US1205462A - Railway-train-control system. - Google Patents

Description

1 c. McD ONALD.

RAILWAY TRAIN CONTROL SYSTEM. APPLICATION FILED AUG-27,1915.

1,205,462. Patented. Nov. 21, 1916.

. v 3 SHEETSSHEET l.

, lNl/ENTOI? I. C. McDONALU.

RAILWAY TRAIN C(ENTROL SYSTEM.

APPLICATION FILED AUG-2T, x915.

.;QQ5,%2 a I Patented Nov. 21, 1916.

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Jim

5 wvewroz 3513 A flt tozmeq I. C. McDONALD.

RAILWAY TRAIN.CONTROL SYSTEM.

APPLICATION FILED AUG-27, I9I5.

1 05,462, Patented Nov. 21, 1916.

3 SHEETS-SHEET 3.

Wu messes:

3 vwewtoz JOHN C. MCDONALD, OF NEW YORK, N. Y.

RAILWAY-TRAIN-CONTROL SYSTEM.

Specification of Letters Patent.

Application filed August 27, 1915. Serial No. 47,581.

7. all whom it In (11 concern:

Be it known that 1, JOHN C. MCDONALD, a citizen of the United States of America, and a resident of New York, in the county of New York and State of New York, have invented a certain new and useful Railwaylrain-Control System, of which the following is a specification.

My invention relates to improvements in railway train control'systems and particularly to combined train-stopping and speedcontrol systems.

I have illust'ated my invention particularly as applied to electric roads wherein the trains are operated by electric motors deriving current from a third rail or other conductor other than the track rails; but it will be apparent that the system is equally applicable to roads whereon the trains are operated by steam or other motive power other than electricity.

In the following descrlption I will generally refer to the conductor from which the trains receive current for motive power and for control, as the third-rail; but it will be understood that any other conductor, for example, an over-head trolley wire, may be substituted for what is, strictly speaking, a third rail, without departure from my invention.

My invention comprises controlling circuits and instruments, the latter being, generally, of the nature of relays, and I have illustrated the track relay of each block as controlled by track circuits; though other well known means for the control of such relays may obviouslybe employed.

My invention further comprises train circuits and instruments carried by the trains passing over the track.

The objects of my invention are to facilitate the operation of railways; to reduce the liability to collision; to provide simple and effective means for the control of speed; to

provide simple and effective means for positively stopping trains; to prevent entry of trains into blocks which are already occupied .to maintain proper block intervals between trains with provision permitting, un-

der exceptional circumstances, (such for example as the stalling of a tram ahead) the passage of a train 1nto a block already occopied; to make the system readily applicable to existing railways; and generally to make the circuits and apparatus of the system simple and reliable, and to cause such circuits and apparatus to afford ample protectlon.

I w1ll now proceed to describe my invention with reference to the accompanying drawmgs, and will then point out the novel features in claims.

Figure 1 is a diagrammatic View showing circuits and instruments for one track of a double track railway, t e direction of normal progress along such track being indicated by an arrow. Fig. 2 is a diagram of train circuits which may. be employed in connection with the circuits shown in Fig. 1. Fig. 3 is a diagrammatic view similar to Fig.1, showing however anarrangement employing alternating current for propulsion current and direct current for train-control current. Fig. l is a diagram of train circuits which may be employed in connection with the circuits shown in Fig. 3. Fig. 5 is a diagrammatic view similar'to Figs. 1 and 3, but showing an arrangement employing alternating current of one frequency for propulsion and alternating current of another he quency for train control current, and Fig. 6

is a diagram of train circuits which may be Patented Nov. 21 1916.

tions, such sections being insulated from.

each other. The length of such track sections will depend upon traflic conditions and may be determined readily by those skilled .in the art. -The third rail is also, preferably, divided into block sections, corresponding generally to the division of the track rail -into block sections as above described, the sections of the third rail being not necessarily, however, absolutely co-terminous with the corresponding sections of the t 'ack rail.

