https://irse.signalpost.org/ Thu, 16 Apr 2026 13:18:32 +0000 MyBB https://irse.signalpost.org/showthread.php?tid=2163 Thu, 29 Dec 2016 13:31:26 +0000 soylemezv]]> https://irse.signalpost.org/showthread.php?tid=2163 Hi,

I have been working on technical specifications. In basically , Which informations should be included in a technical specification for a new  line? I only consider informations that to be written quantitative, such as headway, dwell time, maximum speed , temporary speed restrictions etc. I exclude the interfaces between signal system and other systems.

What can be written about the following topics?(From the railway administrator perspective)

Interlocking
Track circuits&Axle counters
Switches
Signals
Train-wayside communication
ATP and ATO
Reliability,availability,maintainability and safety

Especially ,about the track circuits & axle counters, signals and point machines Can you share with me If you have technical specification? Happy New Year to all! Thanks.
]]> Hi,

I have been working on technical specifications. In basically , Which informations should be included in a technical specification for a new  line? I only consider informations that to be written quantitative, such as headway, dwell time, maximum speed , temporary speed restrictions etc. I exclude the interfaces between signal system and other systems.

What can be written about the following topics?(From the railway administrator perspective)

Interlocking
Track circuits&Axle counters
Switches
Signals
Train-wayside communication
ATP and ATO
Reliability,availability,maintainability and safety

Especially ,about the track circuits & axle counters, signals and point machines Can you share with me If you have technical specification? Happy New Year to all! Thanks.
]]> https://irse.signalpost.org/showthread.php?tid=1116 Mon, 05 Nov 2012 18:24:18 +0000 PJW]]> https://irse.signalpost.org/showthread.php?tid=1116 T1 (warm temperate, warm dry)
T2 (Cold temperate) and
TX (Cold)

Gives information about the environment in which equipment should be able to perform-

· Pressure (altitude, pulse pressure due to tunnel etc)

· Temperature (extremes, rate of change)

· Humidity (ambient, in cubicle, in shelter, in building, sudden rate of change)

· Wind (natural, passing trains)

· Rain (also considered combined with wind)

· Snow and Hail (all types of snow, driven snow by wind / vehicles passing and on board)

· Ice

· Solar radiation

· Lightning

· Pollution (chemical, biologically active, mechanically abrasive, electrically conductive)

· Fire protection

· Vibration (energy level, distribution across frequency range)

· Shocks (for mounting: on rail, on sleeper, in ballast, trackside)

· Electromagnetic Compatibility (victim, source)

· Power Supply (spec, tolerance of voltage and frequency)]]> T1 (warm temperate, warm dry)
T2 (Cold temperate) and
TX (Cold)

Gives information about the environment in which equipment should be able to perform-

· Pressure (altitude, pulse pressure due to tunnel etc)

· Temperature (extremes, rate of change)

· Humidity (ambient, in cubicle, in shelter, in building, sudden rate of change)

· Wind (natural, passing trains)

· Rain (also considered combined with wind)

· Snow and Hail (all types of snow, driven snow by wind / vehicles passing and on board)

· Ice

· Solar radiation

· Lightning

· Pollution (chemical, biologically active, mechanically abrasive, electrically conductive)

· Fire protection

· Vibration (energy level, distribution across frequency range)

· Shocks (for mounting: on rail, on sleeper, in ballast, trackside)

· Electromagnetic Compatibility (victim, source)

· Power Supply (spec, tolerance of voltage and frequency)]]> https://irse.signalpost.org/showthread.php?tid=994 Thu, 22 Mar 2012 18:21:14 +0000 PJW]]> https://irse.signalpost.org/showthread.php?tid=994
Thought it worth copying my answer here as I expect this may be helpful to others. Also I have never even been to Australia can only assume that it follows current UK terminology, so perhaps someone else can comment from that perspective.

I just got a doubt what is the difference between functional testing and Principle testing. Can you please tell me and what is this verification and validation testing.

I can tell you what it now means in a UK context; I guess that Australia would be the same, HOWEVER I should also tell you that when I started of the Western Region of British Rail in 1981 then what we THEN called "functional testing" is precisely what NOW is called "Principles testing"! Hence beware- usage can vary....

