North End
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Post by North End on Apr 13, 2021 22:50:05 GMT
Yes, the new Watford South Junction is pants compared with the former alignment but it does allow a faster curve on the local line to Watford. Anyway I digress...... It's got to be remembered that at the time, the majority of Amersham services ran fast along the main lines, so the realignment to give a faster curve on the local made sense, as the most benefit was provided to the traffic patterns of the day. Unfortunately a year later that all changed... It annoys me that with so much money spent on new signalling, they still can't get anywhere near the end-to-end running times achieved in the 70's / 80's, although it's partly down to speed limits being more liberally observed (and enforced) back then. Yes, but there were significantly fewer trains in those days, both due to a lower demand and a shortage of stock or crews (or sometimes both). With lower demand and fewer trains running around there are less opportunities for delay and less need for recovery time. The introduction of the various Migration Areas are linked to potential improvement in JTC (Journey Time capability - nothing like an old PPP acronym one in a while), once SMA5 goes in I expect we will see a timetable change on the SSR taking advantage of the performance improvements that CBTC offers. The point about recovery times is well made. If we take the Northern Line, there’s now an all-day 3-minute service to every terminus. For the likes of Barnet and Edgware with their three platforms this means in reality the turnaround time is at best never going to be better than about 6 minutes. Add in real-life issues like your occasional driver being slow to change ends, someone holding a door open, a minor defect appearing as the new cab is opened up or whatever, and all too often this is getting down to the point where there is no breathing space at all. Drivers are allowed four minutes, but this isn’t really very long - it allows a quick toilet visit or a quick snack, but not both, and it doesn’t take much else for example finding some lost property or coming across a passenger issue for things to get very tight indeed. So it doesn’t take much in the way of late running before you pass the point where late running won’t naturally “ride out”. In the old days if there was 10-15 minutes at the terminus, this would sort out a lot of things naturally. You simply can’t do this on railways where a late arrival at a terminus is likely to result in a similarly late departure. Something like Merseyrail is the same with its notoriously tight timetables on certain routes - how do you manage a service like Chester to Liverpool where one end is a loop with no recovery time at all, and the other is a turnaround where the driver barely has time to walk from one cab to the other? You don’t want to turn short as both ends are the major traffic destinations. The answer is that Merseyrail sometimes remove stops, but on LU this isn’t a done thing (we once did it on the TBTC simulator when someone forgot to put it on pause during a rest break, and it did actually work rather well!). As a passenger I hate recovery time as much as anyone else, especially if I’m on my way home. But seeing things from the other side unfortunately with the nature of today’s railway where we are really running more trains than the infrastructure ideally supports, there’s not much alternative. If you can’t build it in at the termini then it has to be elsewhere, that is the bottom line unfortunately. The only way to smooth out run-of-the-mill issues is to do just enough intervention to get things to a point where breathing space in the timetable gets everything back to where it should be. Otherwise the service will simply never recover - there’s only so many reversing points, and only so many reform opportunities! |
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Post by spsmiler on Apr 24, 2021 9:35:25 GMT
More CBTC today... Monument - Sloane Square
below are a few tweets on the topic (one by me)
re: Embankment, I have some interesting video footage of it in action, although before I can use it I need to return and see it bagged-up.
As an aside, in anticipation of more CBTC roll-outs over the past few days I've been photographing signals on the Upminster branch, was surprised to see so many of them are atop of the signal control box rather than free-standing. Some also have wire mesh cages to ensure that LU signal staff do not accidentally tray too near the mainline's overhead electric wires.
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Colin
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Post by Colin on Apr 24, 2021 11:12:54 GMT
More CBTC today... Monument - Sloane Square Indeed. Word is that unlike previous go live weekends where we open up to the public on the Sunday afternoon, we may well be opening up to the public this afternoon (Saturday)..... |
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Colin
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Post by Colin on Apr 24, 2021 12:51:30 GMT
Not sure when exactly it happened but just had a message at 13.48 to say trains are now running in public service between Monument and Sloane Square.
EDIT: gather it happened at 13.15
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Post by Chris L on Apr 25, 2021 13:21:57 GMT
Not sure when exactly it happened but just had a message at 13.48 to say trains are now running in public service between Monument and Sloane Square. EDIT: gather it happened at 13.15 Had a ride on a train from Monument to Westminster and back this morning. Everything running well. |
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DWS
every second count's
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Post by DWS on Apr 25, 2021 16:26:13 GMT
The train service has been reduced for this weekend, Not the normal number of trains in service. The real proof that it’s a good one will the Normal Monday to Friday service.
