Skip the 1st 14 minutes to get to the trailer, skip to 15:30 to get to the slam gate. That's one sweet user friendly gate!
Skip to 18:00 to see what's impressed me the most, the slam gate with slider door
It's a hell of a nice design!
because the field is soft due to high groundwater or recent rain, they use these front wheel drive (with chains on the tires) car frame looking home made scooper/tractors to gather the hay and push it sliding across the ground to the beaver slide / lift
https://www.facebook.com/photo/?fbid=10209144318760578&set=g.133119313446000