1972 tube stock replacement

[Scotrail12]

We're in 2021 and 72TS are a mess - I can't feasibly see how they could still run in 15 years.

 

[DanNCL]

Long cars do fit on the Bakerloo, although I don’t believe there are any instances of them running in service on the Bakerloo. The track recording train contains a 1973 stock car and has run on the Bakerloo, and 1983 stock also made a few empty trips on the Bakerloo during the 1980s.

 

[Nym]

Long cars do fit on the Bakerloo, although I don’t believe there are any instances of them running in service on the Bakerloo. The track recording train contains a 1973 stock car and has run on the Bakerloo, and 1983 stock also made a few empty trips on the Bakerloo during the 1980s.

As I said above, the TRV recording car is modified to be compatible with the Bakerloo and Central lines.
1983TS wasn't *that* long and had tapered ends with narrower tread plates than 1973TS or 1996TS. Also many other things making them better on tighter curves that I doubt anyone on here will care about.

 

[DanNCL]

As I said above, the TRV recording car is modified to be compatible with the Bakerloo and Central lines.
1983TS wasn't *that* long and had tapered ends with narrower tread plates than 1973TS or 1996TS. Also many other things making them better on tighter curves that I doubt anyone on here will care about.

How significant are the modifications? As if they’re only relatively small adjustments, surely that would be doable on a larger scale?

I also didn’t realise the 83 stock wasn’t the same length as 73/95/96 stock.

That said I don’t see anything other than 2024 stock being suitable for replacing the 72 stock on the Bakerloo. An alternative way of providing extra capacity on the Jubilee and Northern lines without having to use 96 stock on the Bakerloo could be to divert the Piccadilly line’s fleet of 24 stock to the Northern line, transferring 95 stock the other way to the Piccadilly to replace the 73 stock, with some 95 stock left over to supplement the 96 stock fleet on the Jubilee.

 

[Nym]

Completely different couplers, shaved tread plates that proclude passenger use and drivers that take it easy on the tight bits to contract the kinematic profile.

 

[Mikey C]

The 1995s are leased from Alstom and maintained by them (until 2033 I think), so it would be pretty hard to move them before then anyway!

It's interesting that the 1973 stock (and D78s) created a new standard of running fewer but longer carriages, one continued by the 1983 and 1995/96 stock, but not on the 1992 or the 2009 and S stock, which have gone back to the shorter carriages

 

[D365]

It's interesting that the 1973 stock (and D78s) created a new standard of running fewer but longer carriages, one continued by the 1983 and 1995/96 stock, but not on the 1992 or the 2009 and S stock, which have gone back to the shorter carriages

Anything to do with the fact that the two lineages are from (formerly) opposing manufacturers, or is it more to do with the needs of the respective lines that each type serves.

 

[Journeyman]

Anything to do with the fact that the two lineages are from (formerly) opposing manufacturers, or is it more to do with the needs of the respective lines that each type serves.

I'm guessing the 92 Stock needs shorter vehicles as there are some pretty tight curves on the Central, such as around Bank station and at White City.

 

[DanNCL]

Completely different couplers, shaved tread plates that proclude passenger use and drivers that take it easy on the tight bits to contract the kinematic profile.

Wow, didn’t realise it was that extensive! Safe to say we won’t be getting 96 stock on the Bakerloo then!

It's interesting that the 1973 stock (and D78s) created a new standard of running fewer but longer carriages, one continued by the 1983 and 1995/96 stock, but not on the 1992 or the 2009 and S stock, which have gone back to the shorter carriages

Anything to do with the fact that the two lineages are from (formerly) opposing manufacturers, or is it more to do with the needs of the respective lines that each type serves.

I'm guessing the 92 Stock needs shorter vehicles as there are some pretty tight curves on the Central, such as around Bank station and at White City.

I would guess it’s along the same lines as why the B division of the Subway in New York reverted from long cars to short cars for new trains around the turn of the millennium. In New York’s case, long cars couldn’t run on two lines, and were also found to have longer dwell times than the shorter cars (8x long cars though the same length as 10x short cars has fewer doors), so all new B division fleets from the R143 onwards have been short cars again.

Unlike New York’s B division, which can run entirely with short cars once the last R46s and R68s have been replaced, the deep level lines in London will continue to need at least two different carriage lengths, as even if long into the future the Northern and Victoria lines gained stock similar to the NTFL/2024 stock design (and the 2009 stock won’t need replacing until at least the 2040s) the Jubilee will continue to require long cars with the same door layout as the 96 stock because of the platform edge doors.

