Dear Lee,
I am designing a kiln similar to your kiln. 30 years ago I had a woodfired cross down draft. Took a lot of work to build it and fired it 3 times and had to tear it down because of the smoke in a residential area.
I stopped doing clay for years and was a builder in Montana, USA until I was injured on the job. Retrained for computers but prefer clay. I am teaching Developmentally Disabled Students. I fire in 2 electiric with power bills increasing. I believe my classes will grow with need for a much larger kiln.
I have designed a kiln based on Olsens kiln book fastfire kiln. It would be about twice that size. Maybee about 1/3 larger than yours with a catenary arch design because the bricks I have are more arch style. The arch would also be opposite direction of yours.
With your kiln how long does your kiln take to reach temp? What amont of wood does it take?
My design would have 4 fireboxes with 2 on opposite sides. Any suggestions you might have would help!
Thanks form Les In The Big Sky Country!