Referring now to Fig. 1: R and R designate trackrails of which R is shown divided into block sections 2, 3, 4, etc. For each such block there is a corresponding t 'ack relay TR', TR, etc. I have not illustrated atrack relay for block 2, but it will be understood that the same instruments and circuits are'provided for each block. For each block there is also. another relay. commonly termed a line relay. and designated by reference charcters L, If, etc. (It

will be understood that the term i'elay is employed herein in a generic sense, as inthe wheels and axles of a train present on the corresponding block, so as to deenergize the corresponding track relays T3 TR, etc. T designates the third rail, and F a direct current feeder for the several sections of this third rail. In the system asillustrated in Figs. 1 and 2, the use of direct current for motive power is contemplated, and the use of alternating current for train control is contemplated, and therefore the sections of the third rail T are connected by inductive bonds I 1*, etc., which permit the passage ofthe direct power current, but substantially prevent the passage of the alternating train control current. 0 designates a common return conductor for the train control circuits and S S", etc, designate transformers, one for each block section,

supplying alternating current for the train control circuits. SX designates the conductor supplying the alternating current to the primary coils of these transformers.

The line relays L L etc., are time element or delay action relays; that is to say, a predetermined interval of time is required for the closing of contact by these relays following the energization of their magnets. Such delay action relays are well known, and I do not limit myself to the use of any particular type of such relay; but as a diagrammatic illustration of the delay action character of these relays I have shown the armature of each such relay as provided with a. controlling dash-pot D. It is well known that by means of such a dash-pot employin'r either liquid or air as the impeding medium, the time required for the closing of contact by the relay may be anything desired within reasonable limits.

Each of the relays TR, TR, etc, has three independent armature contact points (L, I), and c, with corresponding fixed contact points.

The circuits will be best understood by dcscribing the operation of the system.

Suppose a train to enter block '3 from block As soon as the wheels of that train enter block 3, the track circuit controlling relay TR will be shunted, dele'nergizing the magnet of relay TR, and permitting its armature contacts to drop back. Upon the decnergization of relay TR a circuit will be completed from point 8 of common return conductor 0 through armature contact 0-, of relay Tit and the back contact of that armature through conductor I) and the magnet of line relay L, and thence, through conductor C, to the 1: armature of a track relay of ablock ahead (in contact of relay TR, and the corresponding front contact stop, and the armature contact (Z of the corresponding relay L and the corresponding rear contact, through the secondar windin s of the transformer S to return'conductor O and thence back to starting point 8. By the completion of this alternating current circuit the relay L will be energized (it will be understood that these relays L L5, etc, are alternating cur-* rent relays as well as delay action relays) and therefore the armatures of relay L will be attracted; but since this relay L is a delay'ac'tion relay, a predetermined interval of time will elapse following the energization' of the magnet of this relay L, before contact is made with the front contact of that relay L". Should the train so entering block 3 proceed through that block at a speed greater than that for which delay action relay L has been timed, such train will reach the entrance of block L before the front contact of relay L has been made; in which case (since the front contact of this relay L controls the supply of alternating current from secondary s of transformer S to section-T of the third rail, and to the traclcrail R there will be no alternating current on third rail section T and, therefore, by means hereinafter described the train will be brought to rest at the entrance of block 4. If, however, the train in block 3 proceeds'through that block at a speednot greater than 'that'for which relay L. has been set, by the time that train has reached the entrance of block 4 relay L will have closed its front contact, and thereby' alternating current from secondary coil .9 of the transformer S will be supplied through the front contact of that relay L to the third rail section T thereby permitting the train to proceed, as hereinafter described with reference to the circuits and instruments carried by the train. But now suppose that at the time the train starts to pass from block 2 into block 3, block 6 is occupied. in that event, when the first mentioned train starts to enter block 3, the umguet of track relay TR will be dener gizcd, and the circuit of conductor C through the 1' armature of relay TR, and the front contact corresponding to that armature, will be broken; consequently, the magnet of relay L will not be energized upon the entry of the first mentioned train into block 3, and, when the train proceeds through block 3 and reaches the entrance of block 4, relay L will not have closed thealternating current circuit to the third rail section '1 (supposing block 6 still to be'occupicd, or not to have been vacated for a time corresponding to that to which relay switches 18 aml 18, respectively.

L has been set) and therefore the train seeking to enter block 4 from block 3 will be brought to rest by the means hereinafter described.

.\Vl1en the first mentioned train passes from block 2 into block 3, the magnet of relay L will, in general, already have been energized and the alternating circuit from secondary s of transformer S will have been applied to third rail section T through the front contact of relay L similarly, when the train enters block T* relay L will already have been energized by the action of relay T R as previously described; when thetrain has passed completely into block 4 the 7) armature of relay'TR will maintain the circuit through the magnet of relay L such provision being necessary since, when the train passes completely out of block 3 the magnet of relay TR will be energized and its armature contacts held in attracted position. Vhen the train has passed completely out of block 1 the magnet of relay TR will be energized in turn, its armature contact points held in attracted position, and, therefore, the magnet of relay L will be' deenergized.

