Ensayo de rayado

For the purpose of understanding the circuit can be classified as under:-1. Point Control and point setting circuit.

2. Point indication circuit.

3. Signal lock relay circuit.

4. Route Checking Circuit.

5. Approach & Route locking circuit.

6. Track stick relay circuit.

7. Signal control relay circuit.

8. Signal aspect control circuit.

9. Track stick slow release relay circuit . 10. Panel indication Circuit.

For the explanation of circuitry signal No.1 in layout given below (Fig5:2) is considered. For clearing the signal to road 2 points 101,102,103 and 104 are operated to the required positions by operating the respective point switches to the required positions.

5.3.1 Point Control and Point Setting Circuit.

The point is controlled by a point lock relay (WLR) which is kept in the cabin and point controller (WNR/WRR) kept near the point machine. WLR is a neutral relay and WNR/WRR is are the point control. Relay for normal and Reverse operation of point respectively.

The points can be operated, when the following conditions are satisfied.

1. SM’s key should be in the panel to ensure authorised operation (Fig. No.S5J 2.3.1(a).

2. Point track relay should be energised to prove track locking is freed and

3. Approach stick relays and sectional release route lock relays (TRSRs/TLSRs) are energised to prove that the point have not been locked for any other route.

Approach stick relays are generally provided one for each signal to achieve approach locking , back locking and indication locking. Where sectional release route locking is provided. Track Right stick relays (TRSR) for right ward movement and track left stick relays (TLSR) for leftward movement are used. These relays are normally kept energised. When a signal knob is turned for clearing a signal, the picking up of UCR causes ASR to drop and this in turn causes TRSRs/TLSRs to drop. The back contacts of these relays are used in HR circuit to prove that the points are locked in a route, before a signal is cleared.

Note : Generally t wayside stations where panel interlocking is provided, sectional route release locking is not catered for.

Point operation switch is a two position switch. This can be operated either to ’N’ position or ‘R’

position depending upon the requirement. This has 2N/R contacts. For clearing the signal No.1 to a Road 1 with overlap set to sand hump, switches 102 and 103 are operated to Normal and switch 101 is operated to reverse.

When WNR picks up, the point is operated to normal and when WRR picks up the point is operated to reverse 102 and 103 operate to normal through their respective WNR and point 101 operate to reverse through 101 WRR.

Note : Some Railways Adopt the method of keeping WLR de-energised normally (by including de-energised contact of NWKR/RWKR in WLR circuit) with an advantage of avoiding drainage of power supply continuously.

Fig :5.3 5.3.2 Point Indication (detection) Circuit :

This circuit employs two neutral relays one for proving the points are normal and the other for reverse. When points are set and locked in Normal. Relay NWKR picks and when points are set and locked in reverse relay RWKR picks up. The contact of WNR/WRR is not included in the detection circuits as these relays de-energise, when signal is cleared.

Fig :5.4 5.3.3 Signal Lock Relay Circuits :

As explained earlier, the home and the opposing starters, are controlled by a 3 position humb switch. The switch normally remains in the centre position. This can be turned to right or left depending upon whether it is a rightward or leftward movement. For clearing Home Signal 1 to Road 1 or 2 the switch ‘1’ has to be turned to right and for clearing opposing starters. It has to be turned to left. For clearing Home Signal 5, switch ‘5’ has to be turned to left and clearing opposing starters it has to be turned to right. Each 3 position switch is provided with two relays.

When the knob is turned to clear a despatch signal “SR” (sending or starting relay picks up and when the same knob is turned to clear a reception signal ‘RR’ (Reception or Receiving Relay) picks up. The back contact of one relay is used in the circuit of the other to ensure that both do not energise at a time.

In some circuits the centre position of the knob is proved by a third relay ‘NR’. This is not used in these circuit, as these circuits are wired with metal to carbon relay contacts.

For energising the SR/RR relays, the following conditions are to be satisfied . 1. Knob is to be turned to left or right

2. SM’s key should be ‘N’

3. The back contact of the SR should be available for energising RR and vice versa.

Once these relays pick up, they do not drop even if SM’s key is taken out. This is achieved by bridging

(I) the SMR front contact by NR/RR front contact and

(II) ‘L’/R contact of the thumb switch by SMR back contact, to ensure that these relays do not drop when the panel is locked by SM and the signal switch is turned back to Normal by unauthorised persons.

The circuit for 1 SR,1RR ,1RLR and 1SLR are given here under :

In the above circuit 1RR energised contacts in 1RLR circuit proves that the signal knob is turned to right for reception of a train. De-energised contact of 1SLR, 3LR, 2LR, 9LR and 10RLR are proved since they are conflicting signals. 9LR and 10RLR are bridged by 4RWKR front contact and 7 RWKR front contact in series to facilitate simultaneous movements. Similarly bridging of these contacts by 5RWKR front contact and 6 RWKR front contact is for simultaneous movements.