Functional testing is testing that checks out individual parts of a system, involving the application of power to exercise the circuits etc. So getting points to throw in response to a call, measuring that the voltages and currents are correct, making sure that the clutch slips appropriately and that the timer cuts off after 7.5seconds is an example. Similarly the fact that the point contactor relays operate in response to the interlocking and have the correct voltage and polarity and use the correct cable cores fed from the specified fuse.

So is the circuit testing in the interlocking that proves contact A1/A2 of AE TPR is a front contact and is effective at cutting the feed to 361GR so that the signal goes back to danger. The key thing is that each test done is ticked off or otherwise recorded on the design details another copy of which was used during installation to produce the product being tested. It is VERIFICATION that we have built correctly what the designer designed. "Did we built it right"


Principles testing is about VALIDATION; is what we have built "fit for purpose"? "Did we build the right thing?"
So the tester looking only at the Signalling Plan and signalbox diagram DECIDES FOR THEMSELVES what locking would be appropriate in order that a set of points should be allowed to move or a route to be set or for a signal to show a particular aspect. They then "functionally" investigate to see whether the actual implementation agrees with their expectation and only when satisfied then asserts that the locking exists. They are NOT LOOKING AT THE CONTROL TABLES, but call out to someone else who is looking so that it is then recorded by ticking entry on the Control Tables. The tester calls out the locking that they expected and had found to be effective.

Hence if the designer has made an error and omitted a control, the Principles tester will discover the error because he is not relying upon the designer (as has made up their own mind first); The functional tester however won't have discovered the error as what they have proved is that the installer has correctly wired the circuit as designed, the relay is of the correct spec, there is enough voltage for the relay to pick and then no residual voltage when it should drop.

Principles testing (at least in theory) is undertaken on the completed entire system whereas the functional occurs little by little on increasingly larger assemblies (e.g.test point machine in factory, test prewired location odff-site,, test from location to point machine locally, test relay room interlocking circuits, test between interlocking and location, test panel circuits, test between panel and interlocking etc.

In practice, particularly with Solid State Interlocking some of the distinction (in terms of which grage of staff do what) is a bit blurred; rehearing the operation of points from the control centre to the point machine is technically Verification rather than involving any Validation, yet generaly the activity is led by a "Principles tester", oartly because there may be a need on the same shift to do some Principles, but often just because they are the more experienced people who can
a) get things to work when there are problems and others would flounder, and
b) just might see something very important that the less experienced would miss.

Hope that helps.

PJW
]]>
Thought it worth copying my answer here as I expect this may be helpful to others. Also I have never even been to Australia can only assume that it follows current UK terminology, so perhaps someone else can comment from that perspective.

I just got a doubt what is the difference between functional testing and Principle testing. Can you please tell me and what is this verification and validation testing.

I can tell you what it now means in a UK context; I guess that Australia would be the same, HOWEVER I should also tell you that when I started of the Western Region of British Rail in 1981 then what we THEN called "functional testing" is precisely what NOW is called "Principles testing"! Hence beware- usage can vary....

Functional testing is testing that checks out individual parts of a system, involving the application of power to exercise the circuits etc. So getting points to throw in response to a call, measuring that the voltages and currents are correct, making sure that the clutch slips appropriately and that the timer cuts off after 7.5seconds is an example. Similarly the fact that the point contactor relays operate in response to the interlocking and have the correct voltage and polarity and use the correct cable cores fed from the specified fuse.

So is the circuit testing in the interlocking that proves contact A1/A2 of AE TPR is a front contact and is effective at cutting the feed to 361GR so that the signal goes back to danger. The key thing is that each test done is ticked off or otherwise recorded on the design details another copy of which was used during installation to produce the product being tested. It is VERIFICATION that we have built correctly what the designer designed. "Did we built it right"


Principles testing is about VALIDATION; is what we have built "fit for purpose"? "Did we build the right thing?"
So the tester looking only at the Signalling Plan and signalbox diagram DECIDES FOR THEMSELVES what locking would be appropriate in order that a set of points should be allowed to move or a route to be set or for a signal to show a particular aspect. They then "functionally" investigate to see whether the actual implementation agrees with their expectation and only when satisfied then asserts that the locking exists. They are NOT LOOKING AT THE CONTROL TABLES, but call out to someone else who is looking so that it is then recorded by ticking entry on the Control Tables. The tester calls out the locking that they expected and had found to be effective.

