The third of the commanding heights of the 1940s economy to be nationalised alongside steel and rail was the coal industry. It employed 700,000 employees in the later 1940s, producing around 200 million tonnes of coal a year. The number of employees slumped to just 235,000 by 1979 on the first election of Margaret Thatcher. Many of the employees lost their jobs under Labour governments, who accepted a large number of pit closures as the industry struggled with costs and falling demand. More job losses followed in the 1980s and 1990s, along with a bitter strike about whether individual pits could be economic or were exhausted.
Today there is no deep mined coal produced in the UK, and a very small opencast coal industry. We now import most of the reduced amount of coal we do need. An industry employing well over 700,000 at peak has all but disappeared. It was nationalised for most of the post war period, but this did nothing to arrest the long term decline. Indeed, there were occasions when the nationalised management took too pessimistic a view of the economic prospects for individual pits. I remember helping the miners at Tower Colliery take over their mine from the NCB when the NCB said it had to shut for economic reasons, and go on to make a success of mining more coal from it for many years.
The nationalised concern did have substantial investment programmes from time to time, developing a range of new super pits with better machinery and operating at larger scale. None of this arrested the long term decline in coal use and coal output. More recently governments have turned anti coal on environmental grounds.