The drum does seem a bit smaller than some I’ve seen, but it’s matched to the dryer above it. It’s literally the one you see in laundromats. Amusingly enough the drum is stainless steel and full-width of the machine (nearly) but the door is VERY small compared to its size - I think for durability and maintenance. The “home” version of the same machine (you can tell by the service manuals being similar) has a much bigger door.
Also interesting their top-loader still has a “use all the water and fill me up” mode that they don’t advertise that much, but is great for soaking.
There’s a schematic diagram tucked into the machine itself, and all service manuals are downloadable from their service site. Speed Queen is Alliance Laundry and they also make some HUGE machines under different brands - there’s a Unimac machine that includes instructions on how to bolt it to a solid concrete foundation because it spins : Commercial Washer-Extractors – Industrial Washers – UniMac On-Premises Laundry Equipment