As the UK's global prestige faced peril in the weeks leading up to the Suez Crisis, one Government department pinned its hopes for success in Egypt on a very British secret weapon - the string vest.
In a detailed study circulated in October 1956, the month of the start of the Anglo-French action, the Ministry of Supply preoccupied itself with the relative dangers of "dragging", "chafing" and "unsightly sweat patches" resulting from differing models of vest.
The study, among documents released by the National Archives in Kew, west London, had been based on experiments with members of the 1st Battalion Royal Warwickshire Regiment in the Canal Zone in the summer of 1955.
With temperatures soaring to 98F (36C), soldiers were ordered to try out different models of vest under their bush jackets and rate them to get to the bottom of the vexing question: whether string vests had any "definite advantage" as a summer garment.
Noting growth in the number of string vest "adherents" in the summer months in Britain, the report's authors set out to fathom the "indefiniteness of its function".
Three models of vest were tried: a conventional, non-string singlet; a standard army string vest; and a less stringy civilian version known as the "Sherpa".
While coming down firmly in favour of the Sherpa vest, the real surprise for the authors came in the finding that more than 60 per cent of participants did not usually wear vests at all.
The report shows that a subsequent mini-study was ordered to verify if the trend against vests was widespread.
A further 47 men from other units were questioned about whether they habitually wore a vest - with 55 per cent saying that they did not.
But of the 14 men in the main study who said that they did not usually wear vests - whether string or otherwise - two were "converted" by the experiments, the authors noted.
In their recommendations they noted sternly: "In view of the resistance to any vest by subjects accustomed to doing without, efficient indoctrination and a generous period of experience are important in any future assessment."
Overall the less stringy Sherpa vest came out on top in the tests. Among its noted benefits were an ability to: "obviate the difficulties of dragging and doffing".
It was, the report notes, particularly popular among those working in the kitchens but only those who were habitual vest wearers.
"Those members of the kitchen staff and mess waiters who wore the mesh type vests commented on feeling less sticky and appeared without the usual unsightly sweat patches on their bush jackets," the report concludes.
