Extricating a light car with rope ladders.
"Both Dr. Ball and P.A. Clayton of the Desert Survey helped us a great deal. It was at the latter's suggestion that Giblin had a pair of rope ladders made up, with bamboo rungs lashed to light cords of stranded wire
for laying in front of his car in soft sand in place of our usual rolls of wire netting. In the absence of other means Clayton had originated the idea of ladders in 1927 on a boundary commission with the Italians in the sand dunes west of Siwa."
(R.A. Bagnold, Lybian Sands, London, 1935)