Actually the last go anywhere tube type train was the 72TS, which is essentially a 67TS. The 73TS cars are slightly too long for certain parts of the network from a guaging perspective and 92TS traction is not cleared to operate everywhere.
More obviously there is a section of the roof edge missing from above the red arrow, with the other three sides looking to be held down with bags of sand / cement. It is more likely that is the section that blew off.
Also, here is a pic I managed to snap of the overrun train (the angle of the photograph makes it look more acceptable than it should be IMO). Overrun Train Canary Wharf PM Peak (One lady did walk straight in to the open PED as she disembarked, which is what drew my attention to it!)
I've been on a train that has stopped like that right at the edge of the tolerance. As indicated by Chris M, there has to be a limit to the PED width otherwise you would be creating more risks than it solves. The main thing is that situations like this are outliers on a bell shaped curve (statisticians will understand this), which means it is very infrequent.
All done using the TBTC signalling system - there is a specific sub-system for communicating between train and platform to open the Platform Edge Doors once the door open button is pressed. If I remember correctly the tolerance is +/- 0.25m for the PED equipped stations, so a range of 0.5m, which increases to +/- 0.5m and 1m respectively for non-PED stations.
The old CSDE was responsible for telling drivers that they had achieved an accurate stop and would communicate to the PED controller using trackside loops. This used the ATO controller fitted for the part-abandoned WestRace automatic control system.
I know the DISAB was having extra hopper capacity added to help with the Baker Street to Finchley Road concrete track replacement, so that would tally with the "2 Extension Hopper". The DISAB modules are clamped onto the solebar of the host vehicles, so JLE2, although being a GP wagon, could quite easily be converted into additional DISAB hopper capacity.
I think S Stock has the door open buttons as the doors automatically close after a period of time in order to preserve the saloon temperature and thus reduce HVAC energy consumption. In that instance you need the door open buttons at long dwell locations such as terminii.
95 and 96TS doors don't have quite the same function, some door leaves on a car stay open providing partial retention of heat in winter, so the buttons aren't needed.
Last I heard was W&C then Piccadilly, however it was unclear whether Bakerloo or Central would be next. Both 72TS and 92TS are having major work done so I suspect there is no immediate concern as to which comes first. Maintainability of the signalling system equipment may be the defining factor.
well they didn't have the problem with the old wheels the unions reckon its that as well as some managers although tfl would never admit it even the 25mph speed limits in open sections couldn't stop this years fiasco
So it's uninformed speculation then.
Bear in mind the wheelset is a single point of failure and as such the materials and assembly of it is a very highly controlled and inspected process. Any changes to the materials used has to receive formal engineering approval either through the change process or as a concession, which, if it exists, will be found by those charged with investigating the service disruption.
The equipment may be rated for higher voltages, but particular items like the MA have their output controlled by a MAR set at a fixed value. Part of the mitigation works involves changing out the MAR for an 'electronic MAR' that senses the traction voltage and changes the output to prevent over-voltage of the auxiliaries e.g. gassing the batteries.
Sarah worked for a time on the Southern Region 3rd rail network I believe, so 750V should not be an issue.
That's true for the general supply voltage, but it is the 890V regenerative braking voltage that requires mitigation, something that would not have existed when Sarah Siddons worked railtours on the Southern Region.
Directional control wasn't the issue, it was more general problems with obtaining traction and going into parallel. No doubt the team at Acton will sort it out. Given the significant reconfiguration there is only so much that slow speed moves around the yard can tell you.