People refer to "mental health issues" and use formulas such as, "It's a posh thing" and "I'm just saying, that's all".
The dialogue takes no particular trouble to reproduce period speech. The dangling boy was holding a golf club and for a moment it looked as though the engine would strike him, but the train passed under him, with feet to spare, and as it passed he knocked some coal off the top of the tender for the waiting women below to catch in their skirts." It's not easy to visualise this except in cartoon terms. Some, though not all, of the details are compelling, and some are oddly stranded between persuasiveness and tall tale: "Two children were dangling a boy upside down over a bridge in front of an oncoming train. Rhidian Brook thanks his father and uncle Colin for their memories of the period, when they must have been quite young themselves. When Edmund, uneasily befriending some local trümmerkinder (feral "children of the rubble"), sees some "medicine for venereal disease" and "prophylactics" among their "measly but eclectic" treasures, we need to be told either how he recognises these objects or what he thinks they are.
A scene in a novel can't be done from a neutral camera angle – not if it has started with a defined point of view. Certainly the book has some of the indeterminate quality of a screenplay waiting for a director. Perhaps Brook worked on the versions in tandem. The material was intended for the screen as well as the page, even before Ridley Scott's production company commissioned Brook to write a script.