Indeed Gary,

I remember my mind being blown a decade or more ago about this very fact.
For the last 20 years my father has been building, from scratch, a Hudson 7
1/2 gauge live steam locomotive and tender.  The tender is where these
scoops are located and my dad, who is particular about details, designed
and fabricated a scoop for his tender.  However, in the end he didn't
install it for practical reasons.  Due to scale, any leaves, twigs, or
debris could be easily snagged on the apparatus and it isn't exactly
easy to clean down there while on the ground.  It's one of the few design
features that isn't exactly reproduced on his model from the full size
version.

https://kirkhmb.smugmug.com/Woodworking/Other-Galoots/Paul-Gardner/i-cxX5wWr/A
https://kirkhmb.smugmug.com/Woodworking/Other-Galoots/Paul-Gardner/i-2zM2swz/A

For some reason I have an even more difficult time wrapping my head around
the planes that have similar devices.

https://youtu.be/fuLk5hXMRZY

And to answer Ray's question, I'm not an expert on this but I think it was
done at relatively fast speeds (45-50 mph) on some locomotive/tender
designs.

Paul, in SF who's always fidgety in testing the ListMom's patience with a
little OT locomotive talk. ;^)