72 Stock to Serve Until 2030's

[towerman]

Weren't the 67TS refurbed at Rosyth too?

[Deleted]

I believe so, as they were done as part of the same 1990 work package as the Bakerloo Line cars, It would have made sense, as the trains were very similar (except that the Bakerloo ones had no auto-driving units on them). Some 1972's got put into the 1967's fleet around that time, in order to boost the Victoria Line train service too.

[alpinejohn]

Last Friday I had an interesting peak evening trip on the tube using sections of several central area lines. To say the least it calls into question the idea I have seen floated on here that the Bakerloo has slack capacity, and also emphasises the need for the Bakerloo stock to have a serious update or early replacement.

Leicester square to Charing Cross on the Northeren proved quick and easy even if it was standing room only. The northern line train arrived and departed very swiftly from very busy platforms. After a rather serious hike at Charing cross over to the Bakerloo platforms, I squeezed onto a very crowded platform for a train to Baker Street. The display showed three closely spaced services - +1 +3 and +5 minutes. Given the huge crowd I was not surprised the train crawled into the platform and then suffered an extended dwell time (presumably the reason why following services had bunched up). I managed to board at the front and after a while, the driver came on the tannoy and asked people to stand behind the yellow line (which seemed a physical impossibility with the platform still so crowded), and as his announcement was only inside the train had negligible affect on the crowd still on the platform.

Further annoy appeals were made by the platform staff and eventually the doors closed and we set off - after a dwell time of at least 4 minutes (so not ideal for a peak hours service).

The same extended dwell time occurred at all following stations (except regents park) with the drivers announcements evidently becoming increasingly stressed - eventually followed by a request for the platform staff to come to his cab - presumably to get them to make a further appeal over the platform speaker system for people to get behind the yellow line as he could not see it was safe to close the doors. By the time we reached Baker Street I guess we had a cumulative delay well over 10 minutes.

Switching to the Jubilee showed a marked contrast. The platform was equally crowded but the train hurtled into the platform, doors opened and a huge number alighted and even more squeezed on and we left within 90 seconds (84 actually).

The clear implication was IF TFL want to keep the current Bakerloo stock in use for an extended period, they need to go a lot further than a cosmetic overhaul. The most significant requirement is to retrofit the sort of in cab platform video displays which ensure the driver can actually see the whole length of the train (as installed on Northern and Jubilee). I guess the platform element of this spend will be somewhere in the TFL budget pipeline as but probably only happening when replacement rolling stock was provided. However if the current Bakerloo stock is now being expected to perform for many more years, with increasingly crowded central area stations, then retrofitting the current stock with the sort of in cab video kit would probably pay for itself simply by reducing dwell times and effectively allow a much more efficient despatch of trains from crowded platforms, and be a far cheaper way to improved capacity than the alternative of installing PEDs.

The do nothing option surely means these sort of extended dwell times during peak hour services on the Bakerloo are going to be an increasingly frequent occurrence.

[nig]

Feb 26, 2017 11:08:45 GMT alpinejohn said:

Last Friday I had an interesting peak evening trip on the tube using sections of several central area lines. To say the least it calls into question the idea I have seen floated on here that the Bakerloo has slack capacity, and also emphasises the need for the Bakerloo stock to have a serious update or early replacement.

Leicester square to Charing Cross on the Northeren proved quick and easy even if it was standing room only. The northern line train arrived and departed very swiftly from very busy platforms. After a rather serious hike at Charing cross over to the Bakerloo platforms, I squeezed onto a very crowded platform for a train to Baker Street. The display showed three closely spaced services - +1 +3 and +5 minutes. Given the huge crowd I was not surprised the train crawled into the platform and then suffered an extended dwell time (presumably the reason why following services had bunched up). I managed to board at the front and after a while, the driver came on the tannoy and asked people to stand behind the yellow line (which seemed a physical impossibility with the platform still so crowded), and as his announcement was only inside the train had negligible affect on the crowd still on the platform.

Further annoy appeals were made by the platform staff and eventually the doors closed and we set off - after a dwell time of at least 4 minutes (so not ideal for a peak hours service).

The same extended dwell time occurred at all following stations (except regents park) with the drivers announcements evidently becoming increasingly stressed - eventually followed by a request for the platform staff to come to his cab - presumably to get them to make a further appeal over the platform speaker system for people to get behind the yellow line as he could not see it was safe to close the doors. By the time we reached Baker Street I guess we had a cumulative delay well over 10 minutes.

