Route Control Tables 2004

[interesting_signal]

Here's my revised route control tables. I've included a copy where the changes are visible (might make things a bit clearer).

[PJW]

Here's my revised route control tables. I've included a copy where the changes are visible (might make things a bit clearer).

OK I have these; certainly both of you need a bit more explanation re Comprehensive Approach Locking so once we've dealt with anything on the points I think we'll move onto that subject.

[PJW]

Here are the comments on the routes.

The surprise is that you used Merlin's suggested format, but he didn't! I do think that the format is a good one for the exam; becasue it is so compact however it does make it a bit of a squeeze for me to insert comments.

In general I think that you used the format very well.
One of the main drawbacks with the column format is that it is easy to run out of space, particularly if you later want to add stuff having started the next route. Suggest that you only put two or at most three routes per page and always leave space in all rows- just in case. However the proportions of the CT column width seems pretty good- although the "aspect shown" could be narrower and space used for "route locking tracks" or perhaps the "tracks clear" columns. The acid test will be when you actually handwrite on full size sheets

I have marked with a large red dot those things that I think you'll recognise as silly slips- if you don't then let me know.
For the other additional entries / deletions I have attempted to put a # ref and noted in the margin a summary; in some of these cases I think you may need more explanation so ask away as needed. In essence:
#1 GK/RT0044 can wait for now until the basics are secure.
#4 Comprehensive A/L is something that we'll tackle shortly; perhaps I need to revisit the Study Pack as both of you have difficulty in the same area.
#7 Look at Merlin's answer and ask if you need more info
#8 Overrun protection; again this can wait for now.
#9 Swinging overlaps; perhaps a subject after Comp A/L; it'll be good to get you able to do this but don't get hung up as you'll easily pass the exam without it!

So it may look a lot of red, but really this is certainly a "half decent" attempt; I suppose that the most important things to make sure that you see where you went wrong are:
a) the opposing route locking that you missed (but actually not too much of that)
b) foul tracks.

It'll probably be best for me to use Merlin's sheets for explaining the #4 and #9 just because there is more space; that is not however to say that you need to change from your CT format- if you leave enough space then it can be shown equally satisfactorily.

There was a little more space on your 2nd sheet to add comments directly.
a) Similar issues with last wheel replacement as Merlin.
b) You will need to be consistent between different standards- given that you are following RRI practice then there would almost certainly only be one A/L release timer per signal and thus for all classes of routes to all destinations would be set for the greatest of all time requirements. In SSi etc it is only data; in RRI it is hardware, space and money to provide and install!
c) I notice that you (and indded Merlin more so) have often missed out the odd track, usually where it is on a track cct over a point and you are considering a route that passes over that track but the name hasn't been placed on that portion. This is a common fault- you need to be a little more careful at looking at the extent of all TCs, not just track ID name spotting!

[PJW]

Here are your first route CTs.

You need to declare the practices you are following; i am assuming in your case will be SSI CT, probably relatively recent NR?

Also I notice that both for the points CTs and these CTs that you are prefixing the identities by P or R- I expect this comes from familiarity with SSI data, but NR doesn't do this on Control Tables.

114AM:
You put some superfluous route locking on the CT whereas in reality the locking is achieved via point locking. However you missed 107A(M)

The back-back locking of the platform staring signals is occasionally done but not generally in the UK nowadays.
Watch the route indicators; MARI stands for Minature; it is confsusing that a (M) route can have a SARI and a (S) route can have a MARI!

Need to learn how to determine the time for A/L release; see time values.

Comprehensive A/L- have made some notes but we'll discuss separately

123AM:
Some similar comments but also probably a couple of silly slips on this one.

Specific issue though is missing 211 as trapping / flank as discussed when comenting on that point's CT.


142B(W):
Basically similar comments but also some specifics:
a) foul tracks
b) specific Warning route features; see revision bite.


142B(C ):
Some similarities, but the specifics here relate to the stupidity that having correctly asked for DB or DC occupied when the signaller is setiing the call-on route, that the aspect controls demand the tracks clear! Signal is never going to clear.

You also got carried away by demanding 206R; yes from the selfish viewpoint of 142B(C ) it would be an advantage, but would be a nonsense for the site as a whole to destroy trapping from the sidings to a running line!

144A(S):
You missed out some opposing route locking; mind you it does depend what you are doing with the points to some extent; you were inconsistent re 206.

You attempted to record the fact there would be last wheel replacement, but didn't use the CT format correctly; having put $40 then you didn't fill in the relevant box. Instead you attempted to put the replacement condition into the disengagement box- this is closely related but different. So the examiner is left with the feeling that you have leant a bit form here and some from there and have ended up falling between two stools; actually your fellow student did much the same, so this is another area to tackle!

