I expect SOME disruption, but probably limited.
Any industrial action by the TSSA» will probably hasten reductions in staff numbers, as ways will be found to manage without them.
Ticket office closed due to strike ? Purchase on line instead and thereby hasten the closure of more ticket offices.
Wages and salaries clerks on strike ? Subcontract the whole operation to India.
Timetable planning department on strike ? accelerate the transfer of same to GBR▸ and close down the TOC▸ planning departments.
Advertising and promotions department on strike ? Close it down, wont be needed under GBR "Famous five face the dole"
This reminds me of a huge planned civil service strike, in the days of Maggie Thatcher, that was to "bring the government to its knees" The PM was asked for Her views on the strike and reportedly said "It is a great idea, we can find out which ones we really need, and get rid of the rest" The strike petered out.
There are staff that are in other Unions who if there duty manager is on strike may decline to do certain tasks that require higher authorisation,