Brimpsfield station, disruption.

[Little John]

That pissed me off about series one as well E. It turns out, form the second series onward, they employed a different writer and it shows. From series two, the implicit plot line that those who were best fitted to take charge were the middle class types, fell away a bit and it became far more believable as a consequence. Though, it was still there a bit, of course.

The very last episode was the worst of them all, IMO, and not just because of the 'laird' and his presumption. It all seemed like they were trying to force a tense, watchable drama out of one or three not-very-plausible ideas.

And I've no notion about the mechanics of the hydro system of course; perhaps adam2 will point out the flaws, if any. But the saboteur plot was all too glib and implausible.

Worth watching overall though. 7½ out of 10, a bit more maybe considering its age and naivety.

I think the last episode was just a way of tying up
a drama that had run out of steam and viewing popularity

[adam2]

The scene at the hydroelectric power plant was in some respects plausible, and it was filmed at an actual power station, not a mock up.
The attempted sabotage by placing a log or tree trunk into the water inlet was most implausible.
Such items can fall into watercourses by accident, and screens are fitted to prevent damage.

On a more general note, a significant factual error in the latter episodes was the lack of modernish artificial light and reliance on crude lamps burning animal fat.
In fact, battery lanterns and torches would have been available for many years. With the much reduced population there would be no shortage of batteries. The limiting factor would be shelf life, typically advertised as being 3 or 4 years from manufacture in those days. Significant numbers of batteries would have remained serviceable for at least 10 years.
Bottled gas keeps until the containers are perforated by rust, decades in dry conditions. No shortage of either gas or of gas lights, with the much reduced population.
Solar power was almost unknown then, but small wind turbines were used for lighting isolated premises.
A large water wheel or a traditional windmill could easily belt drive a vehicle dynamo or alternator.