Switching to the Jubilee showed a marked contrast. The platform was equally crowded but the train hurtled into the platform, doors opened and a huge number alighted and even more squeezed on and we left within 90 seconds (84 actually).

The clear implication was IF TFL want to keep the current Bakerloo stock in use for an extended period, they need to go a lot further than a cosmetic overhaul. The most significant requirement is to retrofit the sort of in cab platform video displays which ensure the driver can actually see the whole length of the train (as installed on Northern and Jubilee). I guess the platform element of this spend will be somewhere in the TFL budget pipeline as but probably only happening when replacement rolling stock was provided. However if the current Bakerloo stock is now being expected to perform for many more years, with increasingly crowded central area stations, then retrofitting the current stock with the sort of in cab video kit would probably pay for itself simply by reducing dwell times and effectively allow a much more efficient despatch of trains from crowded platforms, and be a far cheaper way to improved capacity than the alternative of installing PEDs.

The do nothing option surely means these sort of extended dwell times during peak hour services on the Bakerloo are going to be an increasingly frequent occurrence.

They have platform monitors or mirrors same as Piccadilly line which do the same job as in cab monitors the only difference is you can see your the platform when moving away it sounds a bit like the driver was new or being very over cautious

[crusty54]

Feb 26, 2017 12:14:48 GMT nig said:

Feb 26, 2017 11:08:45 GMT alpinejohn said:

Last Friday I had an interesting peak evening trip on the tube using sections of several central area lines. To say the least it calls into question the idea I have seen floated on here that the Bakerloo has slack capacity, and also emphasises the need for the Bakerloo stock to have a serious update or early replacement.

Leicester square to Charing Cross on the Northeren proved quick and easy even if it was standing room only. The northern line train arrived and departed very swiftly from very busy platforms. After a rather serious hike at Charing cross over to the Bakerloo platforms, I squeezed onto a very crowded platform for a train to Baker Street. The display showed three closely spaced services - +1 +3 and +5 minutes. Given the huge crowd I was not surprised the train crawled into the platform and then suffered an extended dwell time (presumably the reason why following services had bunched up). I managed to board at the front and after a while, the driver came on the tannoy and asked people to stand behind the yellow line (which seemed a physical impossibility with the platform still so crowded), and as his announcement was only inside the train had negligible affect on the crowd still on the platform.

Obviously problems with the Bakerloo service at the time.

First point is why didn't you walk from Leicester Square tp Piccadilly Circus?

Secondly Crossrail will reduce the number of people using the Bakerloo to and from Paddington.

72 stock is a fairly simple train with limited cab space. No room for monitors.

[Deleted]

With hindsight now, the original order for the Replacement Bakerloo trains planned for 2014 should have been allowed to proceed as planned, not cancelled at the last moment, all this faffing around will end up costing three times as much as buying a brand new fleet to 40 new trains back in 2014, before Brexit took hold.

[castlebar]

This thread has been going for years. Well before "Brexit" was thought of. Why have you brought Brexit into this?

[North End]

Feb 26, 2017 13:48:03 GMT @kkc35348 said:

With hindsight now, the original order for the Replacement Bakerloo trains planned for 2014 should have been allowed to proceed as planned, not cancelled at the last moment, all this faffing around will end up costing three times as much as buying a brand new fleet to 40 new trains back in 2014, before Brexit took hold.

My mind may be overlooking something, however I can't recall the Bakerloo fleet replacement ever having got as far as orders being planned. For as long as I can recall it's always been expected that the 72 stock would live into the 2020s. It was the Piccadilly Line which was planned to receive new trains by 2014 under PPP, followed by an 8-year deferment due to the PPP collapse and budget pressures. Brexit wasn't even a possibility until the 2015 general election. Sure if inflation goes up then the cost of fleet replacement will increase, although there are other variables too- for example if the rate of immigration reduces then we won't need so many trains, plus a lot of capacity increase work like station rebuilds could be avoided perhaps.

[superteacher]

Feb 26, 2017 13:52:42 GMT castlebar said:

This thread has been going for years. Well before "Brexit" was thought of. Why have you brought Brexit into this?

<<Indeed. Let's keep politics out of this, especially when it's got nothing to do with the discussion.>>

With my mod hat off, there was clearly an issue with the service if the platform was that crowded. Even the more modern lines would suffer from extended dwell times in those circumstances.