Hence if the designer has made an error and omitted a control, the Principles tester will discover the error because he is not relying upon the designer (as has made up their own mind first); The functional tester however won't have discovered the error as what they have proved is that the installer has correctly wired the circuit as designed, the relay is of the correct spec, there is enough voltage for the relay to pick and then no residual voltage when it should drop.

Principles testing (at least in theory) is undertaken on the completed entire system whereas the functional occurs little by little on increasingly larger assemblies (e.g.test point machine in factory, test prewired location odff-site,, test from location to point machine locally, test relay room interlocking circuits, test between interlocking and location, test panel circuits, test between panel and interlocking etc.

In practice, particularly with Solid State Interlocking some of the distinction (in terms of which grage of staff do what) is a bit blurred; rehearing the operation of points from the control centre to the point machine is technically Verification rather than involving any Validation, yet generaly the activity is led by a "Principles tester", oartly because there may be a need on the same shift to do some Principles, but often just because they are the more experienced people who can
a) get things to work when there are problems and others would flounder, and
b) just might see something very important that the less experienced would miss.

Hope that helps.

PJW
]]> https://irse.signalpost.org/showthread.php?tid=933 Wed, 19 Oct 2011 18:49:42 +0000 PJW]]> https://irse.signalpost.org/showthread.php?tid=933 http://irse.org.au/images/stories/Knowle...0%20v2.pdf]]> http://irse.org.au/images/stories/Knowle...0%20v2.pdf]]> https://irse.signalpost.org/showthread.php?tid=896 Sat, 27 Aug 2011 16:54:34 +0000 PJW]]> https://irse.signalpost.org/showthread.php?tid=896
I am no HF expert, but I have gathered together what I hope should be useful material re
a) the role of ergonomics within signalling design generally
b) in particular considerations relating to the interface with specific reference to Control Centres
c) Human Error- categories, causes, estimating error rates etc.

It does not seek to answer any particular exam question, although certain sections could form a lot of the content to various elements within such.]]>
I am no HF expert, but I have gathered together what I hope should be useful material re
a) the role of ergonomics within signalling design generally
b) in particular considerations relating to the interface with specific reference to Control Centres
c) Human Error- categories, causes, estimating error rates etc.

It does not seek to answer any particular exam question, although certain sections could form a lot of the content to various elements within such.]]> https://irse.signalpost.org/showthread.php?tid=825 Tue, 12 Jul 2011 19:07:50 +0000 PJW]]> https://irse.signalpost.org/showthread.php?tid=825
I am hoping that he may permit me to share his Powerpoint presentation on this forum. In the meantime I am attaching a document that I was inspired to produce; I found that I didn't need all the time I had set aside last weekend for reviewing answers for the forthcoming mod2/3 Signet event, which gave me the opportunity to do this.

It is not directly aimed at answering any specific exam question, but hopefully will provide a resource useful for tackling some of these; I have gathered together information from a range of documents and my own experience to attempt to shed some light onto an area of mystery for many. For the IRSE exam you only need an appreciation of the overview, so I have spared you 3 dimensional Maxwell equations- divs, grads, curls and all the rest of university maths that in truth I have all but forgotten]]>
I am hoping that he may permit me to share his Powerpoint presentation on this forum. In the meantime I am attaching a document that I was inspired to produce; I found that I didn't need all the time I had set aside last weekend for reviewing answers for the forthcoming mod2/3 Signet event, which gave me the opportunity to do this.

It is not directly aimed at answering any specific exam question, but hopefully will provide a resource useful for tackling some of these; I have gathered together information from a range of documents and my own experience to attempt to shed some light onto an area of mystery for many. For the IRSE exam you only need an appreciation of the overview, so I have spared you 3 dimensional Maxwell equations- divs, grads, curls and all the rest of university maths that in truth I have all but forgotten]]> https://irse.signalpost.org/showthread.php?tid=658 Thu, 23 Sep 2010 12:16:49 +0000 oxfordjack]]> https://irse.signalpost.org/showthread.php?tid=658
how track circuit affects the design nof traction current supply and return?