 

[40129]

Of course there is the possibility of a political fudge.

The Piccadilly line fleet has 3 train fleet sizes (enough for straight replacement of a 24 trains per hour service, a 27tph which is current plan, and a 30tph version). The new trains have higher capacity so even the 24tph option increases capacity.

It would be quite easy to divert the final few trains into the start of a Bakerloo line order, and then the number of trains for Bakerloo that would need to be added is less. I see this as a likely scenario if Bakerloo stock is struggling to keep going.

From a cost perspective it might also allow some of the Piccadilly line signalling replacement/enhancement to be deferred few years if 24tph continues for now which helps the 72 stock replacement case whlist Capital funding is tight.

It would be simple to return to the frequency enhancement a few years later, if economy picks up sufficiently. Effectively under this scenario the enhancement Piccadilly line trains would follow the Bakerloo fleet.

I suspect the Lewisham extension will be moved to back burner for a few years, so is not going to be relevant to replacing 1972 stock. Similarly replacing the 1990s tube fleets is also going to be parked for few years until late 2020s simply due to lack of capital funding whilst Government works out how to pay for Covid.

This is how I see it happening, this is not an actual revised policy.

Having read through the entire thread and thought about the various possible options for 72TS replacement, this political fudge might be a very neat solution. Although, I havem't had the 'pleasure' of riding the Bakerloo line for several years, I pass it frequently when travelling to/from London Euston, and even when viewed from the WCML fast lines, the trains don't look to be in good condition.

Regarding the suitability of 92TS for the Bakerloo line, as raised by others, as I see it there are 2 issues: 1) AFAIK no replacement stock has been ordered for the Central line; 2) IME the Bakerloo line always feels like an oven, even in the depths of winter and the 92TS's curved windows make them like mobile greenhouses, especially in the summer. I therefore dread to think how uncomfortable the Bakerloo line would be it these trains were redeployed there

 

[Nym]

Also, the Central Line trains are too long and you can't just lob one car out of it like they did with 1967TS , you could run 6 car formations, but that would be a significant drop in capacity.

EDIT:
It's not that simple to turn a 1967TS into a 1972TS, pneumatically "Complicated" and electrically has had issues since the day it was made, made worse by refurbishment fitting T8 lamps, and only just now being 'fixed' by LED lighting (although from what I'm hearing, the 3 car units still have issues that the 4 cars don't so there may still be MA problems.)

 

[rebmcr]

The Jubilee will continue to require long cars with the same door layout as the 96 stock because of the platform edge doors.

It's not impossible to adjust them. Not the sort of thing to do casually, but certainly justifiable as part of a fleet replacement if the benefits of a new layout are great enough.

The 3 car units still have issues that the 4 cars don't so there may still be MA problems.

Master Alternator?

 

[Journeyman]

It's not impossible to adjust them. Not the sort of thing to do casually, but certainly justifiable as part of a fleet replacement if the benefits of a new layout are great enough.

Thing is, you'd have to do it in a "big bang" with a suspension of service to modify all the doors. You wouldn't be able to run trains of two lengths or layouts at once. See what happened with the 7 car upgrade. The line was closed for several days to facilitate it.

Master Alternator?

Motor alternator. Device that converts traction current to lower voltages for auxiliary equipment and lighting.

 

[Nym]

It's not impossible to adjust them. Not the sort of thing to do casually, but certainly justifiable as part of a fleet replacement if the benefits of a new layout are great enough.


Master Alternator?

Apologies.
Motor-Alternator, used to generate auxiliary and control supply voltages from the traction supply. The MA Sets on 1972TS generate 230V at 850Hz that is then transformed down to 115V AC for main lighting, heater contactors, "AC proving" and load shed control for Connect Radio, and 51V (or 53V if it has the wrong transformer) AC that is rectified as a battery charging supply for the Control Supply batteries. Also a couple of control voltages to connect to the Motor-Alternator field compensator windings and the Motor Alternator Regulator (either a Transistor Amplifier, Magnetic Amplifier, or on the more modern ones a semi-well designed electronic controller, which has it's own issues.)

I could go into detail of the issues, but as ever, I don't think anyone really cares.