[norbitonflyer]

The spare capacity on the Bakerloo is in the contrapeak direction, i.e southbound in the evening. It is this which is planned to be exploited by the extension - using the spare capacity in the trains arriving at Waterloo southbound, which are even emptier at Elephant.

[alpinejohn]

NIG - "They have platform monitors or mirrors same as Piccadilly line which do the same job as in cab monitors the only difference is you can see your the platform when moving away it sounds a bit like the driver was new or being very over cautious"

Thank you for this response - as it sort of explains how Jubilee and Northern trains were flowing well through very crowded platforms whilst the Bakerloo driver seemed far less confident.

I agree it probably makes little difference if drivers use CCTV or mirrors to get a clear view down the side of the train to decide when to close the doors. However your subsequent observation about drivers with CCTV still being able to see the platform when moving off seems very important.

Given our happy addiction to try and sue anyone else for accidents most often caused by our own stupidity, I am sure the inability for Bakerloo drivers to monitor the side of the train as they move off, is a real factor in extended dwell times - just in case someone has managed to get their bag, arm, head ... stuck outside and is being dragged along the platform. Inherently if the in cab kit can still supply the CCTV feed for the initial seconds after setting off, it should give the driver a chance to spot any problems and hit the brakes before an incident becomes too serious.

Given the projected growth in traffic in the central area, TFL need to think this one through. Currently Bakerloo drivers lack the ability to view the platform adequately as they move off, so on crowded platforms they inevitably get very exercised and trains are delayed if people consistently fail to stay behind the yellow line. This backs up following trains and obviously reduces line capacity, so doing low cost things to reduce/remove this problem makes sense even if they do not have the funds to replace the Bakerloo stock yet.

If TFL want to ensure reliable peak hour flows on the Bakerloo the options appear to be to somehow link the in cab announcement Tannoy system directly to the relevant platform speakers - so that people on the relevant platform can actually hear when a driver is telling them to stay behind the yellow lines or the train cannot depart! Alternatively at least for peak hours to significantly increase the actual platform staff on all the busy central area stations on the Bakerloo line whose main job will be to try and get people to stay behind the yellow lines, or just get someone to install decent quality CCTV now along all those central area platforms (a cost they will eventually face) and retrofit a compact in cab flat screen monitor to allow drivers to monitor the departure. Whilst I cannot find any photos of a refurbished Bakerloo cab, I cannot believe the cab is so crowded that it is impossible to find a suitable place to attach a small flat screen display to allow drivers to monitor the departure in much the same way drivers on the Northern and Jubilee do.

As for the spare capacity being contra-peak I had not realised that. However I suspect much of that potential would be lost if peak hour trains are all bunched up in the central area due to extended dwell times - in large part down to those pesky passengers not being willing or able to stand behind the yellow line.

[rincew1nd]

Details of a 72ts cab are here:

www.trainweb.org/tubeprune/72%20TS%20Cabs.htm

The problem with fitting monitors is that the stock was designed with a 'desk', stock that is fitted with in-cab CCTV has more of a 'cockpit' design philosophy, as can been seen with the S Stock, here:

www.squarewheels.org.uk/rly/stock/SsubsurfaceStock/

[MoreToJack]

The other issue that will be encountered with the 72TS is being able to supply the various equipment for in-cab OPO monitors. The trains are already at the limit of the available resources for things like this, which is requiring some thought for things like installing a CIS.

[North End]

Mar 4, 2017 10:21:32 GMT alpinejohn said:

NIG - "They have platform monitors or mirrors same as Piccadilly line which do the same job as in cab monitors the only difference is you can see your the platform when moving away it sounds a bit like the driver was new or being very over cautious"

Thank you for this response - as it sort of explains how Jubilee and Northern trains were flowing well through very crowded platforms whilst the Bakerloo driver seemed far less confident.

I agree it probably makes little difference if drivers use CCTV or mirrors to get a clear view down the side of the train to decide when to close the doors. However your subsequent observation about drivers with CCTV still being able to see the platform when moving off seems very important.

Given our happy addiction to try and sue anyone else for accidents most often caused by our own stupidity, I am sure the inability for Bakerloo drivers to monitor the side of the train as they move off, is a real factor in extended dwell times - just in case someone has managed to get their bag, arm, head ... stuck outside and is being dragged along the platform. Inherently if the in cab kit can still supply the CCTV feed for the initial seconds after setting off, it should give the driver a chance to spot any problems and hit the brakes before an incident becomes too serious.