It will be seen that by the expedient of extending backward the circuit of each line relay L, L*, etc, to a contact of a track' relay corresponding to a preceding block, I obtain a control of the speed of the train passing through that preceding block; for should the train exceed the predetermined speed it will be arrested upon entry into .the block to which the particular line relay under consideration belongs.

Referring now to Fig. 2, showing the in-. struments and circuits provided on a car or cars of the train to be controlled: 99 designate contact shoes adapted to make contact with the third rail T, 10 designates the train line bus. having in it an impedance bond 10. and 11 designates a conductor connected to the contact shoes 9 and also connected to the train line bus through the impedance bond 10. 12 designates the air brake line, 13 a circuit breaker, controlling the circuit 1415 leading to the circuit controller of the car, and 1G designates a combined electrically operated valve and relay which, as a valve, controls the air brake line 12. At the operating station or stations of the car I provide a combined valve and switch 17. or 17, also another combined valve and switch 18 or 19. In most cases motor cars, electric loco motives, etc, are arranged for operation from either end. and therefore two operat ing positions are provided: consequently, in Fig. '2, l have shown two valve switches 17 and 17 respectively, also two other valve I have shown the valve 17in the open or running position, that being the position which that a ry valve should occupy when the car is to be controlled from the end at which that valve 17 is locatedgand correspondingly, the valve 17 is shown in the closed or nonrunning position. Both va res 18 and 18 are normally in the open position. The fact that the valve 17 is shown in the open position does not necessarily result in the application of the air brakes, for the valve ofrelay 16 is normally closed.

In the operation of the. circuits and instruments shown in Fig. 2, direct current passes from the third rail T of Fig. 1 through oneor more of the shoes 9 and thence through conductor 11 and the impedance bond 10 to conductor 10, and thence through conductor 19 to the armature of valve relay 1G and through the front stop of that relay and the magnet coil of circuit breaker 13 to the frame of the car and so to the wheels and axles and track rail R thence through one or another of conductors 20 (Fig. 1) back to the second- .9 of the transformer from such train control current was derived. The alternating current in the third rail T also passes through one or more. of the shoes -9, and wire 11, to contact point 21 of switch 17 and thence through the arm of that switch and contact point 22 to the magnet coils of relay 16 and thence to ground at 20. hen two or more cars are which coupled together to form a train, it is cusing trainbus of another car, while per- -m1tt1ng,passage of direct current from the train bus of one car to the train bus of another car and so on. The alternating current so received through one or another of the shoes 9, and passing through conductor 11 and contact points 21 and 22 of switch 17 passes thence through the conductor 23 I and condenser 24 to the magnet coils of 'alve relay 1G and thence to ground at 20; this magnet being held energized and its air brake valve closed, so long as the supply of alternating current continues. But should the alternating current fail (as will occur, for example, when the car or train' exceeds predetermined speed and passes into a block before the delay action line relay L or L etc; of that block has closed its. front contact) then the resulting deiinergization of the magnet of valve relay 16 will cause the air brake valve of that relav to open, so applying the brakes, and at the same time will release the armature of circuit breaker 13, thus cutting off power current from the motors, and so stopping the car or train. Upon reestablishment of supply of alternating current, the magnet of valve relay 16 will be energized again, thus closing the air brake valve of that relay and closing the circuit through the coils of the circuit breaker 13. This circuit breaker may be understood to be one the armature of which is restored by hand.

The condens r 21 excludes direct current from the magnet of air brake valve relay 16.

The valve switches 18 and 18' are provided to permit a train to proceed in case of necessity, even though the alternating train-control current is cut off. These switches 18 and 18 are shown as of the push-button type; though of course they may be of any type. Depressing one of these switches closes the corresponding air brakeline valve forming a part of that switch. Supposing the car, the circuits of which are shown in Fig. 2, to be operated from the right hand end (switches 17 and 17' being then inthe positions shown in Fig. and supposing the car to have been arrested through breaking of the alternating current circuit by one of the line relays L L etc.; in that case the magnet of relay 16 will be (leenergized and the air brake valve of that relay open, the brakes being applied and the circuit breaker 13 also being open: the operator depresses the switch 18, so closing the air brake line and releasing the brakes. in so doing he closes a circuit 2526 across the terminals of conductors lat and 15, so accomplishing the same result as it the circuit breaker 13 were closed; the car or train being thereby permitted to proceed.

