Continuous track haulers clearly had great military benefits for towing heavy artillery over difficult terrain. Developed for farming in peacetime, the American-made Holt tractors were used in their thousands by Allied troops. These soldiers have been identified as New Zealand servicemen, and clues from the film stock itself put the date around 1916. It likely that this piece was filmed in Egypt for use in newsreels.
There is something about the men's posture - sitting straight-backed on the trailers with arms crossed - that suggests they have been asked to pose this way for the cameras. They are struggling against the natural instinct to hold on for dear life as they are tossed back and forth by the tractors' rumbling movement over uneven ground.