When cutting steel began on the Clyde in July for the Royal Navy’s £5bn ($8.2bn) order for two aircraft carriers, it was an upbeat moment in what has been a grim year for the engineering industry.

The order will support more than 3,000 jobs at BAE’s Govan and Scotstoun yards in Glasgow, and sustain 1,600 jobs at Babcock Marine’s naval dockyard at Rosyth on the Firth of Forth, where the ships will be assembled.