[PJW]

Here are your first route CTs.

I missed one, so here it is

142B(M)

Not a bad attempt at a complicated CT.
For opposing moves you missed those that route to 135 but you did see that 107 and 142B(M) do sometimes share an overlap, though you should have made this conditional on 203.

You need to worry about foul tracks BM and EH; the former you can get rid of by calling 208N and then detecting it, but gives slightly more availability by demanding (208N or BM clr) thoughif the signaller then handsignalled from 125 due to the lack of point detection then an aspect reversion would occur. Conversely 206 are best left normal or else the trapping from the siding is destroyed.

Just because it has a PLJI does not necessarily mean that signalis approach released- it depends on the differential speed; however all you have to do is FOLLOW THE ROUTE TABLE INFO.

For modern (i.e. fibre optic or LED) banners it s only necessary to prove that it is not displaying ON in order for the signal in rear to clear to better than yellow- it need not actually be alight.

I'll deal with swinging overlap and comprehensive A/L separately.

[merlin89]

Peter,
Many thanks for your comments they are very much appreciated. I have reviewed my errors (cant believe some of them too) but hope to correct these issue in the next CT's.

[greensky52]

Firstly I want to thanks for the former explanation, I found I have less difficulties in reading others

[PJW]

In route CT:
1? In 123(M), does it need 208N? I am usually confused about similar situation. In the standard, I remember it says flank protection is decided by the distance between 2 points. But in the layout, I can not justify whether 208 provide flank protection to 209.

208 do not provide flank in this instance.
However 208 and 210 are both in the same track circuit and therefore generally candidates for point-to-point locking if that is a feature of the interlocking. Often where point-to-point is appropriate then it does provide flank and hence looking for it can be a way of ensuring a student doesn't overlook flank. Here I agree that don't gain anything by 123 calling 208; however don't lose anything either (provided it os only CALL not DETECT). So not wrong to include but also not wrong to exclude. In many cases it might be wrong to exclude, so therefore I thought it best to teach people always to include; I think this is a useful exam passing technique.

2? In the route 142B(M), why 129A(S) appears in opposing route locking? 129A(S) requires 207N, while 142B(M) requires 207R? And 135 is similar situation. I think 135 requires 212A R, while 142B(M) requires 212A N.

Because of sectional route release.
129A(S) requires INITIALLY 207N but when train using that route passes clear of EJ and is still on EK then 207 becomes free. However the train is still opposing 142B(M) and that is the reason why we need the opposing locking that way around. However in the converse direction it is not needed; 142B(M) holds 207 locked reverse until train has cleared DE and is on DC by which time it is safe for 129A(S) to set. In that direction you are correct that the locking of the points is adequate and there is no opposing locking to show.

3? Also in 142B(M), I think when 203R, it should require 204N. is it right?

204 gives no flank in this case and therefore it really doesn't matter if you include it or exclude it; as above.

4? In his CT, aspect column, BR stands for what?

Banner Repeater signal

5? In 144A(S), why does it not require FB clear?

Because it is a shunting movement whose whole purpose is to be able to join one train with another. Ask yourself where is it sensible for a locomotive to join it wagons. The answer must surely be on FB track within the Up siding! Therefore excluse that track from the aspect controls but include all the others within the route as wuld not want to join a train stood on them.

[quote]
In point CT:
1? If the track is dead locking TC, it should not appear in the column of

[greensky52]

Referring to route CT,
1 In short, two points in a TC are point-to-point interlocking, not flank protection, right?
2 Noted, But still need to think it carefully for a while.
3 Same as item 1
4 Noted
5 Noted. But does shunting to a siding mean that it must be a wagon in siding for coupling?

Point CT:
1 Need to think for a long time
2 Noted
3 Need to think

Anyway, thank you. Have a nice weekend

[PJW]

Referring to route CT,
1 In short, two points in a TC are point-to-point interlocking, not flank protection, right?
2 Noted, But still need to think it carefully for a while.
3 Same as item 1
4 Noted
5 Noted. But does shunting to a siding mean that it must be a wagon in siding for coupling?

Point CT:
1 Need to think for a long time
2 Noted
3 Need to think

Anyway, thank you. Have a nice weekend

Route CT
1. Not exactly.
If it is worth providing each point end with its own track then point-to-point would probably not be appropriate; therefore if you see two point ends in one track circuit this is a clue that point-to-point may be appropriate. One of the reasons for providing point-to-point is that in many instances it does provide flank.
5. There does not NEED to be a wagon, but we need to allow for the POSSIBILITY that there is a wagon.