Given that news and sport both work with studio sets that are mainly large video walls, and need comprehensive graphics and comms facilities, I wonder if they have any kind of reciprocal agreement between the two departments, so that if TC5 has a big failure they could borrow TC7 and vice versa? (I know RTE have done election coverage from TC5 before now).
It's probably possible, but by no means trivial - certainly not at short notice.
The lines in and out of TC7,
N6,
N8 and N9 all go via SCAR, whereas TC5's connectivity is all via CCA.
SCAR is geared up to the same source working into several channels in a row - eg a sat truck doing an insert on the news channel, then World, then 5 Live. It's easy to route the same source to lots of destinations, but then you need to make sure the right clean feed is going back to the source, and they've a queueing system set up for this to mostly happen automatically. Things would get complicated if you started involving a main block studio.
Election programmes involve so many outside sources several temporary hubs are built (in
TVC and elsewhere), which takes in all the OSes, and spotters there look out for interesting stuff to send to TC1, TC5, and to the Nations programmes.
I'm not sure if RTE used TC5 because of its flexible standing set, or because of its excellent connectivity. Could have been a bit of both!