The two great excitements of my ten-year-old self – as for so many of my generation – were the Famous Five novels of Enid Blyton, then brand new, and the hobby of loco-spotting as promoted in the ABC volumes of engine numbers from Ian Allan.

The regular arrival in the local library of the latest sleuthing adventure for the quintet – in the familiar maroon covers of publisher Hodder & Stoughton – was a matter of mighty moment.

The library, incidentally, was one of those supplied in a massive campaign of philanthropy by the Scottish-American industrialist Andrew Carnegie, the world’s richest man until he gave most of his fortune away (a sum equivalent to $65 billion today).

“A man who dies rich, dies disgraced,” he wrote. His immense generosity should be remembered in this centenary year of his death, especially by such as I whose love of reading he helped to foster.

As for my childhood trainspotting, this enthusiasm coincided with the arrival on the tracks of a new generation of powerful locomotives, the Deltics, whose names – Crepello, Tulyar, Pinza, Nimbus (all Derby winners these) – could hardly fail to stir the spirits.

Nearly 60 years on, it is curious to find the Famous Five and trains reunited in my mind again in the inspired (and highly entertaining) advertising campaign across the media by Great Western Railway.

And even as “Five Go on a Great Western Adventure” – as the billboards tell us – so too have I, in a thrilling ride in the cab of one of the company’s Intercity Express Trains on a journey from Oxford to Paddington.

The opportunity to do so arose from an article on this page a few weeks ago about my invitation for a trip in the cab by Chiltern Trains – following a piece I wrote about their bumpy track near Haddenham – and their bizarre failure to follow up on it.

This Gray Matter was read my a member of the GWR staff who was able to arrange in a matter of days what the rival outfit had not been able to manage over more than a year.

This was far from my first such ride, as it happens. In the steam days of the early 1960s, I was transported more than once on the journey of a mile or so between Peterborough’s two stations courtesy of drivers who had allowed me to “cab” them, in trainspotters’ parlance. (A letter ‘C’ was scrawled beside the engine number in the Ian Allan ABC.)

In 1995, at the press launch of Eurostar services between Waterloo and Paddington I was hurtling through northern France beside the driver at a speed undreamed of in my youth. A surprise was to find the tracks curving away into the distance like a big dipper: the sensation for the normal punter is of straight-line travel.

Thirteen years before that, British Rail launched a non-stop service from Oxford to Paddington. travelling in a record time. I rode with driver Clive Batch on the inaugural run. Alas, a delayed departure and a signal check outside West Drayton made us 16 minutes late.

No similar misfortune was experienced on my latest cab ride from Oxford to the capital with driver James Scholes at the controls and driver standards manager Gordon Hardie in attendance.

Our departure from Oxford was precisely at the timetabled 12.22pm and Paddington arrival, after stops at Reading and Slough, exactly at 1.20pm. We made such good speed, in fact, that there was a five-minute wait outside the terminus for a platform to come free.

My seat beside James – with a cockpit-like range knobs, handles, screens and dials – was that occupied, when necessary, by an instructor. Drivers are usually in the cab alone, with a foot always on the ‘dead man’s pedal’ whose disengagement, through sudden illness or other emergency, instantly applies the brakes.

On the first stage of the journey, we travelled at 90mph under power generated by diesel engines beneath three of the five carriages. Only after Didcot did driver James raise the pantographs to the overhead wires as we roared towards the 125mph maximum speed.

The IETs are actually capable of 140mph, though limited to the lower speed in normal traffic.

Viewed from my seat in the cab, with the tracks ahead stretching as far as the eye can see, there is no great sensation of whizzing along, except when a train passes in the opposite direction.

I was amused to see that even with a passing speed of 250mph, James was still waving to drivers coming towards us, and having greetings returned, in the way bus drivers do.

The wide availability of the IETs across the GWR network is making possible a significant increase in speeds when the winter timetable comes into force on December 15.

One train from Paddington to Oxford actually does the journey non-stop in 44 minutes. Others are about 55 minutes, and there are new straight-through services linking Banbury and Paddington in an hour and six minutes. Great stuff.