Given the projected growth in traffic in the central area, TFL need to think this one through. Currently Bakerloo drivers lack the ability to view the platform adequately as they move off, so on crowded platforms they inevitably get very exercised and trains are delayed if people consistently fail to stay behind the yellow line. This backs up following trains and obviously reduces line capacity, so doing low cost things to reduce/remove this problem makes sense even if they do not have the funds to replace the Bakerloo stock yet.

If TFL want to ensure reliable peak hour flows on the Bakerloo the options appear to be to somehow link the in cab announcement Tannoy system directly to the relevant platform speakers - so that people on the relevant platform can actually hear when a driver is telling them to stay behind the yellow lines or the train cannot depart! Alternatively at least for peak hours to significantly increase the actual platform staff on all the busy central area stations on the Bakerloo line whose main job will be to try and get people to stay behind the yellow lines, or just get someone to install decent quality CCTV now along all those central area platforms (a cost they will eventually face) and retrofit a compact in cab flat screen monitor to allow drivers to monitor the departure. Whilst I cannot find any photos of a refurbished Bakerloo cab, I cannot believe the cab is so crowded that it is impossible to find a suitable place to attach a small flat screen display to allow drivers to monitor the departure in much the same way drivers on the Northern and Jubilee do.

As for the spare capacity being contra-peak I had not realised that. However I suspect much of that potential would be lost if peak hour trains are all bunched up in the central area due to extended dwell times - in large part down to those pesky passengers not being willing or able to stand behind the yellow line.

I would make the point that the driver should not be intently studying sntbin-cab monitor when moving off- the driver's main responsibility is to observe the road ahead.

If the pre-departure check has been carried out then in theory there should be no reason to look in a monitor. Sure there's not a single driver who doesn't value the extra reassurance the monitors provide when departing, but they should only be regarded as an added safety 'bonus'. You can't guarantee that the driver will pick up on a potential problem after moving off, as he should only be glancing at the monitors every couple of seconds. This particularly applies on lines which don't have continuous ATP.

[philthetube]

The S stock, and the Vic stock also have the benefit of the sensitive edge equipment which stops the train if anything is being dragged. (really clever system).

[MoreToJack]

Wrong.

Viewing the OPO monitors is *just* as important as viewing the road ahead, both for possible obstructions and for signal aspects. People are inherently unpredictable. Sometimes - particularly in the peak - it isn't always apparent that someone could be trapped in the doors. Or it could be that someone is stubbornly refusing to move away from the train as it departs - it happens, particularly on Night Tube. Train drivers are professionals, and will alter their driving techniques (including looking at the road ahead or the OPO monitors) depending on their route knowledge and passenger loadings.

Drivers (and station staff) don't want to end up in jail. Anyone who suggests that viewing the OPO monitors regularly whilst departing is unnecessary is, frankly, a bit of an idiot, and clearly doesn't value their job/freedom.

No, you can't guarantee that a driver will realise a problem, but most drivers are far more alert and aware of what is the 'norm' than people think. This is clearly more of an issue on the Bakerloo and Piccadilly lines (and, briefly, the District line on D78-operated trains), but 100% mitigation would be impossible. However, as the above linked incidents show, assuming someone will move doesn't cut the mustard anymore.

Sadly, theory isn't a reliable method of determining what the great unwashed will do.

[Dstock7080]

Mar 4, 2017 17:23:03 GMT MoreToJack said:

Viewing the OPO monitors is *just* as important as viewing the road ahead, both for possible obstructions and for signal aspects.

On S Stock the term is 'scanning', equal scanning of the road ahead and in-cab monitors as the train departs, the monitors will extinguish when the train has cleared station limits.

[MoreToJack]

That's it! I couldn't remember the word that I was told when I last had a day on the road... thanks!

[up1989]

On the Northen some of my I/ops told me to adopt the nodding dog technique for the road ahead and opo monitors!

[crusty54]

The Bakerloo line will now get new trains in the mid 20s under the latest programme. This is ahead of the Central line.

[Deleted]

The Bakerloo receiving Batch One of the new trains is sensible, as any issues in service can be evaluated and hopefully cleared up, before the main production run batch commences. Ideally they should build three prototypes and run them on the Bakerloo line, and evaluate them in detail first. Remember the three initial prototypes on the 1935, then 1956, and then the 1986 stock? - a similar scheme could be used to test the new trains which are a major advance from today's technology.

