Long haul trooping flights in that time were commonly conducted by civilian independent airlines contracted by the defence ministry. There were several such carriers and it was, for some, their principal work. Ministry contracts were given out to, inevitably, the bottom bidder, so it was a spartan experience. There have been a range of discussions, some lengthy, here over time about these operations, including some good recollections by onetime participants (a number, inevitably, were children at the time, travelling with families). The catering provisions en route were particularly challenging.
In 1957 a good proportion of the available fleet was made up of the Handley Page Hermes. This was a decidedly mediocre design, delivered to BOAC around 1950 which they got rid of after just a few years, and these independent carriers bought them up as they were not allowed foreign exchange to buy US aircraft. In 1957 Skyways had 8, Britavia had 5 and Airwork (Freddie Laker's company of the era) had 3, which was most of the onetime BOAC fleet of 20. They didn't get intensive use out of them, but long haul trooping, plus other commercial work, was what they did with them.
https://en.wikipedia.org/wiki/Handley_Page_Hermes