In recent installations, separate switches are provided for Home and opposite starter signals as shown in the layout given at Fig.2. In such case, there will not be SR and RR. Concerned signal lock relays or route initiation relays (LR/RRs) will pickup proving the conflicting signal LR/RR dropped. The level crossing and siding points also will have controlling knobs. The circuit for 1LR is as under.

Fig : 5.6

The basic requirements for picking up of LR relay is the de-energisation of conflicting LRs. This can also be achieved by proving concerned point detection relays (NWKR/.RWKRs) in the LR circuits, if it is economical (amounts to reduction in no.of contacts.)

5.3.4 Route Checking Circuit:

The function of this circuit is to check that the route is correctly set before the signal is cleared.

Each signal is provided with a route checking relay (UCR).

The picking up of UCR initiates the route locking circuits, and enables the route locking condition being proved in the HRR circuit.

Fig : 5.7

Note : It is a practice in some Railways to prove the conflicting signal ASR in UCR circuit.

Concerned CHLR is also proved in some Railways.

5.3.5 Approach & Route Locking Circuit:

Generally each signal is provided with an Approach Stick Relay (ASR) to achieve the approach locking, back locking and indication locking. Whenever UCR picks up it results in ASR dropping.

When ASRs de-energise, they cause point lock relays (WLRs) to de-energise thereby locking the points in the route.

When 1UCR picks up it makes 1ASR to drop. 1 ASR dropping causes 3 TRSR to drop.

Dropping of 1ASR de-energises 2WLR and dropping of 3 TRSR de-energises 3WLR & 4WLR, thereby locking all the three points in the route. Two or more signals can be provided with common ASR as shown in P-56, when then route is same and these signals are conflicting.

5.3.6 Track Stick Relay Circuit.

This is a conventional SR circuit used to ensure that “One Train on One Signal”.

This relay (TSR) is normally energised through the front contact of controlling track & back contact of the RLR & SLR. Once this relay pick up, it gets a stick feed bypassing RLR & SLR back contacts. When a signal is cleared RLR/SLR picks up. Even then TSR remains picked up through its own contact. When the train passes the signal and occupies the controlling track.

TSR drops. When the train clears controlling track, TSR cannot pick up till such time the signal switch is replaced to Normal causing RLR/SLR to de-energise. TSR (F) is used in HR circuit.

This arrangement ensures that after the passage of the train, the signal cannot re-clear automatically unless the signal switch is replaced to normal and operated once again.

In latest installations , ASR contact is also proved along with LR back contact in TSR circuit to prove that the previous train cleared the route.

Fig : 5.9 5.3.7 Signal Controlling Relay Circuit (Fig.

Each signal is controlled by a HR relay.

For clearing a signal, the following conditions are to be satisfied.

1. The line should be clear up to the next signal in advance and adequate distance beyond it (TR front contact).

2. All the points in the route are correctly set and locked including the overlap (NWKR/RWKR).

3. Route is checked and Signal knob is operated to the correct position (UCR).

4. Points are electrically locked (WLR ).

5. Points are locked in the route (TRSR / TLSR) 6. Signal is approach and back locked ASR ).

7. Only one train can be admitted on one signal (TSR ).

8. Time release associated with signal is in operation (Mechanical Time release normal contact).

9. Opposing signals are not cleared (Opposing signal ASR).

10. Route lamps are lit before signal is taken off for turnout (UECR).

11. Block Control is available for last stop signal.

12. Signal ahead aspect is available (GECR front contact) when all the above conditions are satisfied HR picks up.

5.3.8 Signal Lamp circuit.

This is the conventional multi-unit colour light signal circuit with cutting in arrangement.

5.3.9 Sequential Route Release Relays (UYRs)

These relays are provided to release the approach track locking of signal when a train has passed the signal, independent of whether the approach track is occupied or not.

These relays are made slow to release as the front contact of this relays used to energise ASR Relay and the back contact of ASR is proved to energise TSSLR/UYRs.

Now a days, the practice is to prove more than one track relays for this purpose to avoid release of route during track circuit bobbing conditions. The pick up and drop contacts of all the back lock track circuits will be used in the circuit as shown in Fig .

5.3.10 Panel Indication Circuits (Fig.)

When route is not set, no indication is given on the panel. When a signal is cleared and points are locked in a route a row of white lights light up the whole length of the route.

These lights are given through the back contact of ASR TRSR/TLSR and the relevant track front contact. When the train occupies the lights turn to Red through the TR back contact irrespective of whether the route is set or not.

The point indications are given through point indication relay front contact and signal indications through lamp proving relay, front contacts.

Fig : 5.12

CHAPTER – 6 S5J1

RELAY INTER LOCKING ROUTE SET METHOD BRISITSH