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

It is great news that the number of serious accidents in mines has dropped to half what it was in 1938. A lot of hard work has gone to achieve this improvement. New entrants are properly trained both in classrooms and training galleries. Working conditions underground are much better. New inventions cut out many of the old risks. Shorter hours mean less fatigue, which means fewer accidents at the end of the shift. And research into the cause and prevention of accidents goes on ceaselessly.

Half the accidents underground are from falls of roof and sides. These steel arches have helped to cut serious casualties from falls on roadways by half. All types of supports are specially tested by the Safety in Mines Research and Testing Branch before they are used. The weight they can bear is known exactly. The trickiest spot is where the haulage road joins the coalface. Special attention has been given to roof supports here

The next most serious cause of accidents is the haulage of coal from the coalface to the pit bottom. These too have been cut by half. Low roads like these are not made now. On sloping roadways, the runaway tubs are a great danger. So the new roadways are made level. Conveyor belts, often right up to the coalface, cut out the tubs altogether. Scientists also test the wire ropes in use underground. First each strand is tested separately. And then the whole rope. Now shaft-winding accidents have been almost eliminated.

At another of their research stations, high up and isolated in the Derbyshire hills, the Safety in Mines scientists are making tests to cut down accidents from explosions. First they introduce a known amount of coal dust into an artificial gallery and make it explode. Then they do the same over and over again. But now they introduce measured amounts of stone dust, so that they can find out how to cut down and eventually eliminate accidents from coal dust explosions.

Higher standards of safety are set in all parts of the industry. The big drop in serious accidents is most encouraging. But the work of scientific improvements that began over 100 years ago with the safety lamp will always go on.