dieturbing adjacent levers in any way. Thig rweakesg the rochine very ficxible nd eary to repair. The machine is e-ul~ned with 2 lanm, which reccives the indic tion of tire f-netion and chows the lever ran thit the function h2a opcratod, Model & Unit kever Tybe inter hock ae VILLA rf ae Es PZT! OUMTUULLSSDLLSULIIDL eee Z ; Z 727 om (o. Z g (aie CASE. Z Crreait Contretler Z a — a j Ba Soe Y Indication a EE ee a “ Inaecation g é : ihe: Ey fe Wey wut [ =<} farized fe ey pew laea) pm a lola oa ven Lae Spring MPS PRBBR aw Ae gees ys DS AS FD Se Sa a) i I a | SS SS SS SSO SSS \ i; yg Nek VO} fare eae So | The indication selectors mounted on the ;r:chine, es chotm on the dr wing, concists of tvo clectro-mcarnots and a contecting crmature which throvs in one direction Vhen the levor is reversed cnd in the other when the Lever is put norual. srt Ve Model 4 Switching Inchine,. The ewitoh mechconicm of the General osilwoy Sire nel Compuny's electro-dynimiso syctem, cre exch under the control of a2 lever in the interlocking mcchine. Por their opcrction there is resuired two wirce only, one for normal ond the other for reverse orerntion cf tre mochznicm. The same wires sre ueed for indio:ting nerporce, the normal wire being used for reverse indic:tion, while the reverse control wire is uced for normal indicontion, Drawing "No. 3 vhen the lever is moved from *, to F, in Fig. o on tho indication eclector controller contucts, current is taken from the positive buss thru the cafety magnet, S, incic:tion selector, lever cont-cts =nd control wires thru the ewitoch motor to the conmon. This csveées the desired movercnt of the eviteh, which nerforrs the following fun- ctions in the order given; 1. The detector bar S$ is reised «nd the ewitch unlocked oe the switeh points sre thrown. &. The ewitch noints sre lockcd :n@ tre bor lovered. A. The current is cut off from the motor «nd ‘the termin-ls of the armature reversed for indieseting pur- nores, leaving the motor nroxvcrly co7mmected for the next moverent. The motor is now on 2. c’oced circuit which ine Gludes the indication moenct. Due to the momentum eaccuiroed during the switch opera tion, the motor sruature continres on eevor:l revolutions for tiie scencration of the momentary current «rich cnergices the inédic tion tx.pnet and thereby permits tre final movement of the levcr to be scommlicted. The chonting of the motor connections is affected by the mech nienl chitfting of the contrct in the pole changer. In addition to being rcehanieslly opcrcted, this céntact blook is wider the control of tvo cets of solenoid mairnets, co thet chonld the ewiteh fil to cornicte its mover.ent, Bhe controlling lever rey be chifted and tiru the cnergicing of one ret of the mornitr carve the ynole chinger to vet un tho circuit for the oneraticn of the switch in the opnosite dir- ection, “his ploces the mech nicm under the control of the lever man, ©o hat cnould the evitch vnointe beecme blocked with enov, ioe nd co on, tre noints msy be moved bck and forth until the obstrvetion is diclocred. Safe Gunegds, The ewiteh eech:intem is cafe st o11 tince, Prom false SU SMa NG Ss a ry AAS ONSEN NS NOR NI ST ESE ie SN Sa cS Eon Amp hr | Amps Za 2 02 2 40 a Ae a Zi ea ae oa aa un Mee Ae ee ay ee ae eA AE Pale