Yep GG, that's it, The fire went underneath & a copper tub with water sat inside the frame for cloths washing. My parents used one in my formative years. It was also used by my Dad for plucking chooks (when Mum wasn't home) as it was easier than the old kero tin we normally used
We also had a Metters wood stove in the house which had a place for the solid, flat iron that my mothe would do the said cloths with. Didn't that keep the house warm!
Might be worth chasing a bit more on the copper.
Steve