When Labour nationalised the yards in1977, they demanded a productivity increase of 20% at no cost, which Labour got. They also wanted an agreement with the unions o remove the 124 working particles which was prevalent within the yards,the Unions refused. It would seven years later before the Unions agreed to review and reduce the working particles, to little to late.
Even with the increased productivity, a ship built in the UK on average took twice as long to build as a European built ship.
Vic