The commentary also doubles as a synopsis, and is therefore reproduced in full:

Back in 1927, the mine at Nantgarw in South Wales was abandoned as uneconomic. For years, the plant lay derelict, until in 1947 reconstruction began on a new plan. In 1950, after 23 years, coal will start coming up this shaft again.

When the pit is fully developed, three quarters of a million tons of saleable coal will be won every year by the latest methods of horizon mining and diesel haulage. It will take several years and cost more than two and a half million pounds sterling to reconstruct the underground workings, build the power station and other surface plant, and direct the battery of 48 coke ovens that will deal with ten thousand tons of coal a week. And a large by-product plant that will be laid down next year.

Part of the plan, too, is the model village close by, to house some of the two thousand future workers of Nantgarw. The mine workers will find the most modern installations waiting for them, both at home and at work.

Nantgarw is a huge mechanised industrial unit, but without smoke or dirt - the coal mine of the future!