Thank you.]]>
how track circuit affects the design nof traction current supply and return?

Thank you.]]> https://irse.signalpost.org/showthread.php?tid=649 Sat, 18 Sep 2010 05:54:36 +0000 oxfordjack]]> https://irse.signalpost.org/showthread.php?tid=649
Can someone let me brain storm on what different of Generic Application Safety Case and the Application Specific Safety Case??

Thank you.]]>
Can someone let me brain storm on what different of Generic Application Safety Case and the Application Specific Safety Case??

Thank you.]]> https://irse.signalpost.org/showthread.php?tid=369 Thu, 08 Apr 2010 18:50:25 +0000 adikarina]]> https://irse.signalpost.org/showthread.php?tid=369 I am struggling to find some information regarding the different types of specifications and when which type should be used.

Please provide some guidance as where to find it.

Thanks
Aditi

Not surprised; I can't immediately put my finger on one good source. Sure there are several references but I'll need some time to get a selection together; also I think they'll be a need to derive what you need from a composite of sources as background reading rather than a ready written comparison.

In the meantime to get you thinking on the right lines, I suggest you consider what you would do in your own life re a variety of possible purchases. For each of the following categories, how would you decide between a range of items on sale when looking to purchase :
a) a house
b) a car
c) a pair of shoes
d) ingredients for cooking a meal
e) a book to read on a long flight
f) a torch battery
g) a replacement cartridge for your inkjet printer

How would your criteria for making a selection differ in each case?
Which items would you feel appropriate to make "sight unseen" over the internet rather than experiencing the item in person?
Suppose you were a very busy and affluent person and you had a "personal shopper" either actually to make a purchase for you or at least make a shortlist of items for you to choose between; how would you instruct them in your selection criteria?
If you start to appreciate what the differences in your approach may be in the various cases, you'll get some feeling of why different types of specification are appropriate in different scenarios.]]> I am struggling to find some information regarding the different types of specifications and when which type should be used.

Please provide some guidance as where to find it.

Thanks
Aditi

Not surprised; I can't immediately put my finger on one good source. Sure there are several references but I'll need some time to get a selection together; also I think they'll be a need to derive what you need from a composite of sources as background reading rather than a ready written comparison.

In the meantime to get you thinking on the right lines, I suggest you consider what you would do in your own life re a variety of possible purchases. For each of the following categories, how would you decide between a range of items on sale when looking to purchase :
a) a house
b) a car
c) a pair of shoes
d) ingredients for cooking a meal
e) a book to read on a long flight
f) a torch battery
g) a replacement cartridge for your inkjet printer

How would your criteria for making a selection differ in each case?
Which items would you feel appropriate to make "sight unseen" over the internet rather than experiencing the item in person?
Suppose you were a very busy and affluent person and you had a "personal shopper" either actually to make a purchase for you or at least make a shortlist of items for you to choose between; how would you instruct them in your selection criteria?
If you start to appreciate what the differences in your approach may be in the various cases, you'll get some feeling of why different types of specification are appropriate in different scenarios.]]> https://irse.signalpost.org/showthread.php?tid=106 Wed, 10 Sep 2008 13:29:17 +0000 KenD]]> https://irse.signalpost.org/showthread.php?tid=106 https://irse.signalpost.org/showthread.php?tid=38 Sat, 05 Apr 2008 21:28:48 +0000 PJW]]> https://irse.signalpost.org/showthread.php?tid=38
Also see this module 5 thread for information regarding Fault Trees which is at least as applicable to module 7 and closely related to this topic]]>
Also see this module 5 thread for information regarding Fault Trees which is at least as applicable to module 7 and closely related to this topic]]> https://irse.signalpost.org/showthread.php?tid=37 Sat, 05 Apr 2008 21:26:42 +0000 PJW]]> https://irse.signalpost.org/showthread.php?tid=37