2007 Q7 RELAYING POINTS; RENEW MACHINE?

[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.