Signal 'systems' failure Aldgate

When last I heard, the Circle was running Mansion House to Ed.Rd. clockwise, so nothing on the North side. Similarly, the H&C was part suspended Moorgate-Barking.

I suspect that the Met could run to Aldgate because it would be the only service there and in any event, has its own platforms. BBC London were reporting that things should be back to normal by "lunchtime".

I see from the Tfl travel update page that all the SSR lines will be closing early in the affected area tonight at 2330.

www.tfl.gov.uk/tfl/livetravelnews/realtime/tube/later.html

Must be some fairly major work taking place tonight.

I heard a power surge fried a number of computers in the area.

So, for not the first day in the past week or so, I found myself running less than 100% of our service, and for the second time in the same period, running a "special" timetable - which in itself is a fairly rare event on the H&C and Met (things have to get pretty bad for that to happen).

The problems today were caused by essentially 2 separate issues in the Aldgate area.

Problem 1. Over the Easter weekend, there was engineering work taking place in the Aldgate/Aldgate East area, to replace the last set of "spring-toggle" points at Aldgate East with power-operated points. Unfortunately, a major part of the new points failed and could not be fixed without a several-hour service suspension. So the decision was taken early this morning to secure the points out of use, and to run only the District service through Aldgate East. This is what initially caused the suspension of the H&C east of Moorgate.

Problem 2. Sometime over the weekend, something somewhere went wrong. It is not known as yet exactly what went wrong, but it appears a higher than recommended voltage was passed through the computer signalling hardware for the Aldgate area, basically frying several of the computer input/output cards, and causing a fair bit of damage to the entire computer interface for the area.

The services offered were as mentioned already. We had 9 trains running Hammersmith-Moorgate, 4 running Edgware Road-Mansion House via Victoria, and a full Met service. The Met was run into Aldgate by basically manually controlling Aldgate using the IMR (Interlocking Machine Room - the levers that are usually controlled by the computer).

It was not possible to also run a full Circle service (or additional H&C reversing services) simply due to the nature and workload of working Aldgate in such a manner. Trust me, it may look simple to operate an ordinary lever frame for the area, but other complications make it far less than easy.

The lower-frequency-than-desired Edgware Road-Mansion House service was as a result of train operator availability and also to ensure the reversing at Mansion House did not impede on the District Line service - who were running a full service throughout today.

By around 2000hrs this evening, Aldgate was back working under computer control - although there is still a lot of testing to be carried out to ensure that future failures do not occur. The early shutdown is planned to hopefully allow enough overnight down-time to fix any computer problems, and will also hopefully allow time to rectify problems on the points at Aldgate East.

At the very least tomorrow, it is hoped the Met can run as normal, with a combined Hammersmith & Circle service operating Hammersmith->Circle Line->Edgware Road and return - that's the normal service but without trains heading east of Liverpool Street towards Whitechapel and Barking. Of course, with the additional work time, we may also be able to use the points at Aldgate East and will be able to run a full Met, H&C and Circle service.

You have to like the presence of literal air gaps

For anyone curious about what a 'V' frame looks like (this photo is of Parsons Green west IMR):

aetearlscourt.fotopic.net/p15538933.html

And what was originally available at Aldgate prior to the modernisation:

www.anorakheaven.com/photos/ald01.jpg

It can be seen above that the physical motion needed to rotate the shaft-based levers in a 'V' frame is substantially less efficient than the motion for an 'N', and this may be one of the reasons why it was decided that the AET, SOM or signaller was only tasked with rotating the levers for the signals and points in and out of the bays at Aldgate.



I wonder how many spares are stocked for the computer interfaces at locations like these, seeing as how this isn't particularly new technology...

We were wondering the same thing, and, as the Bakerloo runs on a similar system, we were keeping an eye on their service status in case something was "borrowed" from there ;D

I wouldn't be at all surprised if the Bakerloo line spares have been raided, knowing who is likely to have been involved in the repairs...

BBC London and others have started to use this to slate the T-cup again. But, answer me this please, with the Circle line, we would have had the whole line completely shut down for 2 days, which is a situation that has been avoided, and the closure has been isolated?

There was also a service until 2000 hours from Manson House to Edgware Road

Well when was the last time it functioned in reasonable approximation to the public timetable ? Some day back in March I believe. It's no wonder that the public are getting completely hacked off with what is happening there.

You beat me to that same answer Colin.

Diana, I chose not to count the 4-day Easter Weekend, because, as far back as the start of the year, if you visited the Tfl website, the suspension of the Circle Line for the Easter Weekend was advertised.

It has been mentioned many times how weekends suffer, but unfortunately, as the old saying goes "To make an omlette, you have to break eggs." Although of course weekends are prime for tourism and the like, we simply carry less people and therefore inconvenience the minority. The work has to be done sometime.

That said, newer initiatives are being tried - probably just as bitter on the tongue for media types. This summer there will be a large multi-week blockade of the Hammersmith branch so that a huge chunk of work can be done in one hit, rather than spread over several months of weekends. There will also be future closures of this type to get the pain out of the way in one go.

If you do have any better ideas for how the investment programme can be carried out then please leave them here. I am by no means the senior grade visiting here. Many people much higher up the chain look into this place, and who knows, one of your suggestions could be taken on board.

Other than that, I feel I would be wasting my breath defending Tfl/LUL's actions any further. Staff have to get to work at weekends too, and it can be just as frustrating to us - but at least we appreciate that there will be benefits in the long run.

I feel I may be trying to preach to the media or the media converted (there appears to be no comment with regard to my suspicions). Therefore, rather than listening to reason and honesty, your latest copy of the free papers will be available tomorrow (but wasn't over the Easter Weekend and won't be come the weekend - sound familiar?)

Not true. In the first instance, Earl's Court control room (from where the train was last signalled) cannot put up a Moorgate description. Add to this the fact that the decision to send the train through to Moorgate was probably made after the train left High Street Ken (so even if Earl's Court could send the right TD, it would have left the last point where such a change could be made.)

It has been mentioned before, and I will mention it again. All trains at Paddington Eastbound (Circle Line Station) will generally terminate at Edgware Road and customers should board the first train and change there. But, on a typical day, there will be a handful of exceptions. During service disruption, this handful may well increase to a bucket-load ;D

The announcer in the first instance could well have been making a "general announcement" and, having maybe taken a quick glance at the DMI via the CCTV, continued to announce all trains as being "Edgware Road."

Now. Maybe somebody at the station was told of the train continuing on to Moorgate. The information may have reached the person doing the announcements in time for them to update the announcement.

Then comes a judgement call. Does the announcer, who has been telling people to get on the Edgware Road trains and change, now suddenly tell everyone that the next train will go all the way to Moorgate - no doubt instilling confusion to a large part of the awaiting crowd. Do they announce that the DMI is wrong, and to effectively ignore it and board the next train as it is going to Moorgate? What then? Loads of people who then stay at Paddington in the hope that their destination will be catered for next?

There is no right or wrong answer. There is no way of knowing how early on the station got the information. There is also no way of knowing just how many people spotted the contradiction in destinations. Hopefully, at some point en-route to Edgware Road, an on-train announcement will have been made.