Complex sentence: Each of them was required to bring a year's supply of food by the Canadian authorities in order to prevent starvation; in all, their equipment weighed close to a ton, which for most had to be carried in stages by themselves.
Split into simpler sentences: Each of them was required to bring a year's supply of food by the Canadian authorities in order to prevent starvation. In all, their equipment weighed close to a ton, which for most had to be carried in stages by themselves.