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

These lads are going to be miners. But how are they going to learn the job? Should they be sent straight down the pit, where they'll be in everybody's way, or should they go to college, where they won't learn anything of the practical side?

At Bestwood Colliery near Nottingham, they get the best of both worlds. Every boy going into the South Notts mines comes here for ten weeks. The scheme's been going for five years. A year ago, they built this schoolhouse.

In the laboratory, they learn the scientific side of mining by doing their own experiments. This is one on the effects of afterdamp. In the handicraft room, carpentry is taught, and the boys also get to know mining equipment by making models. At the same time, regular PT classes teach the importance of keeping fit.

And here's the really new thing about Bestwood. Under the school buildings, there's a model mine. Layout and equipment are faithful replicas of the real thing. The mine is small in area, but instructors who have spent their lives in the pits say that it's the perfect training ground. The main road to the coalface is only a few yards long, but that's enough to show what it's like. The roof's made of concrete, so there's no danger of its falling in. All the same, the boys have to prop it up in professional style.

Here are some lads studying longwall technique in the face galleries. They also see a coal cutter in action and try their hands at filling coal onto the face conveyor.

There are some jobs you can't learn in the best model mine. So for two days a week the boys go and work in a real pit alongside their future workmates. By the time they leave they know enough about the job to give them a flying start, and save months of unproductive work in the pit.