TBTC Testing

[rincew1nd]

Jan 18, 2011 22:53:16 GMT ta said:

...trains running onto the Jub will normally be TBTC equipped.

Jan 18, 2011 23:00:26 GMT @bronzeonion said:

What if 1972 stock trains need to get off the Bakerloo?

The trains will normally be TBTC equipped it would appear! ;D

Or failing that there's always the connections further north on the line to the big railway.

[tubeprune]

Jan 18, 2011 22:41:53 GMT @chorleywood said:

Bizarrely, parts of the Piccadilly line have (had?) an early form of Automatic Train Regulation, which was effectively a simply analogue computer. From distant memories of bookwirings, this used a pair of wires running between stations, an arrangement to switch resistors across these wires dependent on train positions, and a comparator unit at some stations which would hold trains dependent on the relative resistance across the pairs of wires ahead and in rear of the station. A "Balance Headways" switch in the control room enabled the system. Does anyone know if this system is still in use?

It was also called "Headway/Hindway Control". It was installed at Hyde Park EB and Finsbury Park WB on 10 Dec 1970. It was decomissioned on 5 Oct 1980 and restored on 17 Jan 1981. I don't know if it's still in place.

[Deleted]

It was at the last count. I will check.

[Deleted]

Jan 18, 2011 3:08:00 GMT version3point1 said:

I was relatively surprised at how one train would depart, and literally 25 seconds later (and yes – I counted using the dot matrix timers) another train had already fully berthed the platform and opened its doors.

Out of interest, was this 25 seconds counted from the previous trains wheel start, or from when the rear of the train cleared the platform?

[version3point1]

Jan 19, 2011 11:28:42 GMT @stephenk said:

Out of interest, was this 25 seconds counted from the previous trains wheel start, or from when the rear of the train cleared the platform?

I counted from when the rear of the train passed me in the middle of the platform – the next train had already approached the tail-end of the platform within 15 seconds.

[Deleted]

Jan 19, 2011 0:11:34 GMT rincew1nd said:

Jan 18, 2011 23:00:26 GMT @bronzeonion said:

What if 1972 stock trains need to get off the Bakerloo?

The trains will normally be TBTC equipped it would appear! ;D

Or failing that there's always the connections further north on the line to the big railway.

For the Bakerloo, I don't believe there is another option - the Baker St crossovers are its only links to another LU line (feel free to correct me if I'm wrong).

[Deleted]

That is the only connection, apart from the connection to BR metals further north, meaning it needs to be dragged to Ruislip Depot from there

[Deleted]

Jan 19, 2011 22:49:27 GMT version3point1 said:

Jan 19, 2011 11:28:42 GMT @stephenk said:

Out of interest, was this 25 seconds counted from the previous trains wheel start, or from when the rear of the train cleared the platform?

I counted from when the rear of the train passed me in the middle of the platform – the next train had already approached the tail-end of the platform within 15 seconds.

Thanks. So the RORIT would be around 40secs. That's pretty impressive!

[tubeprune]

Jan 19, 2011 10:26:38 GMT @reganorak said:

It was at the last count. I will check.

I did check and it is still operational.

[jardine01]

Hi do you know if all the Jubilee line trains are now running in ATO?

many thanks
Tom

[Deleted]

Yes, they are all generally in ATO all the time, unless there is a technical issue or LU want to drive them in PM for some reason.

[londonstuff]

Just a quick thought that someone could maybe answer - if ATO/TBTC went t1ts up at the control centre or something not easily remediable, it's been mentioned on here that there is a plan to revert back to the conventional signalling fairly quickly.

However, this signalling now hasn't been used for the best part of a month - are there any maintenance issues involved in getting it back running again or should it still be doable?

[Tubeboy]

I havent been at work for almost two weeks, but I believe the option to "switch back" to tripcock mode is still there. It would have to a pretty major failure though. Bar failures here and there, including overshoots, TBTC has worked well in general.

Its still in tripcock mode Dollis Hill-Stanmore.

[Deleted]

It won't be switched back now - it was only likely for the first couple of weeks, and although technically it could probably be switched back, the old is not being maintained anymore and it is not a five minute job - more like half a day or complete Engineering hours.

[jardine01]

When the Jubilee line goes fully ATO. will they increase the prefomance on the 1996 stock? like they did on the central line? Also does anybody know what power the 1996 stock is restricted to?

Thanks

[Deleted]

I believe 1995 and 96 stocks are restricted to somewhere between 60 and 75 percent of their full power, but I'm not sure.

[Deleted]

1995 Stock is limited to 60% at the moment, 1996 stock I think is on full power now the new TBTC is switched on (apart from Dollis Hill - Stanmore). Does anyone know why only Jubilee line ATO seems to try to keep its target speed by taking the throttle on and off? Ive never felt it happen on the Central or the Victoria

[Deleted]

Jan 29, 2011 21:54:38 GMT @bronzeonion said:

1995 Stock is limited to 60% at the moment, 1996 stock I think is on full power now the new TBTC is switched on (apart from Dollis Hill - Stanmore). Does anyone know why only Jubilee line ATO seems to try to keep its target speed by taking the throttle on and off? Ive never felt it happen on the Central or the Victoria

It's by a company called Thales... say it out loud.