Eventually, a condenser '27 (Fig. 1) 'may be interposed in the train-control-circuit to exclude propulsion current from the train control circuit."

Current for the track circuits may be derived from any suitable source; but I have indicated each transformer S, S, etc., as provided with a third secondary coil 8 connected to the track rails ofthe corresponding block;

While the use of direct current for propulsion current, and alternatiing current for train control current, has many mlvantages, yet in a broad sense it is immaterial which type of current be used for propulsion, and which type for train control. In Figs. 3 and 4 I have indicated an arrangement. wherein direct current is employed for train control and alternating current for propulsion. R and R are, as before the track rails, R being divided into block sections, and T is the third rail or train-control conductor, likewise divided into block sections. F" is the alternating current feed line for propulsion current, and S" the line through which direct train control'current is supplied. L, L, etc., are direct current line relays and TR and TR", etc, are direct current track relays. The circuits are substantially the same as above described with reference to Figs. 1 and 2, except that the several sections of the third rail are connected through condensers 28 which permit the passage of the alternating propul sion current, but excluding the direct train control current. 29 are interposed in the train control circuits to exclude the alternating propulsion current from such circuits.

30 are provided for excluding the direct train control current from that bus, and inductive resistance 31 is provided in the circuit of the valve relay 16 for excluding the alternating propulsion current from that rclav. 1

Obviously, instead of employing direct 4 Referring to Fig. 4, in the train line bus 10 condensers,

and alternating current, either the direct trol circuits, to make each circuit resonant to the current of the particular frequency pertaining to that .circuitand thereby to excludefrom such circuit thecurrent of the other frequency. The circuits of Figs. 5 and 6 will be understood readily from consideration of the previous figures.

\Vhat I claim is: i

1. A railway train control system cornprising in combination a track, a conductor exteiiding along said track and divided into block sections. means for the supply of train control current for each such block, comprising a time-elementcircuit controller, and train actuated means for each block, each suchtrain actuated means controlling the said time-element circuit controller of its own block and. the said time-element circuit controller of a block in advance.

2. A railway train control system comprising in combination a track, a conductor extending along said track and divided into block sections, means for the supply of train control current for each such block comprising a time-element circuit controller, and train actuated means for each such block, each such train actuated means controlling the said time-element circuit controller of 5 Also, inductive resistances -j controller of a block in advance, and the said time-element circuit controller .of a block in rear, the time-element circuit controllerpt each block also controlling the tnne-elei'nent circuit controller of a block in rear. I

'4. A railway train control system comprising in combination a track, a conductor extending along said track and divided into block sections, means for the supply of train control current for each such block comprising a time-element circuit controller, and train actuated means for each such block. each such train actuated means controlling the said time-element circuit controller of its own block, and the said time-element circuit controller of a block in advance, and the said time-element circuit controller of a block irrear, the train actuated means and time-element circuit controller of each block jointly; controlling the time element circuit controller of a block in rear.

5. A railway train control system comprising in combination a track,- a conductor extending along said track and divided into block sections. means for the supply of train control current for each such block, comprising a time-clement relay and train actuated means for each block and a circuit controlled thereby and passing through the magnet ot' the time-element relay ot' a block in advance.

6. A railway train control system comprising in combination a track, a conductor extending along said track and divided into block sections, means for the supply of train control current for each such block, comprising a timeelement relay and train actuated means for each block and a circuit controlled thereby and passing through the magnet of the time-element relay ot' a block in advance. each such train actuated means also controlling the time-clement relay of its own block. p

7. A railway train control system comprising in combination a track, a conductonextending along said track and divided into block scctions, neans tor the supply of train .control current for each such block. comp'risin a time-elei'nent relay, and train actuated inc-ans for each block, and a circuit .tor

each time-clement relay passing through a contact of the train actuated means of a block in rear and through contacts of the train actuated means and time-element relay of a. block in advance.

