2007 Q7 RELAYING POINTS; RENEW MACHINE?

[IJP]

The york study group set 2007 Q2 and one other question to be attempted, I have attempted Q7 from 2007 mod 1 (the question is attached)
I am approaching the question from a maintenance background, with a small amount of exposure to New Works testing, however the way the question is worded leads me to suspect it could be a maintainance renewal using template design, and SMTH method statement.

IJP

[Peter]

The york study group set 2007 Q2 and one other question to be attempted, I have attempted Q7 from 2007 mod 1 (the question is attached)
I am approaching the question from a maintenance background, with a small amount of exposure to New Works testing, however the way the question is worded leads me to suspect it could be a maintainance renewal using template design, and SMTH method statement.

IJP

Parts two and three I think have been done quite well. Not sure that you have quite answered the question they asked in part one. I've put some comments on the attached scans. You said in your post that you have answered this from a maintenance view. Your answer reads like this, but you have not stated such things and you don't have the benefit of an explanatory post written later to go with your exam answer!

[fnnnj001]

As part of the York Study group we were set question 2 to attempt from the 2007 module 1 paper and any other question from previous paper i chose Q7 from the same paper.

I have answered them from a MTCE background and would appriciate any feedback good or bad.

[Peter]

Comments on Q7

I think that you have answered the first part in the same way as IJP did in this thread - that is to say you have given the advantages of changing to another point machine per se, rather that, what I think the question was asking which is what is the advantage of changing the point machine when the pway are doing work anyway. This means that in the disadvantages section, you have looked at the problems with not having a new machine, rather than the things like "the pway will be in the way". What you have written is not wrong in itself, I just do not think that is what the examiner was looking for to give you marks.

Personally, I think you have made work for yourself on part 2. The question was looking for THE testing and commissioning process. It did not ask what sort of testing regimes could be required. Hence you have spent time outlining two different regimes when you could have stated the assumption that it is similar enough for "like for like" (or different enough to need to be works, depending on what you are more comfortable with) and then going into detail. I also think, like IJP, you have concentrated a bit too much on some of the specific tests, rather than what the T&C process would be (eg some sort of planning, some levels of testing and documentation, then bringing into service).

Part 3 says about fitting monitoring to all other sites. I would imagine that if replacement of the other machines is not cost effective, putting a monitoring system on there would also be similarly prohibitive. You did not mention some sort of inspection regime (in the UK example this si crying out for a dectiption of the SIN process (note a description of it, not just stating that a SIN would be issued). You have however redeemed things a bit at the end by talking about finding an replacing the affected module. The detailed analysis you suggest to find the root cause is a sensible point.

Peter

[PJW]

Comments on Q7

I think the question was asking which is what is the advantage of changing the point machine when the pway are doing work anyway.....

The question was looking for THE testing and commissioning process.... you have concentrated a bit too much on some of the specific tests...

Part 3: You did not mention some sort of inspection regime....

Peter

I see what Peter means. but I think I might well have interpreted with the emphasis on the different rather than at the time. I suspect the examiners would adjust their marking according to how interpreted. The smart thing to have done would to have been alert to the possibility of alternative interpretations and have started your answer with a sentence of "context" that could have included your assumption in this regard.
As an employee of a company which over the years has produced several generations of machines, M3 and its variants, 63 etc but has yet, as far as I know, to supply a Surelock to Network Rail I do find your wording somewhat ironic! What other point machines with modular replaceable units within it exist? Perhaps you count the IBCL but although it has many advantages over the traditional clamplock, I don't see that it is at all different in this regard.
The Surelock was designed to be able to have specific connection to condition monitoring but the reality seems to be that there is seen to be no business case; the HPSS has good built in diagnostics designed to be connected to a SCADA system- but has that ever happened? Don't get me wrong- I think the things you mentioned are perfectly sensible, but perhaps if answering from an NR context you should have indicated that you knew the reality of the situation by emphasising that these are potential advantages which could be gained rather than wording as if current practice.
Also beware when asked for advatages and disadvantages that you give some of each- effectively you have given the advantages of replacing with a new machine and the disadvantages of retaining the old style of machine; these are really the same. What you should have said are things like:
a) maintenance staff need training on new machine
b) extra spares holding required; space requirement and money tied up
c) operational staff need training and another form of point handle etc; delays if take the wrong type when attempting to operate in degraded mode or within possession.

