The photograph is courtesy of the family of George Dey. George took many forestry photographs in his forestry career and many of those are now shown on this web site. Check under ‘Groups’ and George Dey Collection.
The picture shows the Unimog with hydraulic hoist lifting bags into a hopper and delivery chute. The advantage of this system is the chute stores the correct load amount and once the helicopter delivers the empty bucket below the chute it is immediately filled up and ready to fly off again. There is no time wasted changing buckets.