8. A railway'train control system comprising in combination a track, a conductor extending along said track and divided into block sections, means for the supply of train control current for each such block, comprising a time-element relay, and train actuated means for each block, and a circuit for each time-element relay passing through a contact of the train actuated means of a block in rear and through contacts of the train actuated means and time-ele1nent relay of a block in advance. each such train actuated means comprising means for holding the time-element relay of the corresponding block in position for the supply of train control current to that block.

9. A 'ailway train control system coinprising in combination a track, a contact conductor extending along said track and divided into block sections, circuits, one for each such block, for the supply of train controlcurrent to the several blocks of that conductor. a delay action relay for each such block section controlling the corresponding train-control cm'rent'circuit, means located at a predetermined distance in advance or" f each such block: section. and arranged to be actuated l a pa sing train and when so actuated to cause the relay correspoi-uling to such block to act to close the train control circuit of that block. and means for hold- 'ing each such relay in closed circuit posimeans therefor arranged to cause such relay to be operated by a passing train, and a circuit connecting each such second relay to the delay action relay of a block ahead. each such second relay arranged when actuated by a passing train to causethe delay action relay ot' the said block ahead to act to close r the corresponding train control c1,rcu1t ot that block, each such second relay also arranged when actuating by a passing train to hold in closed circuit position the delay action relay of its own block. v

11. A railway train control system comprising in combination a track; a contact conductor extending aldng' said track and divided into block sections, circuits, one for each such block, for the supply of train control current to the several blocks of that conductor, a delay action .relay for each such block section controlling the-corresponding a passing train, to cause the delay action relay of the said block ahead to act to close the corresponding train control circuit of that block, provided the said advance block be not occupied, each such second relay further comprising means for holding in closed circuit position the said delay action relay of its own block While that block is occupied.

12. A railway train control system com prising in combination a track, a contact conductor extending along said track and divided into block sections, means for the supply of train control current and propulsion current to each block, such train control current and propulsion current being the one an alternating current and the other a direct current, a delay action relay for each such block section controlling the supply of train control current to that block, a second relay for each such block section and operating means therefor arranged to cause each such second relay to be operated by a passing train, and a circuit connecting each such second relay to the delay action relay of a block ahead and thence extending through a normally closed contact of the second relay of a further advance block and through a normally closed contact of the delay action relayofsuch further advance block, each such second relay arranged, wvhen actuated by a passing train, to cause the delay acton relay qr the. said block ahead to act to CLOSE the corresponding train control circuit of that block, provided the said advance block be not occupied, each such second relay further comprising means for holding in closed circuit position the said delay action relay of its own block While that block is occupied.

13. A railway train control system comprising in combination a track, a contact conductor extending along said track and divided into block sections, means for the supply of train control current and propulsion current to each block, such train control current and propulsion current being the one an alternating current and the other a d' tot current, said contact conductor comraoaaea prising means permitting the passage of propulsion current from section to section and for preventing passage of train control current from section to section, a delay action relay for each such block section controlling the supply of train control current to thatblock, a second relay for each such block section and operating means therefor arranged to cause each such second relay to be operated by a passing t am, and a circuit connecting each such second relay to the delay action relay of a block ahead and thence extending through a normally closed contact of the second relay of a further advance block and through a normally closed contact of the delay action relay of such further advance block, each such second relay arranged, When actuated by a passing train, to cause the delay action relay of the said block ahead to act to close the corresponding train controlcircuit of that block,

provided the said advance block be not octrol current being the one direct current and the other alternating current, of train equipment comprising contact means adapted to make contact with that conductor, a train control relay and a circuit therefor con-' nected to said contact means, said circuit comprising means for excluding the propulsion current from said tram control relay, and brake-operating means and power-con trolling means controlled by that relay, andillo means arranged when operated to make ineffective the operation of such intake-operating means and power controlling means.

15. in a railway train control system, train equipment comprising contact means adapted to make contact with a conductor extending along a track, a tr incontrol relay and a .circuit therefor connected to said contact means, a brake-line containing a valve operated by said relay, and one or more brake-line valve switches each ar; ranged in one position to open the brake-line beyond the relay-opcrated valve and in such position to close a contact in said relay .circui t and in another position to close said brakcdine and open a contact in such relay circuit. 7

16. hr a railway train control system, train equipment comprising contact means adapted. to make contact with a conductor ex its tending along a track. a train-control relay and a circuit therefor connected to said contact means, said circuit including means for the exclusion of propulsion current from said relay, a brakeline containing a valve operated by said relay. and one or more brake-line 'alve switches each arranged in one position to open the brake-line beyond the relay-operated 'valve and in such position to close a contact in said relay circuit,

and in another position to close said brake- -line and open a contact in such relay circuit.