aA ee Sh OE) pee ae 9a nl Pirlo) » Io} rah ta y | ’ ‘ Pe a CTA 7 A rk, £3 thee isan saa eC A AY Fe eae Ch ee er A ke 1A all elle OY LA ee 8 4 Table Nod Patt rres General Data Legqd Stfteraye ms, 8 F < i ee a Se: Bh yee DC-2C Meteor Ac-De Meter ~ RY Sy TVSS\ RAR LEGS oe CPI Ee Generofor Sets 3 3%> RRS Ora tea pecan RS yy DN Si PAS RRs Semper Fleer Space | Imps? | Fer sr SS : A (Lad) rade EAM. a eS inches | KV Py eo ie Ae ee ee A450 | BIYXIE 4.00 60. | 7.5 | 4252251475 | 7x19 |200| Zixig |4£0 8o aN ee iy Xe ee ie | FS elle a ee ee ly me ak I oe | 00 460 | 20 | 936°|5,75| $as'| $5x29 5.00| FIALF fc ee tell heat CN ie OY de ene eee Oe oT a ees “ag ae Se 7 - 6.00 60x%2z8 vie ge OSA cD re) ° es ee 7.20 1 -aC ae ) ne 56x28 2%o0 J2ZO | FO | 6.50 |11.25) G00 | 63 XTF/ 7 SAx2I F000 4oo | So | 8.06 \/9.00\/0.00| 79x33 44$0\| €0x 3 fe it Ta ble WoF pare Sa ee ed ila De-De Moter Generohr Sons, ad alil 7 whenosed for ony , ry aL Charging Cay pel Demensions set Wei Lia Vaal ; : hc ret iate tmivfot. | /0i7ete PO ee aed EM eG EGS Miata AS Mess La # 77 s * L2Ss 4o 7 1800 ied ie Ea, “ ” 4 Hy Pay var) 7] er id a sles 2.d0 8o jo re 92" ash” Pe 2.40 /20 1S 1800 Pe ae bY ag 20%" SA 2. oF a Xe) er ». ~ oO eo) 350 a S77 y Desizn of Plisnt. ‘moere hour cs. acity re ulired for oncr:tion of Plant fe obtnincd Ly multinlying the number of lever move- rents ner dey by the number of cays between charges and by a function conetent. This function constant is inflvenced mainly by tro tings; l. ‘verare lenght of time that elenols core held in prooeed pocition and ratio of number of rignal move- ments to ewitBA movercnts, This cinstant is taken usurlly 2s .006. Canacity of Fattery wien Number of Voverents is not KNOWN ¢ The dnt in the following t-tle is sufficiently la fe enourh to ec: re for ordinury conéditons. Inte end Cslculations,. Model 4 Switeh Lachines nm eseennnnwcaeeonamewmne § Model 2 Solenodd Lwarf Vipnal -s-sess-cecewenenee 5 Interlocking Urching em-memmeenwomnwwecnmanwnmeree § levers From tables on the following chcets we kave these recuits for an elig¢eht lever plant. Table l. Interlocking *cchine ----- 8 levers Cenacity of Tattery -«-«--40 ammere hr. - 110 volte, Humber of Eatterice ---=-9-55 to 57 and pilot coll. Table 2, Sisco of Dattery cana ity ---- 40 amp. hrse Normal chaurfing current «-e-- 8 hr. rote=- 5 ann. Vumber of plates ver ccll «<< 6§ bimencions of battery jar Length wocesem= VLdth emeennene Noleth «-----<< cand Tray Length eonswcos VAdth wnmnenne TnNLiGEnces seoe= Cell Cover Tidth ecnce-en- LEneth wmaceene 7=7/6 4~1/4 11 9-1/2 6-1/2 27/8 6 inches. inchcs{ inches. inches. inchcs, inches, inches, inchcs, epprozinute \.elght of cell cormlete ----------20. 27,55 nounds “pproxinnite Leicht of = ectrolyto ---«-ese.---6 10.75 " Prom able 3, hequdires a motor penerator cet with ao ccpecity which is es follows; Input GD 6D OD > CD aD HO OD Eb GO ED Ow OD OD OD OS 1.25 eve Floor “n2ce «-enewmmnrewne 45 ¥ 15 inches Cenerator Ounacity -~e-== 160 volt min. = 1.00 £7, Dimexzcions of Motor Generator, Input OP OD AD Gb GD OD GD 4m 0 00 Ot ae ae OD Ow 1.25 vr oe Sretie Input te motor at ----2-= £220 volte - spproz. 7 RR. P, Ye SR ennwnsanneeeen L500 Width of cet <2) GD on OE Ge OD ER ww OD wD we 59 inohes,. cl inche S$. 20=2/8 inches.