Self Truncating?

You are here: Home > Forum > Simulations > Timetables > Three Bridges > Self Truncating?

Page 1 of 1

Self Truncating? 28/10/2020 at 22:11 #133380
DaveHarries
Avatar
1287 posts
Evening all,

I have just loaded up my Three Bridges TT to do a bit more work on it and I am told that one of the seeds - 2x SN 5/377 @ 102m each = 204m - has truncated at startup to 174m. However as "TAT1" divides to separate trains for the first two workings I need to have it at 204m. Anyone know why it has shortened to 174m and how I can fix that?

Cheers,
Dave


Post has attachments. Log in to view them.
Log in to reply
Self Truncating? 28/10/2020 at 22:34 #133381
GeoffM
Avatar
6380 posts
I assume you're seeding in Tattenham Corner platforms. They are officially only 191.5m to 198m long in the Sectional Appendix so 204m won't fit. However, Google Earth shows the track being ~205m but that leaves half the front carriage off the platform. Seed in the siding, perhaps, and bring out the portions separately?

However, if there is convincing gen to show trains of that length are allowed then I'll update the sim.

SimSig Boss
Log in to reply
Self Truncating? 28/10/2020 at 22:38 #133382
clive
Avatar
2799 posts
From memory, this happens when the train won't fit behind the seeding signal, including if points are in a wrong position. There isn't a good answer to this problem; truncating is what we chose.

If you're seeding in a siding or bay, try seeding at the buffer stop arrow rather than the exit signal. By convention these have the same number as the exit signal with an X suffix. But be warned that some developers suppress these as seed points.

Log in to reply
Self Truncating? 28/10/2020 at 23:20 #133383
DaveHarries
Avatar
1287 posts
GeoffM in post 133381 said:
I assume you're seeding in Tattenham Corner platforms. They are officially only 191.5m to 198m long in the Sectional Appendix so 204m won't fit. However, Google Earth shows the track being ~205m but that leaves half the front carriage off the platform. Seed in the siding, perhaps, and bring out the portions separately?

However, if there is convincing gen to show trains of that length are allowed then I'll update the sim.

Hi Geoff,

Thanks for the useful info. What doesn't help is that on the date on which I am basing this timetable - 22nd November 2020, the day of a large T3 possession - it is not clear what the two trains that "TAT1" divides into - 2P12 and 2P14 - have worked as their last turns the day before (according to RealTimeTrains - I realise that could get updated) and both berth in P2 overnight as shown here:
https://www.realtimetrains.co.uk/search/detailed/TAT/2020-11-22/0000-2359?stp=WVS&show=all&order=wtt

It could well be that both trains are, in fact, scheduled to start from P2 but that still doesn't help even so.

As for Tattenham Corner CS the only two workings to/from there all day, which I have already programmed into the TT, are:
- 5P14 (0903 Purley - Tattenham Corner CS)
- 5P73 (2347 Tattenham Corner CS - Purley)

of which the latter joins 5G73. As can be seen, all the trains bar a couple, use Platform 1 on the above link. I will have to keep my eyes open. The other option, of course, would be to seed them on different platforms which, if RTT is anything to go by, could be tricky.

Cheers,
Dave

Last edited: 28/10/2020 at 23:24 by DaveHarries
Reason: None given

Log in to reply
Self Truncating? 29/10/2020 at 09:42 #133387
TimTamToe
Avatar
664 posts
DaveHarries in post 133383 said:


Thanks for the useful info. What doesn't help is that on the date on which I am basing this timetable - 22nd November 2020, the day of a large T3 possession - it is not clear what the two trains that "TAT1" divides into - 2P12 and 2P14 - have worked as their last turns the day before (according to RealTimeTrains - I realise that could get updated) and both berth in P2 overnight as shown here:
https://www.realtimetrains.co.uk/search/detailed/TAT/2020-11-22/0000-2359?stp=WVS&show=all&order=wtt

It could well be that both trains are, in fact, scheduled to start from P2 but that still doesn't help even so.

As for Tattenham Corner CS the only two workings to/from there all day, which I have already programmed into the TT, are:
- 5P14 (0903 Purley - Tattenham Corner CS)
- 5P73 (2347 Tattenham Corner CS - Purley)

of which the latter joins 5G73. As can be seen, all the trains bar a couple, use Platform 1 on the above link. I will have to keep my eyes open. The other option, of course, would be to seed them on different platforms which, if RTT is anything to go by, could be tricky.

Cheers,
Dave
Dave,

I would have one seeding in the platform and one in the siding? and move the siding seed into the platform once the other has departed? Even if that may not be 100% accurate as to what happens on the night/morning, it won't make much difference in the grand scale of things.

ps looking forward to the tt

Gareth

Log in to reply
The following users said thank you: headshot119, TUT
Self Truncating? 29/10/2020 at 11:21 #133389
markt
Avatar
60 posts
Spot on with the platform lengths Geoff. The diagrammers show maximum capacity as 9 car 20m stock in each platform.
20 years of Simsigging
Log in to reply
The following user said thank you: GeoffM
Self Truncating? 29/10/2020 at 11:23 #133390
markt
Avatar
60 posts
The platform workings on RTT may not have been 100% accurate if the platform number wasn't updated on the STP bid from TPU.

If you have a date from your timetable, let me know and I'll see if I have the amended workings for that date.

20 years of Simsigging
Log in to reply
Self Truncating? 01/11/2020 at 19:37 #133464
Edgemaster
Avatar
332 posts
Given that a RHTT is also booked to reverse in P1 on top of the berthed units, I suspect the platform workings there aren't correct.
Twitter
Log in to reply
Self Truncating? 01/11/2020 at 23:33 #133467
kaiwhara
Avatar
587 posts
GeoffM in post 133381 said:
I assume you're seeding in Tattenham Corner platforms. They are officially only 191.5m to 198m long in the Sectional Appendix so 204m won't fit. However, Google Earth shows the track being ~205m but that leaves half the front carriage off the platform. Seed in the siding, perhaps, and bring out the portions separately?

However, if there is convincing gen to show trains of that length are allowed then I'll update the sim.
I've reviewed the 2016 CWN, and there were no 10 car operations to Tattenham Corner. Plenty of 5 cars though.

The trains that would seed in that timetable at least, were all 4 or 8 car 455's. The two 5/377's that were down there were both in the Up Siding.

Sorry guys, I am in the business of making people wait!
Last edited: 01/11/2020 at 23:37 by kaiwhara
Reason: None given

Log in to reply