In St Pancras station, John Betjeman watches out for the next train; in Paddington, Brunel sits moodily in his chair; and in Marylebone, a huge Adrian Shooter looms over the passengers. That is a measure of Shooter’s importance in recent railway history, a rare example of a statue being erected for a living person. Shooter, who has died aged 74, was the driving force behind the expansion of a forgotten minor railway line, which in the 1980s had once been threatened with closure and even transformation into a road, to become a new intercity service stretching to both Birmingham and Oxford.

Unusually, he combined engineering skills with commercial nous to become, as one former colleague put it, the only “genuinely entrepreneurial railwayman I knew”. While, for the most part, privatisation of the railways has been an expensive failure delivering little new at great cost, Shooter was the one person who exploited its potential.

Like many of the managers who ran train operating companies after the mid-1990s privatisation, Shooter had worked for British Railways in various capacities before taking over as the boss of Chiltern Railways. It was an unprepossessing prospect – despite some recent investment in rolling stock and signalling – one of the smallest of the 25 franchises, operating out of the near-deserted Marylebone, London’s newest terminal station, completed in 1899 by Edward Watkin, an entrepreneur who had overreached himself by building the Great Central Railway.

When Shooter took over in 1994, there were a few desultory trains out to Gerrards Cross and Banbury and a handful of commuter services for the benefit of affluent Chiltern towns such as Aylesbury, Amersham and the villages around Chalfont and Latimer station. Most industry-watchers thought that Shooter, too, had overreached himself by taking on such a moribund railway.

They were to be proved wrong. Shooter led the management buy-out team that won the franchise and was backed by John Laing and 3i, who provided the capital for investment. Uniquely, whereas most franchises were for seven years, in 2002 he wangled a 20-year deal out of the government which therefore made investment viable, affording him the opportunity to expand the railway.

His first ambition was to provide a service to Birmingham, and the key to being able to run a half-hourly timetable was the double tracking of nearly 30 miles of line in Buckinghamshire. According to Steve Murphy, one of his colleagues at Chiltern: “There was absolutely no chance of getting this done. No one had any interest in doing it and yet within a couple of years the diggers were at work.” Shooter was expert at lobbying the right people, banging heads together and not taking no for an answer. Soon services were running up to Birmingham costing only £15, far cheaper than the rival Virgin services from Euston and in very comfortable trains with no first class, which Shooter abolished in order to accommodate the growing number of passengers.

There were numerous other innovations: a parkway station in the middle of a field near Warwick, which turned out to be a great success; the refurbishment of the best old British Rail trains (Mark 3s, as they are called) to provide the most comfortable carriages currently on the network; a new link to Oxford, which required considerable trackwork; and a pioneering service between London and Wrexham, which failed only because the regulator banned services from stopping in Birmingham and Wolverhampton.

To cap it all, as a sideline that he pursued with vigour after leaving Chiltern, in 2012 he founded Vivarail, which bought a stock of redundant London Underground trains and fitted them with new power sources – either battery or diesel, or indeed both. The idea was to deploy them on little-used lines, and they have been snapped up by several rail companies, though sadly, without Shooter’s leadership, the company went into receivership earlier this month.

At play, it was also the railways. Shooter actually had a working narrow-gauge railway with a steam engine from the Darjeeling Himalayan Railway in his garden, which he used to run for his guests on summer Sunday afternoons. He built a fully fledged workshop to accommodate it and carried out all the maintenance and repairs personally.

Shooter was born in London, the son of doctors, Jean (nee Wallace) and Reginald Shooter, and went to school in Bristol and Epsom. Rather astonishingly, he failed A-level maths, which cost him his place at Leeds University. Instead he studied mechanical engineering at North Staffs Polytechnic. He started his career at British Rail and was centrally involved in several key projects, notably the ill-fated Advanced Passenger Train, which was the precursor to the Pendolinos that now run on the West Coast, and he was responsible for developing the safety lock that prevented passengers opening doors between stations. He was always a hands-on manager, who once rushed to Halfords to buy up its stock of de-icing sprays when a cold snap led to the doors sticking on a fleet of trains running out of St Pancras for which he was responsible.

He progressed quickly but there were setbacks, notably when he headed the parcels service for BR. It included Red Star, which he had largely created, but some financial shenanigans by his senior staff led to his being hastily transferred to the nebulous job of director, engineering quality. Soon he was rescued, by being moved to take on the Chiltern operation while it was still part of BR.

A measure of the respect and affection he inspired in the industry was that his statue was funded entirely by donations from fellow managers across the industry.

Shooter is survived by his second wife, Barbara (nee Harding), whom he married in 2006, and by a son and daughter from his first marriage, to Diana Crombie, which ended in divorce.

• Adrian Shooter, railway executive, born 22 November 1948; died 13 December 2022

• This article was amended on 16 January 2023 because an earlier version counted a “Chalfont St Latimer” in a list of affluent Chiltern towns. This has been corrected to the intended reference of the villages around Chalfont and Latimer station. Some contextual information on Chiltern Railways was added on 23 January 2023.