No official Railway Board PDF has been traced for this entry yet. The text below was read from the document held in the library.
| Type | Commercial Circular |
|---|---|
| Topic | ticket-checking |
| Currency | Currency not verified |
When a Train is required to enter BS, already obstructed by any other Train or due to Accident.
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# DAIDO HANDLE TYPE TOKENLESS SINGLE LINE BLOCK INSTRUMENT
S VELRAJ MDTC DWR
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PARTS & FUNCTIONS
BUTTONS
PB 1 To Transmit Bell Code.
PB 2 Pressed with PB1 to turn OH of other end B I.
COMMUNICATION
BELL : - Sounds, PB1 pressed from other end.
TELEPHONE:- To Communicate with SM at other end.
KEYS : S M Key:- Locks BI when taken out.
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SHUNT KEY
Provided in the Block Instrument.
Can be extracted in any condition except in TCF condition.
Given to LP as an authority for shunting
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OPERATING HANDLE
It has 3 positions as shown by arrow on the Handle.
Turned to required position only with co-operation of SM at other end by pressing PB1 & PB2.
If OH not in any of 3 positions exactly, bell signals cannot be transmitted.
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| SL No | POSITION | POSITION OF THE OPERATING HANDLE | POSITION OF THE ARROW | INDICATION |
| --- | --- | --- | --- | --- |
| 1 | Line closed | Vertical (Normal position) | Upward | B S clear |
| 2 | TCF | Horizontal | R H S | L C given for Train |
| 3 | TGT | Horizontal | L H S | L C obtained for Train |
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GALVANOMETER
It indicates flow of current.
When OH turned, needle gets a jerk.
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BUZZERS
BUZZER 1
It sounds when FVT actuated.
Provides audible indication at both Stations when Train enters BS.
BUZZER 2 (LVT BUZZER)
Provides audible indication when Train arrives at receiving Station.
Sounds when LV passes LVT circuit.
Not an indication for complete arrival of Train.
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CANCELLATION SWITCH - S1
Cancelling LC for a Train before Train enters BS.
Each operation registers in S1 counter.
CANCELLATION SWITCH - S2
Operated to receive Train on signals, returning back to starting Station.
Each operation registers inS2 counter.
During HOC/TOC S1, S2 counter numbers shall be recorded in TSR by both SMs.
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TRAIN ON LINE INDICATOR
When Block section clear, a White Indication at both ends.
When Train enters BS, FVT actuated and White changes to Red and TOL appears at both ends.
TIME RELEASE INDICATOR
Normally shows LOCKED.
When S1 is reversed for cancelling LC , FREE indication appears after 120 seconds.
After FREE indication, Line Clear can be cancelled.
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OUTDOOR APPARATUS
F V T CIRCUIT
Slightly in advance of LSS, actuated when First vehicle passes over.
WHILE DESPATCHING A TRAIN
LSS replaced to ON & TOL indication appears on both Instruments.
Continuous Buzzer sounds at both Stations, stopped by pressing PB1 at receiving Station.
WHILE RECEIVING A TRAIN
F S S replaced to ON, however knob not to be put back to ON until LVT Buzzer sounds.
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LAST VEHICLE TRACK CIRCUIT
LVT placed in advance of HS , between OMFP & LSS.
When LV of Train passes, LVT buzzer sounds continuously till HS put back to normal.
LVT buzzer doesn’t indicate complete arrival of Train.
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TESTING BEFORE TAKING OVER CHARGE
During TOC, SM shall,
i) Try to take OFF LSS without setting BI to TGT.
If it is possible, BI shall be suspended. Otherwise, in proper order.
ii) Without other end SM’s Co-Operation, test OH by turning it to any other position. It shall not be turned to any other position. An entry be made in TSR.
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PRECAUTIONS BEFORE ASKING IS LINE CLEAR
In TSR, Train Out of Block Section / Obstruction Removed signal received and entered for previous Train and B S is clear.
L C not given / Obtained by any other means.
P N obtained for the Train & SNR indication available.
Shunt key available in B I & S1, S2 switches in normal position and O H in Line Closed position.
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PRECAUTIONS BEFORE GIVING LINE CLEAR
In TSR, Train Out of B S signal received and entered for previous Train and Block Section is clear.
Line Clear not given / Obtained by
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