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Control Tables
#1
Is there any solved papers for control table questions which can be help new students.
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#2
mangeshwakankar Wrote:Is there any solved papers for control table questions which can be help new students.

Which railway practice are you familiar with - ie are you looking for UK, Australia etc and are you from a metro or mainline background?

Peter
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#3
Presumably given your entry in the Bio section (thanks! one of the minority who have completed this) you are familiar with Indian railway practices. Whilst I have quite a few answers to IRSE exam CTs, these are to various UK practices and so may not be entirely appropriate.

However I have posted an attachment which is a document which I started to write some years ago to help a certain group of students; other things took priority so I have never had a chance to finish it, but it should be useful for point locking and for route locking, though it didn't get very far into route and aspect I am afraid.

For any particular railway's situation there are in fact lots of worked examples out there that can be studied- the signalling records for each real interlocking installation! I also do wonder how much can actually be learned from just looking at a "solved" answer; if you don't comprehend the Principles in use then the answer by itself is not likely to be comprehensible. The best learning is from comparing where your attempt differs from what would be a good answer to the same Principles.

Can I suggest that you have a go at a past layout and post your attempt on this site, remembering to declare the standards to which you are working. This should enable you to get some useful feedback; obviously the closer your practices are to those with which others are familiar the better the quality of the feedback, but even if differ significantly it should still be possible to identify areas that "certainly look wrong" and which may require more study / investigation. Indeed this may be a good way to achieve your aim of understanding where railways' practices differ.

The message therefore is have a go yourself and get stuck-in- that is the way to learn how to do Control Tables. Don't expect to find "the solved question answer" that can be learnt- the same layout won't come up again in the exam. What you do need to learn is your railways generic Principles and then get familiarity in applying these. Do you have any Past IRSE exam paper layouts?

PJW

Peter Wrote:
mangeshwakankar Wrote:Is there any solved papers for control table questions which can be help new students.

Which railway practice are you familiar with - ie are you looking for UK, Australia etc and are you from a metro or mainline background?

Peter


Attached Files
.doc   Control Tables PJW.doc (Size: 963 KB / Downloads: 412)
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#4
Peter Wrote:
mangeshwakankar Wrote:Is there any solved papers for control table questions which can be help new students.

Which railway practice are you familiar with - ie are you looking for UK, Australia etc and are you from a metro or mainline background?

Peter

I suppose the railway practice followed in UK & Australia would be similar and that to with Metal to carbon relay.
Indian Railways use metal to metal relay for interlockings.
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#5
Certainly where Network Rail use relays in a safety critical application, the philosophy is to use dependable relays (=non-weldable front contacts and the guarantee that no back contact on a relay can make at a time that any front contact is made). Sounds like India is more like most of the Continental railways where the relays could potentially weld as use all metal contacts and thus the safety is ensured by forms of sequential and cyclical checking, cross-proving etc.
Although this is a very important issue for interlocking design and certainly does require specific controls, this is more of a Module 1/7 question than Module 3 (it may be an essay question but not the Control Tables part).

The Control Tables are really about the Principles almost in ABSTRACT. Not so much the HOW they are achieved and the necessary TECHNOLOGY issues, more to do with the fundamental LOGIC of WHAT signalling element needs to interlock with any other. The purist would say that it doesn't matter if the interlocking "black box" uses computer data, bespoke electonic design, bespoke relay design- free wired or geograhical, compressed air, mechanical clockwork or indeed a little man inside it. Obviously the things that are technically possible differ in each case as indeed does the safety integrity (!- thinking of my dwarf!) and thus the reality is that any real Control Tables do have to reflect technology issues to some extent- often to make sure that the overall design mitigates identified hazards.
A very interesting argument and one that would make a good IRSE exam question which could with the correct "spin" arise in any of the modules except 2,4,6.

For Control Tables though, the examiners would not really be looking for the "technology specifics"- it could make the difference between Credit v Distinction, but not Fail v Pass.

To get a Pass you need to get the point calling and locking correct, inclusing trapping, flank, foul tracks, overlap locking annd releasing. You need to get opposing locking correct (direct, indirect, time out where applicable). You need to get the route setting conditions correct (point availability, opposing, crossproving). You need to get the aspect level correct (points including flank, tracks including foul, overlaps, approach release and route indicators). You need to get aspect sequence correct (in the NR UK case sequence, junction approach release, transitions etc).

Do this consistently and fast enough to attempt all the items set and you'll get a Pass; put a few of the frills on (e.g. swinging overlaps, permissive move locking etc) and you'll pic up those extra marks for a Credit. Show that you really know all the ins and outs of what you are doing as applicable to your sepcific railway and you'll get a Distinction BUT ONLY if you've got all the BASIC OK.


PJW


Peter
Quote:I suppose the railway practice followed in UK & Australia would be similar and that to with Metal to carbon relay.
Indian Railways use metal to metal relay for interlockings.
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#6
hay word file not loading/opening please tell how to load ms word file

neeraj
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#7
(20-02-2019, 10:55 AM)neerajtamrakar Wrote: hay word file not loading/opening please tell how to load ms word file

neeraj

I am sorry, but we had a problem some years ago when some attachments got lost in a migration of the forum. This, unfortunately is one of them.

Peter
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