It has become necessary to increase the capacity of recuperative soaking-pit chambers for ingot heating, due to the increased heat weight in the converter shop at our plant. The pits are fueled by a coke-oven/blast-furnace gas mixture with a heat of combustion of 1800 kcal/m 3 (STP). Chamber capacity was increased by a 600 mm increase in length toward the channeled walts. In these circumstances the bottom coolers provided in the design were replaced by stainless-steel sheets 5 mm thick. As a result, two additional 8.5-ton ingots can be loaded into the chamber (14 instead of 12), and the previous distances of 350-400 mm between the ingots were practically retained.To assess the effect of redesigning, comparative studies were made of heat engineering and production indices in the operation of the pits, as first designed and after redesigning, in the first 2-3 months after major overhaul, when the recuperators, brickwork, and equipment were in good condition.The ingots studied were of identical weight and steel grade, cast by the same method and put into the pit at the same temperature. Comparative results of pit operation after redesigning (A) and as first designed (B) are given betow-

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