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vincenture
Quiz tryhard, and an advocate for simpler, less complicated rail routes
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Post by vincenture on Apr 25, 2021 16:29:15 GMT
Am curious of the speeds, how was it? |
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Post by Chris L on Apr 25, 2021 18:56:04 GMT
Am curious of the speeds, how was it? Heading towards Tower Hill from Westminster the acceleration seemed very good for the first few stops. After Mansion House not so rapid but the stations are pretty close together. |
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vincenture
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Post by vincenture on Apr 25, 2021 19:45:04 GMT
I see, let's hear about Westminster to Sloane Square if anyone has footage or experience :DD
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Colin
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Post by Colin on Apr 26, 2021 0:35:40 GMT
Having done a number of trips both east & west over the weekend, I can tell you that it very much depends on whether the train is on time or late.
The CBTC system runs the trains as per the timetable and the District line timetable is quite relaxed in its timings. I've found its not unusual to plod along at 21mph all the way from Temple to Blackfriars, or 19pmh each way between Aldgate East & Whitechapel as it maintains the timetabled path.
Obviously it will run faster (up the the permitted maximum speed for a given section) if its looking to make up time on a late running train.
Of note at the moment is that Victoria to Sloane Square w/b has been capped at the old legacy maximum of 35mph due to a long standing kink in the track approaching Sloane Square - the CBTC maximum is 40mph but it was proving to be a bit too much of a rough ride on Saturday morning.
As a driver though, I still can't fathom all this fascination with speed! Until there's a timetable uplift, there's not going to be any dramatic overall difference.
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Chris M
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Post by Chris M on Apr 26, 2021 0:43:35 GMT
Is there a plan for when the next timetable will be?
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Post by MoreToJack on Apr 26, 2021 0:45:53 GMT
Having done a number of trips both east & west over the weekend, I can tell you that it very much depends on whether the train is on time or late. The CBTC system runs the trains as per the timetable and the District line timetable is quite relaxed in its timings. I've found its not unusual to plod along at 21mph all the way from Temple to Blackfriars, or 19pmh each way between Aldgate East & Whitechapel as it maintains the timetabled path. Obviously it will run faster (up the the permitted maximum speed for a given section) if its looking to make up time on a late running train. Of note at the moment is that Victoria to Sloane Square w/b has been capped at the old legacy maximum of 35mph due to a long standing kink in the track approaching Sloane Square - the CBTC maximum is 40mph but it was proving to be a bit too much of a rough ride on Saturday morning. As a driver though, I still can't fathom all this fascination with speed! Until there's a timetable uplift, there's not going to be any dramatic overall difference. I echo Colin’s views about speed from a service control perspective too. Much of the reason for 4LM as a whole is about headway and frequency, not speed. These things are released by every train being driven the same way more than anything. |
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Post by Dstock7080 on Apr 26, 2021 3:14:25 GMT
Is there a plan for when the next timetable will be? Pencilled in for September 2021, before SMA 5 is commissioned (likely 6/7 November) |
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Post by norbitonflyer on Apr 26, 2021 7:15:46 GMT
As a driver though, I still can't fathom all this fascination with speed! The drivers are on their employer's time, but the passengers are on their own time. If speed wasn't important, they'd walk or get the bus! |
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North End
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Post by North End on Apr 26, 2021 9:37:51 GMT
Having done a number of trips both east & west over the weekend, I can tell you that it very much depends on whether the train is on time or late. The CBTC system runs the trains as per the timetable and the District line timetable is quite relaxed in its timings. I've found its not unusual to plod along at 21mph all the way from Temple to Blackfriars, or 19pmh each way between Aldgate East & Whitechapel as it maintains the timetabled path. Obviously it will run faster (up the the permitted maximum speed for a given section) if its looking to make up time on a late running train. Of note at the moment is that Victoria to Sloane Square w/b has been capped at the old legacy maximum of 35mph due to a long standing kink in the track approaching Sloane Square - the CBTC maximum is 40mph but it was proving to be a bit too much of a rough ride on Saturday morning. As a driver though, I still can't fathom all this fascination with speed! Until there's a timetable uplift, there's not going to be any dramatic overall difference. I echo Colin’s views about speed from a service control perspective too. Much of the reason for 4LM as a whole is about headway and frequency, not speed. These things are released by every train being driven the same way more than anything. Increased speed does, however, mean a train can complete a round trip faster, which means you can fit in more round trips with the same number of trains, in turn giving you a potential improvement in headway and frequency. This might be quite beneficial, for example, on a line where there’s an extension soon to open for which no additional trains have been built! |
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class411
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Post by class411 on Apr 26, 2021 10:01:23 GMT
Why are the signals that are no longer in use left in place?
