It's been reported in several places.
A 2.5 ton computer - complete with 828 valves (i.e. electron tubes for US readers) plus 480 relays - gets rebooted following its three year restoration in the UK.
So without further ado, may I present the Harwell Dekatron/WITCH:
Woo-hoo! It works!!!
More articles here, here, and here.