On a more serious note; the Vic won't have such a problem as it doesn't have target speeds- just the 3 running safety box codes.

That being:
180- max 25mph, no motoring, should be braking
270- max 25mph, motoring permitted
420- full speed

Even if the train was under a 270 code, you wouldn't notice jerking, as the traction system is so crude by modern standards.

On the Central, I actually don't know. It might just go to a low step acceleration to hold speed. Don't see why the Jub can't do this; it is an effectively stepless speed stock like the 92ts.

[Deleted]

EPIC THALE ;D

[North End]

Jan 29, 2011 21:54:38 GMT @bronzeonion said:

1995 Stock is limited to 60% at the moment, 1996 stock I think is on full power now the new TBTC is switched on (apart from Dollis Hill - Stanmore). Does anyone know why only Jubilee line ATO seems to try to keep its target speed by taking the throttle on and off? Ive never felt it happen on the Central or the Victoria

I was trying to emulate the Jubilee Line's ATO technique on a 1995 stock today, but I couldn't manage to get it as uncomfortable as the TBTC. Maybe because the 1995 stock is still governed down, one doesn't have as much power to switch on & off.

The general driving technique for the Northern tends to be to motor out of a platform to line speed, at some stage shut off and coast, then brake upon entering the next platform, obviously this will vary depending on the section concerned, speed restrictions, signals etc. TBTC will reach line speed quicker, which I imagine will be followed by constant on/off motoring/braking. Not comfortable.

This will be more noticeable on the Northern because of the lower line speeds -- and I suspect there will be little increase in speeds in the tunnel sections as many of the speed restrictions are due to infrastructure constraints.

Although the Central and Victoria Line ATO systems are pretty comfortable in my opinion (unlike the TBTC which is currently horrible), you can't beat a properly trained human driver for ride comfort, who can take into account a range of factors such as loading, gradient, distance to train in front etc. and make an intelligent decision on how to drive the train. Even the best ATO systems can't match this.

More controversially, if LU allowed its drivers to fully exploit the signalling systems installed, as they were trained to do in past times, we could get a lot more trains per hour without going to the expense of TBTC or whatever.

[mrfs42]

Jan 30, 2011 0:46:32 GMT North End said:

More controversially, LU allowed its drivers to fully exploit the signalling systems installed, as they were trained to do in past times, we could get a lot more trains per hour without going to the expense of TBTC or whatever.

<rant>

Apologies for the emboldening - SPOT ON!

Done of this 'defensive driving' rubbish - that came out of a generation of people what hadn't bothered to learn what the signals did. Unfortunately, that means that the majority of trains will be driven slower than the timetable is designed for and slower than the signalling system is designed for.

I expect a few ill-informed comments after the next question <fx: throws gauntlet down>: what is wrong with over-running a signal and coming to a stand in the overlap? </fx>

In all honesty, signalling and timetabling do their level best BUT if a culture of fear is being installed (and that fear grows because there is no actual tangible signal!), where the T/Ops are educated *not* to trust the signal and then - Lo! You must trust the signal - all singing/dancing/busbyberkeley new stuff! Change isn't going to happen overnight.....

I'd better add as a note - as a Controller on another railway, I have had several occasions where a train has slid past a signal into the overlap and come to a stand. Said Driver on each and every individual occasion was very worried - insofar as I took the can and would be the person before the judge and the bar I calmly took them to one side and said - you've used the overlap for the purpose intended.

Perhaps I'm too old-fashioned in these sort of things, and would rather listen to old, experienced railway(wo)men than some PFY with an inappropriate university degree [1] : marketers do not make operators.

[1]I acknowledge the logical inconsistency here - for those of you that both know what my degree was in and my operating grade!

EDIT: </rant>

[Colin]

This is going off topic really and should therefore be split off into a new thread, but I shall indulge you for now....

The culture that's been instilled by the company - well the railway industry as a whole - is that SPAD's are not a good thing and will lead to disciplinary action.

Now quite frankly it doesn't matter what anyone thinks about the merits of LU's tripcock system, or whether overlaps have been built into the system; the bottom line is the railway deals with signals passed at danger - and let's not forget that is what SPAD stands for - as a safety related incident.

So what you're saying is that a signal passed at danger shouldn't be treated as a safety related incident? If it's not a safety related incident, why is it called a danger signal?!!

Look at the likes of Leytonstone - not once but twice!! And if you want the ultimate consequence of a SPAD, Ladbroke Grove on the mainline just goes to prove the rule.