Is there some technical reason for it, or is it just that it's more convenient to leave them in situ until they can be removed when some routine maintenance is undertaken at their location?
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Colin
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Post by Colin on Apr 26, 2021 10:16:16 GMT
Initially they are left in place bagged up just in case it’s decided to revert back to the old legacy system. I believe there’s a period of something like two weeks where the CBTC system needs to prove itself as stable enough to considered as definitely remaining the permanent signalling system forevermore.
Once the old assets are declared surplus to requirements they can then be removed. They’re unlikely to be removed though as there is a cost involved in such work and there just isn’t the budget available for it.
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Post by A60stock on Apr 26, 2021 15:20:31 GMT
re speeds, it would be interesting to know how fast trains will go on the met on the sections with longer gaps between stations or fast/semi fast trains.
By the sounds of it, the system will make trains crawl very slowly if theyre running early, which makes it sound as if manual driving is quicker for the customer to reach their destination quicker. On the central london sections, its more important to get the frequency right as opposed to speed, but in the outer sections where frequency of trains is far lower, speed is needed regardless of late or early running
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Chris M
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Post by Chris M on Apr 26, 2021 16:00:13 GMT
Initially they are left in place bagged up just in case it’s decided to revert back to the old legacy system. I believe there’s a period of something like two weeks where the CBTC system needs to prove itself as stable enough to considered as definitely remaining the permanent signalling system forevermore. Once the old assets are declared surplus to requirements they can then be removed. They’re unlikely to be removed though as there is a cost involved in such work and there just isn’t the budget available for it. I expect that removing signals, being safety critical equipment that need to be precisely sited (and sighted) and were likely designed to remain in situ for decades will not actually be a trivial job. They are probably also physically larger (and thus heavier) than you might expect given they are things you almost always see at a distance and very rarely adjacent to things you do have a good grasp of the scale of. Unless and until it becomes more expensive to maintain them such that they don't fall over/otherwise cause a danger it is going to be cheaper and less disruptive to leave them where they are. |
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Post by Chris L on Apr 26, 2021 17:26:54 GMT
Initially they are left in place bagged up just in case it’s decided to revert back to the old legacy system. I believe there’s a period of something like two weeks where the CBTC system needs to prove itself as stable enough to considered as definitely remaining the permanent signalling system forevermore. Once the old assets are declared surplus to requirements they can then be removed. They’re unlikely to be removed though as there is a cost involved in such work and there just isn’t the budget available for it. I expect that removing signals, being safety critical equipment that need to be precisely sited (and sighted) and were likely designed to remain in situ for decades will not actually be a trivial job. They are probably also physically larger (and thus heavier) than you might expect given they are things you almost always see at a distance and very rarely adjacent to things you do have a good grasp of the scale of. Unless and until it becomes more expensive to maintain them such that they don't fall over/otherwise cause a danger it is going to be cheaper and less disruptive to leave them where they are. There's a repeater fitted to the westbound train describer at Cannon Street. Covered with a bag now. May be tricky to remove as it wired through the train describer. |
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Deleted
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Post by Deleted on Apr 26, 2021 17:54:12 GMT
I expect that removing signals, being safety critical equipment that need to be precisely sited (and sighted) and were likely designed to remain in situ for decades will not actually be a trivial job. They are probably also physically larger (and thus heavier) than you might expect given they are things you almost always see at a distance and very rarely adjacent to things you do have a good grasp of the scale of. Unless and until it becomes more expensive to maintain them such that they don't fall over/otherwise cause a danger it is going to be cheaper and less disruptive to leave them where they are. There's a repeater fitted to the westbound train describer at Cannon Street. Covered with a bag now. May be tricky to remove as it wired through the train describer. Snip it with wire cutters job done |
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North End
Beneath Newington Causeway
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Post by North End on Apr 26, 2021 19:27:27 GMT
