I think it's worth adding, that, the UK's ability to deliver large projects wasn't entirely due to financial or outmoded constraints. Beginning, roughly, in the late 70's, engineering ( generic sense)for example became a almost literally dirty word. In some respects, manufacturing was responsible for this demise with some appalling facilities, some are still around, sadly, but there was a distinct shift away from technical colleges / degrees because social perceptions were such that no way were little Tabatha (rare but there were some) and certainly Tarquin going to be working as something as unbecoming as engineers ...certainly not hands on engineers getting dirty when a nice air cond office and impressive job title was becoming more available...also, apprenticeships virtually ceased to exist.
However, society does evolve, well in the main, and ironically given the sectors infamy for killing its workforce over the years, the construction sector did start to become both more inclusive and also demonstrated it could deliver capital projects...and yes, I'm well aware of well known cost overruns ....likewise manufacturing engineering has adapted in the same way.