2004 Point CT

[apparao_medapati]

Hi,

I have tried point CT for 2004 layout.

Sorry, Now file is atttached.

Kindly review.


Thanks & Regards,
Appa Rao.M

[Peter]

I don't seem to have a 2004 layout, can anyone oblige so that I can have a look at this post?

[apparao_medapati]

I don't seem to have a 2004 layout, can anyone oblige so that I can have a look at this post?

Hi,

Find the attachments.

[Peter]

Before I comment, I should stress that I am not a wizz on CTs - it was my worst mark when I did the exam, but given that I did pass module 3, I can't be too far off the mark.

I've had a look at your table for 203 points and as far as I can see, it is very good. You appear to have adopted the practice that shunt moves will not have overlaps which is fine, but you may be advised to state this.

As far as I can see, the only route that you omitted in the "Set by" was 142B(W) calling them R to N - there is only one ROL shown, so there is not a swinging O/L issue there, but you had not mentioned the route atall. The warner should probably be shown in the TOL box as well (you got 142B(M) in there).

The condition for releasing the locking on R>N for the line (142B(M) or 250R...etc) has all the right TCs to be clear, but I wonder whether you should have DB or DC in the occ col - look at the length of the platform against the length of the train. Something could well come in to the up loop from 142 and sit at the right hand end of the platform never touching DB track.

Where you have showed the swinging overlap controls, you have done so, as far as I can see, correctly for R>N but on the N>R sheet you have shown the essence of it, but not used the swinging O/L columns and I wondered why. Perhaps is it that there are no additional TC required to be clear, so you did not need to use that col!

All in all, a very good effort. I'll try to look at 211 for you later.

[Peter]

Another very good attempt. You have grasped probably the most important part of this one - the tie up with 212 points.

I'm not sure on this one - should (BR or 212N) be in both the N>R and R>N TC clear. I thought it should be because whichever way 211 are set, if 212 are R, and there is something on BR, would we want 211 to move?

The only thing that I think you missed is that you identified 137A(S) and 144A(S) as calling the points N>R but you then did not enter them as routes required to be normal in the R>N (and hence missed the sectional release conditions).

Otherwise, what you out was what I would, so assuming I am not completely out of it, you should be pretty confident.

[apparao_medapati]

Thank you for your Detailed review comments.

[PJW]

I'm not sure on this one - should (BR or 212N) be in both the N>R and R>N TC clear. I thought it should be because whichever way 211 are set, if 212 are R, and there is something on BR, would we want 211 to move?

There is obviously no point (excuse the pun) in getting 211R unless 212 also R; this is a classic case of point-to-point locking that would traditionally have been provided; hence historically:
211N>R req 212 detected R
212R>N req 211 detected N.
Although we don't put in such locking nowadays, it is well worth being aware of it since it helps when contemplating questions such as this one.

It is not essential to make BR lock 211R>N and there is a very small advantage in omitting since
a) can reinstate trapping that moment earlier
b) it's simpler!
However if you do put in that locking, then the "ever so slightly excessive" point locking is only what would always have occurred anyway with point-to-point, so including it is not wrong either. Nowadays when tend to have route locking on every track all over the layout I'd go for not putting the extra locking it, but recogbise that if BR locked 211 both ways, then wouldn't actually need route locking from 144 as the lack of route normal and dead track locking from the post would be adequate (assuming no need for track bob protection).

Of course you could decide that you are not going to have BR locking 211 at all; the risk that BR is foul to a signalled movement is covered by 212A points, which it will lock purely because it is dead track over 212B. Think about it; all moves over 211 (except for an unauthorised one that will derail at 211A if normal) also involve 212!

Like so much else, DEPENDS ON WAHT STANDARDS YOU ARE ADOPTING TO FOLLOW.

[apparao_medapati]

Thank you

[greensky52]

I am new to Mod 3, and I have read your posters for learning. It is really gainful in this discussion forum. Now I have some questions as follows: Could someone kindly please help me?~~Thanks in advance.
For Point 203:
1. comparing to others

[PJW]

[quote='greensky52' pid='1620' dateline='1276065521']
I am new to Mod 3, and I have read your posters for learning. It is really gainful in this discussion forum. Now I have some questions as follows: Could someone kindly please help me?~~Thanks in advance.


My question is: should we consider in all the signals in the layout? I supposed that we only need to consider those with control box