17. In a railway train control system. train equipment comprising contact-means adapted to make contact with a conductor extending along'a track. a train control rclay and a circuit therefor connected to said contact means. said circuit including means for the exclusion of propulsion current from said relay. a brake-line containing a valve operated by said relay. a circuit breaker also controlled by said relay. and a plurality of brake-line valve switches each arranged in running position to open the brake-line beyond the relay-operated valve and in such position to close a contact in said relay circuit. and in another position to close said brake-line and open a contact. in such relay circuit. said switches arranged when in the non-running; position to close a shunt across the said circuit reaker.

1b. railway train control systei'n comprising in combination a track. a coiuluctor extending along such track and divided into block sections, means for the supply of train control current for each such block. comprisin; a time-element circuit controller, train actuated means for ach block. each such train actuated means controlling the said time element circuit controller of-its (.wn block, and the said time-element cir cuit controller of :i block in advance. train equipment comprising contact means adapted to make contact with that conductor. a train control relay and a' circuit therefor connected to said contact means, and brakeoperating' means and power controlling means controlled by that relay.

19. A railway train "control system comrising in combination atrack. a conductor extending along such track and divided into arranged when operatedto make ineffective the operation of such brakeoperating means and power-controlling means.

20. In a railway train control system, the con'ibination with a conductor extending along a railway track and divided into block sections, means for the supply of propulsion current to that conductor. and means for the supply of train control current to that conductoand for the control of such train control current to effect control of a train.

said propulsion current and train control.

that conductor and for the control of such train control current to effect control of a train. said propulsion current and train control current being the one direct current and the other alternation current. of train equip ment comprising contact means adapted to make contact with that conductor. a train control relay and a circuit therefor connected to said contact means. said circuit com prising means for excluding the propulsion current from said train control relay. and bralie-operating means and power-controlling: means controlled by that relay.

'2. A railway train control system romprisingr in combination a track. a conductor extending along said track and divided into block sections, means for the supply of propulsion current to said conductor. means for the supply of train control current to -ach block of such conductor. comprising a timeelement circuit controller. and train actuated means for each block. ach such train actuated means controlling the said lime-element circuit controller of its'own block. and the said time-element circuit controller of a block in adyance. means for excluding: the train control current supply to any one block from the adjacent blocks. and train equipment comprising contact means adapted to make contact with that coi'iductor. a train control relay and a circuit therefor ,connected to said contact means. said circuit comprising means for excluding the propulsion current from said train control relay, and means controlled by said train control ,relay for the control of the train.

"23. in a railway train control system,

train equipment comprising two contact. jncans insulated one from the other and" adapted the one to make contact with one conductor extending along a track, and the other to make contact with another conductor extending along such track, a train-control relay and an energizing circuit therefor connected at opposite ends to said two contact means, brake-controlling means operated by said relay, and one or more switches controlling the energizing circuit of said relay and also controlling brake-applying means.

24.111 a railway train control system, tram equipment comprising tWo contact means insulated one from the other andone adapted to make contact with one conductor extending along a track, and the other adapted to make cont-act with another conductor extending along such track, a traincontrol relay and an energizing circuit therefor connected at opposite ends to said two contact means, a brake-line containing a valve operated by said relay, and one or more brake-line valve switches controlling the energizing circult of said relay and each arranged in one position to open the brake line beyond the relay-operated valve and in such position to close a Contact in such re lay energizing circuit, and in another position to close such brake line and open a contact 1n such relay circuit.

25. In a railway train control system,-

train equipment comprising two contact means insulated one from the other and one adapted to make contact with one conductor extending along a track, and the other adapted to make contact with another conductor extending along such track, a train-control relay and an energizing circuit therefor connected at opposite ends to said two contact means, a brake-line containing a valve operated by said relay, and one or more brakeline valve switches controlling the energizing circuit of said relay and each arranged in one position to open the brake line beyond the relay-operated valve and in such posi tion to close a contact in such relay ener-- gizingcircuit, and in another position to close such brake line and open a contact in such relay .circuit, a train control ,imircuit controlled by said train control relay, and one -or more emergency valve switches arranged when operated to closethe brake line and to close a bridge across the train-con-

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