Initially they are left in place bagged up just in case it’s decided to revert back to the old legacy system. I believe there’s a period of something like two weeks where the CBTC system needs to prove itself as stable enough to considered as definitely remaining the permanent signalling system forevermore. Once the old assets are declared surplus to requirements they can then be removed. They’re unlikely to be removed though as there is a cost involved in such work and there just isn’t the budget available for it. I expect that removing signals, being safety critical equipment that need to be precisely sited (and sighted) and were likely designed to remain in situ for decades will not actually be a trivial job. They are probably also physically larger (and thus heavier) than you might expect given they are things you almost always see at a distance and very rarely adjacent to things you do have a good grasp of the scale of. Unless and until it becomes more expensive to maintain them such that they don't fall over/otherwise cause a danger it is going to be cheaper and less disruptive to leave them where they are. The rationale for leaving them is simply the cost of removing them. Only the Victoria Line Upgrade seemed to make a rather thorough job of removing all the old assets (I seem to remember this was specifically included in the contract), the Jubilee and Northern lines has been quite piecemeal - indeed there’s still bits in place even now. Unfortunately these old assets can become a nuisance, even a liability, quite quickly. The bags seem to collect water, but there were certainly a couple of issues on the Northern where problems arose - including on one occasion a complete signal head (at Finchley Central IIRC) falling off its post - no doubt due to corrosion. Given how much an outdoor signal head weighs, this is something which could end up turning into something more serious. In short it isn’t ideal to be having unmaintained assets sitting around for too long. |
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North End
Beneath Newington Causeway
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Post by North End on Apr 26, 2021 19:38:14 GMT
re speeds, it would be interesting to know how fast trains will go on the met on the sections with longer gaps between stations or fast/semi fast trains. By the sounds of it, the system will make trains crawl very slowly if theyre running early, which makes it sound as if manual driving is quicker for the customer to reach their destination quicker. On the central london sections, its more important to get the frequency right as opposed to speed, but in the outer sections where frequency of trains is far lower, speed is needed regardless of late or early running The slow running when early is more to do with the system running the legacy timetable than anything else. Once the timetables are rewritten with ATC in mind it’s highly likely slow running will be seen rather less often. It doesn’t make any difference if the train is manually driven or not - what happens is the system calculates a velocity ceiling if it identifies the train will arrive early at its next station, and this is applied regardless of whether it is operating in ATO or PM. Indeed for PM driving it’s pretty unpleasant, as it essentially means having to hold the speed at something irritating like 21 mph for a long period, which if on a downhill gradient could well mean constantly having to brake. No professional driver would ever drive in that way with conventional signalling - the correct way to drive when running early is to use experience to identify a point where power can be “shut off” and then coast to the next station. A bit longer in a platform isn’t really a problem - indeed it’s useful if there’s something like a VIP getting on, or for that matter if the driver needs or wants to do anything, even as simple as having a few mouthfuls of water! |
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Deleted
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Post by Deleted on Apr 26, 2021 19:39:10 GMT
Hence why we have to do a structural yearly inspection since the Northern line issue
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Post by spsmiler on May 1, 2021 14:21:04 GMT
Snip it with wire cutters job done yes but use electrically insulated wire cutters plus wear 'electric safe' gloves ... 'just in case' (voice of experience from when doing electrical work at home, although in my case I made a last second decision to turn the power off in advance of cutting the wire; afterwards when I restored the power and tested the wire where I had cut it I found it to be live) |
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Deleted
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Post by Deleted on May 1, 2021 15:37:47 GMT
Before anything is removed all fuses are pulled and we do test the equipment before we go snipping wires off.
There is only a few circumstances where live working is allowed these days and removing redundant equipment is certainly not one of them.
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Post by Chris L on May 1, 2021 17:31:34 GMT
Before anything is removed all fuses are pulled and we do test the equipment before we go snipping wires off. There is only a few circumstances where live working is allowed these days and removing redundant equipment is certainly not one of them. Many years ago we isolated the two power supplies to a way out sign at Acton Town only to find there was a third. The repeater I mentioned at Cannon Street is actually attached to (and wired through) the train describer. It prevented the replacement with a new describer. A simple snipping of the wires after isolating the power will not be enough as the wires also have to be disconnected at the distribution board. |
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Deleted
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Post by Deleted on May 1, 2021 20:48:52 GMT
When it comes to the removal it will be assessed and left safe
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DWS
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Post by DWS on May 19, 2021 17:16:44 GMT
We seem to be get off track about the Signalling upgrade of the Subsurface Lines .
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Tom
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Signalfel?
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Post by Tom on May 19, 2021 17:21:30 GMT
We seem to be get off track about the Signalling upgrade of the Subsurface Lines .
EDIT: Done! |
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