Power failure Clonsilla station
 

Seemingly no power at Clonsilla this morning around 10, ticket machines, smartcard validators, booking office and ticket barriers off. What's the official position on travelling without a ticket(or tagged on smartcard) here?

If ticket-selling facilities are unavailable, you buy on arrival with no penalty. I would suggest taking photos with a camera phone to have as proof and smooth your way, but you aren't obliged to.

As it happens, when I got to Pearse I just showed the smartcard to the barrier attendant and told him there was a power failure and he waved me through gratis.