[North End]

Mar 4, 2017 17:23:03 GMT MoreToJack said:

Wrong.

Viewing the OPO monitors is *just* as important as viewing the road ahead, both for possible obstructions and for signal aspects. People are inherently unpredictable. Sometimes - particularly in the peak - it isn't always apparent that someone could be trapped in the doors. Or it could be that someone is stubbornly refusing to move away from the train as it departs - it happens, particularly on Night Tube. Train drivers are professionals, and will alter their driving techniques (including looking at the road ahead or the OPO monitors) depending on their route knowledge and passenger loadings.

Drivers (and station staff) don't want to end up in jail. Anyone who suggests that viewing the OPO monitors regularly whilst departing is unnecessary is, frankly, a bit of an idiot, and clearly doesn't value their job/freedom.

No, you can't guarantee that a driver will realise a problem, but most drivers are far more alert and aware of what is the 'norm' than people think. This is clearly more of an issue on the Bakerloo and Piccadilly lines (and, briefly, the District line on D78-operated trains), but 100% mitigation would be impossible. However, as the above linked incidents show, assuming someone will move doesn't cut the mustard anymore.

Sadly, theory isn't a reliable method of determining what the great unwashed will do.

The problem is that the in-cab monitors are a distraction from the road ahead. This is not so bad on the ATO lines, where the chances of something going wrong are reduced, although still non-zero, but on conventional lines it is a big issue. Many, many SPAD investigations refer to distraction by the in-cab monitor.

A few real-life examples of why the driver needs to maintain a focus on the road ahead:

- A repeater signal within the area where the monitors are live. RFNX640A was a notorious example leaving Borough northbound. Miss the yellow and half a minute later you've had a guaranteed high-speed SPAD. Better hope the brakes are good, the signal overlap holds true, and there's no grease on the rails.

- A tree falling on the line just as you are departing the platform. As once happened immediately north of Golders Green, fortunately the train stopped short.

- PWay on the track and driver omits to blow the whistle, due to watching something unusual on his monitor. Contributory factor in a near-miss.

It's fine to glance at the monitor, as I said in the previous post. It's *not* fine to "watch" it. I don't believe it's reliably possible to watch both monitors and road ahead at the same time, and human-factors studies I have seen back this up. On the 92 stock the monitor is offset to the left, making it even more awkward. Also bear in mind some platforms will have 4 (any advance on that?) different views all on the same small monitor for the driver to study.

On comparable mainline trains like the Electrostars the monitors switch off as the trains start moving - this tells you all you need to know about the views of the safety authorities. Likewise the fact that LU has never deemed it sufficiently worthwhile to retrofit to old stocks.

Finally, do remember that if the monitor is not working, the driver can self-despatch from a category B platform, or with staff assistance from a cat A one. Not much point 'scanning' a blank monitor! Again, LU deems this safe. You may disagree, many may disagree, but this is the official position, which presumably is fully agreed with the safety authority.

The bottom line is that if you're not happy that it's safe to start the train, you don't start it until you are.

[aslefshrugged]

Mar 4, 2017 10:21:32 GMT alpinejohn said:

Given our happy addiction to try and sue anyone else for accidents most often caused by our own stupidity, I am sure the inability for Bakerloo drivers to monitor the side of the train as they move off, is a real factor in extended dwell times - just in case someone has managed to get their bag, arm, head ... stuck outside and is being dragged along the platform.

Its nothing to do with being sued, its a case of whoever has responsibility for operating the doors not wanting to face possible criminal charges which could lead to a prison sentence

[North End]

Mar 5, 2017 7:57:27 GMT aslefshrugged said:

Mar 4, 2017 10:21:32 GMT alpinejohn said:

Given our happy addiction to try and sue anyone else for accidents most often caused by our own stupidity, I am sure the inability for Bakerloo drivers to monitor the side of the train as they move off, is a real factor in extended dwell times - just in case someone has managed to get their bag, arm, head ... stuck outside and is being dragged along the platform.

Its nothing to do with being sued, its a case of whoever has responsibility for operating the doors not wanting to face possible criminal charges which could lead to a prison sentence

Yes this is something I am forever emphasising to train staff. Many drivers, especially those fresh from Ashfield House, are over concerned about closing the doors on people, yet way under-aware of the importance of the check needing to be carried out in between the pilot light illuminating and the train moving off.

