As a steam locomotive speeds through the station, a group of young boys are trainspotting. In its heyday - between the wars - driving a locomotive was every lad's dream.

Since then, a new word has come into play: Modernisation. Two new forces begin to supersede steam. On the one side, the technological trappings of electric traction, on the other, the smooth, clean efficiency of diesel-powered trains. We see the updated roles these two occupy alongside steam-travel. The old runs alongside the new, right up until the time when the new takes over for good.

A systematic look at this process begins, startingwith goods handling, then moving on to the modern depot. A new language has developed as well, with words like 'pallet-isation' and 'conveyor-isation.' If one is mechanically minded, it can be quite interesting to be employed in this way.

Labour-intensive work has also become a great deal more human with the new technology. Track making in the old days required 'muscle-boys' and their slavish devotion to repetitive, gruelling activity. Now tracks are pre-fabricated and men operating mobile cranes swing them artfully into place. Likewise, shunting - the process of sorting items of rolling stock into complete train sets in the railway yard - could be exciting, but also quite dangerous. It is on the way out, to be replaced by automation. Men with radio links help direct the trains, and mechanised retarders guide them to their destination - one must still have a good sense of timing to orchestrate the whole process. Signalling is another activity revolutionised thanks to modernisation. A lone operator controls up to 33 miles of track simply by flipping a switch, which sends a message to all-new electric signal boxes.

Finally, a look at two last jobs - fireman and driver. Again, the negative - work conditions - outweighs the positive - the heroic aspect. Moving to the new, we get a firsthand look at what it means to operate "a sleek bit of 20th century technology," the diesel train. A closer relationship not only to the controls but also in proximity to the passengers means a renewed sense of job satisfaction and responsibility. All in all, it adds up to a new generation of young people for whom the railways are a viable and attractive career choice.