Yes, it is a self-unloading forage wagon, still used today here in the US. You unload it at the front left area, there is a chute. In real life, there are chains with "scraper bars" that pull the forage to the front, and auger(s) that unload it through the chute. I grew up using these. They are meant for unloading into a tall silo, into the blower attached to a tractor that blows the forage up a chute into the silo. :)

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