Ship building declined due to lack of modifications to the way they worked.
The Far East came and looked at our methods and went back and and built massive docks to build ships instead of slipways and narrow rivers which restricted the size of ships.
I worked in the structural steelwork industry from 1958 to 2003.
There it was always the new kids on the blocks took over from the olde firms but the 1988 crash made the firm that I worked become uncompetitive and it closed in 1992/3.
Part of that was that we always bought British Steel products but others bought products from abroad Russia and EU and Far East.
Maggie gets blamed for an awful lot. The coal mining industry was over producing and uncompetitive as well.
Darling Arthur really killed it off, but for him there would have probably been a more gradual reduction in the number of pits. However that is conjecture.
These days it’s better to build or set up a company away from the old industrial areas to avoid Unions. In a few years that may change hopefully. When I left Tyneside in 1969 it was to a company that had no union problems followed going to two other companies that again had been no union problems.
Allan C.