There are a lot of details in this kiln. Looks like over 10 arches in total. Here are the arched hobs.
When I first saw pics of them in one of Donovan's other kilns I thought it over kill. They are 4 1/2" not 9" bricks. The stepping up of the bricks in the chimney is creating a rather large collection box to cool down the exiting flame.
NCECA Panelist- Milwaukee, Wisconsin March 19-22 Panelist along with Mark Hewitt NC and Lisa Hammond UK. Moderated by Dr. Mary Ann Steggles- U of Manitoba Topic- Where have all the potter's gone? Last gasp or rebirth!