My personal view as a driver? Damn right SPAD's should be treated seriously - in 99% of cases the driver has a passed a danger signal when they shouldn't have because they weren't paying attention - what else will happen because they weren't paying attention? Drivers need to keep their concentration up at all times and if the big stick needs to waved regarding SPADs in order to achieve that, I'm all for it.

[Chris M]

I think MRFS's point was that there is a difference between
1. a train passing a signal at danger and coming to a stand within the overlap of that signal
2. a train passing a signal at danger and coming to a stand beyond the overlap of that signal

In 1 there is no danger of a collision with another train as the overlap is designed as a safety margin in case a train passes the signal at danger.
In 2 that safety margin has been exceeded, and obviously this is when the incidents like those you mention happen.

I'm less sure of this, but I think he's saying that there are two safe scenarios in which a railway can operate in relation to drivers passing signals at danger for reasons within their control.
A: Any occurrence of the signal being passed by any distance is treated as an extremely major event that leads drivers to be fearful of the consequences of doing so
B: Very occasional occurrences of signals being passed by a distance less than the safety margin are treated as incidents that should be learned from and are not career-threatening. Signals being passed by a distances that exceeds to safety margin and/or repeated occurrences of shorter passings are treated as extremely major events.

Again I'm not completely sure about this but I believe MRFS is saying that scenario B will lead to a better utilised railway than scenario A.

[messiah]

I'm quite glad that it could be Colin driving the tube I am on rather than mrfs42

[Deleted]

Are TBTC SPADs treated in the same way? I think its called a target point overshoot, leading to an Emergency Brake. Its not so obvious as the tripcock is not activated, but I believe the control centre have to release the brakes rather than the driver. So is this kind of 'new' SPAD still reportable in the same way if the train is driven manually?

[Colin]

I wouldn't have a clue, not being a jubilee driver, but in terms of a conventional SPAD a driver has to be very careful about when he or she re-sets the trip cock as the question does come in the resulting post incident interview.

Anyway, I'm only posting again as I forgot to add to my original post #381above that the whole point of ATO is to drive the train beyond the limits no human would ever dare to go, nor probably be able to safely manage. Comparing it to defensive driving is like comparing piloting a two seat prop plane with piloting a Boeing 747 - both will transport you from one airport to another, but that's where the similarities end.

[mrfs42]

Jan 30, 2011 8:16:00 GMT Chris M said:

Again I'm not completely sure about this but I believe MRFS is saying that scenario B will lead to a better utilised railway than scenario A.

The distinction that I am drawing is between a 'technical' SPAD and a 'non-technical' SPAD - which is indeed scenario B.

In no way am I attempting to give the impression that an over-run is a trivial matter, merely that some are less worse than others.

Jan 30, 2011 9:07:49 GMT @sw206 said:

Are TBTC SPADs treated in the same way? I think its called a target point overshoot, leading to an Emergency Brake. Its not so obvious as the tripcock is not activated, but I believe the control centre have to release the brakes rather than the driver. So is this kind of 'new' SPAD still reportable in the same way if the train is driven manually?

That's an interesting question - in that case the 'blame' (if you wish to call it such) for a 'technical' SPAD (maybe the terminology has changed, but I'm using this term to cover over-runs that are not the Driver or T/Ops fault: flank protection kicking in, poor railhead conditions, ATO errors) will change slightly.

If I've understood the comment about target point overshooting and the remote reset then a lot more responsibility will lie in the Control Room reporting such things - after all there will be black box recorders for everything - if they're working, that is!

Jan 30, 2011 9:22:43 GMT Colin said:

Comparing it to defensive driving is like comparing piloting a two seat prop plane with piloting a Boeing 747 - both will transport you from one airport to another, but that's where the similarities end.

Maybe so - but if the parameters for the TBTC based signalling are
produced using sub-optimal sets of data, then the net result is very much like defensive driving! AIUI the data is being refined as it is being harvested/analysed from the VOBC.

[frankoids]

Not making any judgements here, but should point out the following re the above mentioned incidents

Leytonstone - Caused not by the SPAD itself, but by correct procedure not being followed after a SPAD an 'aggravated' SPAD

Ladbroke Grove - Root causes of this found to be totally inadequate training, bi-directional working in that area with no flank protection, poor sighting of the signals, no signal sighting meetings convened although this was mandatory at Multi-Spadded signals. Train had AWS which is not the same and inferior to the LU system.

Sometimes I think we need to look further than the easy option of driver error and look a bit deeper at the problems of SPADS

[21146]

I had an awful ride on the Jubilee last Friday. Between Dollis Hill and Willesden Green S/B the (ATO) driving-style was 5 seconds motoring, 5 seconds coasting, on and off, all the way between stations. No one would chose to drive this way manually and indeed would probably fail a Road Test or TD1 (IIRC) if they did. Are the trains designed to run like this and is it doing the traction package and associated equipment any good? Plus two successive trains without heaters on one of the coldest days of the year!

[Deleted]

Defective train today. Services suspended between London Bridge and Stratford when I traveled at around 3PM I think.