In this video, the radial auger doesn't seem to contact the floor so they have to do some scoop shovel work. Before augers, life was gravity dump wagons and a lot of shoveling. Note that they have already emptied some grain out of the bin into grain trailers. These would be the same grain wagons they use during harvest season to unload the combine. So when the truck does arrive, they can load it faster by pouring in grain from multiple auger wagons. This reduces the time the truck driver has to spend at the farm waiting for the truck to be loaded.
A timelapse video of cleaning out a bin.
A more expensive alternative to the radial auger is sucking the grain out. If a bin does not have an auger from a center hole, this is the only alternative to a scoop shovel.
|Screenshot, skip to 1:44 to see it work|
If you search You Tube for "cleaning grain bins" you can find more videos, including more vacuum solutions: Walinga Grain-Vac 7614F and Rem 2100 GranVac. The Walinga is a little different because it blows the grain up into a truck rather than use an auger.
|This video has a better overall shot of a Walinga Agri-Fac 6614 Deluxe. Skip to 7:20 to see the grain being sucked into the hose. You can tell by how the corn is piled that this bin does not have a center unload hole and auger to the side like some of the other bins we have seen. Since the bin was unloaded by putting an auger through the door, there is a lot more residual grain to remove.|
There are a couple of serious grain vacuum trucks in this 1.6million bushel grain recovery operation.
Some of the photos in a Sukup album (source) show the unloader in a 2018 world's largest bin. Some of the comments indicate that they stole the design of another manufacturer.