He did pause briefly to celebrate his birthday... But then he was back at the coalface — inventing, innovating and inspiring.I am assuming "back at the coalface" is roughly equivalent to the American idiom "back to the drawing board." Love it, and its association with coal mining, key English and Welsh industries that long pre-dated the Industrial Revolution.
Close, but no cigar. ‘Back at the coalface’ means “Actively doing a certain job.”
More like, “Back to the salt mine.”