The availability of technicians and staff is very relevant here.
It is illogical that when we talk about drivers overtime, the union agree the railway should not depend on volunteers, yet you seem to advocate for exactly the opposite here.
It is rare that two neighbouring regions will have a problem like this simultaneously and therefore sensible to the point of obvious that staff should be trained for and covering other regions, when it is required, not just when they feel like volunteering.
There are no figures provided concerning how many people volunteer and whether volunteering currently gets the enough of the right people where they are needed but it not should be left to that.
Just because there isn’t a bad infrastructure problem does not mean that the technicians/staff aren’t busy. There will be the normal failures (point failures, track circuit/axle counter failures, signal, AWS, TPWS, etc.) to deal with and where possible, normal maintenance work. Obviously if there is a major failure, Network Rail management have to prioritise on what gets the limited resources.
I’m not advocating anything, I was just stating how it was. The introduction of Modernising Maintenance changes things in theory. Only time will tell if it will make any significant difference.
The issue with train crew working overtime on Sundays is no different to that for infrastructure staff. The difference being that S&T had Sundays incorporated into their normal working week in 1992. The other infrastructure staff had the same in 1999. As the railway did not take on any extra staff, all that happened (at that time) was either less work during the Monday to Friday week or more overtime during the Monday to Friday week. Unless the railway is willing to employ more staff (not going to happen under the current financial climate) the problem will remain.
This seriously going off topic, so I will leave it there.
Back on topic, there is always going to be a significant disruption to services in the Old Oak - Paddington area if there is an infrastructure failure or a train failure, or other incident. Simply because this area is so busy.