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Reg Points Crank Handle - Locking in Control Table
#1
Dear Members,

I am studying UK control table for Module 3 IRSE examination. In this I didn't find any locking related to Points crank handle.

I have working experience in Indian railway control table. There we mention for "Signal Control" concern point crank handle key should be in and locked in EKT and also we write the safe condition for crank handle release also. These condition we will implement in logic also. Apart from we are ensuring the safe condition to release the crank handle in degrade mode also (SSI failure)

I enquired few friends who are very familiar in UK signalling but I didn't get clear idea. Kindly clarify to me.

Thanks in advance !!!

Regards,
NJK
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#2
In the UK there is no locking with crank handle; indeed the days of "release from signalling panel" are long over and it has been just under a padlock security local to the points (for at least the last 25 years I think).

However other practices vary and I certainly have heard previously that this is the practice in Indian Railways, so if those are the practicees you are adopting for your control tables then do show the interlocking. If using the standard IRSE control Table blank, then you'll need to consider the best way of depicting on it or decide better to apply some general note.

(25-04-2013, 08:21 AM)NJK Wrote: Dear Members,

I am studying UK control table for Module 3 IRSE examination. In this I didn't find any locking related to Points crank handle.

I have working experience in Indian railway control table. There we mention for "Signal Control" concern point crank handle key should be in and locked in EKT and also we write the safe condition for crank handle release also. These condition we will implement in logic also. Apart from we are ensuring the safe condition to release the crank handle in degrade mode also (SSI failure)

I enquired few friends who are very familiar in UK signalling but I didn't get clear idea. Kindly clarify to me.

Thanks in advance !!!

Regards,
NJK
PJW
Reply
#3
(25-04-2013, 02:14 PM)PJW Wrote: In the UK there is no locking with crank handle; indeed the days of "release from signalling panel" are long over and it has been just under a padlock security local to the points (for at least the last 25 years I think).
However other practices vary and I certainly have heard previously that this is the practice in Indian Railways, so if those are the practices you are adopting for your control tables then do show the interlocking.

Actually it is not the crank handle itself which is interlocked into the points circuit but a key which is kept locked into a KLCR(Key Locking Relay).In order for the point proving relay(NWKR/RWKR)to pickup,this key must be proved "in" in the KLCR.
Hence,if any maintenance work needs to be undertaken on the points which needs hand-cranking,a slot can be released from the panel for the concerned point.Once the slot is released,the key becomes free in the KLCR and can be removed and then inserted into the point machine.The crank handle is kept in a glass-fronted padlocked and sealed case.The handle is removed from the box and it can be used to operate the machine.Entries in appropriate registers need to be made.
The interlocking itself is relatively simple in that the concerned NWKR/RWKR of the point will pickup only if the slot is not released and the key is inserted and locked in the KLCR.The front contacts of the NWKR/RWKR are proved in the signal clearance relay circuit.

Khalid.
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#4
Thanks for this.
Could you confirm whether the electrically released key has to be inserted into the point machine in order
a) to be able also to insert the winding handle
or
b) for the winding handle to be effective in moving the mechanism.

As I understand what you wrote, the winding handle itself is kept in a locked cupboard but it is only procedural arrangements which prevent someone having an appropriate key taking it out


(23-09-2013, 05:42 PM)khalid Wrote:
(25-04-2013, 02:14 PM)PJW Wrote: In the UK there is no locking with crank handle; indeed the days of "release from signalling panel" are long over and it has been just under a padlock security local to the points (for at least the last 25 years I think).
However other practices vary and I certainly have heard previously that this is the practice in Indian Railways, so if those are the practices you are adopting for your control tables then do show the interlocking.

Actually it is not the crank handle itself which is interlocked into the points circuit but a key which is kept locked into a KLCR(Key Locking Relay).In order for the point proving relay(NWKR/RWKR)to pickup,this key must be proved "in" in the KLCR.
Hence,if any maintenance work needs to be undertaken on the points which needs hand-cranking,a slot can be released from the panel for the concerned point.Once the slot is released,the key becomes free in the KLCR and can be removed and then inserted into the point machine.The crank handle is kept in a glass-fronted padlocked and sealed case.The handle is removed from the box and it can be used to operate the machine.Entries in appropriate registers need to be made.
The interlocking itself is relatively simple in that the concerned NWKR/RWKR of the point will pickup only if the slot is not released and the key is inserted and locked in the KLCR.The front contacts of the NWKR/RWKR are proved in the signal clearance relay circuit.

Khalid.
PJW
Reply
#5
(23-09-2013, 09:08 PM)PJW Wrote: Thanks for this.
Could you confirm whether the electrically released key has to be inserted into the point machine in order
a) to be able also to insert the winding handle
or
b) for the winding handle to be effective in moving the mechanism.
As I understand what you wrote, the winding handle itself is kept in a locked cupboard but it is only procedural arrangements which prevent someone having an appropriate key taking it out
The key enables a combination of the two as at first the key is inserted by swinging aside a flap on the outside of the machine.Turning the key will operate a switch to disconnect the negative of the machine supply as also activate a mechanical wedge which will open the hole for the inserting the handle.
Disconnecting the negative ensures that the machine can no longer be operated from external supply.

Khalid.
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#6
In the example of 3 aspect case, Consecutive yellow (Signal in rear to the approach controlled signal will show yellow, Approached controlled signal will show RED, once the train occupies the berth track of approach controlled signal, then it will go to yellow ) will be provided.
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#7
(12-11-2013, 01:29 PM)erum Wrote: In the example of 3 aspect case, Consecutive yellow (Signal in rear to the approach controlled signal will show yellow, Approached controlled signal will show RED, once the train occupies the berth track of approach controlled signal, then it will go to yellow ) will be provided.
No this is not what we would say is "consequtive yellow"; whereas you are correct that the driver will pass a signal at yellow reading up the the approach released signal (initially at red and then clearing to its relevant aspect- which may or may not be yellow), the first signal will have been replaced to red before the next signal clears so that they are never simultaneously at yellow.
PJW
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