 

[rebmcr]

Motor-Alternator, used to generate auxiliary and control supply voltages from the traction supply. The MA Sets on 1972TS generate 230V at 850Hz that is then transformed down to 115V AC for main lighting, heater contactors, "AC proving" and load shed control for Connect Radio, and 51V (or 53V if it has the wrong transformer) AC that is rectified as a battery charging supply for the Control Supply batteries. Also a couple of control voltages to connect to the Motor-Alternator field compensator windings and the Motor Alternator Regulator (either a Transistor Amplifier, Magnetic Amplifier, or on the more modern ones a semi-well designed electronic controller, which has it's own issues.)

I could go into detail of the issues, but as ever, I don't think anyone really cares.

It certainly underscores the value of modern MOSFET-based packages doing the same job.

 

[bramling]

Having read through the entire thread and thought about the various possible options for 72TS replacement, this political fudge might be a very neat solution. Although, I havem't had the 'pleasure' of riding the Bakerloo line for several years, I pass it frequently when travelling to/from London Euston, and even when viewed from the WCML fast lines, the trains don't look to be in good condition.

Regarding the suitability of 92TS for the Bakerloo line, as raised by others, as I see it there are 2 issues: 1) AFAIK no replacement stock has been ordered for the Central line; 2) IME the Bakerloo line always feels like an oven, even in the depths of winter and the 92TS's curved windows make them like mobile greenhouses, especially in the summer. I therefore dread to think how uncomfortable the Bakerloo line would be it these trains were redeployed there

I don’t think redeploying the 92 stock is really an option. The CLIP project might be their making who knows, but given just how many issues there are with them I suspect it will more turn out to be just enough to keep them going for another decade without the line falling over completely.

Much as I have a soft spot for them, the combination of 1990s electronics, quite a few pioneering design features, shoddy build quality, and the Central Line being a strenuous line for trains due to its intense workload, have meant they really are falling to bits.

 

[Nym]

It certainly underscores the value of modern MOSFET-based packages doing the same job.

D78 Stock's static converters highlight how efficient a close designed system like the MA circuits actually are. The 6kVA static converter from the 2000s was roughly the same size as the MA and MAR set.
The 850Hz operating frequency significantly reduced the size of the wound machines, and worked very effectively at driving T12 tubes in the saloon.

The bigger issue of course is maintenance.

 

[Revaulx]

Having read through the entire thread and thought about the various possible options for 72TS replacement, this political fudge might be a very neat solution. Although, I havem't had the 'pleasure' of riding the Bakerloo line for several years, I pass it frequently when travelling to/from London Euston, and even when viewed from the WCML fast lines, the trains don't look to be in good condition.

Regarding the suitability of 92TS for the Bakerloo line, as raised by others, as I see it there are 2 issues: 1) AFAIK no replacement stock has been ordered for the Central line; 2) IME the Bakerloo line always feels like an oven, even in the depths of winter and the 92TS's curved windows make them like mobile greenhouses, especially in the summer. I therefore dread to think how uncomfortable the Bakerloo line would be it these trains were redeployed there

That’s interesting. I travelled extensively on the Victoria, Bakerloo and Central on a three day visit to London last week (as well as multiple sub-surface lines) and the Central was by far the hottest.

The Bakerloo stock, while undoubtedly showing its age, seemed in no worse condition than the 92 stock on the Central.

 

[Falcon1200]

I actually enjoy travelling on the Bakerloo Line, because it is the only place other than heritage railways still using the stock I encountered as a young trainspotter ! But given its age, surely the 1972 stock has to be at or near the top of the list for replacement ?

 

[bramling]

I actually enjoy travelling on the Bakerloo Line, because it is the only place other than heritage railways still using the stock I encountered as a young trainspotter ! But given its age, surely the 1972 stock has to be at or near the top of the list for replacement ?

The complication is the 92 stock, whose performance is dire, with the Central Line being the busier and more high-profile line. The 92 stock is getting money spent on it, on the basis that something needs to be done *now* just to keep the fleet going, there isn’t time to wait for replacement.

What happens next, IMO, will depend how successful the 92 stock work turns out in improving that fleet’s performance.

 

[AlbertBeale]

The complication is the 92 stock, whose performance is dire, with the Central Line being the busier and more high-profile line. The 92 stock is getting money spent on it, on the basis that something needs to be done *now* just to keep the fleet going, there isn’t time to wait for replacement.

What happens next, IMO, will depend how successful the 92 stock work turns out in improving that fleet’s performance.