I see so many people self-despatch when the monitor is defective by pressing the close buttons on the bulkhead having seen no one is now boarding, then immediately closing the cab door and returning to the driving position before the doors have even fully closed. If anything were to happen the driver would straight away be in trouble.

[Deleted]

Mar 4, 2017 22:44:45 GMT North End said:

Mar 4, 2017 17:23:03 GMT MoreToJack said:

Wrong.

Viewing the OPO monitors is *just* as important as viewing the road ahead, both for possible obstructions and for signal aspects. People are inherently unpredictable. Sometimes - particularly in the peak - it isn't always apparent that someone could be trapped in the doors. Or it could be that someone is stubbornly refusing to move away from the train as it departs - it happens, particularly on Night Tube. Train drivers are professionals, and will alter their driving techniques (including looking at the road ahead or the OPO monitors) depending on their route knowledge and passenger loadings.

Drivers (and station staff) don't want to end up in jail. Anyone who suggests that viewing the OPO monitors regularly whilst departing is unnecessary is, frankly, a bit of an idiot, and clearly doesn't value their job/freedom.

No, you can't guarantee that a driver will realise a problem, but most drivers are far more alert and aware of what is the 'norm' than people think. This is clearly more of an issue on the Bakerloo and Piccadilly lines (and, briefly, the District line on D78-operated trains), but 100% mitigation would be impossible. However, as the above linked incidents show, assuming someone will move doesn't cut the mustard anymore.

Sadly, theory isn't a reliable method of determining what the great unwashed will do.

The problem is that the in-cab monitors are a distraction from the road ahead. This is not so bad on the ATO lines, where the chances of something going wrong are reduced, although still non-zero, but on conventional lines it is a big issue. Many, many SPAD investigations refer to distraction by the in-cab monitor.

A few real-life examples of why the driver needs to maintain a focus on the road ahead:

- A repeater signal within the area where the monitors are live. RFNX640A was a notorious example leaving Borough northbound. Miss the yellow and half a minute later you've had a guaranteed high-speed SPAD. Better hope the brakes are good, the signal overlap holds true, and there's no grease on the rails.

- A tree falling on the line just as you are departing the platform. As once happened immediately north of Golders Green, fortunately the train stopped short.

- PWay on the track and driver omits to blow the whistle, due to watching something unusual on his monitor. Contributory factor in a near-miss.

It's fine to glance at the monitor, as I said in the previous post. It's *not* fine to "watch" it. I don't believe it's reliably possible to watch both monitors and road ahead at the same time, and human-factors studies I have seen back this up. On the 92 stock the monitor is offset to the left, making it even more awkward. Also bear in mind some platforms will have 4 (any advance on that?) different views all on the same small monitor for the driver to study.

Try Baker Street platform 3 heading south - 8 separate images, sharp left hand bend on departure and the advance starter less than a train's length out of the platform, located on the inside of the bend. It has a repeater on the same head as the starter (invisible from a correctly berthed S Stock) but not on the starter's co-actor. Fortunately it's usually off by the time it's reached.

The training instructions for drivers of S Stock trains state that time spent scanning the monitors should decrease and road observation should increase proportionately as the train leaves the platform. Plenty of locations on the SSL where equal measures of both until the train has left the platform is a SPAD in the making.

[carltona]

Mar 4, 2017 18:35:16 GMT crusty54 said:

The Bakerloo line will now get new trains in the mid 20s under the latest programme. This is ahead of the Central line.

Is this now correct, that the 72s will be replaced in the mid twenties?

[Deleted]

Well I hope so - I do hope that the Three Prototypes method will be used again here, just like they once did in 1935, 1956, and 1986.

[norbitonflyer]

May 31, 2017 16:02:02 GMT @kkc35348 said:

Well I hope so - I do hope that the Three Prototypes method will be used again here, just like they once did in 1935, 1956, and 1986.

....and 1960 (three complete eight car trains, albeit identical)

1935 stock actually had four six-car prototype trains, three of them identical.

[superteacher]

Well the 1986 stock didn't exactly lead to a great production train (1992 stock).

[t697]

May 31, 2017 18:52:00 GMT superteacher said:

Well the 1986 stock didn't exactly lead to a great production train (1992 stock).

Trains like 86TS add many years and much cost to the overall renewal programme. Better in my view to concentrate on a proper process towards the train you really intend for fleet builds. Things like 86TS never get fully sorted because everyone knows they are not going to be just genuine pre-production.