Pat Jackson: Director who learnt his trade on 'Night Mail' and went on to make one of the finest wartime films

The death of the film director Pat Jackson breaks the last link with the pioneer British documentary movement of the 1930s, and with its masterpiece Night Mail (1936), on which he worked as a youthful apprentice.

By the end of an eccentric, unlucky career he had shown himself one of the most versatile and talented members of that celebrated group.

Born in Eltham in 1916, Jackson had his education severely disrupted by illness. On recovering, he drifted into films, first as a camera assistant at Welwyn, then, in 1934, as a junior member of John Grierson's documentary unit, which was attached to the General Post Office. He used to say that he got himself taken on only because his father, a London merchant, was acquainted with the Postmaster General, and pulled strings on his behalf; and at first he was overawed by the array of intellectuals who surrounded him at the unit, many of them, like Humphrey Jennings, with Firsts from Cambridge. But in film terms they were all in the same boat, learning by trial and error, and Jackson learned fast. As he later told a interviewer, "it was really the first film school – a wonderful way of learning a job."

Night Mail, which makes the journey of the postal express from London to Scotland into an epic of modern communications, was a crucial rite of passage. Jackson was an integral part of the small team who made it. It was he, for instance, who solved the problem of how to record the clickety-clack of the train, which sounded all wrong when a microphone was exposed to the real thing: he brought into the studio a section of model railway track, and a Bassett-Lowke engine to push back and forth on it, and that is what we hear. At the film's first public screening he listened to the audience responding with an enthusiasm that had attended none of the unit's earlier, more earnestly didactic efforts.

There was already a tension in the movement between the purists who saw documentary film as a separate kind of product, making no concession to the methods, and audiences, of commercial cinema, and those who wanted to reach and influence that audience. Jackson from this moment aligned himself with the second group, and never left it. Like his great friend Harry Watt, Night Mail's director, he remained loyal to the central ideals of documentary – realism, and social responsibility – while embracing dramatisation, narrative, and, where appropriate, professional actors.

His first film as director was a typically modest GPO assignment, The Horsey Mail (1938), set in rural Norfolk, but, like Watt and Jennings and others, he had his career transformed, or at least accelerated, by the war. With no TV service available, documentary film suddenly found itself with an urgent job to do of informing, explaining, and inspiring; to mark its new national role, the GPO Unit was rebranded as Crown. Jackson was one of the team that put together the celebrated short film of the Blitz, London Can Take It (1940), which had a dramatic effect on public opinion in neutral America. He went on to direct Health in War (1940), a lucid exposition of the emergency system that would, in effect, become the NHS, and then Ferry Pilot (1941), a half-hour dramatisation of the work of moving planes around, with pilots playing themselves, and stunning aerial photography.

It was like a trial run for his first full-length feature, Western Approaches (1944), one of the great films of the war. A U-boat spots a lifeboat drifting in the Atlantic, and lies in wait for the convoy ship that will surely come to pick up its crew. On the basis of this ultra-simple plot, the film builds up a strong Hitchcock-like suspense. Hitchcock himself was engaged at the same time in making Lifeboat, set likewise in the Atlantic, and the two films make a fascinating pair: while Hitchcock filmed his boatload of actors in a Hollywood studio tank, in black and white, Jackson took his non-actors out to sea in a real lifeboat for week after week, along with the bulky Technicolor equipment of the time. The images produced by his cameraman, the young Jack Cardiff, have a beauty that helped to gain the film an admiring new audience half a century later, through the Imperial War Museum's video release.

Western Approaches did respectably in the cinemas and brilliantly with the critics, and Jackson was signed to a Hollywood contract by MGM. He postponed this till after the war, developing for Crown an ambitious project about the Beveridge Report on social services; the Labour government aborted this, despite the fact that the film would have offered radical support for its reforming agenda. It turned out that the golden age of documentary cinema had ended with the war, and it was a good time to be moving on.

But Jackson's years in Hollywood were not happy, apart from giving him lots of time off to indulge his passion for fishing. Alexander Korda, to whom he owed his contract, had left the company, and no one, from Louis B Mayer downward, knew what to do with him and his realist agenda, other than offering him the latest Lassie film. In the event, all he achieved was one decent minor melodrama, Shadow on the Wall (1949), centred on child therapy, and giving a first role to an actress named Nancy Davis – later Nancy Reagan.

Jackson had thus missed out on the brief boom period of British cinema during which others like Powell and Pressburger, David Lean, Carol Reed, and the Ealing team built so impressively on their wartime achievements. By the time he returned, the boom was ending and the enlightened hands-off sponsorship of J Arthur Rank was giving way to the rule of the accountants. He had time to make one magnificent film, the hospital drama White Corridors (1951), which operates both as a drama-documentary about the workings of the new NHS and as an absorbing multi-character melodrama, hard-edged forerunner of the TV genre of hospital soap opera.

Jackson took a special pride in the seamless way he integrated several non-professionals into a cast of actors including Googie Withers and Petula Clark. Shot in five weeks, it was a popular and critical success. The young and hard-to-please Gavin Lambert, then editing Sight and Sound magazine, wrote: "White Corridors should set a new standard for popular entertainment in films of this country".

These hopes were not fulfilled. Made wary by his MGM experience, and by his distrust of Rank's executives, Jackson turned down the offer of a contract and picked up work here and there. A contribution to one of the Somerset Maugham anthology films, Encore (1952); a second hospital drama in The Feminine Touch (1956, for Ealing); a bleak drama about a middle-class professional jailed for thoughtless petty smuggling in The Birthday Present (1957) – films like these were honourable and craftsmanlike, but made little impact, while his bolder personal projects were turned down. In the 1960s he was further marginalised by the younger, flashier "new wave" of film-makers; suddenly he and his admirable generation of wartime achievers, from Michael Powell to Thorold Dickinson, had become sidelined as yesterday's men.

Still in his prime, Jackson divided his time between minor films, some of them for the Children's Film Foundation, and work on the filmed TV series that were now proliferating. Hisbest TV work was done with a young stage actor he had introduced tothe screen, Patrick McGoohan: episodes of Rendez-Vous, Danger Man, and McGoohan's brainchild The Prisoner (1967), whose cult status ensures that, unlike most of Jackson's work, it remains in circulation.

Like many reluctantly retired film-makers, he continued to nurse pet projects, notably a realist modern Western set in the Canadian wilderness which he had come close to making for Ealing in 1955. When he finally felt too old for it, the one younger film-maker whose work he admired enough to offer it to was Ken Loach, and it was a disappointment when his tentative approach met with no response. But there were compensations. A low-budget horror comedy he directed in 1962 – further evidence of his versatility – had its title appropriated for a dazzling 1994 novel by Jonathan Coe, What a Carve Up!, whose narrator is obsessed by that film and by its star, Shirley Eaton. When Coe gave an illustrated reading from the novel at the Festival Hall, Jackson turned up to hear him, and the result was a meeting of minds which delighted the audience as much as the two protagonists. In 1999 he published his own engaging memoir, A Retake Please! Night Mail to Western Approaches, whose timespan testifies to the enduring importance of his documentary roots.

Patrick Jackson, film director: born Eltham, south London 25 March 1916; married firstly (two daughters), secondly Lila Valmere; died 3 June 2011.