A future for 1973 tube stock?

I'm not sure where to start, but in no particular order:

1) Converting the 1973 tube stock to operate on the Northern line would require the Thales CBTC system and the track to train CCTV system. The former is a very big modification and the only spare space for the kit in on the trailer cars (identified when there was a plan to fit the Bombardier CBTC system well over 10 years ago to interrun with the sub-surface signalling upgrade). The Thales CBTC would have to be tuned for a far less flexible braking system which might affect stopping accuracy. Providing the equipment from redundant trains as outlined above is the easy bit, and, in any event some of it is part of the problem.
2) Higher performance is required on the Northern line. The 1973 tube stock was designed with higher performance capability which has never been used. But enabling it now would put huge strain on the traction system.
3) part of the reason for the underframe cracks on the 1996 tube stock is the additional longitudinal traction and braking forces arising from the addition of the 7th car. If 1995 tubes stock were to be converted to 7-car then they would suffer similarly.
4) it is impossible to compare reliability between lines, there are so many factors affecting it. The most extreme example being the Central and W&C - same train but very different reliability figures. One really does need to get behind the headline figures and understand what sub-systems or components are causing the failures and set about fixing them. There is also a lot more kit on the modern trains compared with the 1973 tube stock.
5) Major engineering modifications to old trains are almost always more expensive and take longer than anyone expects even after making ample allowance. D train has not been a rip roaring success, the class 769 conversion from class 319 has been extremely troublesome and 1992 tube stock engineering change has been going on for a very long time with no service date in sight.

Piccadilly line trains have become reliable because its management took the trouble to understand why it was failing and put in place the actions - in terms of people, process and eauipment to address the root causes. These principles should be applied to the other fleets.

I've responded seriously but I realise, Jimbo, that your post might have been tongue in cheek!

I agree that it wil be a shame to see the loss of the 1973ts but am scratching my head as to what any second life could look like - beyond (perhaps) drinks cans.

Maybe a museum railway would take a few, make them work as either loco hauled or battery trains.

The only other possibility would be if the Bakerloo extension was built but the required new trains were unfunded.

It is a shame that their full potential performance was never enabled, it would be great if that situation was changed (providing that the power supply infrastructure could cope) as these trains do seem to dawdle too much. But this is a different issue.

6)Northern line drivers would rightly revolt and commence industrial action in response to being asked to transfer from 95TS to the far less safe and less ergonomic 73TS cabs.

TBH barring possibly maybe one or two units being retained as engineers vehicles (i.e. maybe permanent RAT), and one car for Acton museum, I see and predict no future for them other than scrap. Unless some fire brigade somewhere wants a car or two for fire training. Or some nutter wants a big garden shed.

Is that taking into account the availability of stabling berths today or when the two depots are being taken to bits at the same time for upgrades?

Gap filler trial seems to have been abandoned during covid pandemic. Baker St platform 2 gap mitigation is looking at other options juggling stopping positions. Not entirely sure the rationale for stopping the gap filler work right now. Safely ensuring it deploys and retracts at the right moment was always a bit tricky with limitations the project put on itself.

Trying to stay on topic here, I note the 1973 stock run as 3 car units on their current RAT (rail adhesion train) duties but I wonder if there is a plan to form a 5 car train like the similar(ish) D stock on the Metropolitan to allow a bit more power into the train.

For those not well acquainted with the D stock train, it is a typical 3 car train but with two non driving motor cars added giving 4 out of 5 cars powered.

Don't they need more oomph for more getoutofthewayness on a high intensity high frequency CBTC line when pathed between high performance passenger stock ?

AIUI thats why the D RAT is 4 motor cars for total 5 cars - for the future all CBTC railway.

I would expect any Picc RAT post new stock and resignalling will be same even if resignalling is years away and might be something different it will still want ooomph for the same reasons.

Less safe - the 73TS cab does not meet modern crashworthiness standards as-built, let alone with fifty years of fatigue and corrosion.
Less ergonomic - again, what was acceptable half a century ago is not today. 73TS cabs offer great driver visibility, but are very cramped compared with 95TS.
Such a step backwards on a fleetwide scale would not be acceptable.

It appears that the current plan is to retain 1973TS on the Piccadilly Line for RAT duties when the new fleet arrives. This could operate in 6-car formations to provide spare units. Is there any possibility that further 1973TS RAT conversions could replace the RATs on the Central Line? They are getting pretty old now! 1973TS did run through the Central Line, from Ruislip to Hainault for trials on the Woodford shuttle, as the Experimental Tube Train (ETT). So, it would fit despite its longer cars.

Keep them convertible between passenger and RAT duties and then they can earn their keep (when not needed for RAT duties) as heritage trains carrying premium fare paying passengers!