Won't the Central get less busy when/if Crossrail opens?? I know they only really duplicate one another a bit - but given the central London part of Crossrail is pretty parallel to the Central, I'd imagine that many journeys that aren't one-hop end-to-end on the Central might end up being done differently, with different combinations of routes/changes, once people get used to the extra line and new travel patterns settle down. The central London part of the Central Line must surely end up with more slack? And less pressure means more chance for maintenance? Even less route-miles per vehicle to drag out their useful life a bit?

 

[birchesgreen]

Transferring the 92ts to the Bakerloo Line as an "upgrade" must be an example of the famous British sense of humour?

 

[D365]

Transferring the 92ts to the Bakerloo Line as an "upgrade" must be an example of the famous British sense of humour?

I highly doubt there’s been any serious proposal.

 

[Mikey C]

Won't the Central get less busy when/if Crossrail opens?? I know they only really duplicate one another a bit - but given the central London part of Crossrail is pretty parallel to the Central, I'd imagine that many journeys that aren't one-hop end-to-end on the Central might end up being done differently, with different combinations of routes/changes, once people get used to the extra line and new travel patterns settle down. The central London part of the Central Line must surely end up with more slack? And less pressure means more chance for maintenance? Even less route-miles per vehicle to drag out their useful life a bit?

Crossrail will also relieve the Bakerloo, as presumably it will remove much of the traffic which would have used the Bakerloo to access Paddington

 

[Falcon1200]

Crossrail will also relieve the Bakerloo, as presumably it will remove much of the traffic which would have used the Bakerloo to access Paddington

Definitely, Crossrail will provide long-overdue enhanced onward transport from Paddington, not just direct to Liverpool St and beyond but via the interchanges; Farringdon I think will be particularly useful with its access to Thameslink.

 

[LiftFan]

Crossrail will also relieve the Bakerloo, as presumably it will remove much of the traffic which would have used the Bakerloo to access Paddington

Even for people changing between Waterloo - Paddington, it may turn out a little quicker to get the Jubilee and Crossrail rather than direct on the Bakerloo when it's (finally) opened.

 

[Bikeman78]

The 72 Stock is on the verge of outlasting the A and 38 Stocks, and in the process becoming the oldest Underground trains in service ever (excluding the ones sent to the Isle of Wight).

A stock just cleared 51 years in service so they'll easily beat that. When did 1938 stock start and finish? Still a fair way to go to catch up with the New York R32 cars which ran from 1964 to 2020.

 

[Journeyman]

A stock just cleared 51 years in service so they'll easily beat that. When did 1938 stock start and finish? Still a fair way to go to catch up with the New York R32 cars which ran from 1964 to 2020.

1938 Stock lasted continuously from June 1938 to November 1985, with a few units then reinstated in September 1986, lasting until May 1988. So...just short of fifty years, but with a brief gap.

 

[DanNCL]

A stock just cleared 51 years in service so they'll easily beat that. When did 1938 stock start and finish? Still a fair way to go to catch up with the New York R32 cars which ran from 1964 to 2020.

1938 Stock lasted continuously from June 1938 to November 1985, with a few units then reinstated in September 1986, lasting until May 1988. So...just short of fifty years, but with a brief gap.

Almost certain in that case that the 72 stock will beat both of them. To beat New York's R32s, they'll need to last in service until 2029, which is certainly a possibility with the current state of TFL's finances.

Considering the 72 stock was only built as a stop gap to expedite withdrawal of 38 stock trains ahead of a then-planned new fleet on the Northern line (which eventually arrived in the form of the 95 stock), the 72 stock has done exceptionally well. No doubt however the 72 Mark II stock's longevity is in part down to the large availability of spare parts, from the withdrawal of the majority of the 72 Mark Is in the late 1990s, and the withdrawal of the 67 stock 10 years ago. The recent departure of the Asset Inspection Train for scrap will also have provided more parts assuming it was stripped for spares first, and there's also the possibility of the Aldwych unit providing spares in the coming years should proposals to get rid of it go ahead.

 

[AlbertBeale]

Even for people changing between Waterloo - Paddington, it may turn out a little quicker to get the Jubilee and Crossrail rather than direct on the Bakerloo when it's (finally) opened.

Given the scale of the platforms and infrastructure on Crossrail (much bigger than the Underground), and hence - from what I can see - interchange distances/times tending to be much worse too, then I can't imagine that it could possibly "turn out a little quicker" than a direct (even if on a slower line) journey. And add in the longer distance from the mainline platforms to the Jubilee at Waterloo too ... then surely not.