Module 3 study pack activity 1.2 part of answer

[merlin89]

In answer to activity 1.2 of Module 3 study pack using 2002 layout.

Currently with no routes are set one can assume that with the Multiple Unit (MU) sat in station C that controlled signal 116 will be showing a red aspect and the associated CD/RA indicator is extinguished. Signal 122 also controlled with no route set from it will also be showing a red aspect, the distant signal in the rear signal 124 will therefore be showing a yellow aspect.

The loco that is approaching signal 124, is 30 seconds from the signal, (travelling at a linespeed of 100km/h means that it is currently 833 m away from the signal) and has not yet reached the sighting point of signal 124 which is 10 secs at train speed on the approach side of the first signal displaying a warning aspect.

The MU has priority over the approaching loco as such the signaller will set the route from signal 116 to signal 114. With s114 showing a red aspect, s116 will display a yellow aspect with route junction indicator position 1 lit (assuming no other traffic in the vicinity the signaller may well set the route from s114 to s133 and from s133 to s137 should this be the case then with s137showing a red aspect, distant signal s135 will display a yellow aspect, s133 a green aspect, s144 will show a green with route junction indicator position 1 lit consequently s116 will change from a yellow to a green aspect). The platform staff will press

[PJW]

In answer to activity 1.2 of Module 3 study pack using 2002 layout.
Currently with no routes are set one can assume that with the Multiple Unit (MU) sat in station C that controlled signal 116 will be showing a red aspect and the associated CD/RA indicator is extinguished. Signal 122 also controlled with no route set from it will also be showing a red aspect, the distant signal in the rear signal 124 will therefore be showing a yellow aspect.
The loco that is approaching signal 124, is 30 seconds from the signal, (travelling at a linespeed of 100km/h means that it is currently 833 m away from the signal) and has not yet reached the sighting point of signal 124 which is 10 secs at train speed on the approach side of the first signal displaying a warning aspect.

Agreed

The MU has priority over the approaching loco as such the signaller will set the route from signal 116 to signal 114. With s114 showing a red aspect, s116 will display a yellow aspect with route junction indicator position 1 lit (assuming no other traffic in the vicinity the signaller may well set the route from s114 to s133 and from s133 to s137, should this be the case then with s137 showing a red aspect, distant signal s135 will display a yellow aspect, s133 a green aspect, s114 will show a green with route junction indicator position 1 lit consequently s116 will change from a yellow to a green aspect).

Generally agreed (ignoring the typo corrected!) but for the fac that s114 is reading from a 100km/h line onto a 50km/h branch over 50km/h turnouts so therefore must be approach released; hence when s114 is routed to s133 the best aspect that s116 can show is Yellow.

You could also perhaps have noted that as s116 clears the driver would observe for a short time the signal at red and PLJI pos 1 during which time the lamp proving occurs and then the red changes to yellow- more noticeable with SSI than RRI but the issue is that it is sequential- the interlocing controls are in the route indicator and then the signal itself follws once it has been proved to be displayed.

[quote='merlin89' pid='735' dateline='1237733573']
The platform staff will press

[merlin89]

Apologies for not replying with answer but have moved house and have had no internet access until now. Have decided to come back to this one a little later as requires a little more thought but for now will plough ahead with the other activities.