Corbel repairs of coke ovens

A corbel comprising:

• a first tier having first blocks, each of the first blocks comprising a first, substantially horizontal aperture extending through the first block from a front surface to a back surface and a second, substantially vertical aperture formed through a top surface of the block, extending into the first aperture, the first blocks being arranged on a substantially planar surface to align the respective first apertures to define a first, substantially horizontal passageway;
• a second tier having second blocks, each of the second blocks comprising a third, substantially vertical aperture extending through the second block from a top surface to a bottom surface, the second blocks being disposed above the first tier of blocks to align the third aperture of each of the second blocks with the second aperture of the first blocks to form a second passageway;
• a third passageway extending diagonally from the top of the one of the second blocks to a side of at least one of the first and second blocks;
• and
• a gas source for providing gas to the first passageway.