I completely agree with Peter re 2nd part; do remember that this question was asked in a MODULE 1 paper, so answer accordingly rather than as you would had it been module 5 question!

For the last part I think there is something within the wording that you should have picked up upon. "The defect is believed to affect a number of similar point machines"; it didn't say every. You need to play on that:
a) is there a "bad batch" of components resulting from manufacturing error or out of specification raw material- are they traceable to being incorporated in machines of specific serial numbers that can then be located on the railway?
b) has a change been made in the design of that component, (or indeed another component which could have a knock-on effect on the failing component)- similar to above but perhaps easier to trace by being aware of a specific "mod state"
c) does the defect only manifest itself when the machine is used in a certain environment (susceptible to aggregate dust, sea air) / manner (high speed facing points, switch diamonds).
Certainly the some weeks tends to rule out the wear-and-tear or deterioration applicable to c), but a) and b) are certainly possibilities.

[losler]

Hello again!

The Brisbane study group attempted this question too, here is our attempt

[PJW]

Hello again!

The Brisbane study group attempted this question too, here is our attempt

A few comments inserted into your answer. I wasn't too enthused by this one; I think it would have scored something like 4+ 4 +4 and I'd probably then be slightly more generous and just about allow it to scrape a pass overall.

So what do I think was wrong with it?
In essence it didn't convince me that you fully knew what you were talking about; there was too much vaguary and buzz-words that I am dubious whether you actually understand.

Actually Part 1 was reasonable and scored as such, though didn't demonstrate awareness of the wide range of potential issues. See also earlier comments re interpretation of meaning of the question set.

Part 2 I felt was weak, rather vague and a bit confused in places. Whereas one can asume that a module 1 question is not likely to be wanting great technical detail, you should have given a clear overview of the different activities in the process; it read as a rather disjointed jumble of more or less relevant items but failed completely to give the impression of PROCESS.
I guess that as designers you may not have got that personal experience but have just acquired a hazy idea; certainly gave me that impression. It was fair enough to supplement the actual testing activities by the ancilliary items you included and had the core been sound, then these would have been the "icing on the cake"; as it was these only served to further the impression that you felt the need to include them because you knew that the kernel was somewhat lacking. This perhaps may be unfair, but I guess that an examiner has fundamentally to mark partially on subjective impression like this and so I suggest you would not have got a pass mark within this section.

Part 3. Like the "curate's egg", parts of this were excellent. It was however spoilt for me by the impression given that you didn't really appreciate fully what it would actuslly mean in the real world. It was generally too vague and hence I conclude that your understanding is quite weak.
A good answer would I think have given some specific examples of things that might be failing of various consequences, for example
a) a weak contact spring which meant that detection might be intermittent as a train passes in the vicinity (reliability implications, signal reversion issues) g
b) a key component in the drive gear that could become dislodged / seize up and cause the points to jam in midstroke and defy attempts even to manually wind across,
c) a defect that could mean that the firm retention of the switch tongues could not be relied upon during the passage of a train and thus give immediate safety concerns.
This approach would have demonstrated some better understanding of point machines (detect, set, lock) and the relationship between faults and failures and the variation of their RAMS consequences and would also have given contrasting examples for which different remedial actions / mitigations would be appropriate.

So not a disaster but certainly not one of your better efforts. At this stage it is probably more important that
a) you recognise what it was about this question / answer that meant that I didn't view you in the best light and learn re amending your presentation (if you think that was the problem) or determine to avoid such a question,
than
b) learning re the subject topic themselves